Endocrine Abstracts

Background and aims: Maternal subclinical hypothyroidism during early pregnancy has been shown to be associated with impaired neuropsyhological developement of children.Recent consensus guidelines have recmmended aggressive case finding for thyroid or other autoimmune disorders.We have examined the efficacy of these criteria in identifying women with thyroid dysfunction during early pregnancy.

Subjects and methods:During july 2002 to june 2003,we propectively screened thyroid function tests (TSH,FT4 and FT3)in 1811 pregnant women at booking.We also analysed thyroid peroxidase(TPO) antibodies in 618 of these women.All women gave informed written consent.

Results:Thirty-three (1.8%)of the 1811 pregnant women screened had a TSH level greater than 5 micrograms per litre;16 of these women also had low FT4(less than 12 pico moles per litre).Of the 33 women with high TSH,15 had a history of thyroid disease,1 had a history of systemic lupus erythematosus and 16 had a family history of thyroid disease.However,9(27%) women with high TSH had neither a personal history nor a family history of thyroid or other autoimmune disorder.A suppressed TSH level(less than 0.05)was found in 40(2.2%)women;3 of them had a history of thyrotoxicosis and 3 were on thyroxine replacement.TPO antibodies were positive in 59 out of 618(9.5%);raised and suppressed TSH levels were found in 4 and 5 TPO positive women, respectively.Overall,52(2.9%) women were on thyroxine replacement at booking,of whom TSH levels were high in 13(25%) and suppressed in 3 (6%).

Conclusions:Screening only high-risk pregnant women would fail to identify a significant number of women with thyroid dysfunction in early pregnancy.This study also highlights the need for improved straegies for optimising thyroid replacement in hypothyroid women during early pregnancy.