Detection rate of the Japan society of obstetrics and gynecology's definition of fetal growth restriction for predicting small-for-gestational-age neonates.

PURPOSE

To identify the ability of the definitions of fetal growth restriction (FGR) according to the Japan Society of Obstetrics and Gynecology (JSOG) and the Society for Maternal-Fetal Medicine (SMFM) to predict small-for-gestational-age (SGA) neonates.

METHODS

A retrospective cohort of Japanese women with singleton pregnancies who delivered at our hospital was analyzed. The primary outcome measure was the incidence of SGA neonates. The odds ratios (ORs) of SGA neonates according to the FGR definitions at 18 weeks (17-20 weeks, period 1) and 28 weeks (27-30 weeks, period 2) were calculated.

RESULTS

During periods 1 and 2, the incidence rates of SGA neonates were 7.6% and 7.7%, respectively. The ORs of the JSOG and SMFM definitions were 8.24 [95% confidence interval (CI) 4.27-14.4] and 5.88 (95% CI 3.90-8.88), respectively, during period 1 and 22.7 (95% CI 12.6-40.8) and 15.5 (95% CI 10.4-23.1), respectively, during period 2. Compared to the JSOG definition, the SMFM definition was more sensitive for predicting SGA neonates. During both periods, the positive likelihood ratio (LR +) of the JSOG definition was higher than that of the SMFM definition for predicting SGA neonates.

CONCLUSION

The JSOG definition more strongly predicts SGA neonates and is associated with a higher LR + . The SMFM definition is highly sensitive for screening fetuses at risk for SGA status.