Fungal community structure is not determined by common perinatal factors. A) Host sex does not significantly alter fungal community composition. PCoA of Bray-Curtis dissimilarity matrices, PERMANOVA R2 = 0.0209, P = 0.529. RDA, variance = 3.19, f = 1.02, P = 0.348. The subset displays a discriminant analysis of principal components. B) Prenatal antibiotic exposure (PAE) does not significantly alter fungal community composition. PCoA of Bray-Curtis dissimilarity matrices, PERMANOVA R2 = 0.202, P = 0.598. RDA, variance = 3.51, f = 1.12, P = 0.083. C) Mode of delivery does not significantly alter fungal community composition. PCoA of Bray-Curtis dissimilarity matrices, PERMANOVA R2 = 0.202, P = 0.598. RDA, variance = 3.51, f = 1.12, P = 0.083. D) Illness severity does not significantly alter fungal community composition. PCoA of Bray-Curtis dissimilarity matrices, PERMANOVA R2 = 0.0251, P = 0.146. RDA, variance = 2.68, f = 0.85, P = 0.947. For all analyses n = 71.