Abstract

OBJECTIVE:

To assess the effect of treatment of maternal subclinical hypothyroidism on infertility outcome.

METHODS:

Between April 1, 2006, and April 22, 2007, we conducted a prospective, randomized trial in infertile women with subclinical hypothyroidism who elected to undergo in vitro at the Shatby University Hospital for Women in Alexandria, Egypt. Patients were randomly assigned to 2 groups: treatment group (group A) and placebo group (group B). Male-factor infertility was ruled out. One month before the assisted reproduction technology procedure, group A underwent levothyroxine treatment with a dosage of 50 to 100 mcg daily, while group B started placebo. All patients underwent controlled ovarian stimulation. Patients who achieved pregnancy were followed up throughout their pregnancy until delivery. Levothyroxine treatment and placebo were maintained throughout pregnancy in group A and group B, respectively.

RESULTS:

Mean thyrotropin value was significantly lower in group A than in group B (1.1 ± 0.3 mIU/L vs 4.9 ± 0.7 mIU/mL, respectively). Mean number of retrieved oocytes was similar in both groups (6.19 ± 0.74 [group A] vs 6.08 ± 0.79 [group B]). Miscarriage rate was significantly lower in group A than in group B (9% vs 13%, respectively), and the clinical pregnancy rate and delivery rate were significantly higher in group A than in group B (35% and 10% vs 26% and 3%, respectively), indicating that the quality, not the quantity, of retrieved oocytes was more important.

CONCLUSION:

These preliminary data suggest that levothyroxine supplementation should be recommended to achieve clinical pregnancies in women with subclinical hypothyroidism who are undergoing in vitro fertilization-intracytoplasmic sperm injection.