Comparison of early and late ultrasound examination for estimation of due date: a systematic review
Systematic review
|Published
We conducted a systematic review with the aim of comparing precision between early (gestational weeks 11-14) and late (gestational weeks 17-20) ultrasound examinations for estimating the due date.
Key message
Precise determination of the expected date of birth is important to ensure optimal prenatal care and timing for necessary medical follow-up and treatment. Ultrasonic biometrics is the standardized method used in most high-income countries.
We conducted a systematic review with the aim of comparing precision between early (gestational weeks 11-14) and late (gestational weeks 17-20) ultrasound examinations for estimating the due date. The results from this systematic review will be part of the evidence base used to evaluate a revision of the national guidelines for maternity care.
We systematically searched five electronic databases (March 2025) and OpenAlex (June 2025) for controlled studies that compare the accuracy of due date estimation determined by ultrasound in weeks 11-14 (early ultrasound) with weeks 17-20 (late ultrasound). The outcome was precision in the estimated due date between early and late ultrasound examination and compared with actual due date.
The literature search identified 5708 unique publications. Two reviewers independently assessed the titles and abstracts of the identified references, and next potentially relevant studies in full text, according to our predefined inclusion criteria. We considered 25 publications as potentially relevant and read them in full text. We did not find any studies that compared the accuracy of early ultrasound (in weeks 11-14) compared to late ultrasound (in weeks 17-20) for due date estimation.