Fetal blood sampling immediately before and within 24 hours of death in monochorionic twin pregnancies complicated by single intrauterine death.

OBJECTIVE

Our goal was to investigate the mechanisms that play a role in intrauterine death in monochorionic twins and that contribute to the high perinatal mortality and morbidity in the survivors.

STUDY DESIGN

In 8 monochorionic twin pregnancies complicated by the intrauterine death of a single twin, we took samples from 5 twin fetuses immediately before death and from 4 of their cotwins and also from 4 surviving fetuses within 24 hours after death of the cotwin.

RESULTS

Four of the 5 fetuses sampled who subsequently died were acidemic and 3 were hypoxemic. None of these fetuses or their cotwins were anemic at that time. All 4 survivors sampled within 24 hours of the death of each cotwin had low hematocrits.

CONCLUSION

Fetal anemia, probably the consequence of acute blood loss just before the time of death of the cotwin, may play a role in the high mortality and morbidity found in the surviving twin. It is unlikely that immediate delivery of the surviving twin after death could affect the outcome.