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