Overall congenital malformations
A meta-analysis of seven studies assessing the risk of congenital malformations concerning neuraminidase-inhibitor exposure during pregnancy indicated that the combined OR of congenital malformation risk was 0.9 (95% CI 0.72–1.12, P = 0.341) (Figure 2). No heterogeneity was observed among the studies (I2 = 0%, P = 0.852). As shown in Figure S1, we did not observe any evidence of publication bias (Begg’s test, P = 1; Egger’s test, P = 0.63). The sensitivity analyses revealed no substantial change in the pooled risk estimates upon the exclusion of any single study from the same database. Six studies reported the risk of congenital malformations in relation to oseltamivir exposure during pregnancy; the combined OR was 0.89 (95% CI 0.69–1.14, P = 0.361; I2 = 0%) (Figure S2).
We also analyzed the association between neuraminidase-inhibitor exposure and heart malformations, which was reported by two studies. The rates of heart malformations (OR 1.11, 95% CI 0.61–2.03, P = 0.735; I2 = 0%) (Figure S3) were similar in the two groups.