Placenta Previa Increases Risk of Smaller Babies


A study in the journal “Obstetrics & Gynecology” finds that women with placenta previa who have given birth before are at an increased risk of having a baby who is small for gestational age (SGA). First-time moms aren’t at risk, researchers concluded.

According to the Mayo Clinic, placenta previa occurs when a baby’s placenta partially or completely covers the mother’s cervix.

Researchers looked at 596,562 single births, from 2000 to 2010, that were included in the Finnish Medical Birth Register and the Hospital Discharge Register. According to MedScape, the scientists found an astounding two-fold increased risk for impaired fetal growth in moms-to-be with placenta previa who had given birth previously, even when they accounted for other known risk factors, such as advanced maternal age, smoking and the use of in vitro fertilization. Moreover, these women were more likely to deliver prematurely, before 37 weeks.

“[SGA] was positively associated with higher number of prior births, prior cesarean delivery, prior preterm birth, prior SGA newborn, prior preeclampsia and placenta previa in multiparous women,” the study’s authors say.

“This study shows that placenta previa, which occurs in 5 in 1,000 pregnancies, appears to be associated with an increased risk for undersized newborns, otherwise known as small for gestational age, in women who have given birth to other children,” says Christine Mullin, M.D., a reproductive endocrinologist at North Shore University Hospital who was not involved in this study.

“This finding is not surprising, since an abnormally placed placenta most likely will perform less efficiently, thus resulting in a smaller fetus and newborn. In addition, it is not surprising that this association is found in women who have already carried a child as opposed to first-time mothers, as there has always been an increased risk of placenta previa with women who have undergone a cesarean section,” Mullin says.

If you have the risk factors discussed in this article, talk to your doctor.