Placental pathology, antiphospholipid antibodies, and pregnancy outcome in recurrent miscarriage patients.

OBJECTIVE: To examine whether there are characteristic histological features in placentas from ongoing pregnancies of patients with a history of recurrent miscarriage, with and without primary antiphospholipid antibody syndrome, in relation to clinical pregnancy outcome.
METHODS: Patients attending a recurrent miscarriage clinic were investigated and treated according to an established protocol. One hundred twenty-one consecutive patients achieving a potentially viable pregnancy (at least 24 completed weeks' gestation), including 60 primary antiphospholipid antibody syndrome-positive cases and 61 primary antiphospholipid antibody syndrome-negative cases were included. After delivery, placental pathologic examination was carried out by a pathologist unaware of the clinical details. Histological sections were examined by two pathologists independently. Pregnancy outcome and placental findings were reviewed in relation to the maternal antiphospholipid antibody status.
RESULTS: Pregnancy outcome was similar in primary antiphospholipid antibody syndrome-positive and primary antiphospholipid antibody syndrome-negative groups regarding gestation at delivery and antepartum obstetric complications. Several histological placental abnormalities were identified in both groups, but most pregnancies were clinically uncomplicated, with no significant placental abnormalities. In cases with pregnancy complications, the placental pathology was primarily that of uteroplacental vasculopathy, such as placental infarction and preeclampsia, but there were no specific placental lesions or patterns of abnormalities characteristic of primary antiphospholipid antibody syndrome-positive patients. A small subgroup of primary antiphospholipid antibody syndrome-positive patients may be at increased risk of development of maternal floor infarction or massive perivillus fibrin deposition.
CONCLUSION: There are no specific histopathologic placental abnormalities characteristic of treated patients with antiphospholipid antibody syndrome and poor reproductive history, but complications of uteroplacental disease are more common.