Twin pregnancy presenting as a praevia complete hydatidiform mole and coexisting fetus complicated by a placental...

A twin pregnancy consisting of a complete hydatidiform mole and a coexisting normal fetus (CMCF) is a rare and challenging condition when diagnosed prenatally and is associated with major obstetric complications.

We present a case of CMCF in which the molar component presented as a major placenta praevia at 19 weeks, and which was complicated by a placental abscess with maternal septicaemia from 26 weeks. An emergency caesarean section, performed at 28 weeks' gestation due to severe maternal septicaemia, resulted in the delivery of a live male infant. Despite the molar mass being praevia, the delivery was not complicated by extensive haemorrhage.

This is only the second case of CMCF complicated by a molar praevia and the first complicated by a placental abscess. We believe that the 2 conditions are linked and that the absence of normal fetal membranes surrounding the molar mass enabled secondary colonization by vaginal bacteria. Therefore, we recommend that immediate antibiotic treatment is initiated in cases of CMCF presenting as a praevia when maternal and/or fetal symptoms of infection develop.