Routine third-trimester ultrasound for the detection of small-for-gestational age in low-risk pregnancies (ROTTUS...

Area of Science:

• Obstetrics and Gynecology
• Fetal Medicine
• Diagnostic Imaging

Background:

• Small-for-gestational-age (SGA) infants are at increased risk for adverse neonatal outcomes.
• Current standard care for detecting SGA in low-risk pregnancies relies on selective ultrasound based on symphysis-fundus height (SFH) measurements, which may have limitations.

Purpose of the Study:

• To compare the effectiveness of routine third-trimester ultrasound versus selective ultrasound (based on SFH) in detecting SGA infants in low-risk pregnancies.

Main Methods:

• An open-label randomized controlled trial was conducted with low-risk pregnant women.
• Participants were randomized to either routine third-trimester ultrasound or standard care (selective ultrasound based on SFH).
• Fetal growth was assessed using abdominal circumference (AC) measurements; AC < 10th centile indicated SGA.

Main Results:

• Routine ultrasound detected 52.8% of SGA infants versus 7.7% with standard care (P < 0.001).
• Detection rates for severe SGA were 66.7% with routine ultrasound versus 8.3% with standard care (P < 0.001).
• Routine ultrasound demonstrated a significantly higher area under the ROC curve for SGA prediction (0.92 vs 0.68, P < 0.001).

Conclusions:

• Routine third-trimester ultrasound is superior to selective ultrasound based on SFH measurements for detecting SGA in low-risk pregnancies.
• The routine ultrasound approach offers high specificity in identifying SGA fetuses.
• This improved detection can potentially lead to better management of fetal growth abnormalities.