Table 2. Risk of bias assessment of the observational studies using the Newcastle-Ottawa Scale.

	Selection*		Comparability†		Exposure‡		Risk of bias
	Score	Notes	Score	Notes	Score	Notes
Chippaux et al (1993)32	2	Pregnancy tests were not done and therefore no independent validation of pregnancy was available	NA	Study was not controlled for age, history of pregnancy-related serious adverse events, or any other substantial factor	2	Exposure to ivermectin was self-reported	High
Doumbo et al (1992)33	2	Pregnancy tests were not done and therefore no independent validation of pregnancy was available; adverse pregnancy outcomes were self-reported	NA	Study was not controlled for age, history of pregnancy-related serious adverse events, or any other substantial factor	2	Exposure to ivermectin was self-reported	High
Gyapong et al (2003)34	2	Pregnancy tests were not done and therefore no independent validation of pregnancy was available	NA	Study was not controlled for age, history of pregnancy-related serious adverse events, or any other substantial factor	1	Exposure to ivermectin was self-reported; the study reports exposure to albendazole or ivermectin during pregnancy, in which it is unclear if all cases received ivermectin	High
Makene et al (2003)35	2	Pregnancy tests were not done and therefore no independent validation of pregnancy was available; adverse pregnancy outcomes were self-reported	1	..	2	Ascertainment of exposure was not described	Moderate
Pacque et al (1990)13	2	Pregnancy tests were not done and therefore no independent validation of pregnancy was available	1	..	3	..	Moderate

NA=not available. *Maximum score of 4. †Maximum score of 2. ‡Maximum score of 3.