Stillbirth: know the facts

4.5 million stillbirths occur each year worldwide according to the World Health Organization (WHO). In developed countries, one in 100-200 pregnancies ends in stillbirth. Many of these deaths are avoidable.

Stillbirths are deaths of unborn babies. WHO defines a stillbirth as the death of a baby after 22 completed weeks of pregnancy, or when the baby weighs at least 500 grams. However, there is still no international standard to define when a baby is considered stillborn. In Sweden babies are considered stillborn at 28 weeks. In the United States and Australia, a baby who has passed the 20-week mark is considered stillborn, while in Norway it is at 16 weeks.

Babies die in the womb for many reasons. Stillbirth is not a cause of death. It is a description of when a baby dies. Rarely are these deaths caused by something a woman did or did not do.

Contributing factors in developed countries include infections by bacteria or virus (15 -24% of stillbirths), malformations or genetic abnormalities (7-20%), the placenta tearing away from the uterus, (15-20%), other problems with the placenta including clots, malformations and scarring (15-20%), umbilical cord knots, loops, twists, and compressions resulting in lack of blood flow (3-10%), and blood loss (from twin to twin in 25% of twin deaths, from baby to mother in 3-9% of stillbirths).

Many institutions report up to two-thirds of stillbirths as unexplained, but this often occurs when no efforts are made to find a cause of death. In addition, there is no standard method of performing autopsies and no database to record autopsy results for researchers to draw from. Finding a cause, however, is crucial in counseling families who have had a stillborn baby.

Unexplained stillbirth in late in pregnancy is the single largest cause of death in perinatal life in the Western world. In developing countries, the main challenges remain infections and lack of basic obstetric care.

Risk factors for stillbirth vary with different causes of death.

The risk of stillbirth goes up with the number of cigarettes smoked by the mother, with increasing age of mothers, and with overweight mothers (body mass index over 25).

Several maternal conditions such as diabetes, high blood pressure and blood clotting disorders increase the risk of stillbirth if the conditions are not detected and adequately treated in pregnancy.

This is also true with preeclampsia, high hemoglobin levels, viral infections and certain bacterial infections. Among characteristics or signs that can be detected in the baby itself, the most important risk factors for stillbirth are a growth-restricted (too small) baby, babies who stop kicking normally or show a sudden change in their normal movement pattern, severely restricted blood flow through placental and fetal circulation (measured by Doppler-ultrasound) and babies affected by serious malformations. Although infections and serious malformations often lead to early stillbirths, the risk for other causes of stillbirth in a pregnancy rises significantly after approximately 35-36 weeks of pregnancy. The risk continues to rise and reaches the highest point in pregnancies which go past the due date.

www.stillbirthalliance.org