Role of foetal umbilical artery Doppler on prediction of adverse pregnancy outcomes in patients with systemic lupus erythematosus.

OBJECTIVES: To investigate the foetal outcomes and examine the predictive value of the third-trimester umbilical artery Doppler in systemic lupus erythematosus (SLE) pregnancies.

METHODS: Data of 180 pregnancies in 175 SLE patients from Jan 2007 to Jan 2017 were analysed retrospectively. Pulsatility index (PI), resistance index (RI), and systolic/diastolic ratio (S/D) of the umbilical artery flow velocity data were monitored by Doppler ultrasound.

RESULTS: One or more composite adverse pregnancy outcomes (APOs) occurred in 46.7% of patients with SLE. A total of 62 (34.4%) pregnancies were pre-term birth, and 34 (18.9%) newborns were small for gestational age (SGA). Twenty-two of pregnancies (12.2%) resulted in foetal distress. In multivariate analysis, predictors of composite APOs included positive anti-Ro (OR 5.5, 95% CI 1.7-18.2, p=0.005) and low complement (OR 3.9, 95% CI 1.1-13.6, p=0.04). Doppler PI, RI, and S/D were significantly higher in the pre-term birth, SGA, and composite APO groups than in the patients without APOs. RI with cut-off values of 0.57 and 0.70 indicated the highest risk of pre-term birth and composite APOs, with sensitivities of 50.0% and 21.4%, as well as specificities of 59.6% and 97.7%, respectively. PI emerged as the best predictor of SGA. The optimal cutoff value for PI was 0.77, at which sensitivity (90.9%) and specificity (49.2%) had the best combination.

CONCLUSIONS: Pregnancies in lupus still had an increased risk of APOs in terms of pre-term birth. Third-trimester umbilical artery Doppler was useful in predicting pre-term birth, SGA, and composite APOs in lupus pregnancies.