Miscarriage
Women with poorly controlled hyperthyroidism, especially in the first trimester, are at an increased risk of spontaneous miscarriage. Elevated thyroid hormone levels can interfere with normal fetal development, leading to pregnancy loss.
Preterm Labor
Uncontrolled hyperthyroidism raises the risk of preterm labor. Premature birth can result in complications for the newborn, including respiratory distress syndrome, jaundice, and feeding difficulties. Managing thyroid hormone levels is essential to reduce the risk of early delivery.
Preeclampsia
Pregnant women with hyperthyroidism, particularly those with Graves’ disease, are more prone to developing preeclampsia, a dangerous condition marked by high blood pressure and proteinuria. If not managed, preeclampsia can escalate to eclampsia, resulting in seizures, organ failure, or even maternal and fetal death. Regular monitoring of blood pressure and thyroid function is crucial to prevent these complications.
Thyroid Storm
A thyroid storm is a rare but life-threatening complication of untreated or poorly controlled hyperthyroidism, particularly during stressful events like labor, surgery, or infection. It is a clinical diagnosis of decompensated thyrotoxicosis rather than a laboratory one: hormone levels are often no higher than in uncomplicated hyperthyroidism, and the picture is fever, tachycardia out of proportion to the fever, agitation or delirium, vomiting and diarrhea, heart failure, and progression to multi-organ failure. The Burch-Wartofsky Point Scale scores temperature, heart rate, atrial fibrillation, heart failure, central nervous system and gastrointestinal-hepatic findings, and the presence of a precipitant: 45 or more is highly suggestive of storm, 25 to 44 suggests impending storm, and under 25 makes it unlikely. Storm complicates roughly 1% of hyperthyroid pregnancies and carries a mortality of 10% to 30%. Prompt recognition and treatment are essential, requiring intensive care, antithyroid medications, beta-blockers, and supportive therapies.
Heart Failure
The increased metabolic rate caused by hyperthyroidism puts extra strain on the heart, raising the risk of heart failure. Pregnant women, who already face increased cardiovascular demands, are particularly susceptible to heart failure if their hyperthyroidism is not well-controlled.
Hypertension
Hyperthyroidism can cause high blood pressure due to increased sympathetic activity and cardiac output. When combined with preeclampsia, hypertension presents a significant danger to both the mother and baby.
