Objective: To determine whether clinically routine clotting tests such as activated partial thromboplastin time (aPTT), prothrombin time (PT), or fibrinogen can be used to predict further miscarriages.
Design: Prospective study.
Setting: Nagoya City University Hospital, Nagoya, Japan.
Patient(s): A total of 261 patients with a history of two consecutive first-trimester spontaneous abortions who had no antiphospholipid antibodies or other autoimmune diseases and no anatomic anomalies were examined for aPTT, PT, and fibrinogen before becoming pregnant again.
Intervention(s): Blood tests were performed before pregnancy. Patients then were followed up during subsequent pregnancy and their outcomes were compared with their previous blood test results.
Main outcome measure(s): Activated partial thromboplastin time, PT, and fibrinogen were measured by coagulation time methods.
Result(s): Fifty-eight of 261 patients (22.2%) had a subsequent miscarriage. Mean (+/-SD) values for preconception aPTT in individuals whose subsequent pregnancies ended in success and failure were 88.2%+/-23.4% and 99.3%+/-26.4%, respectively. The difference was statistically significant. Respective values were 106.8%+/-22.8% and 106.3%+/-21.4% for PT and 245+/-61.1 mg/dL and 259.1+/-57 mg/dL for fibrinogen. These findings were not significantly different.
Conclusion(s): A shortened aPTT before conception is associated with further miscarriages in patients with a history of recurrent spontaneous abortions who have no antiphospholipid antibodies.