Prediction of gestational age with symphysis-fundal height and estimated uterine volume in a pregnancy cohort in Sylhet, Bangladesh. Issue 3 (12th March 2020)

• Record Type: Journal Article
• Authors: Lee, Anne C C; Whelan, Rachel; Bably, Nazmun Nahar; Schaeffer, Lauren E; Rahman, Sayedur; Ahmed, Salahuddin; Moin, Syed Mamun Ibne; Begum, Nazma; Quaiyum, Mohammad Abdul; Rosner, Bernard; Litch, James A; Baqui, Abdullah H; Wylie, Blair J
• Is Part Of: BMJ open. Volume 10:Issue 3(2020)
• Publication Date: 2020-03-12
• Subjects: gestational age -- symphysis fundal height -- uterine fundal height -- preterm birth -- estimated uterine volume; Medicine -- Research -- Periodicals; 610.72
• DOI: 10.1136/bmjopen-2019-034942
• Languages: English
• ISSNs: 2044-6055

Abstract

Abstract : Objective: To improve the accuracy of the prediction of gestational age (GA) before birth with the standardised measurement of symphysis-fundal height (SFH), estimation of uterine volume, and statistical modelling including maternal anthropometrics and other factors. Design: Prospective pregnancy cohort study. Setting: Rural communities in Sylhet, Bangladesh. Participants: 1516 women with singleton pregnancies with early pregnancy ultrasound dating (<20 weeks); 1486 completed follow-up. Methods: SFH and abdominal girth were measured at subsequent antenatal care (ANC) visits by community health workers at 24 to 28, 32 to 36, and/or >37 weeks gestation. An estimated uterine volume (EUV) was calculated from these measures. Data on pregnancy characteristics and other maternal anthropometrics were also collected. Primary outcome measure: GA at subsequent ANC visits, as defined by early ultrasound dating. Results: 1486 (98%) women had at least one subsequent ANC visit, 1102 (74%) women had two subsequent ANC visits, and 748 (50%) had three visits. Using the common clinical practice of approximating the GA (in weeks) with the SFH measurement (cm), SFH systematically underestimated GA in late pregnancy (mean difference −4.4 weeks, 95% limits of agreement −12.5 to 3.7). For the classification of GA <28 weeks, SFH <26 cm had 85% sensitivity and 81% specificity; and for GA <34 weeks, SFH <29 cm had 83% sensitivity and 71% specificity. EUV had similar diagnostic accuracy. Despite rigorous statistical modelling of SFH, accounting for repeated longitudinal measurements and additional predictors, the best model without including a known last menstrual period predicted 95% of pregnancy dates within ±7.4 weeks of early ultrasound dating. Conclusions: We were unable to predict GA with a high degree of accuracy before birth using maternal anthropometric measures and other available maternal characteristics. Efforts to improve GA dating in low- and middle-income countries before birth should focus on increasing coverage and training of ultrasonography. Trial registration number: NCT01572532