Entire Pregnancy Research Articles

Exposure to ambient air pollutions and its association with adverse birth outcomes: a systematic review and meta-analysis of epidemiological studies

IntroductionAir pollution is a significant global public health concern. However, there is a lack of updated and comprehensive evidence regarding the association between exposure to ambient air pollution and adverse birth outcomes (preterm birth, low birth weight, and stillbirth). Furthermore, the existing evidence is highly inconsistent. Therefore, this study aims to estimate the overall association between ambient air pollution and adverse birth outcomes.MethodsIn this study, initially a total of 79,356 articles were identified. Finally, a total of 49 articles were included. We conducted compressive literature searches using various databases, including PubMed, Scientific Direct, HINARI, and Google Scholar. Data extraction was performed using Microsoft Excel, and the data were exported to STATA 17 software for analysis. We used the Joanna Briggs Institute’s quality appraisal tool to ensure the quality of the included studies. A random effects model was employed to estimate the pooled prevalence. Publication bias was assessed using funnel plots and Egger’s regression test.ResultsIn this study, the pooled prevalence of at least one adverse birth outcome was 7.69% (95% CI: 6.70–8.69), with high heterogeneity (I2 = 100%, p-value < 0.001). In this meta-analysis, high pooled prevalence was found in preterm birth (6.36%), followed by low birth weights (5.07%) and stillbirth (0.61%). Exposure to PM2.5 (≤10 μg/m3) throughout the entire pregnancy, PM2.5 (≤10 μg/m3) in the first trimester, PM10 (>10 μg/m3) during the entire pregnancy, and O3 (≤10 μg/m3) during the entire pregnancy increased the risk of preterm birth by 4% (OR = 1.04, 95% CI: 1.03–1.05), 5% (OR = 1.05, 95% CI: 1.01–1.09), 49% (OR = 1.49, 95% CI: 1.41–1.56), and 5% (OR = 1.05, 95% CI: 1.04–1.07), respectively. For low birth weight, exposure to PM2.5 (≤10 μg/m3) and PM2.5 (>10 μg/m3) throughout the entire pregnancy was associated with an increased risk of 13% (OR = 1.13, 95% CI: 1.05–1.21) and 28% (OR = 1.28, 95% CI: 1.23–1.33), respectively.ConclusionThis study highlighted a significant association between ambient air pollution and adverse birth outcomes. Therefore, it is crucial to implement a compressive public health intervention.Systematic review registrationThe review protocol was registered with the record ID of CRD42024578630.

Fine Particulate Matter, Its Constituents, and Spontaneous Preterm Birth.

The associations of exposure to fine particulate matter (PM2.5) and its constituents with spontaneous preterm birth (sPTB) remain understudied. Identifying subpopulations at increased risk characterized by socioeconomic status and other environmental factors is critical for targeted interventions. To examine associations of PM2.5 and its constituents with sPTB. This population-based retrospective cohort study was conducted from 2008 to 2018 within a large integrated health care system, Kaiser Permanente Southern California. Singleton live births with recorded residential information of pregnant individuals during pregnancy were included. Data were analyzed from December 2023 to March 2024. Daily total PM2.5 concentrations and monthly data on 5 PM2.5 constituents (sulfate, nitrate, ammonium, organic matter, and black carbon) in California were assessed, and mean exposures to these pollutants during pregnancy and by trimester were calculated. Exposures to total green space, trees, low-lying vegetation, and grass were estimated using street view images. Wildfire-related exposure was measured by the mean concentration of wildfire-specific PM2.5 during pregnancy. Additionally, the mean exposure to daily maximum temperature during pregnancy was calculated. The primary outcome was sPTB identified through a natural language processing algorithm. Discrete-time survival models were used to estimate associations of total PM2.5 concentration and its 5 constituents with sPTB. Interaction terms were used to examine the effect modification by race and ethnicity, educational attainment, household income, and exposures to green space, wildfire smoke, and temperature. Among 409 037 births (mean [SD] age of mothers at delivery, 30.3 [5.8] years), there were positive associations of PM2.5, black carbon, nitrate, and sulfate with sPTB. Adjusted odds ratios (aORs) per IQR increase were 1.15 (95% CI, 1.12-1.18; P < .001) for PM2.5 (IQR, 2.76 μg/m3), 1.15 (95% CI, 1.11-1.20; P < .001) for black carbon (IQR, 1.05 μg/m3), 1.09 (95% CI, 1.06-1.13; P < .001) for nitrate (IQR, 0.93 μg/m3), and 1.06 (95% CI, 1.03-1.09; P < .001) for sulfate (IQR, 0.40 μg/m3) over the entire pregnancy. The second trimester was the most susceptible window; for example, aORs for total PM2.5 concentration were 1.07 (95% CI, 1.05-1.09; P < .001) in the first, 1.10 (95% CI, 1.08-1.12; P < .001) in the second, and 1.09 (95% CI, 1.07-1.11; P < .001) in the third trimester. Significantly higher aORs were observed among individuals with lower educational attainment (eg, less than college: aOR, 1.16; 95% CI, 1.12-1.21 vs college [≥4 years]: aOR, 1.10; 95% CI, 1.06-1.14; P = .03) or income (<50th percentile: aOR, 1.17; 95% CI, 1.14-1.21 vs ≥50th percentile: aOR, 1.12; 95% CI, 1.09-1.16; P = .02) or who were exposed to limited green space (<50th percentile: aOR, 1.19; 95% CI, 1.15-1.23 vs ≥50th percentile: aOR, 1.12; 95% CI, 1.09-1.15; P = .003), more wildfire smoke (≥50th percentile: aOR, 1.19; 95% CI, 1.16-1.23 vs <50th percentile: aOR, 1.13; 95% CI, 1.09-1.16; P = .009), or extreme heat (aOR, 1.51; 95% CI, 1.42-1.59 vs mild temperature: aOR, 1.11; 95% CI, 1.09-1.14; P < .001). In this study, exposures to PM2.5 and specific PM2.5 constituents during pregnancy were associated with increased odds of sPTB. Socioeconomic status and other environmental exposures modified this association.

Effects of famotidine use during pregnancy: an observational cohort study

BackgroundFamotidine, a histamine2-receptor antagonist (H2Ras), is widely used to treat and prevent gastrointestinal symptoms during pregnancy. Although several studies have reported the use of H2Ras during pregnancy, limited data on famotidine were included in these reports. Therefore, we analyzed pregnancy outcome data to evaluate the effects of famotidine use during pregnancy on the fetus.MethodsPregnancy outcome data were used for females enrolled in two Japanese facilities that provided counseling on drug use during pregnancy between April 1988 and December 2017. For the primary endpoint, the incidence of congenital malformations was calculated from the data of live birth to pregnant women who took famotidine (n = 330) or drugs considered to exert no teratogenic risk (control, n = 1,407) during the first trimester of pregnancy. Considering secondary endpoints, the incidence of obstetric outcomes, including preterm delivery, was calculated from data on the use of famotidine (n = 347) and controls (n = 1,476) during the entire pregnancy. The crude odds ratios (cORs) for the incidence of congenital malformations were calculated using univariate logistic regression analysis, with the control group used as the reference. Adjusted ORs (aORs) were calculated using multivariate logistic regression analysis adjusted for various other factors.ResultsThe incidences of congenital malformations in the famotidine and control groups were 3.9% and 2.8%, respectively. There was no significant difference between the famotidine and control groups (cOR: 1.40 [95% CI:0.68–2.71], aOR: 1.06 [95% CI:0.51–2.16]). Conversely, the preterm delivery rates were 8.1% and 3.8% in the famotidine and control groups, respectively, indicating a significant difference (cOR: 2.00 [95% CI:1.20–3.27]). However, the multivariate analysis eliminated famotidine use as a confounding factor.ConclusionsThis observational cohort study revealed that exposure to famotidine during the first trimester of pregnancy was not associated with an increased risk of congenital malformations in infants. Although a higher rate of preterm delivery was detected in famotidine users when compared with controls, this could be attributed to confounding factors, such as complications.

Critical periods of maternal exposure to ambient fine particulate matter and the risks of stillbirth and spontaneous preterm birth in Western Australia

Few studies have investigated weekly or monthly exposure-lag-response association between fine particulate matter (PM2.5) and preterm birth, and there has been no known such study for stillbirth. We aimed to identify potential critical susceptible periods of the association between monthly PM2.5 exposure during pregnancy and stillbirth and spontaneous preterm birth (sPTB). A total of 414,771 singleton births, of which 0.5% and 3.9% were stillbirth and sPTB respectively, between 1st January 2000 and 31st December 2015 in Western Australia were linked to fine spatiotemporal monthly PM2.5 concentrations. Monthly distributed lag linear and non-linear Cox regressions were performed to investigate PM2.5 exposure during pregnancy and covariate-adjusted hazards of stillbirth and sPTB. The mean PM2.5 exposure during pregnancy was 8.1 μg/m3. Pregnancy PM2.5 exposure showed small dose-response associations with stillbirth and sPTB with critical susceptible periods spanning the 3rd–6th gestational months. Relative to 5 μg/m3, the strongest hazards of PM2.5 exposure were 1.04 (95% CI 0.99, 1.08) and 1.03 (95% CI 1.02, 1.05) during the 4th gestational month for stillbirth and sPTB, respectively. Monthly exposures at late pregnancy were associated with lower hazards. The average pregnancy exposure hazards were 1.08 (95% CI 0.88, 1.32) and 1.07 (95% CI 0.99, 1.15) per 5 μg/m3 increment for stillbirth and sPTB, respectively. The average entire pregnancy exposure showed potential attributable burden, synergistic interaction effects with biothermal stress, and comparatively higher hazards for female births and births to mothers who were Caucasian, < 35 years old, high SES, nulliparous, and smoked during pregnancy.

Prenatal exposure to air pollution during the early and middle stages of pregnancy is associated with adverse neurodevelopmental outcomes at ages 1 to 3 years

BackgroundA large body of data shows that fetal brain development is vulnerable to disruption by air pollution experienced by the mother during pregnancy, adversely affecting cognitive and psychomotor capabilities during childhood (De Asis-Cruz et al., Biol Psychiatry 7:480–90, 2022; Morgan ZEM et al., Environ Health 22:11, 2023). This study has sought to identify gestational windows of susceptibility to prenatal exposure to air pollution.Methods470 African American and Latina mother/child pairs participated in a prospective cohort study based in the low-income communities of Northern Manhattan and the South Bronx, New York City. Gestational exposure to respirable particulate matter (PM2.5) and nitrogen dioxide (NO2) was assessed through validated models in relation to cognitive and motor development assessed at ages 1, 2, and 3 years using the Bayley-II Scales. Multiple linear regression models and distributed lag models (DLM) were used to identify critical windows of exposure by trimester and week of pregnancy.ResultsBy linear regression, average exposures to NO2 during the first and second trimesters and the entire pregnancy were significantly and negatively associated with the mental developmental index (MDI) at age 1. Average exposures to PM2.5 during the second trimester and the entire pregnancy were also significantly, inversely associated with age 1 MDI. No significant associations were found between these exposures and MDI at age 2. NO2 exposure during the first trimester was significantly negatively associated with MDI at age 3. Using DLM, exposures to NO2 at lags 29–30 weeks (within the first trimester) and PM2.5 at lags 17–18 weeks (second trimester) were significantly and inversely associated with MDI at age 1. Significant, inverse associations were found between exposures to NO2 at lag 29 weeks and PM2.5 at lags 27–29 weeks and children’s MDI at age 3. No significant associations were found between psychomotor index (PDI) and prenatal exposures to NO2 or PM2.5 at ages 1, 2 or 3.ConclusionsOur finding that prenatal exposure to air pollution in the first and second trimesters was associated with lower scores for cognitive development at ages 1 and 3 is of concern because of the potential consequences of these outcomes for long-term functioning. They underscore the need for stronger policies to protect pregnant individuals and offspring, particularly during vulnerable, early life-stage of development.

Biparietal diameter vs crown-rump length as standard parameter for late first-trimester pregnancy dating.

To compare the precision of biparietal diameter (BPD) and crown-rump length (CRL) as predictors of gestational age in the human fetus in the late first and early second trimesters, using a population-based approach. We constructed term and gestational-age prediction curves for first-trimester dating, based on 11 041 pregnancies with 12 260 measurements of CRL and/or BPD from a population-based Norwegian clinical database. We used a population-based approach with local linear quantile regression, combined with a time-to-event strategy that compensates for induced births. Term prediction precision was assessed by estimating and comparing the prediction residual curves using a time-to-event analysis. Individual differences in gestational-age predictions from CRL and BPD were assessed using measurements performed on the same fetus on the same day. A sensitivity analysis was performed to evaluate the effect of not distinguishing between non-spontaneous and spontaneous births. CRL and BPD provided almost identical term prediction precision judged from the residual distribution. In about 51% of examinations, the difference in predicted gestational age was 1 day or less; 24% of examinations had a difference of 2 days, 14% had a difference of 3 days, 7% had a difference of 4 days and only 5% of all examinations had a difference of 5 days or more. Incorrectly removing induced births from the analysis, or treating them as spontaneous, would cause a substantial systematic prediction bias of about 2 days. Based on population data, using comparisons at an individual level, our study found that BPD is as precise as CRL when used for first-trimester dating. BPD has advantages from a clinical point of view, since it is technically less challenging and less time-consuming to measure compared with CRL, and can be measured and assessed throughout the entire pregnancy. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Alterations in the placental proteome in association with the presence of black carbon particles: A discovery study

BackgroundExposure to ambient air pollution is known to cause direct and indirect molecular expression changes in the placenta, on the DNA, mRNA, and protein levels. Ambient black carbon (BC) particles can be found in the human placenta already very early in gestation. However, the effect of in utero BC exposure on the entire placental proteome has never been studied to date. ObjectivesWe explored whether placental proteome differs between mothers exposed to either high or low BC levels throughout the entire pregnancy. MethodsWe used placental tissue samples from the ENVIRONAGE birth cohort, of 20 non-smoking, maternal- and neonate characteristic-matched women exposed to high (n = 10) or low (n = 10) levels of ambient BC throughout pregnancy. We modeled prenatal BC exposure levels based on the mother's home address and measured BC levels in the fetal side of the placenta. The placental proteome was analyzed by nano-liquid chromatography Q-TOF mass spectrometry. PEAKS software was used for protein identification and label-free quantification. Protein-protein interaction and functional pathway enrichment analyses were performed with the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) software. ResultsThe accumulation of BC particles in placenta was 2.19 times higher in the high versus low exposure group (20943.4 vs 9542.7 particles/mm³; p = 0.007). Thirteen proteins showed a ≥2-fold expression difference between the two exposure groups, all overexpressed in the placentas of women prenatally exposed to high BC levels. Three protein-protein interactions were enriched within this group, namely between TIMP3 and COL4A2, SERPINE2 and COL4A2, and SERPINE2 and GP1BB. Functional pathway enrichment analysis put forward pathways involved in extracellular matrix-receptor interaction, fibrin clot formation, and sodium ion transport regulation. DiscussionPrenatal BC exposure affects the placental proteome. Future research should focus on the potential consequences of these alterations on placental functioning, and health and disease during early childhood development.

Dynamic monitoring of the endothelium function in pregnant women at high risk of preeclampsia during pathogenetic prevention of its development

BACKGROUND: Today, preclinical diagnosis of preeclampsia presents significant difficulties. In widespread practice, it is diagnosed based on existing clinical signs and laboratory and functional research methods. Most of them are invasive and expensive, which makes it difficult to use them in widespread clinical practice for diagnosis and, especially, for monitoring the effectiveness of therapy over the dynamics of the disease. It is known that the pathogenesis of preeclampsia can have two independent development paths, converging in a common resulting link — the formation of endothelial dysfunction. Methods for studying endothelial function include determining markers of its imbalance in blood samples and non-invasive functional tests. Non-invasive diagnosis of endothelial dysfunction using the EndoPAT test allows us to quantify endothelium-mediated changes in vascular tone during 5-minute occlusion of the brachial artery. AIM: The aim of this study was to evaluate the method for determining the endothelium function in the first, second and third trimesters of pregnancy during ongoing pathogenetic prevention of preeclampsia. MATERIALS AND METHODS: This interventional uncontrolled study of the effectiveness of preventing preeclampsia using non-invasive assessment of vascular endothelial dysfunction during pregnancy was conducted at the Research Institute of Obstetrics, Gynecology and Reproductology named after D.O. Ott, St. Petersburg, Russia. The study involved 108 pregnant women at high risk of developing preeclampsia. All pregnant women underwent a cuff test to determine endothelial dysfunction using the peripheral arterial tonometry technique on the Endo-PAT 2000 device. The dynamic study was carried out in the first, second and third trimesters of pregnancy. As a result of the study, when endothelial dysfunction was detected [logarithmic transformation of reactive hyperemia peripheral arterial tonometry index (LnRHI) less 0.51], a complex glycosaminoglycan was additionally added to the basic prophylaxis with acetylsalicylic acid at a dosage of 250 MU (one capsule three times a day for eight weeks), then a cuff test was monitored after 6–12 weeks. Statistical analysis was performed using the IBM SPSS Statistics 20 software. All tests for significance were two-tailed, and differences were considered significant at p 0.05. RESULTS: Endothelial dysfunction was detected in the first trimester in 59 (55%) patients, then during ongoing complex therapy in the second trimester (n = 72) in 46 (64%) patients and in the third trimester (n = 46) in 4 (1%) patients. Moderate preeclampsia in the third trimester (35–39 weeks of gestation) developed in 28 (25.9%) patients out of 108. At the same time, at the start of the study, 15 patients with endothelial dysfunction received complex therapy, and 13 individuals only took acetylsalicylic acid. Among 46 patients who observed the dynamics of the entire pregnancy, only 4 (8.7%) women developed preeclampsia. After complex treatment prescribed based on the first trimester parameters, out of 36 patients who discontinued complex therapy and did not undergo a functional test subsequently, preeclampsia developed in 16 (44.4%) women. In the second trimester, out of 26 patients who stopped complex therapy, preeclampsia developed in 8 (30.8%) people. Thus, constant monitoring and complex therapy reduced the frequency of preeclampsia. In the group with a history of preeclampsia, the disease developed in 13 (39.4%) women. In the group with a high risk of preeclampsia according to the results of combined prenatal screening in the first trimester, with the exception of a history of preeclampsia (blood pressure test, placental growth factor level in the blood serum, lowest uterine artery pulsatility index value calculated to assess the individual risk of preeclampsia with a titer less than 1 : 100), preeclampsia occurred in 4 (13.3%) women. In the group with extragenital pathology associated with the risk of preeclampsia, including obesity, pregestational diabetes mellitus, chronic arterial hypertension, and chronic kidney disease, with the exception of a history of preeclampsia and a high risk of preeclampsia according to the results of perinatal screening, preeclampsia occurred in 11 (24.4%) women. In the high–risk groups for preeclampsia, we identified the highest-risk group, namely, one with the presence of preeclampsia in the anamnesis. CONCLUSIONS: The effectiveness of the functional method for determining endothelial dysfunction in the first, second and third trimesters of pregnancy during pathogenetic prevention of preeclampsia has been proven.

Exposure to PM2.5 and its constituents in relation to thyroid function of pregnant women: Separate and mixture analyses

The relationships between exposure to PM2.5 and its constituents and thyroid hormone (TH) levels in pregnant women are still uncertain, particularly regarding the impact of mixed exposure to PM2.5 constituents on thyroid function during pregnancy. This study aimed to investigate the individual and mixed effect of PM2.5 and its constituents on TH levels during pregnancy. Fluorescence and chemiluminescence immunoassays were utilized to measure serum concentrations of free thyroxine (FT4) and thyroid-stimulating hormone (TSH) in pregnant women participating in the Fujian Birth Cohort Study (FJBCS). PM2.5 and its constituents were obtained from the ChinaHighAirPollutants dataset. Generalized linear regression model and mixture analysis were applied to explore the individual and mixed effect of PM2.5 and its constituents on TH levels. 13711 participants from the FJBCS were taken into the final analysis. In the context of separate exposure, an increase of one interquartile range (IQR) in PM2.5 exposure during the 1st trimester, 2nd trimester, and entire pregnancy was associated with a decrease of −0.042 (−0.050, −0.034), −0.017 (−0.026, −0.009), and −0.011 (−0.017, −0.004) in FT4 level, respectively. As well, significant negative associations were observed between FT4 level and PM2.5 constituents. Additionally, PM2.5 and its constituents were in relation to an increased risk of hypothyroxinemia in pregnant women. It is noteworthy that, in the context of mixed exposure, the weighted quantile sum regression (WQS) indices were significantly associated with both FT4 level (1st trimester: −0.031 (−0.036, −0.026); 2nd trimester: −0.026 (−0.030, −0.023); whole pregnancy: −0.024 (−0.028, −0.020)) and hypothyroxinemia risk (1st trimester: 1.552 (1.312, 1.821); 2nd trimester: 1.453 (1.194, 1.691); whole pregnancy: 1.402 (1.152, 1.713)). PM2.5 and its chemical constituents may affect thyroid function in pregnant women individually and in combination, with the effect observed during early gestational exposure being most pronounced.

Neuregulin 1 Signaling Attenuates Tumor Necrosis Factor α-Induced Female Rat Luteal Cell Death.

The corpus luteum (CL) is a transient ovarian endocrine structure that maintains pregnancy in primates during the first trimester and in rodents during the entire pregnancy by producing steroid hormone progesterone (P4). CL lifespan, growth, and differentiation are tightly regulated by survival and cell death signals through luteotrophic and luteolytic factors, including the epidermal growth factor (EGF)-like factor family. Neuregulin 1 (NRG1), a member of the EGF family, mediates its effect through ErbB2/3 receptors. However, the functional role of NRG1 in luteal cells (LCs) is unknown. Thus, this study investigated the role of NRG1 and its molecular mechanism of action in rat LC. Our experimental results suggest a strong positive correlation between steroidogenic acute regulatory protein (StAR) and NRG1 expression in mid-CL and serum P4 and estrogen (E2) production. In contrast, there was a decrease in StAR and NRG1 expression and P4 and E2 production with an increase in tumor necrosis factor α (TNFα) expression in regressing CL. Further in vitro studies in LCs showed that the knockdown of endogenous Nrg1 promoted the expression of proinflammatory and proapoptotic factors and decreased prosurvival factor expression. Subsequently, treatment with exogenous TNFα under these experimental conditions profoundly elevated proinflammatory and proapoptotic factors. Further analysis demonstrated that the phosphorylation status of ErbB2/3, PI3K, Ak strain transforming or protein kinase B (Akt), and ErK1/2 was significantly inhibited under these experimental conditions, whereas the treatment of TNFα further inhibited the phosphorylation of ErbB2/3, PI3K, Akt, and ErK1/2. Collectively, these studies provide new insights into the NRG1-mediated immunomodulatory and prosurvival role in LCs, which may maintain the function of CL.

Placental Nanoparticle-mediated IGF1 Gene Therapy Corrects Fetal Growth Restriction in a Guinea Pig Model.

Fetal growth restriction (FGR) caused by placental insufficiency is a major contributor to neonatal morbidity and mortality. There is currently no in utero treatment for placental insufficiency or FGR. The placenta serves as the vital communication, supply, exchange, and defense organ for the developing fetus and offers an excellent opportunity for therapeutic interventions. Here we show efficacy of repeated treatments of trophoblast-specific human insulin-like 1 growth factor (IGF1) gene therapy delivered in a non-viral, polymer nanoparticle to the placenta for the treatment of FGR. Using a guinea pig maternal nutrient restriction model (70% food intake) of FGR, nanoparticle-mediated IGF1 treatment was delivered to the placenta via ultrasound guidance across the second half of pregnancy, after establishment of FGR. This treatment resulted in correction of fetal weight in MNR + IGF1 animals compared to sham treated controls on an ad libitum diet, increased fetal blood glucose and decreased fetal blood cortisol levels compared to sham treated MNR, and showed no negative maternal side-effects. Overall, we show a therapy capable of positively impacting the entire pregnancy environment: maternal, placental, and fetal. This combined with our previous studies using this therapy at mid pregnancy in the guinea pig and in two different mouse model and three different human in vitro/ex vivo models, demonstrate the plausibility of this therapy for future human translation. Our overall goal is to improve health outcomes of neonates and decrease numerous morbidities associated with the developmental origins of disease.

Sources of PM2.5 exposure misclassification in three Finnish register-based study populations and the impact on attenuation of health effect estimates

Air pollution is a leading environmental health risk factor. The risk estimates, primarily based on air pollution epidemiology, are sensitive to exposure misclassification, which can result in underestimation. To address some of these challenges, our aim is to investigate how the length of the period over which the exposure is averaged, trends in long-term PM2.5 concentrations, and the seasonal variability are associated with each other. Furthermore, we assess the impact of residential relocation on exposure levels and quantify random exposure misclassification due to modelling and its impact on the attenuation of effects with respect to averaging time.We used nested air quality modelling across Finland, gridded population, and address histories from three study populations: the MATEX pregnancy and preschool children cohorts, as well as the FINPARK study's individuals diagnosed with Parkinson's disease and their controls, to estimate PM2.5 exposures. The prediction error was estimated by comparing modelled concentrations to observations and by using previous estimates for random monitoring instrument error.Due to the decreasing trend in PM2.5 concentrations, exposure levels rose progressively with longer averaging times, increasing by up to 28 % over a 16-year period. The shorter the exposure period, the more pronounced the seasonal effects: pregnant mothers' trimester-specific exposures were 13–22 % higher for trimesters ending in spring and 10–16 % lower for those ending in autumn compared to the average for the entire pregnancy. Residential relocation had a relatively minor impact on the exposure levels of the preschool children and adult FINPARK study population, but this effect was possibly partly masked by the decreasing trend. The results indicated that using predicted concentrations led to random exposure misclassification and potentially attenuated health effects. This effect became more notable when increasing the length of the exposure period from 3 months to 5 years, doubling the underestimation ratio from 1.5 to 3.1.

Interpregnancy interval, air pollution, and the risk of low birth weight: a retrospective study in China

BackgroundBoth interpregnancy intervals (IPI) and environmental factors might contribute to low birth weight (LBW). However, the extent to which air pollution influences the effect of IPIs on LBW remains unclear. We aimed to investigate whether IPI and air pollution jointly affect LBW.MethodsA retrospective cohort study was designed in this study. The data of birth records was collected from the Jiangsu Maternal Child Information System, covering January 2020 to June 2021 in Nantong city, China. IPI was defined as the duration between the delivery date for last live birth and date of LMP for the subsequent birth. The maternal exposure to ambient air pollutants during pregnancy—including particulate matter (PM) with an aerodynamic diameter of ≤ 2.5 μm (PM2.5), PM10, ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO)—was estimated using a hybrid kriging-LUR-RF model. A novel air pollution score was proposed, assessing combined exposure to five pollutants (excluding CO) by summing their concentrations, weighted by LBW regression coefficients. Multivariate logistic regression models were used to estimate the effects of IPI, air pollution and their interactions on LBW. Relative excess risk due to interaction (RERI), attributable proportion of interaction (AP) and synergy index (S) were utilized to assess the additive interaction.ResultsAmong 10, 512 singleton live births, the LBW rate was 3.7%. The IPI-LBW risk curve exhibited an L-shaped pattern. The odds ratios (ORs) for LBW for each interquartile range increase in PM2.5, PM10, O3 and the air pollution score were 1.16 (95% CI: 1.01–1.32), 1.30 (1.06–1.59), 1.22 (1.06–1.41), and 1.32 (1.10–1.60) during the entire pregnancy, respectively. An additive interaction between IPI and PM2.5 was noted during the first trimester. Compared to records with normal IPI and low PM2.5 exposure, those with short IPI and high PM2.5 exposure had the highest risk of LBW (relative risk = 3.53, 95% CI: 1.85–6.49, first trimester).ConclusionThe study demonstrates a synergistic effect of interpregnancy interval and air pollution on LBW, indicating that rational birth spacing and air pollution control can jointly improve LBW outcomes.

The relationship between maternal environmental temperature exposure and preterm birth: A Risk prediction based on machine learning

Global warming and the risk of preterm birth are both major factors that impact population health. This study investigated the impact of environmental temperature during different stages of pregnancy on the probability of preterm birth (PTB) in Wuhan, China through 2014 to 2016. The results revealed that temperature exposure throughout the entire pregnancy exhibited a U-shaped relationship with the risk of PTB; when temperature exposure during the entire pregnancy was below 14 °C or above 20 °C, the risk of PTB increased. Early pregnancy exposure to temperatures below 7 °C or above 22 °C, and late pregnancy exposure to temperatures below 7 °C or above 26 °C, were associated with an increased risk of PTB. Additionally, elevated PM2.5 exposure increased PTB risk, while O3 exposure exhibited a U-shaped relationship with preterm birth. Compared to non-high-risk pregnancies, high-risk pregnancies exhibited a higher risk of preterm birth across all stages of pregnancy. Notably, when late pregnancy temperature exposure exceeded 28 °C, the risk of PTB rapidly increased for non-high-risk pregnancies. This research has significant implications for improving maternal and new-born health by future sustainable city planning and the optimization of temperature forecast warning systems, particularly under the dual pressures of rapid urbanization and climate change.

A prospective birth cohort study on the association between gestational blood pressure and neurodevelopment in 2-year-old children

Objective: To investigate the association between gestational blood pressure and neurodevelopment in 2-year-old children. Methods: Based on the"Wuhan Healthy Baby Birth Cohort", 3 754 mother-infant pairs were enrolled in this study. Based on multiple blood pressure measurements during pregnancy, the mean, cumulative, and variability of blood pressure throughout the entire pregnancy and each trimester were calculated. Blood pressure variability was evaluated using standard deviation (SD), coefficient of variability (CV), and variability independent of mean (VIM). Follow-up testing of neurodevelopment in infants and young children at the age of two was conducted to obtain the Mental Development Index (MDI) and the Psychomotor Development Index (PDI). The multivariate linear regression and generalized estimation equation were used to analyze the association between gestational blood pressure data and neurodevelopmental index. Results: The age of 3 754 pregnant women was (29.1±3.6) years, with a pre-pregnancy BMI of (20.9±2.7) kg/m² and a gestational age of (39.3±1.2) weeks. The birth weight of 3 754 children was (3 330.9±397.7) grams, and the birth length was (50.3±1.6) centimeters. The results of the multivariate linear regression analysis showed that after adjusting for relevant confounding factors, the mean blood pressure, cumulative blood pressure, standard deviation of blood pressure, coefficient of variation of blood pressure, independent blood pressure variability of systolic blood pressure, diastolic blood pressure, and pulse pressure throughout pregnancy were negatively associated with the MDI and PDI scores of 2-year-old children. The analysis results of the generalized estimation equation showed that after adjusting for relevant confounding factors, the average systolic blood pressure in the first, second, and third trimesters was negatively associated with MDI/PDI. The negative association between cumulative blood pressure and MDI/PDI was only found in the first trimester. The negative association between blood pressure variation during pregnancy and MDI/PDI was mainly concentrated in the second and third trimesters. Conclusion: There is a negative association between gestational blood pressure and the neurodevelopmental index of 2-year-old children.

Population-level changes in perinatal death for pregnancies prior to and during the COVID-19 pandemic: A pregnancy cohort analysis.

Results of population-level studies examining the effect of the COVID-19 pandemic on the risks of perinatal death have varied considerably. To explore trends in the risk of perinatal death among pregnancies beginning prior to and during the pandemic using a pregnancy cohort approach. This secondary analysis included data from singleton pregnancies ≥20 weeks' gestation in Alberta, Canada, beginning between 5 March 2017 and 4 March 2021. Perinatal death (i.e. stillbirth or neonatal death) was the primary outcome considered. The risk of this outcome was calculated for pregnancies with varying gestational overlap with the pandemic (i.e. none, 0-20 weeks, entire pregnancy). Interrupted time series analysis was used to further determine temporal trends in the outcome by time period of interest. There were 190,853 pregnancies during the analysis period. Overall, the risk of perinatal death decreased with increasing levels of pandemic exposure; this outcome was experienced in 1.0% (95% confidence interval [CI] 0.9, 1.0), 0.9% (95% CI 0.8, 1.1) and 0.8% (95% CI 0.7, 0.9) of pregnancies with no overlap, partial overlap and complete pandemic overlap respectively. Pregnancies beginning during the pandemic that had high antepartum risk scores less frequently led to perinatal death compared to those beginning prior; 3.3% (95% CI 2.7, 3.9) versus 5.7% (95% CI 5.0, 6.5) respectively. Interrupted time-series analysis revealed a decreasing temporal trend in perinatal death for pregnancies beginning ≤40 weeks prior to the start of the COVID-19 pandemic (i.e. with pandemic exposure), with no trend for pregnancies beginning >40 weeks pre-pandemic (i.e. no pandemic exposure). We observed a decrease in perinatal death for pregnancies overlapping with the COVID-19 pandemic in Alberta, particularly among those at high risk of these outcomes. Specific pandemic control measures and government response programmes in our setting may have contributed to this finding.

PSLBII-8 Evaluation of the in vitro ruminal methane production in heifers fed high-forage or high-concentrate diets during entire pregnancy

PSLBII-8 Evaluation of the in vitro ruminal methane production in heifers fed high-forage or high-concentrate diets during entire pregnancy

Réduction embryonnaire pour demande maternelle en cas de grossesse gémellaire : enquête nationale française

IntroductionIn France, embryo reduction is controversial in twin pregnancy, especially when there is no underlying pathology. The objective of this study was to establish the status of this practice in France and to depict the ethical issues around this problematic. Study designA questionnaire drafted by Maternal and Fetal Medicine physicians and family planning teams of the University Hospital from Strasbourg was distributed to the 48 French Multidisciplinary Prenatal Diagnosis Centers, among which 28 answered (58,3%). ResultsEmbryo reduction in twin pregnancy on maternal request has already challenged 71% of the centers; 29% have performed such a reduction. The overall position of the centers to these requests is negative (3.1/10), with very mixed levels of in-team agreement. The main arguments against this practice are that twin pregnancy is not a pathology, that embryo reduction exposes to the risk of loosing the entire pregnancy, the feeling of being held hostage with the alternative of abortion of the whole pregnancy, and the lack of legal framing. On the contrary, the arguments in favor of the reduction are: that the reduction can avoid an abortion, that this type of reduction can be related to a partial abortion, that it responds to women's rights and that mental health is an integral part of women's health. ConclusionThere is no consensus about how to respond to patients requesting for embryo reduction in twin pregnancy. However, the majority of Centers have been confronted with it and it would be necessary to open the debate on this problem and the ethical questions it raises.

Exposure to Low-Level Air Pollution and Hyperglycemia Markers during Pregnancy: A Repeated Measure Analysis.

Epidemiologic evidence has emerged showing an association between exposure to air pollution and increased risks of gestational diabetes mellitus (GDM). This study examines the effect of low-level air pollution exposure on a subclinical biomarker of hyperglycemia (i.e., HbA1c) in pregnant people without diabetes before conception. We measured HbA1c in 577 samples repeatedly collected from 224 pregnant people in Rochester, NY, and estimated residential concentrations of PM2.5 and NO2 using high-resolution spatiotemporal models. We observed a U-shaped trajectory of HbA1c during pregnancy with average HbA1c levels of 5.13 (±0.52), 4.97 (±0.54), and 5.43 (±0.40)% in early-, mid-, and late pregnancy, respectively. After adjustment for the U-shaped trajectory and classic GDM risk factors, each interquartile range increase in 10 week NO2 concentration (8.0 ppb) was associated with 0.09% (95% CI: 0.02 to 0.16%) and 0.18% (95% CI: 0.08 to 0.28%) increases in HbA1c over the entire pregnancy and in late pregnancy, respectively. These associations remained robust among participants without GDM. Using separate distributed lag models, we identified a period between 8th and 14th gestational weeks as critical windows responsible for increased levels of HbA1c measured at 14th, 22nd, and 30th gestational weeks. Our results suggest that low-level air pollution contributes to hyperglycemia in medically low-risk pregnant people.

Newborn glomerular function and gestational particulate air pollution

Nephron number variability may hold significance in the Developmental Origins of Health and Disease hypothesis. We explore the impact of gestational particulate pollution exposure on cord blood cystatin C, a marker for glomerular function, as an indicator for glomerular health at birth. From February 2010 onwards, the ENVIRONAGE cohort includes over 2200 mothers giving birth at the East-Limburg hospital in Genk, Belgium. Mothers without planned caesarean section who are able to fill out a Dutch questionnaire are eligible. Here, we evaluated cord blood cystatin C levels from 1484 mother-child pairs participating in the ENVIRONAGE cohort. We employed multiple linear regression models and distributed lag models to assess the association between cord blood cystatin C and gestational particulate air pollution exposure. Average±SD levels of cord blood cystatin C levels amounted to 2.16±0.35mg/L. Adjusting for covariates, every 0.5μg/m³ and 5μg/m³ increment in gestational exposure to black carbon (BC) and fine particulate matter (PM2.5) corresponded to increases of 0.04mg/L (95% CI 0.01-0.07) and 0.07mg/L (95% CI 0.03-0.11) in cord blood cystatin C levels (p<0.01), respectively. Third-trimester exposure showed similar associations, with a 0.04mg/L (95% CI 0.00-0.08) and 0.06mg/L (95% CI 0.04-0.09) increase for BC and PM2.5 (p<0.02). No significant associations were observed when considering only the first and second trimester exposure. Our findings indicate that particulate air pollution during the entire pregnancy, with the strongest effect sizes from week 27 onwards, may affect newborn kidney function, with potential long-term implications for later health. Special Research Fund (Bijzonder Onderzoeksfonds, BOF), Flemish Scientific Research Fund (Fonds Wetenschappelijk Onderzoek, FWO), and Methusalem.