A Comparison of the Accuracy of the Use of Last Menstrual Period and Symphysio-Fundal Height for Gestational Age Determination among Nigerian Women

Aims: The aim of the study was to evaluate the accuracy of the symphysio-fundal height (SFH) in comparison to the last menstrual period (LMP) for gestational age assessment.
Study Design: Hospital-based prospective cross sectional study.
Place and Duration of Study: Maternity unit of the Jos University Teaching Hospital, Jos, Nigeria, between December 2012 and April 2013.
Methodology: A total of 289 consecutive consenting women with singleton uncomplicated pregnancies at gestational ages of less than or equal to 20 weeks were recruited at the maternity unit of Jos University Teaching Hospital between December 2012 and April 2013. Ultrasound scan (USS) was used to confirm eligibility after which other information including the LMP were documented on a questionnaire. The women returned after 22 weeks’ gestation based on ultrasound recorded GA for SFH assessment and some weeks thereafter for a second SFH assessment.
Results: Mean age of the women was 28.9±4.8 years with a range of 16-42 years. Most of them were of parity 1 – 4 (58.1%). The mean GA at booking was 15.3±3.1 weeks based on LMP and 14.9±3.1 from early ultrasound scan. The mean percentage accuracy for SFH method compared to USS dating was 95.8% while that of LMP was 91.0%. This difference was found to be statistically significant (P = .02).
Conclusion: The study showed a significant difference between the LMP and early ultrasound scan dating but not between SFH and early ultrasound scan. Also, the mean percentage accuracy was statistically higher for SFH, suggesting that SFH was a more accurate tool for gestational age assessment among these women.