Maternal serum alpha-fetoprotein and coagulation profiles after multifetal pregnancy reduction

Our purpose was to determine the effect of first-trimester multifetal pregnancy reduction on maternal serum alpha-fetoprotein and coagulation profiles in the second trimester.

Maternal serum alpha-fetoprotein was determined in 57 patients 1.5 to 10 weeks after multifetal pregnancy reduction, and coagulation profile was determined in 17 patients 2 to 5 weeks after the procedure. All but one had living twins at the time of testing.

All patients had elevated maternal serum alpha-fetoprotein levels (mean 11.6 +/- 7.6 multiples of the median) compared with normal twin values (< 3.5 multiples of the median). There was a positive correlation between maternal serum alpha-fetoprotein level and the number of dead fetuses and a negative correlation between maternal serum alpha-fetoprotein level and the number of weeks elapsed since multifetal pregnancy reduction. Amniotic fluid alpha-fetoprotein was measured in 10 patients and was normal. Fibrin split products were positive in 1 of 17 patients, intermediate in two of 17 and negative in 14 of 17. Prothrombin time, partial thromboplastin time, fibrinogen, and platelet counts remained normal. None of the patients had clinical evidence of disseminated intravascular coagulation, and treatment for that condition was not given.

Maternal serum alpha-fetoprotein in the second trimester is always elevated after multifetal pregnancy reduction and is not necessarily indicative of fetal defects. This elevation is probably caused by release of tissue or serum from the dead fetus(es). Amniocentesis is not indicated in these cases, but ultrasonography to evaluate fetal anatomy should be considered because maternal serum alpha-fetoprotein cannot be used in these patients to screen for fetal defects. Some patients can have laboratory evidence of disseminated intravascular coagulation after multifetal pregnancy reduction, but it may resolve spontaneously.