Maternal thyroid hypofunction and pregnancy outcome

Area of Science:

• Obstetrics and Gynecology
• Endocrinology
• Perinatal Medicine

Background:

• Maternal thyroid function is crucial for fetal development.
• Thyroid dysfunction during pregnancy can potentially lead to adverse outcomes.
• Understanding the specific risks associated with different types of maternal thyroid hypofunction is essential for effective prenatal care.

Purpose of the Study:

• To investigate the association between maternal thyroid hypofunction and pregnancy complications.
• To differentiate the risks posed by subclinical hypothyroidism versus hypothyroxinemia.
• To assess the impact of antithyroid antibodies on pregnancy outcomes.

Main Methods:

• Serum samples from 10,990 pregnant patients were analyzed for TSH, free T4, and thyroid antibodies in the first and second trimesters.
• Thyroid hypofunction was defined as subclinical hypothyroidism or hypothyroxinemia based on TSH and free T4 levels.
• Multivariable logistic regression analysis was used to compare outcomes between hypothyroid and euthyroid patients, adjusting for confounders.

Main Results:

• Subclinical hypothyroidism (2.2%) was not associated with adverse outcomes.
• Hypothyroxinemia (2.1-2.3%) in the first trimester was linked to preterm labor and macrosomia.
• Hypothyroxinemia in the second trimester was associated with gestational diabetes.
• Antithyroid antibodies were associated with an increased risk of preterm premature rupture of membranes.

Conclusions:

• Maternal thyroid hypofunction does not present a uniform pattern of adverse pregnancy outcomes.
• Specific conditions like hypothyroxinemia and the presence of antithyroid antibodies warrant attention due to their associations with certain complications.