Obstetric dating and growth scans in a tertiary health facility in Nigeria; are we doing it correctly?

Abstract

The study was prompted by the observed heterogeneity in performing dating and growth scans in Nigeria. The primary aim of the study was to determine whether the conduct of dating and growth scans in Nigeria conform to international norms. The secondary goal was to assess the implication of the scans for maternal and foetal care. The study was of mixed design – observational and cross-sectional with audit component, carried out at the Rivers State University Teaching Hospital (RSUTH), Nigeria from November, 2020 to February 2021. A literature search was carried out on the subject and standards were deduced from the review. 417 consecutive patients were recruited from the antenatal clinic and data on their history and the conduct of the scans were collected. The content of the individual scan report was compared with the international standards. Data were analysed using Epi. Info 2018 software. The results showed that there were no guidelines nor uniformity in the conduct of dating and growth scans at the RSUTH. Out of the total 744 scans that were done, 175 (25.36%) and 569 (74.64%) took place inside and outside the RSUTH respectively. The gestational ages at the first and the second scans were 8-41 weeks but 24-42 weeks for all the third scans. Appropriate biometric parameters were used in 115 (28.19%), 33 (14.10%) and 3 (2.94%) out of the 408 first, 234 second and 102 third scans respectively while in the rest, inappropriate or incomplete parameters were used. During subsequent scans after the first one, different EDD were assigned to pregnancies in 210 (93.59%) out of the 234 second scans, and 100 (98.04%) out of the 102 third scans, the differences ranging from 27 days earlier to 26 days later in both scans. The deficiencies in dating and growth scans would likely lead to wrong dating and inaccurate growth assessment with associated adverse maternal and foetal outcomes, including failure to diagnose important obstetric problem like SGA/FGR, LGA babies and wrong timing for obstetric interventions. The findings underscore the urgent need for formulating national guidelines on the subject, effective referral cascade for scans and adoption of practical approach to training in maternal and foetal medicine.