Preterm Birth Odds Ratio Research Articles

Gestational urinary concentrations of glyphosate and aminomethylphosphonic acid in relation to preterm birth: the MIREC study.

Few high-quality studies have evaluated associations between urinary glyphosate or its environmental degradate (aminomethylphosphonic acid (AMPA)] and preterm birth (PTB). To quantify associations between urinary glyphosate and AMPA and preterm birth in the pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study and determine if associations differ by fetal sex. We measured first trimester urinary glyphosate and AMPA concentrations in MIREC participants who were recruited between 2008-2011 from 10 Canadian cities. Of the 1880 participants whose first trimester urine samples were analyzed for glyphosate or AMPA, 1765 delivered a singleton, live birth. Our primary outcome was preterm birth (PTB) defined as births occurring between 20 and <37 weeks. Secondary outcomes were spontaneous preterm births (sPTB) and gestational age. We modelled the hazard of PTB and sPTB using discrete time survival analysis with multivariable logistic regression to calculate odds ratios (OR). We used multivariable linear regression models to quantify associations between analytes and gestational age. To assess effect modification by fetal sex, we stratified all models and calculated interaction terms. In the logistic regressions models we additionally calculated the relative excess risk due to interaction. Six percent (n = 106) of the study population delivered preterm, and 4.7% (n = 83) had a spontaneous preterm birth. Median specific-gravity standardized concentrations of glyphosate and AMPA were 0.25 and 0.21 µg/L. Associations between both glyphosate or AMPA and PTB, sPTB, and gestational age centered around the null value. The adjusted ORs of PTB for each doubling of glyphosate and AMPA concentrations were 0.98 (95% CI: 0.94, 1.03) and 0.99 (95% CI: 0.92, 1.06) respectively. We observed no evidence of differences by fetal sex. In this Canadian pregnancy cohort, neither glyphosate nor AMPA urinary concentrations was associated with PTB or reduced gestational length.

Uses of antiseizure medication among pregnant women with epilepsy and risk of adverse obstetric outcomes: A group-based trajectory analysis.

This study was undertaken to examine the association between different patterns of antiseizure medication (ASM) use during pregnancy and adverse obstetric outcomes (preterm birth, low birth weight [LBW], and small for gestational age [SGA]). This retrospective cohort study used the Birth Certificate Application and National Health Insurance data in Taiwan (January 1, 2004 through December 31, 2018). We retrieved weekly ASM among pregnant women with epilepsy who were prepregnancy chronic users and used group-based trajectory modeling to identify distinct patterns of use. Logistic regressions were adopted to examine the association between patterns of ASM use and risk of preterm birth, LBW, and SGA. In addition, we revealed postnatal ASM utilization pattern among these prepregnancy chronic users as an exploratory study. Of 2175 pregnant women with epilepsy, we identified four patterns of ASM use during pregnancy: frequent and continuous (64.87%), frequent but discontinuous (7.08%), intermittent (19.72%), and intermittent and discontinuous users (8.32%). Compared to frequent and continuous users, the adjusted odds ratios for preterm birth in frequent but discontinuous, intermittent, and intermittent and discontinuous users were .83 (95% confidence interval [CI] = .47-1.48), .71 (95% CI = .47-1.05), and .88 (95% CI = .52-1.49), respectively. Similar results were observed for LBW and SGA. In the exploratory study, we found that most of our study subjects maintained the same patterns before and after delivery. After considering duration and timing of exposure, our study did not find an association between four distinct patterns of ASM use and adverse obstetric outcomes among women with epilepsy. The findings suggested that optimal seizure control could be received for pregnant women with epilepsy after evaluating the risks and benefits.

Addressing bias in preterm birth research: The role of advanced imputation techniques for missing race and ethnicity in perinatal health data

ObjectivesTo evaluate the effectiveness of Bayesian Improved Surname Geocoding (BISG) and Bayesian Improved First Name Surname Geocoding (BIFSG) in estimating race and ethnicity, and how they influence odds ratios for preterm birth. MethodsWe analyzed hospital birth admission electronic health records (EHR) data (N = 9985). We created two simulation sets with 40 % of race and ethnicity data missing randomly or more likely for non-Hispanic black birthing people who had preterm birth. We calculated C-statistics to evaluate how accurately BISG and BIFSG estimate race and ethnicity. We examined the association between race and ethnicity and preterm birth using logistic regression and reported odds ratios (OR). ResultsBISG and BIFSG showed high accuracy for most racial and ethnic categories (C-statistics = 0.94–0.97, 95 % confidence intervals [CI] = 0.92–0.97). When race and ethnicity were not missing at random, BISG (OR = 1.25, CI = 0.97–1.62) and BIFSG (OR = 1.38, CI = 1.08–1.76) resulted in positive estimates mirroring the true association (OR = 1.68, CI = 1.34–2.09) for Non-Hispanic Black birthing people, while traditional methods showed contrasting estimates (Complete case OR = 0.62, CI = 0.41–0.94; multiple imputation OR = 0.63, CI = 0.40–0.98). ConclusionsBISG and BIFSG accurately estimate missing race and ethnicity in perinatal EHR data, decreasing bias in preterm birth research, and are recommended over traditional methods to reduce potential bias.

Paternal use of selective serotonin reuptake inhibitors and adverse health outcomes: A nationwide cohort study on 13,547 exposed children.

The use of selective serotonin reuptake inhibitors (SSRIs) has increased over time. Several studies indicate that paternal use of medication may adversely affect the developing fetus. Only a few studies have investigated the association between preconceptional paternal exposure to SSRIs and the risks of adverse health outcomes in children. This study aimed to assess adverse birth outcomes and adverse early life events in children fathered by men using SSRIs prior to conception. All live-born singleton children born in Denmark from 1997 until 2019 and their parents were included. The exposed cohort comprised all children fathered by men using SSRIs 3 months prior to conception and the unexposed cohort comprised all other children. We estimated the odds ratios for adverse birth outcomes: small for gestational age (SGA), preterm birth, low Apgar score, and major congenital malformations. Furthermore, we estimated the hazard ratios for adverse early life events of infections and hospitalizations within 1 year from birth. We also examined adverse birth outcomes and the adverse early life events according to SSRI subgroups. There was a statistically significantly increased odds ratio 1.15 (confidence interval, CI: 1.06-1.23) for preterm birth. No significant results were found for SGA, low Apgar score, and major congenital malformations. The adjusted hazard ratios for hospitalizations and infections were 1.06 (CI: 1.02-1.11) and 1.02 (CI: 0.97-1.07), respectively. There was a statistically significantly increased odds ratio for preterm birth with respect to the SSRI subgroups citalopram and escitalopram, and for hospitalizations with respect to citalopram. Although the risks of certain adverse birth and adverse early life outcomes were statistically significantly increased, the ratios were small and may have limited clinical importance. Paternal use of SSRI was in general safe in the preconceptual period.

Effects of land cover and air pollution on the risk of preterm births.

To evaluate the association between gestational age and green areas, urban built areas, and the concentration of particulate matter 2.5 (PM2.5) in the city of São Paulo, analyzing the irregular distribution of these areas and pollution levels above the recommended level. The study population consisted of a cohort of live births from 2012, and data from the Live Birth Information System (Sinasc) of the city of São Paulo were used. Using satellite images and supervised classification, the distribution and quantity of green areas and built areas in the city of São Paulo was obtained, as well as the concentrations of PM2.5. Logistic regressions were used to obtain possible associations. The results of the study show that a lower percentage of green areas is significantly associated with a higher chance of preterm births. A higher building density was positively associated with the odds ratio for preterm birth. We did not find any significant associations between air pollution (PM2.5) and preterm births. The results of this study show that greener areas are less associated with preterm births when compared with less green areas.

Assessing the Clinical Significance of Third-Trimester Post-Coital Bleeding.

This study aimed to evaluate the impact of third-trimester post-coital bleeding (PCB) on pregnancy outcomes. A retrospective cohort study was conducted at two tertiary medical centers, including all pregnant women between 24 and 34 weeks of gestation referred due to vaginal bleeding over an 11-year period. The study population includes all singleton deliveries; within this population, women were further classified into three groups: those admitted due to vaginal bleeding related to PCB, those admitted due to vaginal bleeding not related to PCB, and those who did not report vaginal bleeding. The primary outcome measure was delivery prior to 37 weeks of gestation, while secondary outcome measures included maternal and neonatal complications. Baseline characteristics of the two groups were compared. During the study period, there were a total of 51,698 deliveries. Among these, 230 cases involved bleeding between 24 and 34 weeks of gestation, 34 (14.8%) were identified as PCB, and 196 as bleeding unrelated to intercourse. In addition, 51,468 pregnancies without bleeding were analyzed as the general population for comparison. The incidence of preterm labor before 37 weeks of gestation was notably higher in both women with PCB (14.7%) and those with bleeding unrelated to coitus (20.9%) compared to the general population (5.6%); however, there was no statistically significant difference between the two bleeding groups (p = 0.403) while both were significantly different from the general population (p &lt; 0.001). The odds ratio for preterm birth before 37 weeks of gestation after PCB was 3.29 (95% CI: 1.26-8.56, p = 0.0149). There were no significant differences between the PCB and bleeding unrelated to intercourse groups in terms of maternal and neonatal complications. This study found that third-trimester PCB is a risk factor for preterm delivery, with rates similar to other causes of third-trimester bleeding but significantly higher than the general population without bleeding. These findings challenge the assumption that PCB is benign.

Racial and Ethnic Disparities in Phthalate Exposure and Preterm Birth: A Pooled Study of Sixteen U.S. Cohorts.

Phthalate exposures are ubiquitous during pregnancy and may contribute to racial and ethnic disparities in preterm birth. We investigated race and ethnicity in the relationship between biomarkers of phthalate exposure and preterm birth by examining: a) how hypothetical reductions in racial and ethnic disparities in phthalate metabolites might reduce the probability of preterm birth; and b) exposure-response models stratified by race and ethnicity. We pooled individual-level data on 6,045 pregnancies from 16 U.S. cohorts. We investigated covariate-adjusted differences in nine urinary phthalate metabolite concentrations by race and ethnicity [non-Hispanic White (White, 43%), non-Hispanic Black (Black, 13%), Hispanic/Latina (38%), and Asian/Pacific Islander (3%)]. Using g-computation, we estimated changes in the probability of preterm birth under hypothetical interventions to eliminate disparities in levels of urinary phthalate metabolites by proportionally lowering average concentrations in Black and Hispanic/Latina participants to be approximately equal to the averages in White participants. We also used race and ethnicity-stratified logistic regression to characterize associations between phthalate metabolites and preterm birth. In comparison with concentrations among White participants, adjusted mean phthalate metabolite concentrations were consistently higher among Black and Hispanic/Latina participants by 23%-148% and 4%-94%, respectively. Asian/Pacific Islander participants had metabolite levels that were similar to those of White participants. Hypothetical interventions to reduce disparities in metabolite mixtures were associated with lower probabilities of preterm birth for Black [13% relative reduction; 95% confidence interval (CI): , 8.6%] and Hispanic/Latina (9% relative reduction; 95% CI: , 0.8%) participants. Odds ratios for preterm birth in association with phthalate metabolites demonstrated heterogeneity by race and ethnicity for two individual metabolites (mono-n-butyl and monoisobutyl phthalate), with positive associations that were larger in magnitude observed among Black or Hispanic/Latina participants. Phthalate metabolite concentrations differed substantially by race and ethnicity. Our results show hypothetical interventions to reduce population-level racial and ethnic disparities in biomarkers of phthalate exposure could potentially reduce the probability of preterm birth. https://doi.org/10.1289/EHP12831.

Subsequent pregnancy outcomes after second trimester miscarriage or termination for medical/fetal reason: A systematic review and meta-analysis of observational studies.

Women with a prior stillbirth or a history of recurrent first trimester miscarriages are at increased risk of adverse pregnancy outcomes. However, little is known about the impact of a second trimester pregnancy loss on subsequent pregnancy outcome. This review investigated if second trimester miscarriage or termination for medical reason or fetal anomaly (TFMR/TOPFA) is associated with future adverse pregnancy outcomes. A systematic review of observational studies was conducted. Eligible studies included women with a history of a second trimester miscarriage or termination for medical reasons and their pregnancy outcomes in the subsequent pregnancy. Where comparative studies were identified, studies which compared subsequent pregnancy outcomes for women with and without a history of second trimester loss or TFMR/TOPFA were included. The primary outcome was livebirth, and secondary outcomes included: miscarriage (first and second trimester), termination of pregnancy, fetal growth restriction, cesarean section, preterm birth, pre-eclampsia, antepartum hemorrhage, stillbirth and neonatal death. Studies were excluded if exposure was nonmedical termination or if related to twins or higher multiple pregnancies. Electronic searches were conducted using the online databases (MEDLINE, Embase, PubMed and The Cochrane Library) and searches were last updated on June 16, 2023. Risk of bias was assessed using the Newcastle-Ottawa scale. Where possible, meta-analysis was undertaken. PROSPERO registration: CRD42023375033. Ten studies were included, reporting on 12 004 subsequent pregnancies after a second trimester pregnancy miscarriage. No studies were found on outcomes after second trimester TFMR/TOPFA. Overall, available data were of "very low quality" using GRADE assessment. Meta-analysis of cohort studies generated estimated outcome frequencies for women with a previous second trimester loss as follows: live birth 81% (95% CI: 64-94), miscarriage 15% (95% CI: 4-30, preterm birth 13% [95% CI: 6-23]).The pooled odds ratio for preterm birth in subsequent pregnancy after second trimester loss in case-control studies was OR 4.52 (95% CI: 3.03-6.74). Very low certainty evidence suggests there may be an increased risk of preterm birth in a subsequent pregnancy after a late miscarriage. However, evidence is limited. Larger, higher quality cohort studies are needed to investigate this potential association.

Paternal preconception exposure to non-steroid anti-inflammatory drugs or opioids and adverse birth outcomes: A nationwide registry-based cohort study.

Paternal use of analgesics during the time of conception and adverse birth outcomes are poorly studied. We investigated the association between paternal exposure to non-steroid anti-inflammatory drugs and opioids within 3 months before the date of conception and the risk of adverse birth outcomes (preterm birth, small for gestational age, low Apgar score, and major congenital malformations). We used nationwide data from the Danish health registers. We included information on all singleton live births, and their fathers and mothers from 1997 to 2018. We created two exposed cohorts, children with preconception paternal exposure to (1) non-steroid anti-inflammatory drugs and (2) opioids. The unexposed cohort was children without preconception paternal exposure to non-steroid anti-inflammatory drugs or opioids, and we performed a sub-analysis against paternal use of acetaminophen (paracetamol). We used logistic regression models to estimate the odds ratios of adverse birth outcomes including 95% confidence intervals. We identified 1,260,934 children, 45,667 children with paternal exposure to non-steroid anti-inflammatory drugs, 10,086 children with paternal exposure to opioids, and 1,205,181 unexposed children. The adjusted odds ratio for preterm birth was 1.08 (95% confidence interval, 1.03-1.13) after paternal exposure to non-steroid anti-inflammatory drugs and 1.21 (95% confidence interval, 1.08-1.35) after paternal exposure to opioids. The adjusted odds ratio for small for gestational age was 1.09 (95% confidence interval, 1.03-1.17) after paternal exposure to non-steroid anti-inflammatory drugs, and 1.03 (95% confidence interval, 0.88-1.21) after paternal exposure to opioids. We found null-associations for a low Apgar score and major congenital malformations. Estimates were attenuated when compared against paternal paracetamol exposure. Overall, we found null-associations across the comparisons made. Weak associations were found for paternal exposure to non-steroid anti-inflammatory drugs or opioids and preterm birth and small for gestational age, but not with low Apgar score or major congenital malformation. All associations were attenuated when compared against an active comparator of paternal paracetamol exposure. The effect sizes were small and less likely to be of clinical relevance.

Intestinal barrier disruption with Plasmodium falciparum infection in pregnancy and risk of preterm birth: a cohort study

Malaria in early pregnancy is a risk factor for preterm birth and is associated with sustained inflammation and dysregulated angiogenesis across gestation. This study investigated whether malaria is associated with increased gut leak and whether this contributes to systemic inflammation, altered angiogenesis, and preterm birth. We quantified plasma concentrations of gut leak markers, soluble CD14 (sCD14) and lipopolysaccharide binding protein (LBP) from 1339 HIV-negative pregnant Malawians at <24 weeks gestational age. We assessed the relationship of sCD14 and LBP concentrations with markers of inflammation, angiogenesis, and L-arginine bioavailability and compared them between participants with and without malaria, and with and without preterm birth. Plasma concentrations of sCD14 and LBP were significantly higher in participants with malaria and were associated with parasite burden (p <0.0001, both analyses and analytes). The odds ratio for preterm birth associated with one log sCD14 was 2.67 (1.33 to 5.35, p=0.006) and 1.63 (1.07-2.47, p=0.023) for LBP. Both gut leak analytes were positively associated with increases in proinflammatory cytokines CRP, sTNFR2, IL18-BP, CHI3L1 and Angptl3 (p <0.05, all analytes) and sCD14 was significantly associated with angiogenic proteins Angpt-2, sENG and the sFLT:PlGF ratio (p <0.05, all analytes). sCD14 was negatively associated with L-arginine bioavailability (p <0.001). Malaria in early pregnancy is associated with intestinal barrier dysfunction, which is linked to an increased risk of preterm birth. Open Philanthropy, Canadian Institutes of Health Research, Canada Research Chair program, European and Developing Countries Clinical Trials Partnership, Bill & Melinda Gates Foundation.

Uterocervical angle versus cervical length in the prediction of spontaneous preterm birth in women with history of spontaneous preterm birth: a prospective observational study

BackgroundPreterm delivery is a leading cause of neonatal mortality and morbidity. History of spontaneous preterm birth is the greatest risk factor for another preterm delivery. So, every effort should be made to prevent the recurrence of preterm delivery in this vulnerable group. This study aimed to evaluate the predictive ability of the anterior uterocervical angle and cervical length in preterm birth.Patients and MethodsThis was a prospective cohort study that included 70 patients with a history of spontaneous preterm birth. Ultrasound measurements of cervical length and anterior uterocervical angle were set to be measured for each patient at three visits; first between 16 0/7 and 24 0/7 weeks, second between 24 1/7 and 32 0/7 weeks, and the third was between 32 1/7 and 36 6/7 weeks. The correlation between both measures and the prediction of preterm birth among study participants was the primary outcome of the study. Neonatal outcome among the study patients was a secondary measure of outcome.ResultsThe incidence of preterm birth among study participants was 31.41%. Cervical length and uterocervical angle showed progressive decrease and increase respectively throughout pregnancy. At the 2nd visit, the two measures were significantly different between those who delivered at term and those with preterm delivery with the cervical length being significantly shorter in the preterm arm (3.0 ± 0.49 versus 3.38 ± 0.36, p < 0.001) and uterocervical angle being significantly bigger among the same arm (110.1 ± 18.48 versus 84.42 ± 12.24, p < 0.001). A uterocervical angle > 89.8° at the second visit predicted preterm birth with 81.8% sensitivity and 70.8% specificity while cervical length ≤ 3.22 cm at the second visit predicted preterm birth with 68.1% sensitivity and 62.5% specificity. Multivariant logistic regression analysis showed that uterocervical angle > 89.8° at the second visit increased the odds ratio for preterm birth by 9.ConclusionUterocervical angle can be a useful ultrasound marker for the prediction of preterm birth among high risk patients. A cutoff value of 89.8° can be used as a threshold above which prophylactic measures such as cervical cerclage or progesterone therapy can be provided.Trial registrationNCT05632003 (First posted date: 30/11/2022).

Association between gestational age at threatened preterm birth diagnosis and incidence of preterm birth: the Japan Environment and Children’s Study

We evaluated the association between gestational age at threatened preterm birth (TPTB) diagnosis and preterm birth (PTB) incidence using a nationwide birth cohort. Data of 94,236 women with singleton deliveries from the Japan Environment and Children’s Study (enrolled between 2011 and 2014) were analysed. Participants were divided based on parity and gestational age at TPTB diagnosis (22–24, 25–27, 28–30, 31–33, and 34–36 weeks). Multivariable logistic regression models were used to calculate the odds ratios (ORs) for PTB before 37 and 34 weeks in women from all groups, using participants without TPTB as the reference. The adjusted ORs for PTB before 37 weeks were the highest in the latest gestational age group in nulliparous and multiparous women without previous PTB, while those before 34 weeks were the highest in the earliest and latest gestational age group in multiparous women without previous PTB and in the earliest gestational age group in multiparous women with previous PTB. The association between gestational age at TPTB diagnosis and PTB incidence varies based on maternal parity and PTB before 37 or 34 weeks. Further studies with detailed clinical data and a unified TPTB diagnosis protocol are necessary to clarify this association.

Association between Parity and Preterm Birth-Retrospective Analysis from a Single Center in Poland.

Preterm births and parity are two medical areas that seem to be entirely different from each other. The aim of this study was to analyze the relationships between parity and maternal and neonatal outcomes associated with preterm birth. This study involved a retrospective analysis of electronic medical records from St. Sophia Hospital in Warsaw (Poland). This study was conducted among women who gave birth to preterm infants between 1 January 2017 and 31 December 2021. A total of 2043 cases of preterm births were included in the final analysis. A higher odds ratio of preterm birth in primiparas was found in women living in a city/town (OR = 1.56) and having secondary (OR = 1.46) and higher education (OR = 1.82). Multiparas who gave birth to preterm infants were more frequently diagnosed with gestational diabetes (19.69%) than primiparas. Multiparas were more likely to give birth to preterm infants who received an Apgar score of ≤7 both at 1 and 5 min after birth (25.80% and 15.34%). The results of our study emphasize the differences between primiparas and multiparas who give birth to preterm infants. Knowledge of these differences is essential to improve the perinatal care provided to mothers and their infants.

Adverse birth outcomes and early-life infections after in utero exposure to corticosteroids for inflammatory bowel disease: a Danish nationwide cohort study

BackgroundSystemic corticosteroids are often used to treat inflammatory bowel disease (IBD) flares during pregnancy as maintenance of disease remission is crucial to optimize pregnancy outcomes. However, there is little data regarding the effect of in utero exposure to corticosteroids on the risk of adverse birth outcomes and early-life infections in the offspring.MethodsWe used the Danish national registries to establish a nationwide cohort of all singleton live births in women with IBD from 1995 to 2015. Outcomes in children exposed in utero to corticosteroids were compared to those who were not exposed. In logistic and Cox proportional hazard regression models, we adjusted the outcomes (major congenital malformation, preterm birth, small for gestational age, low 5-min Apgar score, and infections) for confounders such as body mass index, smoking, comorbidity, and additional medical IBD treatment.ResultsAfter in utero exposure to corticosteroids at any time between 30 days prior to conception through the first trimester (n = 707), the adjusted hazard ratio of major congenital malformation was 1.28 (95% CI: 0.82–2.00) compared to children born to women with IBD, but not exposed to corticosteroids in utero (n = 9371). After in utero exposure to corticosteroids at any time during pregnancy (n = 1336), the adjusted odds ratios for preterm birth, small for gestational age, and low 5-min Apgar score were 2.45 (95% CI: 1.91–3.13), 1.21 (95% CI: 0.76–1.90), and 0.91 (95% CI: 0.33–2.52), respectively. Finally, the adjusted hazard ratio of overall infections in the first year of life was 1.14 (95% CI: 0.94–1.39).ConclusionsThis nationwide cohort study suggests that children of women with IBD exposed to corticosteroids in utero had an almost 2.5-fold increased risk of preterm birth. Use of corticosteroids is closely related to disease activity and we cannot adjust for the independent role of disease activity. It is however reassuring that the other examined birth and early-life outcomes were not statistically significantly increased.

Third trimester as the susceptibility window for maternal PM2.5 exposure and preterm birth: A nationwide surveillance-based association study in China

Maternal PM2.5 exposure has been identified as a potential risk factor for preterm birth, yet the inconsistent findings on the susceptible exposure windows may be partially due to the influence of gaseous pollutants. This study aims to examine the association between PM2.5 exposure and preterm birth during different susceptible exposure windows after adjusting for exposure to gaseous pollutants. We collected 2,294,188 records of singleton live births from 30 provinces of China from 2013 to 2019, and the gridded daily concentrations of air pollutants (including PM2.5, O3, NO2, SO2, and CO) were derived by using machine learning models for assessing individual exposure. We employed logistic regression to develop single-pollutant models (including PM2.5 only) and co-pollutant models (including PM2.5 and a gaseous pollutant) to estimate the odds ratio for preterm birth and its subtypes, with adjustment for maternal age, neonatal sex, parity, meteorological conditions, and other potential confounders. In the single-pollutant models, PM2.5 exposure in each trimester was significantly associated with preterm birth, and the third trimester exposure showed a stronger association with very preterm birth than that with moderate to late preterm birth. The co-pollutant models revealed that preterm birth might be significantly associated only with maternal exposure to PM2.5 in the third trimester, and not with exposure in the first or second trimester. The observed significant associations between preterm birth and maternal PM2.5 exposure in the first and second trimesters in single-pollutant models might primarily be influenced by exposure to gaseous pollutants. Our study provides evidence that the third trimester may be the susceptible window for maternal PM2.5 exposure and preterm birth. The association between PM2.5 exposure and preterm birth could be influenced by gaseous pollutants, which should be taken into consideration when evaluating the impact of PM2.5 exposure on maternal and fetal health.

Elective single versus double blastocyst-stage embryo transfer in women aged 36 years or older: a retrospective cohort study

We evaluated if elective single-blastocyst transfer (eSBT) could be adopted in women aged 36 or older. In this retrospective cohort, women aged ≥36 years received IVF ovarian stimulation cycles and had ≥ two blastocysts. A total of 240 women underwent eSBT and 189 double-blastocyst transfer (DBT) in the first transfer cycle. The subsequent frozen-thawed embryo transfer cycles were a combination of single- and double- blastocyst transfers. Analysis was stratified for patients in age groups 36–37, 38–39 and ≥40, considering the quality of the blastocyst transferred. The cumulative live birth rates (cLBR) were 74.2% (178/240) versus 63.0% (119/189) after eSBT versus DBT, respectively (aOR: 1.09 (0.68, 1.75)). Time to live birth did not vary significantly between the two groups (HR: 0.85 (0.68, 1.08)). The total number of children born was 194 after eSBT (162 singletons and 16 pairs of twins) versus 154 (84 singletons and 35 twins) after DBT. The odds ratios for preterm birth (0.37 (0.21–0.64)), and low birth weight (0.31 (0.16, 0.60)) were all lower in eSBT. In women aged ≥36 years, cLBR following single- versus double- blastocyst transfer was comparable while the odds of multiple live births and adverse perinatal outcomes were reduced.

Nonsurgical periodontal treatment during pregnancy and rates of preterm birth

Periodontitis during pregnancy is associated with an increased risk of preterm birth (<37 weeks of gestation) or low birthweight (<2500 g) offspring. Beyond periodontal disease, the risk of preterm birth varies both by previous history of preterm birth and in association with social determinants prevalent among vulnerable and marginalized populations. This study hypothesized that the timing of periodontal treatment during pregnancy and/or social vulnerability measures modified the response to dental scaling and root planing for the treatment of periodontitis and prevention of preterm birth. This study aimed to determine the association of timing of dental scaling and root planing for gravidae with a diagnosed periodontal disease on the rates of preterm birth or low birthweight offspring among subgroups or strata of gravidae as part of the Maternal Oral Therapy to Reduce Obstetric Risk randomized controlled trial. All participants in the study had clinically diagnosed periodontal disease and differed by the timing of the periodontal treatment (dental scaling and root planing at <24 weeks [per protocol] or after delivery) or by baseline characteristics. Although all participants met the well-accepted clinical criteria for periodontitis, not all participants acknowledged a priori that they had periodontal disease. This was a per-protocol analysis of data from 1455 participants of the Maternal Oral Therapy to Reduce Obstetric Risk trial evaluating dental scaling and root planing on the risk of preterm birth or low birthweight offspring. Adjusted multiple logistic regression to control for confounders was used to estimate associations comparing the timing of periodontal treatment in pregnancy to receiving treatment after pregnancy (referent control) on rates of preterm birth or low birthweight among subgroups of gravidae with known periodontal disease. Study analyses were stratified, and the associations with the following characteristics-body mass index, self-described race and ethnicity, household income, maternal education, recency of immigration, and self-acknowledgment of poor oral health, were explored. Dental scaling and root planing during the second or third trimester of pregnancy were associated with an increased adjusted odds ratio of preterm birth among those at the lower body mass index strata (18.5 to <25.0 kg/m2) (adjusted odds ratio, 2.21; 95% confidence interval, 1.07-4.98), but not among individuals who were overweight (body mass index of 25.0 to <30.0 kg/m2; adjusted odds ratio, 0.68; 95% confidence interval, 0.29-1.59) or obese (body mass index of ≥30 kg/m2; adjusted odds ratio, 1.26; 95% confidence interval, 0.65-2.49). There was no significant difference in pregnancy outcomes related to the other evaluated variables: self-described race and ethnicity, household income, maternal education, immigration status, or self-acknowledgment of poor oral health. In this per-protocol analysis of the Maternal Oral Therapy to Reduce Obstetric Risk trial, dental scaling and root planing had no preventive benefit against adverse obstetrical outcomes and were associated with increased odds of preterm birth among individuals at lower body mass index strata. There was no significant difference in the occurrence of preterm birth or low birthweight after dental scaling and root planing periodontitis treatment concerning other analyzed social determinants of preterm birth.

In Vitro Fertilization and Adverse Pregnancy Outcomes in the Elective Single Embryo Transfer Era.

Our objective was to estimate the association between in vitro fertilization (IVF) pregnancy and adverse pregnancy outcomes during delivery hospital admission in a contemporary, nation-wide cohort of births in the United States. This retrospective, population-based cohort study used the National Inpatient Sample database to identify patients discharged from the hospital following delivery from 2014 to 2019. IVF pregnancies were identified using the International Classification of Disease-Revision 9/10 codes. Crude and adjusted odds ratios of preterm birth and other clinically significant adverse pregnancy outcomes were evaluated using multivariable logistic regression models. Trends in preterm birth and multiple pregnancy were estimated over the study period. The contribution of multiple pregnancy to preterm birth in IVF pregnancy was estimated in a mediation analysis. Among 4,451,667 delivery-related discharges, IVF pregnancies were associated with 3.25 times the odds of preterm birth (95% confidence interval [CI]: 3.05-3.46, p < 0.001) compared with non-IVF pregnancy deliveries. Odds of preterm birth in IVF pregnancy delivery discharges decreased over the study period (p-value for linear trend = 0.009). The proportion of multiple pregnancies decreased in IVF pregnancy delivery discharges but remained stable in non-IVF pregnancy deliveries. The proportion of the adjusted effect of IVF pregnancy on preterm birth mediated through multiple pregnancy was 67.6% (95% CI: 62.6-72.7%). While the odds of adverse pregnancy outcomes are increased compared with non-IVF pregnancies, the odds of preterm birth and multiple gestation have decreased among IVF pregnancies in the United States. · Pregnancies conceived by in vitro fertilization (IVF) are at significantly higher risk of multiple gestation, preterm birth, and other pregnancy complications.. · Recent guidelines for artificial reproductive treatments recommend single-embryo transfer in IVF.. · Using population-wide data, we demonstrate a significant gradual decline in the rates of preterm birth and other pregnancy complications following IVF in the last decade, mostly mediated by a reduction in multiple pregnancies..

Different pathways for preterm birth between singleton and twin pregnancies: a population-based registry study of 481 176 nulliparous women.

To explore the contribution of pregnancy-related complications on the prevalence of extremely, very and late preterm births in singleton and twin pregnancies. To study the risk of spontaneous preterm birth in twin pregnancies compared with singleton pregnancies. Population-based registry study. Medical birth registry of Norway and Statistics Norway. Nulliparous women with singleton (n=472 449) or twin (n=8727) births during 1999-2018. Prevalence rates of pregnancy-related complications for extremely, very and late preterm birth in twin and singleton pregnancies were calculated with 95% confidence intervals. Multivariable logistic regression was applied to assess odds ratios for preterm birth, adjusted for obstetric and socio-economic factors. Extremely preterm (<28+0 weeks of gestation), very preterm (28+0 -33+6 weeks of gestation) and late preterm (34+0 -36+6 weeks of geatation) birth. Preterm birth was significantly more prevalent in twin pregnancies than in singleton pregnancies in all categories: all preterm (54.7% vs 6.1%), extremely preterm (3.6% vs 0.4%), very preterm (18.2% vs 1.4%) and late preterm (33.0% vs 4.3%) births. Stillbirth, congenital malformation and pre-eclampsia were more prevalent in twin pregnancies than in singleton pregnancies, but the prevalence of complications differed in the three categories of preterm birth. Pre-eclampsia was more prevalent in singleton than in twin pregnancies ending in extremely and very preterm birth. The adjusted odds of spontaneous preterm live birth were between 19- and 54-fold greater in twin pregnancies than in singleton pregnancies. Singleton and twin pregnancies seem to have different pathways leading to extremely, very and late preterm birth.

Racial discrimination and adverse pregnancy outcomes: a systematic review and meta-analysis

IntroductionRacial discrimination has been consistently linked to various health outcomes and health disparities, including studies associating racial discrimination with patterns of racial disparities in adverse pregnancy outcomes. To expand our...