The more common thyroid disorders in pregnancy are hypothyroidism and hyperthyroidism, both of which have a definite impact on pregnancy, pregnancy outcome and offspring intelligence. Strengthening preconception screening, pregnancy checkups and postpartum follow-up can reduce the risk factor of the disease in mother and child and largely improve the quality of life.
1, characteristics of thyroid disease: slow progression, not obvious, symptoms are often not taken seriously by patients, easily misdiagnosed by clinicians as other diseases such as hyperlipidemia, menstrual disorders, sterilization, depression.
Maternal thyroid function and pregnancy: Thyroid disorders are common in women during pregnancy. In early pregnancy, fetal development is completely dependent on maternal thyroid hormones, and maternal thyroid hormone (T4) is essential for fetal development.
3. Pregnancy and hypothyroidism: including clinical hypothyroidism, subclinical hypothyroidism, and low T 4 blood
Effects of maternal hypothyroidism on pregnancy and fetus
Effects of maternal hypothyroidism on offspring intelligence
Treatment
L-T4 is the preferred replacement therapy drug
L-T4 treatment goals and dose adjustment
Diagnosis of hypothyroidism before pregnancy, L-T4 dose adjustment, TSH normalization before pregnancy
During pregnancy, increase L-T4 dose by 30%-50% compared to non-pregnancy period
If hypothyroidism is diagnosed during pregnancy, treat immediately with L-T4 at 0ug/kg/d
Adjust the L-T4 dose according to the pregnancy-specific normal range of TSH
Some scholars recommend TSH2,5mIU/L as the target value for L-T4 supplementation
4. Pregnancy and hyperthyroidism
There are two main types: transient thyrotoxicosis of pregnancy (GTT) associated with increased HCG concentration
Graves’ disease of pregnancy, associated with thyroid autoimmune abnormalities
The risks of hyperthyroidism in pregnancy
Maternal: hypertension, pre-eclampsia, heart failure, thyroid crisis, miscarriage, placental abruption
Fetus: intrauterine growth arrest, prematurity, stillbirth, congenital malformation, neonatal death, small full-term babies (9 times more than normal pregnant women) Neonatal hyperthyroidism: 1-2% prevalence among GD pregnant women
Pregnancy outcomes in 342 hyperthyroid patients
Increased incidence of stillbirth, preterm delivery and thyroid crisis in the untreated group compared to the treated group
The incidence of these disorders was reduced with treatment to control hyperthyroidism
Treatment of hyperthyroidism during pregnancy
1.Anti-thyroid drug treatment – preferred
2.Surgical treatment – appropriate timing
3.Radioactive 131 iodine therapy—Contraindicated
Indications and timing of surgery
Indications for surgery
1.Allergy to antithyroid drugs
2.Anti-thyroid drug treatment is not effective and cannot be taken regularly
3.Significant goiter, need high dose ATD
4, excessive psychological burden, excessive worry about drug side effects
Timing of surgery: 4-6 months of pregnancy is more appropriate
Application of ATD during pregnancy
1.Maximum dose PTU5-100mg, q8h or MM120mg/day
2.Check liver function every two weeks at the beginning of treatment, and then extend to once every 2-4 weeks
Clinical symptoms and thyroid function improve, the dose of ATD should be reduced by half, and most patients return to normal thyroid function in 3-8 weeks
3. When patients rely on the smallest dose of ATD (PTU50mg/day or MMI5mg/day) to maintain normal thyroid function for several weeks, the drug can be discontinued.
4. At present, maintenance treatment is not recommended until 32 weeks of pregnancy to avoid relapse.
5. If there is a relapse, you can treat with ATD again.
Timing of pregnancy in patients with hyperthyroidism
1.Patients with previous hyperthyroidism, such as in ATD treatment, serum TSH reaches the normal range, after stopping ATD or reducing the dose of ATD, so that serum FT4 is at the upper limit of normal value.
2. Some scholars advocate that MMI should be discontinued and replaced by PTU before pregnancy to avoid malformations that may be caused by MMI.
3.Six months after radioactive iodine 131 treatment.