Does postterm pregnancy increase risk of neonatal morbidity?

January 27, 2016

A retrospective study examines if postterm pregnancies increase the risk of neonatal morbidity, even in low risk pregnancies. Plus: What's the impact of maternal consumption of fish during pregnancy on the child's brain development?

Israeli investigators say that the results of their recent retrospective study indicate that post-term pregnancy increases the likelihood of neonatal morbidity even in low-risk singleton gestations. The conclusion about the association appears in a new report in Archives of Disease in Childhood-Fetal and Neonatal Edition.

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Conducted in a tertiary university-affiliated medical center, the study was designed to determine the independent association of post-term pregnancy with neonatal outcome in low-risk newborns. Over a 5-year period, the investigators analyzed data from all newborns of low-risk singleton pregnancies born at 39+0 to 44+0 weeks’ gestation. Pregnancies that involved multiple gestations or were complicated by maternal hypertensive disorder, diabetes or cholestasis; placental abruption or intrapartum fever; small for gestational age; or major congenital or chromosomal anomalies were excluded.

The outcomes of interest to the authors were neonatal intensive care unit (NICU) admission, hospital length of stay, 5-minute Apgar score, birth trauma, and respiratory, neurological, metabolic and infectious morbidities and neonatal mortality. Adverse outcome rates were compared among 3 groups based on gestational age at birth: post-term (≥42+0 weeks), late term (41+0 to 41+6 weeks) and full term (39+0 to 40+6 weeks).

A total of 23,524 neonates were studied, of whom 18,145 (77.1%) were born full term, 4632 (19.7%) were born late term, and 747 (3.2%) were born post-term. Rates of cesarean delivery and of operative vaginal delivery were significantly higher in the women with the post-term vs late-term deliveries (8.9% vs 5.6%; P<0.001 and 9.6% vs 7.4%, P=0.024, respectively). In the post-term group versus the full-term group, risks were increased of NICU admission (OR 2.0, 95% confidence interval [CI] 1.4-2.8), respiratory morbidity (OR 2.2, 95% CI 1.3-3.8) and infectious morbidity (OR 1.88, 95% CI 1.32-2.69). Similar increases were seen in comparisons of post-term pregnancy vs late-term pregnancy (OR 2.0, 95% CI 1.4-2.9 for NICU admission, OR 2.7, 95% CI 1.5-5.0 for respiratory morbidity, OR 1.8, 95% CI 1.2-2.7 for infectious morbidity, and OR 2.6, 95% CI 1.2-5.4 for hypoglycemia). Post-term delivery was not associated with neonatal mortality.

NEXT: Impact of maternal fish consumption on their child

 

Prenatal fish consumption and child neuropsychological development

A report by Spanish investigators suggests that children whose mothers eat large fatty fish during pregnancy may reap some benefit in terms of neuropsychological development. Published in The American Journal of Epidemiology, the findings are from what may be the first large cohort study to look at the relationship between prenatal consumption of subtypes of seafood and offspring cognition.

The population-based analysis looked at 1892 and 1589 mother-child pairs at ages 14 months and 5 years, respectively, from a birth cohort established between 2004 and 2008. Neuropsychological development was assessed using Bayley and McCarthy scales and the Childhood Asperger Syndrome Test. The multivariate linear regression models were adjusted for sociodemographic characteristics and for umbilical cord blood mercury or long-chain polyunsaturated fatty acid concentrations.

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Overall, maternal consumption of more than the 340 g per week of seafood recommended was associated with 10-g/week increments in offspring neuropsychological scores. As with lean fish, consumption of large fatty fish had a positive association. Children of mothers with the highest quantile (>238 g/week) had an adjusted increase of 2.29 points in McCarthy general cognitive score (95% confidence interval; 0.42-4.16). The findings were similar for the Childhood Asperger Syndrome Test. After adjustment for mercury or long-chain polyunsaturated fatty acid concentration, beta coefficients diminished 15% to 30%.

Consuming large fatty fish during pregnancy, the researchers concluded, ”presents moderate child neuropsychological benefits, including improvements in cognitive functioning and some protection against autism-spectrum traits.”