ASSESSING THE IMPORTANCE OF THIRD-TRIMESTER ULTRASOUND SCAN IN A LOW-RISK OBSTETRIC POPULATION: A SYSTEMATIC REVIEW

Abstract

Background: Routine third-trimester ultrasound for low-risk pregnancies remains controversial. While its benefit in high-risk pregnancies is established, its role in universal screening is debated. This review synthesizes evidence on detection rates for fetal growth restriction (FGR), small-for-gestational-age (SGA) fetuses, and perinatal outcomes.

Objective: To assess the clinical value, benefits, and limitations of routine third-trimester ultrasound scans in low-risk obstetric populations.

Methods: A systematic review was conducted following PRISMA 2020 guidelines. Databases including PubMed, Scopus, Web of Science, and Embase were searched for studies published between 2000 and 2025. Eligibility included RCTs, cohort studies, and meta-analyses reporting on detection rates, perinatal mortality, and intervention outcomes.

Results: Fifteen studies met inclusion criteria. Universal late ultrasound increased detection rates for FGR by 5–10% but showed inconsistent evidence of impact on stillbirth rates. Doppler and biomarkers improved detection when combined with standard biometry.

Conclusions: Routine third-trimester ultrasound improves detection of growth restriction but may not significantly reduce adverse outcomes in low-risk pregnancies. Targeted strategies and customized charts may balance benefits and minimize unnecessary interventions.