Prevalence of thyroid dysfunction and autoimmunity among pregnant women with gestational diabetes mellitus in a tertiary care hospital, Visakhapatnam

Background: The most common endocrine conditions encountered in pregnancy are gestational diabetes mellitus (GDM) and thyroid disease which have been known to mutually exist and impact each other to variable extents.Methods: A Cross sectional study was conducted from September 2019 to February 2020 among 150 pregnant women (75 women with GDM and 75 women without GDM) with 24-28 weeks of gestation in a tertiary care hospital. Thyroid function tests (Serum TSH, FT4 and TPO antibodies) were evaluated in all the pregnant women. All the information regarding family history of diabetes mellitus, GDM and thyroid disease was determined in both groups and analyzed by statistical methods in SPSS trial version 21.Results: Obtained data showed that TSH level (p=0.14) and anti- TPO (p=0.04) in women with GDM were more than in euglycemic pregnant women and FT4 (p≤0.001) level was lower. There is higher prevalence of hypothyroidism among GDM patients compared to that of euglycaemic women (29.3% vs 14.6%). TPO Ab was positive among 29.3% of GDM and 8% of the normal pregnant women (p<0.05). High prevalence of hypothyroidism was noticed among TPO Ab positive patients in both the groups, but more in the GDM group comparatively indicating that TPO Ab positivity is associated with a higher risk of hypothyroidism in GDM (p<0.05).Conclusions: The high prevalence of thyroid disorders and autoimmunity among GDM group warrants the importance of evaluating thyroid function in pregnant women with impaired glucose tolerance, in view of their increased risk of hypothyroidism.