Intrauterine fetal death, also known as stillbirth, is usually defined as a death in utero greater than 20 weeks of gestation and/or at a weight of greater than 500 grams. The fetal death rate in the United States is approximately 7 per 1,000 total births and accounts for approximately half of perinatal mortality, or fetal and neonatal deaths.
Risk of Recurrence of Intrauterine Fetal Death
The risk of recurrent fetal demise is unknown, but is likely dependent upon the cause of the index death. If this is unknown, the risk of recurrence is probably approximately 1%.
In most cases of fetal death where the etiology is known, a recurrence risk can be determined and sometimes prenatal diagnosis and prevention are possible. Also, for women who have undergone a thorough workup without evidence of any underlying abnormalities, they can be reassured that the recurrence risk is likely very low.
If the cause was unknown, no evidence-based recommendations can be made for therapy in the following pregnancy, aside from close monitoring. Empiric use of heparin is not recommended without evidence of clotting abnormality. Use of low-dose aspirin is unlikely to be harmful and this could, in theory, prevent placental clotting.
Without any specific therapy to prevent recurrence, efforts should focus on early detection of placental disease to optimize timing of delivery. Ultrasound to assess fetal growth and amniotic fluid volume every 4 weeks starting at 20 weeks is typically suggested. In the setting of poor fetal growth, Doppler studies can be used to assess placental function. Weekly fetal surveillance should start at 32 weeks, unless there is evidence of placental insufficiency earlier. In the absence of placental insufficiency, delivery at term should be considered if fetal lung maturity is confirmed by amniocentesis.
Women with a prior fetal demise usually (and quite understandably) have significant anxiety in the next pregnancy. Many require frequent prenatal visits for reassurance, and some require formal therapy and/or medications to manage the fear and anxiety. It is important for women to realize that this is normal and expected. Due to this, despite the low risk of recurrence, many women with a prior IUFD choose to be delivered several weeks early (around 37 weeks).