The chance of a live birth after assisted reproduction in women with thyroid disorders.

PURPOSE

Women with thyroid disorders may have increased infertility and poor reproductive outcomes, but it is unclear if assisted reproductive technology (ART) is effective in this population. The aim of this study was to examine the chance of a pregnancy (biochemical and clinical), and a live birth after ART, in women with thyroid disorders undergoing ART treatment, compared to women without thyroid disorders. Among live-born children, we assessed the risk of congenital malformations.

PATIENTS AND METHODS

In a nationwide cohort study of all women undergoing ART treatments in Denmark from 1 January 1994 throughout June 2017, we calculated the chance of a pregnancy and a live birth after embryo transfer. Women with thyroid disorders were stratified into two groups: those diagnosed with hypothyroid or hyperthyroid disorders. The adjusted OR (aOR) of a biochemical and a clinical pregnancy, a live born child and a congenital malformation was computed using multilevel logistic regression models.

RESULTS

In total, 199,674 embryo transfers were included in 2,101 women with thyroid disorders and in 65,526 women without thyroid disorders. The chance of a biochemical pregnancy was significantly reduced in women with hyperthyroidism (aOR=0.80, 95% CI 0.69-0.93), and the aOR of a live birth was 0.86, 95% CI 0.76-0.98. The aOR for a live birth in women with hypothyroidism was 1.03 (95% CI 0.94-1.12). Children of women with hypothyroidism, who were conceived after ART treatment, had a significantly increased risk of any congenital malformation (aOR=1.46 [95% CI 1.07-2.00]).

CONCLUSION

Women with hyperthyroidism receiving ART treatment had a decreased chance of a live birth per embryo transfer compared to women without thyroid disorders. Women with hypothyroidism did not have a decreased chance of a live birth but their offspring had an increased risk of congenital malformation.