What you need to know about placental abruption

For most women, the placenta is a part of pregnancy that doesn’t get much thought. The organ that supports the life of the fetus typically develops alongside it, and then is delivered about 30 minutes after the baby is born. But rarely—in less than one percent of pregnancies—a serious complication called placental abruption occurs. Placental abruption is when the placenta partially or completely separates from the uterine wall, in some cases leading to heavy bleeding for the mom and nutrient and oxygen deprivation for the baby.

The cause of abruptions isn’t entirely understood, but there are factors that put some women more at risk, says Andrea Neilson, an OB/GYN from the Women’s Health Clinic of Edmonton. Risk factors include illicit drug use, smoking during pregnancy and high blood pressure. A sudden impact, like falling or being in a car accident, can also lead to an abruption. 

Most placental abruptions are partial, and therefore less serious. Still, a partially detached placenta can mean less oxygen and nutrients are flowing to the growing fetus. If the placenta becomes partially detached close to the due date, the baby is often delivered via C-section. If it happens earlier in the pregnancy, doctors will watch the baby’s development and the mother’s health closely through ultrasounds. In most cases, with proper monitoring a baby will survive a partial placental abruption. 

But when the placenta completely detaches from the uterus, “The baby has no means of supporting itself in terms of oxygenation or getting any nutrients,” says Neilson, adding that an emergency delivery, often by C-section, is necessary to save the baby’s life. “It’s an extremely serious condition and it can be life threatening to both the mom and to the baby.” About half of all abruptions happen before 37 weeks, with about 14 percent occurring before 32 weeks. 

The biggest risk to the mother when the placenta detaches completely is the possibility of haemorrhaging, or excessive internal bleeding.

Although abruptions are rare, Neilson says it’s important to have any vaginal bleeding in the second and third trimesters investigated immediately. Other signs of abruption include a hard or painful uterus, severe abdominal or back pain, and continuous sudden contractions before your baby is full term.

Read more: Late pregnancy aches and pains What is placenta previa