Adverse pregnancy outcomes and long-term morbidity after early fetal hypokinesia in maternal smoking pregnancies

Maternal Prenatal Smoking and Autism Spectrum Disorder in Offspring: A California Statewide Cohort and Sibling Study

We examined associations between maternal smoking and autism spectrum disorder (ASD) in children in a statewide population-based cohort and sibling-comparison design using California birth records (n = 2,015,104) with information on maternal smoking, demographic factors, and pregnancy (2007-2010). ASD cases (n = 11,722) were identified through California Department of Developmental Services records with diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders-IV-TR. We estimated odds ratios for ASD with and without intellectual disability in the full cohort using logistic regression and in a sibling comparison using conditional logistic regression. In the full cohort, the adjusted odds ratio for ASD and maternal smoking 3 months before/during pregnancy compared with nonsmoking was 1.15 (95% confidence interval (CI): 1.04, 1.26), and it was similar in cases with (odds ratio = 1.12, 95% CI: 0.84, 1.49) and without intellectual disability (odds ratio = 1.15, 95% CI: 1.04, 1.27). Heavy prenatal smoking (≥20 cigarettes/day in any trimester) was related to an odds ratio of 1.55 (95% CI: 1.21, 1.98). In the sibling comparison, the odds ratio for heavy smoking was similarly elevated but the confidence interval was wide. Our findings are consistent with an increased risk for ASD in offspring of mothers who smoked ≥20 cigarettes/day during pregnancy; associations with lighter smoking were weaker.

Breech presentation at term and associated obstetric risks factors-a nationwide population based cohort study

PURPOSE

The aim of this study was to estimate whether breech presentation at term was associated with known individual obstetric risk factors for adverse fetal outcome.

METHODS

This was a retrospective, nationwide Finnish population-based cohort study. Obstetric risks in all breech and vertex singleton deliveries at term were compared between the years 2005 and 2014. A multivariable logistic regression model was used to determine significant risk factors.

RESULTS

The breech presentation rate at term for singleton pregnancies was 2.4%. The stillbirth rate in term breech presentation was significantly higher compared to cephalic presentation (0.2 vs 0.1%). The odds ratios (95% CIs) for fetal growth restriction, oligohydramnios, gestational diabetes, a history of cesarean section and congenital fetal abnormalities were 1.19 CI (1.07-1.32), 1.42 CI (1.27-1.57), 1.06 CI (1.00-1.13), 2.13 (1.98-2.29) and 2.01 CI (1.92-2.11).

CONCLUSIONS

The study showed that breech presentation at term on its own was significantly associated with antenatal stillbirth and a number of individual obstetric risk factors for adverse perinatal outcomes. The risk factors included oligohydramnios, fetal growth restriction, gestational diabetes, history of caesarean section and congenital anomalies.

Systematic review and meta-analysis of miscarriage and maternal exposure to tobacco smoke during pregnancy

We conducted a systematic review and meta-analysis to characterize the relationship between smoking and miscarriage. We searched the PubMed database (1956-August 31, 2011) using keywords and conducted manual reference searches of included articles and reports of the US Surgeon General. The full text of 1,706 articles was reviewed, and 98 articles that examined the association between active or passive smoking and miscarriage were included in the meta-analysis. Data were abstracted by 2 reviewers. Any active smoking was associated with increased risk of miscarriage (summary relative risk ratio = 1.23, 95% confidence interval (CI): 1.16, 1.30; n = 50 studies), and this risk was greater when the smoking exposure was specifically defined as during the pregnancy in which miscarriage risk was measured (summary relative risk ratio = 1.32, 95% CI: 1.21, 1.44; n = 25 studies). The risk of miscarriage increased with the amount smoked (1% increase in relative risk per cigarette smoked per day). Secondhand smoke exposure during pregnancy increased the risk of miscarriage by 11% (95% CI: 0.95, 1.31; n = 17 studies). Biases in study publication, design, and analysis did not significantly affect the results. This finding strengthens the evidence that women should not smoke while pregnant, and all women of reproductive age should be warned that smoking increases the risk of miscarriage.