Hashimoto's disease is an autoimmune disorder in which the immune system mistakenly attacks the thyroid gland. This can lead to reduced production of thyroid hormones, a condition known as hypothyroidism. These hormones are essential for many bodily functions, including metabolism and reproduction. When hormone levels are too low, it can cause challenges with fertility, pregnancy, and even postpartum health.

Although having Hashimoto's doesn't mean you can't become pregnant or have a healthy pregnancy, it does come with increased risks. It is crucial for anyone with this condition to work closely with their healthcare provider when planning to conceive or once they become pregnant.

How Hashimoto's Can Affect Fertility

Thyroid hormones play an important role in regulating the menstrual cycle. If hormone levels are too low due to Hashimoto's, it can result in irregular periods, making it more difficult to predict ovulation and conceive. However, proper management with thyroid hormone replacement therapy can help restore regular cycles and improve the chances of pregnancy.

It's ideal to ensure that thyroid hormone levels are stabilized before attempting to get pregnant. If pregnancy happens unexpectedly while the thyroid is not well-controlled, early medical attention is important. In such cases, referral to a high-risk pregnancy specialist may be necessary.

Some individuals with Hashimoto's also have a higher likelihood of developing polycystic ovary syndrome (PCOS), another condition that affects ovulation and can make conception more difficult. Treatments are available to stimulate ovulation, and an obstetrician-gynecologist can help tailor a plan for fertility support.

Pregnancy Complications Linked to Hashimoto's

Without proper management, Hashimoto's can lead to several pregnancy complications that may affect both the expectant parent and the baby. These risks include:

  • High blood pressure conditions such as preeclampsia

  • Low red blood cell count (anemia)

  • Miscarriage

  • Placental abruption (when the placenta separates too early from the uterus)

Understanding Preeclampsia

Preeclampsia is a potentially serious condition marked by high blood pressure and signs of damage to other organs, often the kidneys. It typically appears in the second half of pregnancy and may cause symptoms like swelling in the face or hands, persistent headaches, blurry vision, and pain in the upper right abdomen.

In some cases, doctors may recommend low-dose aspirin starting between 12 and 28 weeks of pregnancy (ideally before 16 weeks) to lower the risk of developing preeclampsia. If preeclampsia is diagnosed, delivery of the baby may be the only effective treatment, with timing based on how far along the pregnancy is and the severity of the condition.

Risks of Anemia During Pregnancy

Anemia, a condition where the body doesn't have enough healthy red blood cells or hemoglobin, is more likely to occur in individuals with Hashimoto's. Symptoms might not be noticeable at first, but can include fatigue, pale skin, shortness of breath, and a rapid heartbeat.

Treatment generally includes iron supplements and dietary adjustments to increase iron intake. In more severe cases, intravenous iron or blood transfusions may be necessary.

Miscarriage and Immune Dysfunction

Hashimoto's is associated with an increased risk of miscarriage, largely due to hormonal imbalances and immune system issues. In a healthy pregnancy, the immune system naturally shifts to tolerate the fetus, which has different genetic material from the mother. In Hashimoto’s, this immune adjustment may not occur properly, potentially leading the body to treat the fetus as a threat.

Signs of miscarriage can include vaginal bleeding, cramping, and back pain. Not all bleeding during pregnancy means a miscarriage is occurring, but any such symptom should be evaluated by a doctor immediately.

Certain supplements like selenium and vitamin D have been studied for their potential to reduce immune-related miscarriage risk, but current evidence is inconclusive.

Placental Abruption Risks

Placental abruption happens when the placenta detaches from the wall of the uterus too early. This condition is most common in the third trimester and can reduce or cut off the baby’s supply of oxygen and nutrients. It may lead to preterm birth, or in rare cases, stillbirth.

Symptoms of a placental abruption include vaginal bleeding, abdominal pain, and a change in fetal movement. Immediate medical attention is essential. Depending on the severity, treatment may range from rest and monitoring to urgent delivery.

Hashimoto’s Diagnosis During Pregnancy

Hashimoto’s disease is diagnosed in approximately 2% to 3% of pregnancies. Because its symptoms—such as fatigue, constipation, and cold sensitivity—are also common in pregnancy, diagnosis can be challenging.

Blood tests that measure thyroid hormone and thyroid-stimulating hormone (TSH) levels can help confirm the diagnosis. Routine thyroid screenings are not always part of standard prenatal care, so individuals with a history of thyroid issues should inform their provider early in pregnancy.

Postpartum Concerns with Hashimoto’s

The period after childbirth can be physically demanding, and Hashimoto's may increase the risk of certain complications.

Postpartum Hemorrhage

One risk is excessive bleeding after delivery, known as postpartum hemorrhage. This can happen if the uterus does not contract effectively after childbirth, failing to stop bleeding from the site where the placenta was attached. It is more likely to occur in individuals with Hashimoto's and may require immediate intervention such as medications, blood transfusions, or in severe cases, surgery.

Monitoring Thyroid Levels After Delivery

After childbirth, thyroid hormone needs may change. It’s important to monitor hormone levels, especially if the dose of thyroid medication was increased during pregnancy. Many people return to their pre-pregnancy dose within a few weeks or months.

Symptoms of overmedication include nervousness, irritability, sensitivity to heat, and a racing heartbeat. If any of these symptoms occur, the healthcare provider may adjust the dosage accordingly.

Breastfeeding with Hashimoto’s

Breastfeeding is generally safe and possible for people with Hashimoto’s. Levothyroxine, the standard treatment for the condition, is considered safe while nursing. Only minimal amounts of the medication pass into breast milk, and no harmful effects on the infant have been identified.

Conclusion

While Hashimoto’s disease can present unique challenges during conception, pregnancy, and the postpartum period, these challenges are manageable with proper medical support. Maintaining stable thyroid hormone levels before and during pregnancy is critical to reducing risks. With regular monitoring, appropriate treatment, and attention to symptoms, most people with Hashimoto’s can experience a healthy pregnancy and recovery.

Open communication with healthcare providers, early intervention when issues arise, and continued care postpartum are all essential. Understanding the potential complications empowers individuals to take proactive steps toward ensuring the best outcomes for both parent and baby.