Objective:

To longitudinally assess fetal growth in PCOS pregnancies and evaluate whether assisted reproductive technology (ART) modifies associated fetal growth restriction.

Approach:

• Study Design: Prospective multicenter cohort study (UNIHOPE; NCT03220750) involving 12,189 advanced maternal age pregnancies, with 364 diagnosed with PCOS.
• Data Collection: Longitudinal fetal biometry in the second and third trimesters following ISUOG guidelines, with Z-scores derived using advanced-age reference.
• Statistical Analysis: Generalized linear models adjusted for maternal demographics, lifestyle factors, and gestational diabetes mellitus, with subgroup analyses by ART conception.

Key Findings:

• PCOS fetuses showed reduced second-trimester Z-scores for femur length (MD: −0.13; 95% CI, −0.25 to −0.02) and head circumference (MD: −0.14; 95% CI, −0.23 to −0.04).
• Third-trimester deficits included biparietal diameter (MD: −0.18) and abdominal circumference (MD: −0.16).
• Birth length (MD: −0.16) and weight (MD: −0.13) Z-scores were lower in PCOS neonates.
• Growth restriction was evident only in spontaneous conceptions; no significant differences in ART-conceived pregnancies.
• Findings were robust to adjustments for gestational diabetes mellitus.

Interpretation:

Fetal growth restriction in PCOS pregnancies is detectable from the second trimester and persists to delivery.

Limitations:

• The study may not account for all confounding factors affecting fetal growth.
• Results are based on a specific population and may not be generalizable.

Conclusion:

Dynamic ultrasound surveillance is necessary in PCOS pregnancies.

Sources:

• Clinical Trial Registration