Obesity, multiple gestations may be factors in stillbirths

Advanced maternal age, nulliparity, obesity, and multiple gestations may be factors in a reported increase of stillbirths in some parts of the developed world, according to a report in the Nov. 17 issue of The Lancet.

Gordon C.S. Smith, MD, of Cambridge University in the United Kingdom and a colleague conducted an extensive review of databases and literature covering a total of 10 years. They noted that there has been a recent reported increase in the rate of stillbirths in England, Wales, and Northern Island, for unknown reasons.

Different health organizations have varying definitions of stillbirth, the authors report, and there are more than 30 reported systems for how perinatal deaths are classified. Between 25% and 60% of all fetal deaths are unexplained by fetal, placental, maternal or obstetric factors. About half of unexplained stillbirths are characterized by low birthweights presumably related to poor placental function. The greatest risk factor for stillbirth is being born in the developing world, where the stillbirth rate is estimated to be between 20 and 32 per 1,000 births, as compared to between 4.2 and 6.8 per 1,000 births in the developed world.

Smith GC, Fretts RC. Stillbirth. Lancet. 2007;370:1715-1725.