Prevalence of major structural congenital abnormalities detected on infant surface examination in Botswana, 2014-2022: a birth outcomes surveillance study.

BACKGROUND

Population-level research focused on major congenital abnormalities (MCAs) in sub-Saharan Africa is needed. The Tsepamo study estimated the prevalence of MCAs evaluable on neonatal surface examinations in Botswana.

METHODS

Data were collected from up to 18 government hospitals throughout Botswana. Surface examinations were conducted by trained nurses after birth, and photographs and/or descriptions were used to identify and classify MCAs. Birth defects were categorised as MCAs if they were of clinical, surgical or cosmetic importance. We estimated MCA prevalence for all live and stillborn infants who were not exposed to HIV in utero. Variation by site, calendar year and season of MCAs (and, separately, of neural tube defects (NTDs)) was evaluated with the χ2 and Benjamini-Hochberg methods.

RESULTS

There were 1066 newborns with at least one MCA (59.3 (95% CI 55.8 to 62.9) per 10 000 births). NTDs accounted for 112 (10.5%) MCAs (6.2 (95% CI 5.2 to 7.5) per 10 000 births). Limb defects accounted for the majority of the birth defects (32.4 (95% CI 29.9 to 35.1) per 10 000 births), followed by major nervous system defects (16.7 (95% CI 14.9 to 18.7) per 10 000 births). The most common individual MCA was talipes (clubfoot) (18.5 (95% CI 16.6 to 20.6) per 10 000 births). While there was no meaningful variability of total MCAs by calendar year or season of conception, there was notable variation of NTDs by these factors.

CONCLUSIONS

The estimated prevalence of MCAs was 59.3 (95% CI 55.8 to 62.9) per 10 000 births. While NTD prevalence varied by calendar year and season of conception, overall MCA prevalence did not. Ongoing surveillance of MCAs is needed to monitor the occurrence of birth defects and support preventive interventions in Botswana and the region.