Fetal exposure to lead during pregnancy and the risk of preterm and early-term deliveries.
Cheng Lu,Zhang Bin,Huo Wenqian,Cao Zhongqiang,Liu Wenyu,Liao Jiaqiang,Xia Wei,Xu Shunqing,Li Yuanyuan
International journal of hygiene and environmental health
Studies have reported the association between lead exposure during pregnancy and preterm birth. However, findings are still inconsistent. This prospective birth cohort study evaluated the risks of preterm and early-term births and its association with prenatal lead exposure in Hubei, China. A total of 7299 pregnant women were selected from the Healthy Baby Cohort. Maternal urinary lead levels were measured by the Inductively Coupled Plasma Mass Spectrometry. The associations between tertiles of urinary lead levels and the risks of preterm and early-term deliveries were assessed using multiple logistic regression models. The geometric mean of creatinine-adjusted urinary lead concentrations among all participating mothers, preterm birth, and early-term birth were 3.19, 3.68, and 3.17μg/g creatinine, respectively. A significant increase in the risk of preterm births was associated with the highest urinary lead tertile after adjusting for confounders with odds ratio (OR) of 1.96. The association was more pronounced among 25-36 years old mothers with OR of 2.03. Though significant p trends were observed between lead exposure (medium and high tertiles) and the risk of early-term births, their ORs were not significant. Our findings indicate that the risk of preterm birth might increase with higher fetal lead exposure, particularly among women between the age of 25 and 36 years.
Updates on an At-Risk Population: Late-Preterm and Early-Term Infants.
Stewart Dan L,Barfield Wanda D,
The American Academy of Pediatrics published a clinical report on late-preterm (LPT) infants in 2007 that was largely based on a summary of a 2005 workshop convened by the National Institute of Child Health and Human Development, at which a change in terminology from "near term" to "late preterm" was proposed. This paradigm-shifting recommendation had a remarkable impact: federal agencies (the Centers for Disease Control and Prevention), professional societies (the American Academy of Pediatrics and American College of Obstetricians and Gynecologists), and organizations (March of Dimes) initiated nationwide monitoring and educational plans that had a significant effect on decreasing the rates of iatrogenic LPT deliveries. However, there is now an evolving concern. After nearly a decade of steady decreases in the LPT birth rate that largely contributed to the decline in total US preterm birth rates, the birth rate in LPT infants has been inching upward since 2015. In addition, evidence revealed by strong population health research demonstrates that being born as an early-term infant poses a significant risk to an infant's survival, growth, and development. In this report, we summarize the initial progress and discuss the potential reasons for the current trends in LPT and early-term birth rates and propose research recommendations.
Neonatal outcomes of elective early-term births after demonstrated fetal lung maturity.
Tita Alan T N,Jablonski Kathleen A,Bailit Jennifer L,Grobman William A,Wapner Ronald J,Reddy Uma M,Varner Michael W,Thorp John M,Leveno Kenneth J,Caritis Steve N,Iams Jay D,Saade George,Sorokin Yoram,Rouse Dwight J,Blackwell Sean C,Tolosa Jorge E,
American journal of obstetrics and gynecology
BACKGROUND:Studies of early-term birth after demonstrated fetal lung maturity show that respiratory and other outcomes are worse with early-term birth (37-38 weeks) even after demonstrated fetal lung maturity when compared with full-term birth (39-40 weeks). However, these studies included medically indicated births and are therefore potentially limited by confounding by the indication for delivery. Thus, the increase in adverse outcomes might be due to the indication for early-term birth rather than the early-term birth itself. OBJECTIVE:We examined the prevalence and risks of adverse neonatal outcomes associated with early-term birth after confirmed fetal lung maturity as compared with full-term birth in the absence of indications for early delivery. STUDY DESIGN:This is a secondary analysis of an observational study of births to 115,502 women in 25 hospitals in the United States from 2008 through 2011. Singleton nonanomalous births at 37-40 weeks with no identifiable indication for delivery were included; early-term births after positive fetal lung maturity testing were compared with full-term births. The primary outcome was a composite of death, ventilator for ≥2 days, continuous positive airway pressure, proven sepsis, pneumonia or meningitis, treated hypoglycemia, hyperbilirubinemia (phototherapy), and 5-minute Apgar <7. Logistic regression and propensity score matching (both 1:1 and 1:2) were used. RESULTS:In all, 48,137 births met inclusion criteria; the prevalence of fetal lung maturity testing in the absence of medical or obstetric indications for early delivery was 0.52% (n = 249). There were 180 (0.37%) early-term births after confirmed pulmonary maturity and 47,957 full-term births. Women in the former group were more likely to be non-Hispanic white, smoke, have received antenatal steroids, have induction, and have a cesarean. Risks of the composite (16.1% vs 5.4%; adjusted odds ratio, 3.2; 95% confidence interval, 2.1-4.8 from logistic regression) were more frequent with elective early-term birth. Propensity scores matching confirmed the increased primary composite in elective early-term births: adjusted odds ratios, 4.3 (95% confidence interval, 1.8-10.5) for 1:1 and 3.5 (95% confidence interval, 1.8-6.5) for 1:2 matching. Among components of the primary outcome, CPAP use and hyperbilirubinemia requiring phototherapy were significantly increased. Transient tachypnea of the newborn, neonatal intensive care unit admission, and prolonged neonatal intensive care unit stay (>2 days) were also increased with early-term birth. CONCLUSION:Even with confirmed pulmonary maturity, early-term birth in the absence of medical or obstetric indications is associated with worse neonatal respiratory and hepatic outcomes compared with full-term birth, suggesting relative immaturity of these organ systems in early-term births.