Risk of spontaneous miscarriage in euthyroid women with thyroid autoimmunity undergoing IVF: a meta-analysis

Abstract

Objective: To investigate whether thyroid autoimmunity (TAI) is associated with increased risk for spontaneous miscarriage in subfertile, euthyroid women undergoing IVF. Design: Meta-analysis of observational studies. Patient(s): Four prospective studies that reported data on 1098 subfertile women undergoing IVF (141 with TAI and 957 controls) were included in the meta-analysis. Main outcome measure: Miscarriage risk ratio (RR). Secondary outcome measures: Clinical pregnancy rate and delivery rate. Result(s): Euthyroid, subfertile women with TAI undergoing IVF demonstrated significantly higher risk for miscarriage compared with controls (four studies-fixed effects RR: 1.99, 95% confidence interval: 1.42-2.79, P!0.001). No significant difference in clinical pregnancy and delivery rates was detected between groups. Conclusion: Based on the currently available evidence, it appears that the presence of TAI is associated with an increased risk for spontaneous miscarriage in subfertile women achieving a pregnancy through an IVF procedure.

Thyroid disorders and fertility

“…52,53 In a metaanalysis carried out by Toulis et al in 2010 abortus rate was found to be 2 times higher in euthyroid IVF patients with positive thyroid autoimmunity. 54 Revell et al has emphasized in their study that during IVF, in order to increase pregnancy and implantation rates and reduce abortus rate ATA positive patients must be treated even if they are eutyhroid. 55 …”

CONTROVERSIES IN ENDOCRINOLOGY: On the need for universal thyroid screening in pregnant women

“…Positive thyroid autoimmunity is present in about 10% of pregnant women (116,117). Three meta-analyses have demonstrated a positive association between thyroid autoimmunity and both abortion and prematurity (8,116,118), although this association has not been confirmed in another (101).…”

“…Three meta-analyses have demonstrated a positive association between thyroid autoimmunity and both abortion and prematurity (8,116,118), although this association has not been confirmed in another (101). Negro et al demonstrated that T 4 treatment in women with TAI significantly decreased the number of miscarriages (94,119).…”

Pregnancy Outcome in Euthyroid Women with Anti-Thyroid Peroxidase Antibodies

“…On the other hand, a retrospective study by Tierney et al [24] performed in Australia found no difference in preterm deliveries between women who were thyroid antibody positive and women who were thyroid antibody negative.…”

“…Although many types of antithyroid antibodies have been described, the most common is the group of antibodies directed against various parts of the thyroid peroxidase molecule [24][25][26]. Most pregnant women with abnormally elevated serum levels of thyroid peroxidase antibodies are clinically and biochemically euthyroid, but they may be at increased risk of spontaneous abortion, and preterm delivery and other pregnancy complications [11,27].…”