Factors affecting fetal survival after intrauterine transfusion for rhesus isoimmunization.

Intrauterine transfusion of the fetus is described in 165 pregnancies. The overall fetal survival rose from 28 per cent in 1964 to 1969 to 42-5 per cent in 1973 to 1975. Apart from technical complications of the procedure itself, the factors most likely to affect fetal survival were the gestational age and amniotic fluid optical density difference before the first intrauterine transfusion, the birth weight and the cord blood haemoglobin level.