Risk of complications in the late vs early days of the 42nd week of pregnancy: A nationwide cohort study

Abstract

Introduction Uncertainty remains about the most appropriate timing of induction of labor in late‐term pregnancies. To address this issue, this study aimed to compare the risk of neonatal morbidity and pregnancy‐ and birth‐related complications between gestational age (GA) 41+4–42+0 and GA 41+0–41+3 weeks. Material and methods This nationwide registry‐based cohort study included singleton births without major congenital malformations, with registered GA, and with intended vaginal delivery at GA 41+0– 42+0 weeks between 2009 and 2018 in Denmark. Logistic regression models were used to estimate the crude risk ratio and adjusted risk ratio (RRA) of neonatal and obstetric adverse outcomes in births at GA 41+4– 42+0 weeks compared with GA 41+0– 41+3 weeks. The results were adjusted for relevant confounders, including induction of labor. Results A higher incidence of neonatal morbidity and birth complications was observed in births at GA 41+4–42+0 weeks than in births at GA 41+0–41+3 weeks. Neonatal morbidities included an increased risk of low Apgar score (Apgar 0–6 after 5 min; RRA 1.17, 95% confidence interval [CI] 1.01–1.34), meconium aspiration (RRA 1.25, 95% CI 1.06–1.48), need for respiratory support (continuous positive airway pressure; RRA 1.09, 95% CI 1.03–1.15), and a composite outcome of need for comprehensive treatment at a neonatal department or neonatal death (RRA 1.65, 95% CI 1.29–2.11). Birth complications included emergency cesarean section (RRA 1.17, 95% CI 1.14–1.21), severe lacerations (RRA 1.11, 95% Cl 1.04–1.17), and increased blood loss after birth (RRA 1.13, 95% CI 1.06–1.21). Conclusions Births at GA 41+4–42+0 weeks were associated with an increased risk of neonatal morbidity and birth complications compared with births at GA 41+0–41+3 weeks. The results of this study may aid clinicians in deciding when to recommend induction of labor in late‐term pregnancies.

Does induction of labor at 41 weeks (early, mid or late) improve birth outcomes in low‐risk pregnancy? A nationwide propensity score‐matched study

“…First, we performed a pre‐analysis of non‐matched data. The variables used to calculate the propensity score were selected based on the literature and availability in the national registry 1,4,5,7,16,21 . The matching variables used for IOL included late start of antenatal care (≥15 weeks of gestation), parity, ethnicity, infertility treatment (ART), maternal age, socioeconomic status quintiles, year of birth (2010–2019), birthweight percentile in five groups (p5‐p9, p10‐p49, p50‐79, p80‐p89, p90‐p100), and male sex of the child.…”

“…Infants born following a prolonged gestation beyond 41 weeks have progressively higher risks of mortality and morbidity 1–4 . Post‐term pregnancy (42+0 weeks or more) increases the risk for babies, including a greater risk of stillbirth, death shortly after birth and adverse perinatal outcome 5–9 .…”

Risk of complications in post‐term pregnancies: Spontaneous labor should not be included in the intervention group

“…Congratulations on an exciting and timely report concerning induction of labor (IOL) in post‐term pregnancies. 1 In your article, you conclude that “births at GA 41+4 to 42+0 (“late group”) were associated with an increased risk of neonatal morbidity and birth complications compared with births at GA 41+0 to 41+3 weeks (“early group”) (our quotation marks). The intent of your analysis was to “determine the independent impact of GA” and thus “aid clinicians in deciding when to recommend IOL in late‐term pregnancies”.…”

Timing of induction of labour in the prevention of prolonged pregnancy: Systematic review with meta‐analysis

“…Prolonged pregnancy, defined as pregnancy beyond 42 weeks, is associated with increased risk of perinatal complications: higher incidence of perinatal death (stillbirth or neonatal death), 1 and the need for either instrumental or caesarean birth. 2,3 There are several options available for women if spontaneous labour does not begin at full term (40 + 0 weeks): wait until labour begins naturally (expectant management [EM]), induce labour, or choose a caesarean birth.…”