Objective: To assess midtrimester uterine artery Doppler in the prediction of preeclampsia and small for gestational age (SGA) infants in women with primary antiphospholipid syndrome.
Methods: One hundred seventy pregnant women with histories of recurrent miscarriage in association with antiphospholipid antibodies (32 lupus anticoagulant positive, 47 IgG anticardiolipin positive, 78 IgM anticardiolipin positive, and 13 lupus anticoagulant and anticardiolipin antibodies positive) treated with low-dose aspirin and heparin were recruited prospectively. Doppler assessment of the uterine arteries (presence or absence of notches and pulsatility index) were performed at 16-18 and 22-24 weeks. The main outcome measures were the delivery of a SGA infant and the development of preeclampsia.
Results: There were 164 live births and six midtrimester losses. The prevalence of preeclampsia and SGA was similar at 10%. In predicting preeclampsia or SGA, uterine artery pulsatility index at either interval was of no value, and the diagnostic accuracy of the Doppler was limited to bilateral uterine artery notches at 22-24 weeks in the subgroup of women with positive lupus anticoagulant. In this subgroup, bilateral uterine artery notches at 22-24 weeks in predicting preeclampsia generated a high likelihood ratio for positive test (12.8, 95% confidence interval 2.2, 75), sensitivity (75%), specificity (94%), positive (75%) and negative (94%) predictive value. In predicting SGA, the corresponding figures were respectively 13.6 (95% confidence interval 1.9, 96), 80%, 94%, 80%, 94%. Uterine artery Doppler was of limited value in pregnancies associated with anticardiolipin antibodies in isolation.
Conclusion: In pregnancies associated with lupus anticoagulant, uterine artery Doppler at 22-24 weeks is a useful screening test in predicting preeclampsia and SGA infants.