Endocrine Abstracts

Background: Optimal management of hypothyroidism prior to and after conception is associated with improved pregnancy outcomes. Compliance with existing management guidelines in Australia and New Zealand is unknown.

Methods: A validated electronic survey was distributed to endocrinologists, obstetricians and general practitioners via their specialty professional bodies and results were analysed.

Results: There were 394 survey respondents: 80.5% (317) from Australia and 19.5% (77) from New Zealand. They comprised 263 Obstetrics and Gynaecology doctors (OG), 69 Endocrinology doctors (E) and 58 General Practitioners (GP). Four respondents were excluded as they did not meet inclusion criteria. Over half of respondents (57.4%) had more than 10 years of specialty experience. 95.2% of respondents (375/394) completed the clinical questions as the remainder were not involved in managing hypothyroidism in pregnancy or in women of reproductive age. On confirmation of pregnancy, 68.3% of respondents (n=233) reported checking thyroid function tests (TFTs) before adjusting thyroxine dose. 27.7% of respondents reported increasing thyroxine dose by 30–50% or by 2 tablets per week as soon as pregnancy is confirmed as recommended by guidelines. 85.2% of respondents reported adjusting thyroxine dose during pregnancy to recommended TSH targets of TSH < 2.5 mIU/l in the 1st trimester and < 3 mIU/l in the 2nd and 3rd trimesters (46.7%=155/332) or to TSH and free T4 trimester specific ranges for their laboratory (38.5%=128/332). 75.9% of respondents would appropriately treat pregnant women with thyroxine if TSH was > 2.5 mIU/l (36.0%=112/311) or above trimester specific ranges for their laboratory (39.9%=124/311).

Conclusions: Reported practice in management of hypothyroidism prior to and during pregnancy in Australia and New Zealand varies significantly from recommended guidelines. These findings have significant implications for pregnancy outcomes. Further education is needed for all medical practitioners involved in treating women of reproductive age.