Pregnancy outcome in relation to uterine artery flow velocity waveforms and clinical characteristics in women with antiphospholipid syndrome.

OBJECTIVE

To determine whether uterine artery velocimetry is a useful tool for identifying pregnancies with antiphospholipid syndrome at risk for adverse outcome.

METHODS

Twenty-four women with antiphospholipid syndrome, who had experienced 56 fetal losses in 63 previous pregnancies (88.9%), were treated with prednisone (40 mg/day) and aspirin (100 mg/day) during 28 pregnancies. Color Doppler ultrasound was performed at 18-24 weeks' gestation to investigate the resistance index of the uterine arteries.

RESULTS

Treated women delivered 23 live infants in the 28 pregnancies (82.1%). Three infants weighed less than the tenth percentile (13%). Five pregnancies were complicated by preeclampsia and ten by nonproteinuric gestational hypertension. Positive results for all three assays for antiphospholipid antibodies (anticardiolipin antibodies, lupus anti-coagulant, VDRL) at conception identified pregnancies destined to have poor fetal outcome and a significantly lower birth weight compared to pregnancies not having all three assays positive. An abnormal resistance index of the uterine arteries predicted pregnancies with poor fetal outcome in terms of week of delivery, birth weight, and birth percentile, as well as four of five cases of preeclampsia.

CONCLUSIONS

Three assays positive for antiphospholipid antibodies at conception and an abnormal resistance index of the uterine arteries at 18-24 weeks' gestation predicted pregnancies at major risk for obstetric complications. Future studies should determine whether treatment can be modulated based on the Doppler findings.