Placenta praevia - does it really affect intrauterine fetal growth?

Placenta praevia affects about 0.5% of pregnancies and due to constant increase in operative deliveries may become an important, clinical challenge throughout the next decades. Location of the placental plate within lower uterine segment is associated with increased risk of adverse perinatal outcomes. There were several reports pointing increased risk of small-for-gestational-age (SGA)/fetal growth restriction (FGR) in patients affected with abnormal location of the placenta. On the other hand, some studies ended up with opposite conclusions.

Due to ambiguous results we have undertaken a case-control study to investigate intrauterine growth among this group. We ran a pilot study to precisely define maternal, obstetrical and neonatal characteristics in order to avoid cofounders. Our study incorporated 56 patients in singleton pregnancies affected with placenta praevia and 124 patients in the control group (between 35 and 37 weeks of gestation).

Nonetheless, there were no statistical differences in the birthweight between the study and control group (2882.5 g vs. 2805 g, p = ns). Moreover, rates of the newborns with birthweight corresponding <10th percentile and >90th did not differ significantly. Even further analysis that included parity did not reveal any differences between both groups.

Placenta praevia does not affect the intrauterine growth and shall not be considered as a risk factor for SGA/FGR. In patients affected with abnormal location of the placenta additional scans for fetal well-being assessment are not indicated.