The diagnosis of a partial hydatid mole presents a difficult situation
for both physician and parents. On the one hand there may be a normal
pregnancy whereas on the other hand the mother may be threatened by n
umerous complications caused by the hydatid mole if the pregnancy is c
ontinued. We report on a pregnancy in the 18th week during which a par
tial hydatid mole was discovered where we considered it justified to a
dvise the parents, after a thorough consultation, to continue with the
pregnancy. Ultrasound examination had excluded infaust malformations
whereas cytogenetically there was no triploidy of the fetus. Moreover
it was possible to closely monitor the course of pregnancy to discover
any possible complications well in time. Under these conditions conti
nuation of pregnancy until birth is possible in about 60 % of the case
s without enhanced risk to the mother, as is evident from the data in
the literature. In the case under report, however there was a life-thr
eatening uterine haemorrhage with placenta previa in the 22nd week of
pregnancy resulting in mandatory premature termination of pregnancy. R
epeated treatment with cytostatics was subsequently required due to pe
rsistence of the mole, since even hysterectomy could not achieve compl
ete remission of the disease.