Effects of antenatal recognition and follow-up on perinatal outcomes in small-for-gestational age infants delivered after 36 weeks.

Objective. To compare perinatal outcomes of late small-for-gestational age (SGA,
birthweight <10th percentile) infants, according to antenatal recognition. Design.
Retrospective study. Setting. Tertiary referral center. Population. All singleton pregnancies
with SGA (birthweight<10th percentile) infants born!36 weeks’ gestation
from January 2007 to April 2009. Methods: Chart review of 771 pregnancies. SGA
infants identified prior to delivery (group A) were compared with those not identified
(group B). Main outcome measures. Mode of delivery, perinatal complications,
admission to neonatal intensive care unit (NICU). In group A, receiver operating
characteristic (ROC) analysis and area under the curve (AUC) of antenatal tests
to predict NICU admission were calculated. Results. In 17% of infants, SGA was
recognized before birth (group A), whereas in 83% it was recognized only at birth
(group B). Infantswith the most severe degree of SGA (birthweight<3rd percentile)
were more frequently diagnosed antenatally (30%). Admission to NICU (14 vs. 3%,
p < 0.001) and cesarean delivery (42 vs. 26%; p < 0.001) were more likely in
group A. Adverse outcomes related to hypoxia were all observed in group B, but
the difference was not significant. In antenatally detected fetuses a combination of
fetal abdominal circumference, umbilical artery pulsatility index and middle cerebral
artery pulsatility index z-scores was useful for prediction of NICU admission
(AUC = 0.94). Conclusion. Antenatal recognition of late SGA may improve perinatal
outcomes. However, admission to neonatal intensive care and cesarean delivery
were more frequent among SGA infants recognized antenatally.