Maternal hyperthyroidism and pregnancy outcomes: A population-based cohort study

Area of Science:

• Obstetrics and Gynecology
• Endocrinology
• Perinatal Medicine

Background:

• Maternal hyperthyroidism and antithyroid drug (ATD) use are linked to adverse pregnancy and perinatal outcomes.
• Understanding these associations is crucial for optimizing maternal and infant health.

Purpose of the Study:

• To investigate the association between maternal hyperthyroidism and antithyroid drug (ATD) use with pregnancy outcomes.
• To compare outcomes in hyperthyroid mothers versus mothers without thyroid disease.

Main Methods:

• Nationwide register-based study in Finland (2004-2013) including 571,785 singleton births.
• Identified hyperthyroid mothers via Medical Birth Register and ATD use via Prescription Register.
• Used logistic regression to compare odds ratios for adverse outcomes.

Main Results:

• Maternal hyperthyroidism was associated with increased odds of gestational hypertensive disorders, cesarean sections, placental abruption, preterm birth, small-for-gestational-age newborns, and NICU treatment.
• Both active (ATD users) and inactive (non-ATD users) hyperthyroid mothers faced higher risks of complications compared to controls.
• Hyperthyroid mothers also had higher rates of older age, multiparity, smoking, previous miscarriages, and obesity.

Conclusions:

• Women with active or historical hyperthyroidism are at increased risk for pregnancy and perinatal complications.
• Close monitoring of pregnant women with hyperthyroidism is recommended to mitigate risks.