Pregnancy outcomes in mixed connective tissue disease: a multicentre study

Area of Science:

• Rheumatology
• Obstetrics
• Immunology

Background:

• Mixed Connective Tissue Disease (MCTD) is an autoimmune disorder.
• Anti-U1RNP antibodies are a key diagnostic marker for MCTD.
• Pregnancy outcomes in women with MCTD are not fully understood.

Purpose of the Study:

• To investigate fetal and maternal pregnancy outcomes in a large multicenter cohort of women with MCTD and anti-U1RNP antibodies.
• To identify risk factors associated with adverse pregnancy outcomes in this population.

Main Methods:

• A multicenter retrospective cohort study.
• Involved 94 women with MCTD and confirmed U1RNP positivity.
• Analyzed outcomes of 203 pregnancies.

Main Results:

• Live birth rate was 72.9% (146/203).
• Adverse outcomes included miscarriages (18.7%), stillbirths (8.9%), and intrauterine growth restriction (5.4%).
• Maternal complications included pre-eclampsia (3.9%), eclampsia (0.9%), gestational hypertension (15.3%), and gestational diabetes (1.5%).
• Worse fetal outcomes were noted in women with MCTD, antiphospholipid antibodies, and pulmonary or muscular involvement.
• One case (0.45%) of complete congenital heart block and one case of cutaneous neonatal lupus were observed in mothers with isolated anti-U1RNP positivity.

Conclusions:

• Women with MCTD achieved a live birth rate of 72% in this cohort.
• The study suggests considering echocardiographic surveillance for potential congenital heart block in pregnancies with anti-U1RNP antibodies.
• Pregnancy counseling is recommended for women with MCTD.