Urinary Oestriol Excretion in Pregnancies Complicated by Rhesus Immunization

Summary: Urinary oestriol measurements were performed in 239 rhesus immunized patients with rhesus positive infants. Oestriol excretion was low in 31 of the 55 pregnancies (56%) resulting in perinatal deaths, including 17 of the 26 in which the fetus was hydropic at birth. When oestriol excretion was low the perinatal mortality rate was 65% (31 of 48). When the fetus had severe erythroblastosis, oestriol assays sometimes provided useful extra information when amniotic fluid bilirubin was unexpectedly low. The important conclusion from this study was that low oestriol excretion was an accurate index for selection of the fetus in jeopardy in rhesus immunized patients, although normal oestriol values did not guarantee that the fetus was in good condition.