Third-Trimester Ultrasound: The Best Window on Fetal Growth?

Ultrasound screening for fetal growth restriction has traditionally been reserved for pregnancies at high risk based on clinical history, obstetric complications, or abnormal uterine fundal height. Investigators in the U.K. designed a prospective study to determine the efficacy of universal versus targeted third-trimester ultrasonography for detecting small-for-gestational-age (SGA) fetuses. All women underwent ultrasound examination per standard of care, but also had routine serial fetal biometry assessed in a research context.

Of 4512 women enrolled, ultrasound was clinically indicated and performed in 42%. Slightly fewer than 10% of women delivered infants below the 10th percentile for gestational age. Clinically indicated ultrasound dete…