Little-known condition potentially fatal to pregnant women
Maternal mortality is alarmingly high in the United States, including in Texas. In fact, a woman’s chance of dying during or after childbirth is much higher in the United States than any other developed nation.
With maternal mortality on the rise, Dr. Michael Belfort, an obstetrician at Baylor College of Medicine, wants women to be aware of a condition that can sometimes be responsible for it.
“There are many factors that play a role in the increase of maternal mortality; however, one pregnancy condition that is a contributor is placenta accreta, and it isn’t being talked about enough,” said Belfort.
Placenta accreta is a syndrome that involves an abnormal invasion of the placenta during pregnancy and can potentially cause severe blood loss during and after delivery.
When a woman becomes pregnant, the placenta will implant itself in the uterus, becoming a source of oxygen and nutrients to the growing baby. It detaches during delivery and is expelled.
However, for women who develop placenta accreta, the growth of the placenta is abnormal – it attaches too deeply and does not become detached during childbirth. In some cases, it will even grow through the wall of the uterus and into the bladder. It will sometimes even invade in to the patient’s bowel or major blood vessels.
There are different levels of severity for placenta accreta. This condition also is known as placenta increta or placenta percreta depending on the deepness of the placenta attachment.
Causes
Why do some women develop placenta accreta? The most common cause is existing scar tissue on the uterus from a previous procedure.
“A scar is just fibrous tissue, so when the placenta starts to grow and is looking for blood so that it can do its job, it doesn’t find it, and as a result the placenta continues to grow through that scar tissue until it comes out the other side, into the bladder and so on,” Belfort said.
Women are at greater risk of placenta accreta if they have had a Cesarean section(s) or other procedures involving the uterus, such as dilation and curettage procedures due to miscarriage, or even infertility treatments that might have damaged the uterus. This is especially important if the scars in the uterus are combined with a placenta that is covering the cervix (placenta previa).
Signs, symptoms and delivery
Often there are no symptoms of the condition during pregnancy. In some rare cases, women may experience abnormal bleeding during pregnancy. An ultrasound around 20 or 22 weeks of gestation will usually – but not always – detect placenta accreta.
Women who have been diagnosed with the condition during pregnancy will typically be required to deliver around 34 to 35 weeks by C-section. When the condition is not detected until delivery, there may be significant, life-threatening blood loss when the placenta does not detach like normal, as well as other serious complications.
If managed correctly, many women will be able to have a full recovery with no lasting complications; although in many cases they may need a hysterectomy. In such cases the surgery should be performed in a hospital that has an experienced obstetric anesthesia service, a large blood bank, and the ability to give a massive transfusion.
Babies are usually not affected by the condition except for the fact that they are delivered preterm and should be in a unit capable of treating very preterm babies. Women who may be at risk for placenta accreta should get their prenatal care and deliver at medical centers with specially trained obstetricians and gynecologists.
“Placenta accreta contributes to about seven percent of the maternal mortality rate. There is no way to prevent this condition, but it’s important to understand your risks to avoid any complications before and during birth,” Belfort said.
Dr. Belfort is the Ernst W. Bertner Chair and professor of obstetrics and gynecology at Baylor and obstetrician and gynecologist-in-chief at Texas Children’s Hospital. Learn more about obstetric and gynecological services at Baylor.
