Induction at 38 weeks for large-for-gestational-age or macrosomic fetuses decreases the incidence of cesarean delivery: meta-analysis of randomized controlled trials.

BACKGROUND

Several studies compared induction of labor to expectant management in singleton pregnancies with suspected large-for-gestational-age (LGA) or macrosomic fetuses. However, the most appropriate management, including the option of induction of labor, and at what gestational age, remains unclear.

OBJECTIVE

To evaluate the effects of labor induction for pregnancies with LGA or macrosomic fetuses on mode of delivery, and maternal and perinatal morbidity, and to evaluate the best gestational age for such induction if beneficial.

STUDY

DESIGN

A systematic literature search of electronic databases was conducted through November 1, 2025. Randomized controlled trials (RCTs) including term singleton pregnancies with suspected large-for-gestational-age (LGA) or macrosomic fetuses comparing induction of labor (IOL) with expectant management were included. The primary outcome was cesarean delivery, with secondary maternal and neonatal outcomes assessed. Pooled estimates were initially calculated using a fixed-effects model; random-effects analyses using a restricted maximum likelihood (REML) estimator were subsequently performed and heterogeneity was assessed using the I² and τ² statistics.

RESULTS

Five randomized trials including 4083 pregnant individuals were analyzed. Baseline characteristics were comparable between groups. Most participants underwent induction at 38 weeks with the largest RCT (71% of the total sample of this meta-analysis), inducing labor at 38 0/7 to 38 4/7 weeks, for LGA > 90th percentile. For the primary outcome, IOL was associated with significant lower risk of cesarean delivery (27.9% vs 31.9%; risk ratio 0.87, 95% confidence interval 0.79 to 0.96) with no heterogeneity. Among secondary outcomes, induction of labor reduced the incidence of macrosomia ≥4000 g (RR 0.53, 95% CI, 0.48 to 0.59) and ≥4500 g (RR 0.22, 95% CI, 0.12 to 0.39). Shoulder dystocia (RR 0.73, 95% CI, 0.50 to 1.03) and fetal fracture (RR 0.35, 95% CI, 0.12 to 1.05) showed a trend toward risk reduction without reaching statistical significance in random-effects analyses. Phototherapy was more frequent following induction of labor (RR 1.62, 95% CI, 1.17 to 2.25), whereas other neonatal and maternal outcomes did not differ significantly between groups.

CONCLUSION

Induction of labor between 38 0/7 to 38 4/7 weeks for suspected LGA (EFW >90th percentile) or macrosomic fetuses may be a reasonable management option, as it is associated with significant reductions in cesarean delivery, and a potential reduction in shoulder dystocia, and neonatal fractures, compared to expectant management. As the strongest evidence derives from induction at 38 0/7 to 38 4/7 weeks, counseling should emphasize this gestational window. Approximately 25 inductions of labor for EFW >90th percentile at 38 0/7 to 38 4/7 weeks would be required to prevent 1 cesarean delivery. El resumen está disponible en Español al final del artículo.