There are many causes of stillbirth. More than one of these causes may be involved a the baby’s death. Other less common causes of stillbirth include trauma (such as car accidents), post-term pregnancy (longer than 42 weeks), Rh disease and lack of oxygen during a difficult delivery. Of the deaths where a cause has been found, following are some of the more common causes:

Birth Defects

Birth defects are involved in about 15 to 20 percent of all stillbirth deaths. Nearly half of these babies have a chromosomal abnormality, such as Down Syndrome. Others have birth defects resulting from genetic or environmental causes.

Placental Problems

Placental problems cause between 10 and 20 percent of stillbirths. Placental abruption is one of the most common placental problems. The placenta separates (partially or completely) from the uterine wall before delivery, resulting in heavy bleeding that can threaten the life of the mother and the baby. Women who smoke cigarettes or use drugs during pregnancy are at increased risk for placental abruption.

Poor Fetal Growth

Poor fetal growth accounts for about 20 percent of stillborn babies. This means that the fetus is growing too slowly. Women with pre-eclampsia (high blood pressure) are at an increased risk of having a growth-restricted baby. Smoking can also increase this risk. An ultrasound can help your doctor identify poor fetal growth and more closely monitor the pregnancy.

Cord Accidents

Accidents involving the umbilical cord may contribute to a stillbirth death in about 15 percent of the cases. This can include a knot in the cord or abnormal placement of the cord into the placenta. This can deprive the baby of oxygen.

Infectious Disease

Infections in the mother, baby or placenta seem to cause anywhere from 10 to 25 percent of stillbirths. Infections may not even cause symptoms for the mother, such as a genital and urinary tract infections or certain viruses such as parvovirus B19 (Fifth Disease). If these infections go undiagnosed, they can cause serious s complications such as fetal death or preterm birth.

Chronic Health Conditions

Chronic maternal health conditions are associated with about 10 percent of stillborn babies. These include high blood pressure, diabetes and kidney disease. These conditions can also contribute to poor fetal growth or placental abruption.  Fortunately, as a result of improvements in medical care, stillbirth deaths due to maternal health conditions have greatly decreased. Last revised: October 2009