The Endocrine Pregnancy Clinic provides dedicated care for women with endocrine disorders during pregnancy and the early post-partum phase. Thyroid dysfunction is important due to the inter-relationships between thyroid and pregnancy, and the potential implications for both mother and child
1.To assess adequacy of thyroid hormone replacement in pre-existing hypothyroidism.
2.To document range of TSH values and presence of autoantibodies in newly diagnosed hypothyroidism in pregnancy.
An audit of the first two years of women referred to the Endocrine Pregnancy Clinic from March 2012 to March 2014. Data collected included age of pregnant woman, gravidity, parity, gestation, past and family history of thyroid dysfunction, thyroid function tests (TFTs), presence of a goitre and autoantibody status.
210 women were referred for assessment of hypothyroidism, at a mean gestation of 20 weeks. 100 women (47.6%) were treated for hypothyroidism prior to the current pregnancy. At referral, 62 patients (62%) had elevated TSH levels (2.5-5.0 IU/L, n=35; 5.1-10 IU/L, n=14, >10.1 IU/L, n=13). A mean thyroxine dose adjustment of 33% was required throughout the pregnancy. 110 women had newly diagnosed hypothyroidism in pregnancy and 40% had positive thyroid peroxidase (TPO) antibodies. At referral, 101 patients (92%) had elevated TSH (2.5-5.0 IU/L, n=51; 5.1-10 IU/L, n=36, >10.1 IU/L, n=14). They required a mean dose adjustment of 25% during the pregnancy. 19 patients with new hypothyroidism had a normal TSH on repeat and did not require replacement.
Women frequently have TSH levels above the ideal range, despite recommendations for management of pre-existing hypothyroidism in pregnancy. Thyroid hormone replacement should be optimised prior to conception with early measurement of thyroid function upon confirmation of pregnancy. Those with hypothyroidism in pregnancy should be followed closely until TSH reaches target. Both groups should be seen at regular intervals thereafter for dose adjustment.