Association between maternal serum analytes and third trimester fetal growth restriction

Area of Science:

• Maternal-fetal medicine
• Prenatal diagnostics
• Neonatal outcomes

Background:

• Abnormal maternal serum analytes are associated with small for gestational age (SGA) infants.
• Third-trimester fetal growth ultrasounds are commonly used despite limited evidence.
• The study evaluated isolated abnormal analytes, third-trimester fetal growth restriction (FGR), and neonatal complications.

Purpose of the Study:

• To assess the prevalence of FGR with isolated abnormal analytes in the third trimester.
• To determine the association between abnormal analytes and SGA.
• To evaluate the impact of abnormal analytes on neonatal outcomes.

Main Methods:

• Retrospective cohort study of 11,092 pregnancies from 2010-2019.
• Excluded multiple gestations, deliveries <28 weeks, and other indications for third-trimester ultrasound.
• Calculated FGR prevalence and association with SGA, and evaluated associations with neonatal outcomes.

Main Results:

• Among 613 women with third-trimester ultrasounds and isolated abnormal analytes, 1.6% had FGR and 16.1% were SGA.
• Abnormal analytes correlated with increased SGA, intensive care admission, and preterm delivery.
• Only 9.1% of SGA neonates were identified with FGR on early third-trimester ultrasound.

Conclusions:

• Third-trimester FGR is infrequent with isolated abnormal analytes, and ultrasounds may miss SGA.
• Findings support evidence-based fetal surveillance and inform the shift from serum analyte screening to cell-free fetal DNA.
• Early third-trimester ultrasound for abnormal analytes may not be an effective screening tool for FGR or SGA.