The effect of newly diagnosed undifferentiated connective tissue disease on pregnancy outcome

Objective: The purpose of this study was to evaluate pregnancy outcome in a cohort of patients with newly diagnosed undifferentiated connective tissue disease (UCTD). Study Design: We conducted a nested case-control study that compared 41 patients who had early UCTD that was diagnosed at 11-14 weeks of pregnancy with 82 healthy control subjects. Results: During pregnancy, UCTD progressed to a definite connective tissue disease in 2 of 41 patients (4.9%). Sixteen of the 41 patients (39%) with UCTD tested positive for anti-Ro (SSA) antibodies. Compared with the control subjects, the women with UCTD had higher rates of small for gestational age (SGA; 12/40 vs 11/80; P = .05). The rate of complications of pregnancy (preterm delivery at ≤ 37 weeks of gestation, SGA, preeclampsia, late fetal loss) was 39% (16/41) among cases and 13.4% (11/82) in control subjects (adjusted odds ratio, 3.98; 95% CI, 1.59-9.49). Conclusion: Pregnant patients with UCTD are at increased risk of SGA and complications of pregnancy.