Problem: Women with secondary recurrent pregnancy loss (RPL) after a boy have a reduced chance of live birth in the first pregnancy after referral if they carry HY-restricting HLA class II alleles, but long-term chance of live birth is unknown.
Methods of study: Live birth was compared for 540 women with unexplained secondary RPL according to firstborn's sex and maternal carriage of HLA-DRB3*03:01, HLA-DQB1*05:01/02, HLA-DRB1*15, and HLA-DRB1*07. The groups were compared by Cox proportional hazard ratios.
Results: For women with at firstborn boy, maternal carriage of HY-restricting HLA class II alleles decreased chance of live birth: 0 vs 1: hazard ratio 0.75 (95% CI 0.55-1.02); 0 vs 2: HR 0.62 (0.40-0.94). Carriage of HY-restricting HLA class II alleles decreased chance of live birth only if the firstborn was a boy: boy vs girl: HR 0.72 (95% CI 0.55-0.98).
Conclusion: Maternal carriage of HY-restricting HLA class II alleles decreases long-term chance of live birth in women with RPL after a boy.
Keywords: HY-restricting HLA class II alleles; cohort study; immunogenetics; recurrent pregnancy loss.
© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.