Endocrine Abstracts

Maternal thyroid hormones play a critical role in foetal brain development in the first 12 weeks of gestation. Children born to hypothyroid mothers, especially those undertreated, are more likely to suffer lower IQ. Based on BES guidance 2007 and NICE 2011 at confirmation of pregnancy a woman with hypothyroidism should immediately increase the dose of levothyroxine by 25–50 mcg with aim TSH of less than 2.5 mu/l as soon as possible with monitoring of TFT every 4 weeks.

We carried out a retrospective cohort study of 41 pregnant women with hypothyroidism in Warrington hospital medical/Obs clinic between 2009 and 2016. Data was collected using patient’s case notes and SUNQUEST ICE, the hospital pathology system. ICE was interrogated for TSH results from up to 6 months pre-conception, and in each trimester of pregnancy.

53% of patients received TFT checks in the 6 months pre- conception. Of these, 59% had TSH levels outside recommended levels. 22% received correct treatment before pregnancy. 62% of patients received their 1^st TFT of pregnancy in the 1^st trimester, 17% in the 2^nd trimester, and 2% in the 3^rd trimester. 6% were first checked post-delivery, and 13% were never checked. In patients found to be hypothyroid, 96% received appropriate levothyroxine dose adjustment at review in Medical/Obs clinic.

Unfortunately many patients were not referred by their GP or midwives in a timely manner. Just 62% were referred to our clinic in the first trimester, 15% in second trimester and 3% in third. More work is needed to ensure patients receive their first TFT pre-conception and early in their pregnancy and then follow BES and NICE guidance. We need to increase GP and patients awareness of potential problems as many patients with hypothyroidism are not under hospital care. Referral to joint medical/Obs clinic is associated with much tighter control.