Placental disease causes most high MSAFP cases. (Expert Opinion).

SARASOTA, FLA. -- The first clinical sign of antiphospholipid syndrome may be a second-trimester elevation in maternal serum alpha-feroprotein, Dr. Anthony M. Vintzileos said at a symposium on high-risk pregnancy sponsored by Symposia Medicus.

"In my view the most common reason for elevated maternal serum alpha-fetoprotein [MSAFP] is placental disease," said Dr. Vintzileos, professor of obstetrics, gynecology and reproductive sciences, and director of maternal-fetal medicine and obstetrics at Robert Wood Johnson Medical School, New Brunswick, N.J.

In antiphospholipid syndrome, the MSAFP elevation follows placental thrombosis, which results from a cascade that begins with activation of endothelial cells. This is followed by an alteration in the thromboxane/ prostacyclin ratio and platelet aggregation. Placental findings also include fibrinoid necrosis, atherosis of decidual vessels, and intimal thickening.

"The natural history of this condition is lousy," Dr. Vintzileos said, pointing out that, if untreated, the overall pregnancy loss rate is 90%. Intrauterine fetal deaths account for 40% of the losses, which usually occur during the second or early third trimester. An estimated 5%-15% of cases of ...