Date Of Birth Research Articles

Mothers of twins had higher old-age survival than mothers of singletons in Estonian 19th-century birth cohorts.

Do the mothers of twins and singletons differ regarding post-partum and old-age mortality? Twin deliveries were associated with higher post-partum maternal mortality than singleton deliveries, but the lifetime post-partum mortality risk was similar for mothers of twins and singletons; survival of twinners was higher than survival of the mothers of singletons after the 67th lifespan percentile. Twinning is typically associated with higher post-partum maternal mortality. The evidence about whether twinning incurs long-term survival costs of reproduction or is a trait pertinent to long-lived women is scarce and contradictory. The study is based on the data of the Estonian Family Register (operating from 1926 to 1943) and involves 5565 mothers of twins and 119613 mothers of singletons born between 1850 and 1899. The subset for comparing maternal lifespans included 1703-1884 mothers of twins and 19747-36690 mothers of singletons. Post-partum maternal mortality was analyzed in the whole sample (including mothers of a single child) by logistic regression. Most of the analyses were performed in samples where each mother of twins was matched against mothers of singletons based on parity (or number of deliveries), urban versus rural and inland versus coastal origin, whether their lifespan was known, date of birth and age at first birth. Lifespans were compared in linear mixed models. Quantile regression was used to analyze age-dependent variations in maternal mortality rates. All models were adjusted for relevant biodemographic covariates. The twinning rate in the whole sample was 4.4%. During the year after giving birth, maternal mortality for twin deliveries was 0.75% (17/2273) and 0.37% (449/122750) for singleton deliveries (OR = 2.05, 95% CI = 1.21-3.23). However, the lifetime post-partum mortality risk for mothers of twins (0.51%; 28/5557) and singletons (0.37%; 438/119466) did not differ significantly (OR = 1.38, 95% CI = 0.91-1.98). The life spans of the mothers of twins and singletons did not differ in matched samples. Past the 67th lifespan percentile, the odds of survival were significantly higher for mothers of twins than mothers of singletons, as indicated by non-overlapping 95% confidence intervals. Relatively low number of individuals (22802-28335) with known age at death in matched datasets due to discontinuation of the register after 1943. The finding that mothers of twins had higher odds of old-age survival than mothers of singletons is consistent with the contention that twinners represent a non-random subset of women whose robust phenotypic quality allows them to outlive the mothers of singletons in old age. The study was funded by the Estonian Research Council grants PRG1137, PRG2248, and PSG669. The authors declare no competing interests. N/A.

Were fewer boys born in the United States during the early months of the COVID-19 pandemic? A test of the Trivers-Willard hypothesis.

The Trivers-Willard hypothesis predicts that mammalian parents in poor environmental conditions will favor the offspring sex with more reliable chance of reproductive success, which in humans is females. Three months following the onset of the COVID-19 pandemic in South Africa, England, and Wales, there were significant decreases in the sex ratio at birth (SRB) (male births/total live births). We analyzed this ratio with a seasonal autoregressive moving average model, and a logistic regression, using nationwide natality data for all singleton births in the United States from 2015 to 2021 (n = 25,201,620 total births). We identified no significant change in the sex ratio in either analysis. Rather, we observed marked differences in the sex ratio by maternal characteristics of race/ethnicity, age, and education, with more vulnerable groups having lower sex ratios. These findings suggest the SRB may be an important marker of reproductive vulnerability for disadvantaged groups in the United States.

Changes in First and Second Births to U.S. Teenagers From 2000 to 2022.

This study examines trends in the numbers, percentages, and rates of first and second and higher-order births to teenagers younger than age 20 and for those ages 15-17 and 18-19 by race and Hispanic origin. Data for this analysis are from the National Vital Statistics System birth data files from 2000 and 2022. Analyses are limited to births to females younger than age 20. Changes in the numbers, percentages, and rates of total, first, and second and higher-order teen births from 2000 to 2022 were calculated for all teenagers and for non-Hispanic American Indian and Alaska Native, non-Hispanic Black, non-Hispanic White, and Hispanic teenagers. The number of first teen births declined 67% and the number of second and higher-order teen births declined 79%, while the population of female teenagers increased 7% from 2000 to 2022. The declines were greater for younger teenagers compared with older teenagers. First and second and higher-order teen birth rates declined 69% and 80%, respectively. Similar declines were found for each race and Hispanic-origin group. In 2000 and 2022, first and second and higher-order birth rates were lowest among White teenagers. First birth rates were highest among Hispanic teenagers in 2000 and for Hispanic and non-Hispanic American Indian and Alaska Native teenagers in 2022. In 2000, second and higher-order birth rates were highest for non-Hispanic Black and Hispanic teenagers; second and higher-order birth rates were more similar by race and Hispanic-origin group in 2022.

Breast Milk and Necrotizing Enterocolitis in Congenital Heart Disease: A Case-Control Study.

Background: Necrotizing enterocolitis (NEC) is a complication that can affect infants with congenital heart disease (CHD). The objective of this study is to determine whether breast milk, which is associated with decreased incidence of NEC in preterm infants, is protective in infants with CHD. Methods: Retrospective case-control study of infants ≥ 33 weeks gestational age with CHD who underwent cardiac surgery during their admission to the Infant Cardiac Unit from 2008 to 2017. Cases were defined as infants with modified Bell's stage ≥ II NEC. Controls were matched by date of birth, gestational age, and pre- or postcardiac surgery feed initiation. Results: A total of 926 infants with gestational age ≥ 33 weeks and CHD were admitted; 18 cases of NEC were identified and compared with 84 controls. Breast milk intake was higher in controls, but this difference was not statistically significant. Single ventricle (SV) physiology was identified as an independent risk factor for NEC by multivariable analysis. Analysis of infants with SV physiology demonstrated that median age at time of surgery was 9 days (interquartile range [IQR], 7-12) in NEC cases and 5 days (IQR, 4-9) in controls (P = .02). Conclusions: While this study is inconclusive with regard to feeding composition and risk of NEC in infants with CHD, the trend toward greater intake of breast milk in the control group suggests that breast milk may be protective for these infants. Infants with SV physiology are at high risk for NEC. Earlier time to stage I palliation may be a modifiable risk factor for NEC.

Maternal micronutrient biomarkers and risk of non-syndromic cleft lip/palate: A case-control study.

This case-control study investigated the associations between maternal plasma vitamin B12, homocysteine, and red blood cell (RBC) folate levels and the risk of cleft lip with or without cleft palate (CL/P) in offspring. The study compared 94 mothers and children with non-syndromic CL/P from a teaching hospital in Thailand to 94 mother-infant controls from local well-baby clinics, frequency-matched by birth date and mother's education. Data included anthropometric measurements, blood sample analyses, and a questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) estimated the associations through multiple logistic regression, adjusting for confounders. Mothers with higher plasma vitamin B12 levels had a lower risk of having a child with CL/P compared to those in the lowest quartile. This association was more pronounced among mothers without a family history of orofacial clefts and those who were not underweight. Conversely, elevated homocysteine levels, a marker of impaired B vitamin metabolism, increased the risk of CL/P. No association was found between RBC folate and CL/P. Higher maternal vitamin B12 levels are associated with a reduced risk of CL/P, while elevated homocysteine levels may increase the risk.

Place of Birth and Cognitive Function Among Older Americans: Findings From the Harmonized Cognitive Assessment Protocol.

Growing evidence suggests that place of birth (PoB) and related circumstances may have long-lasting and multiplicative contributions to various later-life outcomes. However, the specific contributions to different domains of cognitive function in late life remain less understood. This study investigated the extent to which state of birth contributes to a wide range of domains of later-life cognitive function. A nationally representative sample of Americans aged 65 and older (N = 3,333) from the Health and Retirement Study (HRS) Harmonized Cognitive Assessment Protocol (HCAP) was utilized. Cognitive function was assessed in HCAP and linked to HRS state of birth data to explore the contribution of PoB to later-life cognitive disparities. Regression-based Shapley decompositions were employed to quantify this contribution. PoB significantly contributed to all assessed cognitive domains including memory, executive function, language and fluency, visuospatial function, orientation, and general cognitive function. Geographic disparities in cognitive function were evident across PoB, with individuals born in U.S. southern states and foreign-born individuals performing worse than those born in other states. Overall, state of birth accounted for 2.2%-9.7% of the total variance in cognition after adjusting for age, sex, and race/ethnicity. This contribution declined to 2.0%-7.0% after further adjusting for comprehensive socioeconomic and health factors over the life course, and was robust to the control of current state of residence. PoB has lasting contributions to later-life cognition, with significant geographic disparities observed. Addressing these disparities requires more equalized place-based policies, resources, and early-life environments to promote health equity over the life course.

Living with ‘thin’ documents: a note on identity documents and liminal citizenship in the chars of Assam, India*

ABSTRACT This paper, based on my doctoral ethnographic research amongst the Miya community in one of the chars of Western Assam, shows how a particular category of identity documents shape their subjectivities, experiences, and aspirations. I focus on the identity documents which have errors, like mistakes in names, dates of birth or addresses, and badly angled photos. I refer to them as thin documents. Because of the thin documents, the Miyas find it difficult to assert formal citizenship rights, which they could normally assert based on accurate documentation. For the thin documents to help prove the Miyas’ citizenship, they must be further supported by an additional set of documents. The process questions the Miya’s formal citizenship rights. I present narratives of the Miya people living with thin documents to illustrate how the materiality of the identity document binds the Miya people to a state of liminal citizenship. I ask: what do these errors in the identity document or thin documents tell us about citizenship, particularly liminal citizenship with reference to the Miya community of Assam?

A Digital Trail of Rupture. The German Film Exile 1933-1945 in the Data of Günter Peter Straschek

How can digital humanities methods reveal the productivity and connectedness of a group of historical individuals linked by displacement from a country? German film exile during National Socialism, 1933-1945, has always been a complex subject to research because of the scattered nature of the sources in the international distribution of archives (Asper, Horak, Hilchenbach). It remains challenging to reconstruct the worldwide dispersed separate flight routes of more than 3000 individuals who worked for the German film industry before 1933. This contribution concerns a list of film exiles collected by the exile researcher and filmmaker Günter Peter Straschek (1942-2009), whose collection of files belongs to the German National Library, German Exile Archive 1933-1945, Frankfurt am Main and was inventoried according to their Normdata. To this end, a database of GND exile data containing names, birth and death dates, professions, and countries of exile was compiled and enriched with data from online resources (Wikidata and IMDb). How can a more comprehensive look at the data reveal the devastating loss for German film (2) and, on the other hand, the collaboration on the flight (3) showing exiles remaining defiant? By incorporating new data from the Straschek Estate, digital methods further enhance historical research findings.

Sex differences in the association between plasma branched-chain amino acids and risk of ischemic stroke: A nested case-control study from China

ObjectivesThe aim of this study was to investigate the prospective associations between plasma branched-chain amino acids (BCAAs) and the risk of ischemic stroke in men and women. MethodsWe conducted a nested case-control study within a community-based cohort in China. The cohort consisted of 15,926 participants in 2013-2018. A total of 321 ischemic stroke cases were identified during the follow up and individually matched with 321 controls by date of birth (±1 year) and sex. Females accounted for 55.8% (n = 358, 179 cases vs 179 controls) of the study population. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association between plasma BCAAs and ischemic stroke risk by conditional logistic regression. ResultsElevated plasma isoleucine was associated with a higher risk of ischemic stroke in women. The OR for the highest compared to the lowest quartile was 2.22 (95% CI: 1.11-4.44, P trend = 0.005) after adjustment for body mass index, education attainment, smoking, hypertension, renal function, menopause and physical activity. A similar association was found for total BCAAs (adjusted OR = 2.03, 95% CI: 1.05-3.95, P trend = 0.04). In contrast, no significant association of plasma BCAAs with ischemic stroke risk was observed in men. ConclusionsPlasma isoleucine and total BCAAs were significantly associated with ischemic stroke risk in women, but not in men, highlighting sex differences in BCAAs metabolism and stroke pathogenesis.

Impact of linkage level on inferences from big data analyses in health and medical research: an empirical study

BackgroundLinkage errors that occur according to linkage levels can adversely affect the accuracy and reliability of analysis results. This study aimed to identify the differences in results according to personally identifiable information linkage level, sample size, and analysis methods through empirical analysis.MethodsThe difference between the results of linkage in directly identifiable information (DII) and indirectly identifiable information (III) linkage levels was set as III linkage based on name, date of birth, and sex and DII linkage based on resident registration number. The datasets linked at each level were named as databaseIII (DBIII) and databaseDII (DBDII), respectively. Considering the analysis results of the DII-linked dataset as the gold standard, descriptive statistics, group comparison, incidence estimation, treatment effect, and moderation effect analysis results were assessed.ResultsThe linkage rates for DBDII and DBIII were 71.1% and 99.7%, respectively. Regarding descriptive statistics and group comparison analysis, the difference in effect in most cases was “none” to “very little.” With respect to cervical cancer that had a relatively small sample size, analysis of DBIII resulted in an underestimation of the incidence in the control group and an overestimation of the incidence in the treatment group (hazard ratio [HR] = 2.62 [95% confidence interval (CI): 1.63–4.23] in DBIII vs. 1.80 [95% CI: 1.18–2.73] in DBDII). Regarding prostate cancer, there was a conflicting tendency with the treatment effect being over or underestimated according to the surveillance, epidemiology, and end results summary staging (HR = 2.27 [95% CI: 1.91–2.70] in DBIII vs. 1.92 [95% CI: 1.70–2.17] in DBDII for the localized stage; HR = 1.80 [95% CI: 1.37–2.36] in DBIII vs. 2.05 [95% CI: 1.67–2.52] in DBDII for the regional stage).ConclusionsTo prevent distortion of the analyses results in health and medical research, it is important to check that the patient population and sample size by each factor of interest (FOI) are sufficient when different data are linked using DBDII. In cases involving a rare disease or with a small sample size for FOI, there is a high likelihood that a DII linkage is unavoidable.

Factors associated with depression during pregnancy in women receiving high- and low-risk prenatal care: a predictive model.

Depression during pregnancy can put strain on pregnant women's interpersonal relationships, the formation of emotional bonds with the fetus, and the adaptation to the new routine and social role post-pregnancy. Some studies have associated socioeconomic factors, emotional factors, interpersonal relationships, perceived social support, gestational risk, and the occurrence of certain diseases during pregnancy with higher risk of depression. This study aimed to investigate the prevalence of depression during pregnancy and associated factors in low- and high-risk prenatal patients at a Brazilian university hospital. This study presents a retrospective and prospective cross-sectional design. A total of 684 prenatal psychological analysis records from a Brazilian tertiary university service were retrospectively evaluated to assess depression through the PRIME-MD questionnaire between 2002-2017. Between 2017 and 2018, 76 patients treated at the same service were prospectively evaluated with the aforementioned instrument. Medical records were accessed to obtain labor and birth data. Multivariate analyses assessed the association between sociodemographic, gestational or obstetric, and health variables and the presence of depression during pregnancy. A total of 760 pregnant women were included in the study, with a depression prevalence of 20.66% (n = 157). At the time of assessment, 48 (21.05%) women from the low-risk pregnancy group and 109 (20.49%) from the high-risk pregnancy group were depressed. The mean age was 30.01 ± 6.55 years in the group with depression and 29.81 ± 6.50 years in the group without depression. In the univariate analysis, there was an association of risk for depression with absence of paid work, absence of a partner, low family income and diagnosis of epilepsy, being a protective factor the presence of diabetes during pregnancy. However, in the multivariate analysis, a lower family income, not having a partner at the time of the assessment, and the prevalence of epilepsy were independently associated with an increased risk of depression during pregnancy. This study showed that 1 in 5 women had depression during pregnancy, with no association with obstetric risk, but those women living in unfavorable economic conditions, without a partner, and having epilepsy were at increased risk of depression.

AN ANALYSIS OF THE SECURITY FEATURES ON UNIVERSITY CERTIFICATES IN GHANA: A CASE OF SOME SELECTED PUBLIC UNIVERSITIES

This study examines the security features integrated into academic certificates issued by five public universities in Ghana: The University of Ghana (UG), Legon, University of Cape Coast (UCC), Cape Coast, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, University for Development Studies (UDS), Tamale, and University of Mines and Technology (UMaT), Tarkwa. The research aims to identify the existing security features, evaluate the control processes used to maintain certificate authenticity and compare these features against international standards to determine their effectiveness in preventing forgery. Through a comprehensive analysis, this paper provides insights into how these institutions safeguard the integrity of their academic qualifications. The study reveals that Ghanaian universities employ a variety of traditional and modern security features in the production of academic certificates and the application of control processes to protect the integrity of their academic certificates. The inclusion of the holder's date of birth and photograph on certificates from UMaT, though less common among the rest of the specimens, offers additional security benefits. While these measures are largely effective, the adoption of advanced technologies such as blockchain could further enhance security. Aligning with international standards not only prevents forgery but also facilitates global recognition of Ghanaian academic qualifications.<p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/soc/0744/a.php" alt="Hit counter" /></p>

Trypanosoma cruzi Infection in Pregnancies without Congenital Transmission Is Associated with Reduced Fetal Growth: A Cross-Sectional Study in Argentina, Honduras, and Mexico.

We aimed to measure the association between Trypanosoma cruzi infection in pregnancy and reduced fetal growth in the absence of T. cruzi congenital transmission. We conducted a cross-sectional study of secondary data of all singleton live births between 2011 and 2013 in five hospitals from Argentina, Honduras, and Mexico. We excluded newborns with T. cruzi infection. Noninfected pregnant people were those without any positive rapid tests. The main study outcomes were birth weight, head circumference, and length for gestational age and sex. Logistic regression models were adjusted for country, age, education level, and obstetric history. Of the 26,544 deliveries, 459 (1.7%) pregnant people were found by rapid tests to be positive for T. cruzi. Of these, 320 were positive by enzyme-linked immunosorbent assay and 231 had a positive polymerase chain reaction (PCR) test. Uninfected newborns from T. cruzi-infected pregnant people were more likely to have birth weights below the 5th and 10th percentiles and head circumferences below the 3rd and 10th percentiles. Among T. cruzi-infected pregnant people diagnosed by PCR, the odds ratios were 1.58 for birth weight below the 10th percentile (95% CI, 1.12-2.23) and 1.57 for birth weight below the 5th percentile (95% CI, 1.02-2.42). Higher T. cruzi parasitic loads in pregnancy had a stronger association with reduced fetal growth (both in birth weight and head circumference), with an odds ratio of 2.31 (95% CI, 1.36-3.91) for a birth weight below the 5th percentile. The association shows, irrespective of causality, that newborns of pregnancies with T. cruzi have an increased risk of reduced fetal growth. We recommend further studies to assess other potential confounders and the causality of these associations.

O-036 How much DNA is shared between a human egg and each of the polar bodies? Theory and genomic data from polar bodies and triploid embryos

Abstract Study question What is the proportion of the genome where the egg and the first or second polar bodies descend from the same maternal homolog? Summary answer The egg is about 30% identical to a random haploid genome from the first polar body and about 40% identical to the second polar body. What is known already After crossing over, human female meiosis generates three products: the first polar body (PBI) splits first with two sister chromatids per chromosome; the second polar body (PBII) and the egg split next, each with a single set of chromatids. When meiosis proceeds normally, the egg must be identical (i.e., same maternal homolog) to PBII at the centromeres. However, the proportion of the entire genome where the egg is identical to PBII (or to a random chromatid set from PBI), while being a fundamental property of meiosis, is not intuitively clear and has not been empirically studied. Study design, size, duration We used both theoretical and empirical approaches. We first derived formulas and performed simulations for the identity between the egg and the polar bodies, with or without modeling crossover interference. We then analyzed genotype data from seven egg/PBI/PBII trios and 43 triploid embryos. Finally, we analyzed 8,476 dizygotic twin pairs from research-consented 23andMe, Inc. customers in an attempt to find PBII twins, who would (hypothetically) share maternal genetic material in all centromeres. Participants/materials, setting, methods The egg/PBI/PBII trios came from three female donors and were genotyped at about 300k SNPs (Ottolini et al, Nat Genet, 2015). Embryos were sequenced to depth about 0.05x for routine PGT-A and identified as triploid upon retrospective analysis with LD-PGTA (Ariad et al, Genome Res, 2023). Coverage-based analysis confirmed triploidy predictions for XXY embryos. The DZ twin pairs were genotyped at about 640k SNPs and self-reported dates of birth within two days of each other. Main results and the role of chance In an infinitely long chromosome, the egg would be identical to PBII, or to a random chromatid from PBI, in only a third of its length. Modeling recombination using the human female genetic map and assuming no interference predicted that the egg would be on average 53% identical to PBII and 24% identical to a random haploid genome from PBI. We confirmed these estimates with simulations. However, in seven egg/PB1/PB2 trios, the egg was on average only 40% identical with PBII. Similarly, in 17 triploid embryos with an MII (likely-maternal) error, the two transmitted maternal chromosome sets were on average only 37% identical. Including crossover interference in the simulations reduced the identity between the egg and PBII to 42%, closer to the empirical observations. Hypothetical PBII twins would occur by two sperm from the same father fertilizing both the egg and PBII. They would share, based on the results above, an average of about 45% of their genomes. Such twins would also have identical maternal genetic material in all centromeres. In 8,476 genetically dizygotic twin pairs, only 67 shared at least one haplotype in all centromeres, not significantly more than expected by chance for dizygotic twins. Limitations, reasons for caution The empirical results are based on a small number of egg/PBI/PBII trios (n = 7) from only three donors. The number of triploid embryos was larger, but they were sequenced to very low depth, and the results for MI-error embryos showed much less sharing between the two maternal chromosomes than expected. Wider implications of the findings We show the fundamental and perhaps counter-intuitive result that the egg is only 30-40% identical to the polar bodies. This provides a reference against which deviations from normal crossover patterns could be evaluated in triploid and other aneuploid embryos. Polar body twins, if they occur, must be extremely rare. Trial registration number Not applicable

O-319 A randomised trial of time-lapse imaging of embryos in in-vitro-fertilisation treatment

Abstract Study question Do time-lapse imaging (TLI) systems used in IVF/ICSI treatment improve live birth either due to undisturbed culture conditions or improved embryo selection or both? Summary answer In women undergoing IVF/ICSI treatment the use of TLI systems does not significantly increase the odds of live birth compared to standard care without TLI. What is known already TLI systems used in IVF treatment have the potential to improve fertility outcomes either due to undisturbed culture conditions or improved embryo selection or both. However, there remains uncertainty about its benefits. Existing reviews and primary studies predominantly report no differences between the use of TLI and conventional methods. However none of the previous trials were adequaltely powered to detect meaningful differences in live birth and the quality of most trials was deemed to be low to very low. Study design, size, duration TILT (Time-lapse Imaging Trial) is a multi-centre, three-arm, parallel-group, double-blind, randomised controlled trial. Participants were randomly assigned in a 1:1:1 ratio to the TLI system for both undisturbed culture and embryo selection (TLI arm), TLI system for undisturbed culture conditions alone (undisturbed culture arm), and standard care without TLI (control arm). From June 2018 to September 2022, we randomised 1575 participants based on a pre-specified sample size to detect an 8.75% difference in live births. Participants/materials, setting, methods We randomised 1575 couples undergoing IVF/ICSI with broad inclusion criteria across seven IVF centres. The primary outcome was live birth. Secondary outcomes included clinical pregnancy, pregnancy loss, and multiple pregnancy. Primary analysis was performed based on the intention-to-treat principle for all participants with primary outcome data available and the effect estimate reported as an adjusted odds ratio (aOR). Pre-specified sensitivity analyses and subgroup analyses for age and method of embryo transfer were performed. Main results and the role of chance We recruited 2191 and randomised 1575 participants. Live birth data were available for 1558/1575 (98.92%) participants. The livebirth rates were 33.7% (175/520) in the TLI arm, 36.6% (189/516) in the undisturbed culture arm and 33.0% (172/522) in the control arm. The aOR was 1.04 (97.5% confidence interval (CI) 0.73 to 1.47) for TLI arm vs control and 1.20 (97.5% CI 0.85 to 1.70) for undisturbed culture vs control. The clinical pregnancy rates were 42.2% (219/519) in the TLI arm, 43.4% (225/518) in the undisturbed culture arm, and 40.9% (212/519) in the control arm. There were no significant differences for TLI vs control arm (aOR 1.06, 95% CI 0.82-1.38) and undisturbed culture vs control arm (aOR 1.11, 95% CI 0.86-1.46). The rates of pregnancy loss between clinical pregnancy and 24 weeks’ gestation were not statistically different when TLI (8.7%, 45/515) and undisturbed culture arms (6.4%, 33/513) were compared with control arm (8.1%, 42/517) with aOR 1.09 (95% CI 0.66-1.77) and 0.76 (95% CI 0.45-1.29) respectively. None of the other secondary outcomes demonstrated significant differences between the arms The findings were similar irrespective of the woman’s age and use of fresh or frozen embryo replacement, and for all sensitivity analyses, for primary and secondary outcomes. Limitations, reasons for caution Although the trial recruitment was delayed by the SARS-CoV-2 pandemic, this did not impact the results as patient populations, clinical care pathways and time-lapse technology remained similar. The remit of this trial did not allow assessment of the influence of TLI systems on embryology laboratory workflow or perform a health-economic analysis. Wider implications of the findings Our trial provides high-quality definitive evidence of no benefit of the use of TLI systems for embryo incubation and selection to improve success rates in women having IVF and ICSI treatment. Trial registration number ISRCTN17792989

O-022 Early tubal flushing with oil-based contrast during hysterosalpingography versus no tubal flushing in women with unexplained infertility – H2Oil-timing randomized controlled trial

Abstract Study question In women with unexplained infertility, does tubal flushing with oil-based contrast during HSG early in the fertility work-up reduce time to ongoing pregnancy? Summary answer In women with unexplained infertility, tubal flushing with oil-based contrast during HSG early in the fertility work-up does not reduce time to pregnancy. What is known already In couples with unexplained infertility, tubal flushing with oil-based contrast during HSG is known to increase live births and reduce time to pregnancy compared to HSG with water-based contrast. It is unknown whether tubal flushing with oil-based contrast incorporated early in the fertility work-up will have this effect as compared to 6 months later in the fertility work-up. Study design, size, duration Between August 2019 and May 2023, we performed a multicenter, randomized trial in 15 Dutch hospitals. After informed consent, participating women were randomized to immediate HSG (oil-based contrast) or HSG delayed by six months. This allowed us to assess the effect of tubal flushing versus no tubal flushing over a 6-month period, as well as time to conception after immediate versus delayed flushing over a period of 12 months. We aimed to recruit 554 participants. Participants/materials, setting, methods We included ovulatory infertile women (18-39 years), who were advised expectant management based on a favorable prognosis for natural conception (Hunault prediction-model). The study has two primary endpoints, time to conception leading to live births (I) within 6 months, and (II) over a 12-month period. Here we report on conception within 6 months leading to ongoing pregnancy. Live birth data will be available at the 2024 ESHRE meeting. Analyses were done according to intention-to-treat principle. Main results and the role of chance Between August 2019 and May 2023, we randomized 577 women (287 allocated to the immediate HSG and 290 allocated to the delayed HSG group). Mean (±sd) female age was 30.0±3.6 years and median duration of infertility was 17.0 months. In the immediate HSG group, 239 women had an HSG after a median duration of 0.7 months after randomization, while in the delayed group 83 women had an HSG within 6 months (median time to HSG: 5.2 months after randomization). Conception leading to ongoing pregnancy within 6 months occurred in 90 women (32.5%) in the immediate HSG group and 91 women (33.2%) in the delayed HSG group (HR: 0.96; 95% CI: 0.72-1.29). Conception leading to any pregnancy within 6 months occurred in 119 women (43.0%) in the immediate HSG group and 104 women (38%) in the delayed HSG group (HR: 1.16; 95% CI: 0.89-1.51). The median time to conception leading to ongoing pregnancy was 2.4 months in the immediate HSG group and also 2.4 months in in the delayed HSG group. Limitations, reasons for caution This study was limited to women with unexplained infertility with favorable natural conception chances (>30%). In this abstract, we only report time to ongoing pregnancy and not time to pregnancy leading to live birth. Data on conception leading to live births will be available at the 2024 ESHRE meeting. Wider implications of the findings In women with unexplained infertility and a favorable prognosis to conceive, early tubal flushing with oil-based contrast during HSG does not increase live birth rates nor reduce time to pregnancy within six months as compared to tubal flushing delayed by six months. Trial registration number EU clinical Trials Register, no: 2018-004153-25 AND Clinicaltrials.gov, ID: NCT05608590

P-768 Is it time for a consensus on key performance indicators for cycles involving donation and surrogacy?

Abstract Study question As there are no agreed standards for bench marking in cycles involving donation and surrogacy, how do we measure performance for these treatment types? Summary answer Until an international consensus is undertaken, we must define benchmarks using both in-house and published data from the Human Fertilisation and Embryology Authority (HFEA) register. What is known already Treatment cycles involving donor gametes or surrogacy have increased exponentially in recent years (Horsey, 2023; HFEA, 2020). Key performance indicators (KPIs) are critical for monitoring treatment effectiveness and safety. The Vienna Consensus (2017) is the accepted standard against which clinics should measure performance. However, the publication does not include data on cycles involving donation and surrogacy. In the absence of agreed standards, it is difficult for clinics to measure efficacy for these patient groups. Defining benchmarks for such cohorts is particularly challenging as the gametes used in donation and surrogacy treatment types may come from both fertile and sub-fertile populations. Study design, size, duration Retrospective analysis of anonymised United Kingdom (UK) data, published by the HFEA, from 2014 to 2018, was performed. Outcomes for 26290 donor intrauterine insemination (DIUI), 12262 in vitro fertilisation (IVF), 11341 intracytoplasmic sperm injection (ICSI) and 12453 frozen embryo transfer (FET) cycles, all using donor gametes, were included in this study. In cycles where surrogacy was indicated, gamete origin could not be determined, preventing the data from being included in this study. Participants/materials, setting, methods Using the complete HFEA data set, the average live birth rate, for each treatment type (excluding surrogacy), was calculated. This average was considered the target benchmark when comparing the average live birth rates at the clinic. Each quarter, a rolling 12 months of in-house retrospective data was used to assess clinic performance. Warning and action limits were set using standard deviations calculated using the 5 averages obtained from each year of HFEA data included. Main results and the role of chance The average live birth rates determined using the HFEA data, to be used as benchmarks for performance, were as follows; DIUI (13.7%), IVF (42%), ICSI (37%) and FET (36%). It is noteworthy that live birth rates reported by the HFEA were per embryo transfer (ET), rather than per embryo, meaning more than one live birth could be reported per ET. Discrepancies in outcome reporting meant that the national clinical pregnancy rate could not be determined for all treatment types, nor could fertilisation rate. Therefore, the clinic used in-house data to set benchmarks, action, and warning limits for these donor KPIs. Our findings whilst mining the national published data were that no cycle outcomes had been published beyond 2018, meaning these data may not be reflective of current national rates. Also, the national averages calculated will have been affected by individual clinic success rates. Knowing each clinic’s average would create a larger range, from which real world standard deviations could be determined, resulting in more meaningful warning and action limits. Such data was unavailable. The result being that, whilst UK national data is publicly available, it is flawed and insufficient for creating robust benchmarks that clinics can measure themselves against. Limitations, reasons for caution No national data, beyond 2018, is available for use in bench marking. Waiting for live birth data will delay any actions prompted by under-performance. Individual clinic success rate will have impacted the national average. Both fertile and sub-fertile populations will be included in both data sets. Wider implications of the findings The available UK data cannot be used to set robust benchmarks for donor or surrogacy KPIs. Small and new clinics are therefore unable to adequately measure their performance. With the increasing uptake of treatments involving donation and surrogacy, it is time for an international consensus on expected outcomes. Trial registration number not applicable

P-713 Proposal of model to calculate the trend in the cumulative live birth rate in IVF cycles using Spanish National Register data from 2009 to 2021

Abstract Study question Is it possible to estimate the trend in the cumulative rate of live births in IVF over 12 years, using data from the Spanish Registry? Summary answer With the proposed formula, a constant increase of 1.7% in the cumulative live birth rate is verified throughout the 12 years of study. What is known already The progressive increase in elective freeze-all cycles no longer allows the use of live birth data by fresh transfer, especially in time series. Cumulative live birth rate (CLBR) has been proposed as an appropriate way of reporting success of an IVF program, incorporating both, fresh and frozen embryos. Nevertheless, views on the most appropriate parameters required to calculate such an outcome have been inconsistent and difficult for national aggregate registries. Furthermore, there is not unanimous definition for its calculation and although IVF Register is mandatory in Spain, an analysis of the CLBR has not been carried out. Study design, size, duration Data from the Spanish National Register of Assisted Reproduction including 456302 women undergoing IVF/ICSI (563000 ovarian stimulation cycles started, 359587 fresh transfers, and 36400 cryotransfer) using autologous gametes performed in Spain from 2009 to 2021 were analyzed. Oocyte donation and PGT-a cycles were excluded. Participants/materials, setting, methods The main outcomes of present study were live birth rate per cycle (LBR) and cumulative live birth rate (CLBR). To obtain the CLBR, the probability of achieving at least one live birth for each cycle started was calculated. This includes both live births after fresh transfer and those achieved after cryotransfer of the embryos obtained from each cycle until they have run out, or a full-term pregnancy is obtained. Main results and the role of chance The live birth rate (LBR) per fresh transfer remains steady (around 24%) throughout the period analyzed. However, LBR for started cycle, which remains constant (17%) until 2013, shows a marked decline since then at a rate of 1% per year. In this same period was observed: a progressive increase in the percentage of cycles with frozen embryos (from 29% to 48%), a greater number of cryopreserved embryos (from 0.9 to 1.6 embryos per started cycle), and a constant decrease in the number of embryos in each cryotransfer (from 2.39 to 1.42). LBR after cryotransfer per started cycle has increased exponentially from 4% to 24%. It was also found a steady increase of the percentage of births after a cryotransfer cycle (from 19 to 70%), surpassing since 2017 those obtained after fresh transfer. To calculate the cumulative live birth rate (CLBR), an algorithm has been developed including all pregnancies that can be achieved with the use of all the embryos obtained after each cycle started until alive child is born. CLBR shows a constant increase in the cumulative delivery rate of 1.7% annually since 2012, rising from 22 % to 35% of births per cycle started. Limitations, reasons for caution One of the main weaknesses of the study is that some patients have not attempted a second or third cryotransfer during the timeframe (for unknown reasons), though they had supernumerary embryos available. However, this model reflects the potential capacity to have at least one living child for each cycle started. Wider implications of the findings The LBR per cycle based only on fresh transfers is not useful for a historical analysis of the effectiveness of the technique. Only the calculation of the CLBR per cycle allows us to understand the real progress of IVF effectiveness in recent years. Trial registration number not applicable

P-151 Investigation of pregnancy outcomes for blastocysts with microcellular leakage of trophectoderm or inner cell mass from ICSI-induced zona pellucida microslits

Abstract Study question How does ICSI-induced leakage of trophectoderm (TE) or inner cell mass (ICM) from microslits in the zona pellucida (ZP) affect pregnancy outcomes following blastocyst transfer? Summary answer Microcellular leakage of TE and ICM did not affect pregnancy outcome, but blastocysts with ICM leakage above 53.6% had a lower pregnancy rate. What is known already The leakage of TE cells through the ZP (trophectoderm vesicles; TV) has been reported to be more common in ICSI than in conventional IVF, caused by the opening of the ZP with microslits for ICSI. This phenomenon may be improved through the implementation of assisted hatching during transplantation, however, there are few reports investigating its impact on pregnancy.Furthermore, there are no reports on the impact of inner cell mass leakage (inner cell mass vesicles; IV) on pregnancy outcomes, and it is unclear what level of ICM leakage is acceptable for transplantation. Study design, size, duration In this retrospective study, we analyzed clinical medical reports at the Takahashi Women’s Clinic in Japan. A total of 551 patients (1093 blastocysts) who underwent freeze-thaw single blastocyst transfer with laser assisted hatching between January 2019 and October 2023 were included. Blastocysts used for transfer were 2PN embryos obtained by PIEZO-ICSI and cultured in a time-lapse incubator (EmbryoScope+). Participants/materials, setting, methods The blastocysts were classified into control (N = 682), TV (N = 377), and IV groups (N = 34). Pregnancy outcomes were compared using logistic regression analysis, considering patient age, blastocyst grade (Gardner criteria), culture days, BMI, and basal AMH. Bonferroni correction was used for multiplicity correction, considering P < 0.0167 as significant. The ICM leakage rate (%) was calculated as: (leaked ICM area/ICM area before leakage) × 100. Pregnancy cutoff was determined by ROC analysis. Main results and the role of chance The hatching rates for the control, TV, and IV groups were 69.6% (475/682), 78.8% (297/377), and 82.4% (28/34), respectively. Pregnancy rates (fetal heartbeat) were 44.6% (304/682), 57.0% (215/377), and 50.0% (17/34), respectively, and miscarriage rates were 26.3% (80/304), 26.0% (56/215), and 23.5% (4/17), respectively. Logistic regression analysis considering patient background showed no significant differences in hatching, pregnancy, and miscarriage rates (P > 0.05). Furthermore, mean weight, sex ratio, and congenital anomaly rates for the 107 and 7 children born in the TV and IV groups, respectively, were not significantly different than those for the 175 children born in the control group. In examining ICM leakage, the mean area before leakage was 3162.6 µm2 and mean area of leaked ICM was 1292.1 µm2 in the IV group, with an average of 40.9% of ICM leaking outside the clear zone. ROC analysis showed that the cutoff for ICM leakage rate for pregnancy was 53.6%, with significantly lower pregnancy rates when the ICM leakage rate was ≥53.6% (18.2% [2/11] vs 65.2% [15/23], p = 0.0255, Fisher’s exact test). Limitations, reasons for caution This study was conducted at a single in vitro fertilization center. Pregnancy, miscarriage, and fetal anomaly rates at birth related to embryo transplantation are based on ongoing pregnancy dates, and complete live birth data for all pregnancies are not yet available. Wider implications of the findings No differences in pregnancy outcomes or fetal anomalies were found among groups. However, pregnancy rates decreased when ICM leakage rates were over 53.6%. Blastocysts with IV may successfully establish a pregnancy, but considering the leaked ICM proportion is crucial. If considered for transplantation, obtaining sufficient informed consent is essential. Trial registration number not applicable

The influence of parental occupational status on under-five mortality in Ethiopia

ABSTRACT Few studies have examined the mediators of the association between parental occupational status and under-five mortality risk in Ethiopia. We examine the association between parental occupational status and under-five mortality risk in Ethiopia and the role of two mediating variables, antenatal care visits and delivery by a health professional, in this relationship. Using birth data from the nationally representative 2016 Ethiopia Demographic and Health Survey, the study finds that parental occupation, antenatal care visits, and delivery by a health professional are associated with under-five mortality risk. The study also finds that after controlling for mediating variables, parents engaged in professional, agricultural, and manual labor still have lower odds of under-five mortality risk than children of non-working parents. Future research should focus on the pathway from parental employment to child mortality risk, not through access to antenatal care and delivery by health professionals.