Maternal Obesity and the Risk of Stillbirth

Obese women are twice as likely to experience stillbirth than those of normal weight. The association between the two is potentially confounded by a number of medical and social factors. Gestational diabetes, hypertensive disorders, placental dysfunction, metabolic syndrome, previous history of pregnancy loss, foetal abnormalities, suboptimal antenatal screening and post maturity are direct risk factors for still birth which are related to obesity. Factors such as age, nulliparity and social class are strongly related to both obesity and stillbirth and it is not always possible to confidently demonstrate an independent causal relationship between obesity and late pregnancy loss in their presence. Data from a single cohort study which adjusted for maternal age, smoking, alcohol, caffeine intake, height, parity, offspring gender, education, working and co-habitation status suggest a higher unexplained stillbirth rate in non-hypertensive, non-diabetic obese women. Strategies for the prevention of stillbirth are the focus of much ongoing research. There is little evidence to support the use of fetal movement counting, doppler studies, and fetal cardiotogography (CTG). Primary prevention of maternal obesity and encouraging women not to delay pregnancy have been suggested. Secondary prevention including weight management in pregnancy, risk scoring systems to highlight pregnancies at high risk for stillbirth and additional surveillance have all been suggested, but the evidence base underpinning these is far from robust. Raising the profile of adverse effects of maternal obesity on pregnancy outcomes including stillbirth is of vital importance to improving future maternal and offspring health.