Thyroid autoimmunity and intracytoplasmic sperm injection outcome: a systematic review and meta-analysis.

BACKGROUND: Since 2010, three meta-analyses have been published on the impact of thyroid autoimmunity (TAI) on pregnancy outcomes in infertile women treated with assisted reproductive technology (ART). The initially observed high risk of miscarriage became very low in the most recent meta-analysis published in 2016. OBJECTIVE: To investigate whether the lower risk of miscarriage in the latest meta-analysis was associated with the increased use of intracytoplasmic sperm injection (ICSI) in recent studies. DATA SOURCE: MEDLINE was searched from January, 1990, to May, 2017. STUDY SELECTION: Data from case-control and cohort studies, on ART (IVF/ICSI) pregnancy outcomes in women with and without TAI. Only studies were included in which women were treated with ICSI. DATA EXTRACTION AND SYNTHESIS: Four studies were retained including 1855 ICSI cycles (290 with and 1565 without TAI). In women with a clinical pregnancy (114 ICSI cycles with TAI and 651 without), there was no difference in miscarriage or live birth rates: respective combined OR 0.95 (95% CI, 0.48 to 1.87) and 1.12 (95% CI, 0.62 to 2.03). There was no difference in age in women with and without TAI: combined mean difference of 0.13 years (95% CI, -0.51 to 0.76), but serum TSH was higher in women with TAI: combined mean difference of 0.20 mIU/L (95% CI, 0.07 to 0.33). CONCLUSION: Infertile women with TAI treated with ICSI had no increased risk of a first trimester miscarriage compared with women without TAI.