Table 1. Summary of current knowledge of factors affecting mother-to-child HIV-1 transmission.
| Known risk factors | Factors for which evidence is suggestive but not conclusive |
Factors for which evidence is inconsistent or limited |
| High maternal viral load Advanced maternal HIV disease Low CD4 count or percent Vaginal delivery Duration of membrane rupture > 4 hours Premature delivery (< 37 weeks) No receipt of antiretroviral prophylaxis Specific to breastfeeding transmission: Breast milk viral load Mastitis (including subclinical) Cracked or bleeding nipples Breast abscess Duration of breastfeeding |
Host genetic factors Immature immune system in infant Viral genotype and/or phenotype Increased viral strain diversity Maternal neutralizing antibody Illicit drug use during pregnancy Frequency of unprotected sexual intercourse Multiple sex partners during pregnancy Maternal nutritional status Anemia during pregnancy Cigarette smoking Chorioamnionitis Abruptio placentae Sexually transmitted infections (e.g., syphilis) Use of fetal scalp electrodes Episiotomy and vaginal tears |
Primary HIV infection in mother Prior HIV-infected sibling Older maternal age Primiparity Alcohol use during pregnancy History of abortions or stillbirths Duration of labor Low neonatal Apgar score Low gastric acid secretion Immaturity of neonatal gastrointestinal tract Infant gender Season of birth Placental P. falciparum infestation Maternal vitamin A deficiency |