LAUSR

STUDY DESIGN: A retrospective cohort study, including all SGA live infants (birth weight <10 percentile for GA) with placental pathology reports, born at a single, tertiary medical center between 2001-2015 at >24 weeks. We categorized infants to one of three groups based on placental pathology: normal size placenta with no MVM (control group), small placentas (<10 percentile) with no MVM (isolated small placenta group), and small placentas with MVM (MVM group). Pregnancy outcomes and Doppler findings were compared between the three groups. RESULTS: Overall, 920 SGA neonates were included in the study: 118 (12.8%) in the control group, 427 (46.4%) in the isolated small placenta group and 365 (39.8%) in the MVM group. The rates of hypertensive disorders and preterm birth were similar between the control and isolated small placenta groups, but were higher in the MVM group (Table 1). Doppler data was available for a subgroup of 222 women (Table 2). The rate of abnormal umbilical artery Doppler in the isolated small placenta group was similar to controls and significantly lower than in the MVM group. However, the rate of abnormal middle cerebral artery Doppler (‘brain sparing effect’) in the isolated small placenta group was higher than in the control group (Table 2). CONCLUSION: In contrast to other MVM placental lesions, isolated small placenta in pregnancies with SGA is not associated with hypertensive complications, prematurity and low Apgar scores. However, isolated small placenta is associated with abnormal middle cerebral artery which is considered to be suggestive of FGR, especially in cases of late-onset FGR. These findings suggest that in pregnancies with SGA infants, a finding of an isolated small placenta should be interpreted as a marker of mild late-onset FGR rather than constitutional SGA.