Stillbirth: The other half of perinatal mortality

Abstract

Stillbirth is fetal death after 20 weeks gestation1. There are a number of definitions and classifications. WHO defines a stillbirth as a baby BW ≥500g, ≥22 weeks gestation who died before or during birth. However for international comparisons it recommends that reporting be restricted to those with BW>1000g and gestation ≥28 weeks. In Ireland stillbirths must be registered, the definition being BW≥500g or having reached a gestational age ≥ 24 weeks. Stillbirth affects 1 in 160 pregnancies2 and numerically it equals the number of infant deaths in the first year of life. At the beginning of the third trimester of pregnancy the baby weighs 1 Kg and the risk of stillbirth is 1- 2%. The possibility of a stillbirth increases with maturity throughout the third trimester and is 3 times greater at 40 weeks than at earlier gestational ages3. This is relevant for the 5-10% of pregnancies that continue ≥42 weeks. If managed expectantly one in 400 post-term pregnancies will end in a stillbirth. Since 2003 the stillbirth rate has remained static in the US at 3.0 stillbirths per 1000 births. Prior to 2003 the stillbirth rate had declined 1.4% annually while the infant mortality rate fell twice as fast at 2.8%. Globally there are 2.6 million stillbirths annually. In Ireland the stillbirth rate is 3.3 per 1000 births which equates to 230 deaths per year. Despite its frequent occurrence stillbirth has been a relatively neglected component of perinatal medicine. Because a definitive cause cannot be identified in many cases, counselling is very difficult. This lack of scientific causation data has resulted in professional fatalism towards the stillbirth problem.