Transplacental haemorrhage may explain the intrapartum transmission of HIV. A pilot study uses flow cytometry to quantify maternal red blood cells in infants born vaginally or by caesarean section.

摘要

Intrapartum transmission is epidemiologically important for some viruses such as HIV and hepatitis B virus, but its precise mechanism is unknown. We hypothesised that the ability of elective caesarean section to prevent HIV may be due to prevention of transplacental microtransfusions of blood during labour. Their frequency is not known so we performed a pilot study which showed evidence of transplacental transfusion from mother to fetus in one of ten mother-infant pairs delivering vaginally and none of ten delivering by elective caesarean section. We conclude that transplacental transfusion occurs and is one possible mechanism for the intrapartum transmission of viruses from mother to baby.