Hema Divakar1, Rita Singh2, Poorni Narayanan3, Divakar G. V4, Bhagyashree Kulkarni5, Asha Hegde6
There have been rising trends in the incidence of hyperglycaemia in pregnancy and hypothyroidism in pregnancy. Both are known to cause adverse maternal and foetal outcomes. An attempt is being made to look at both these problems in conjunction rather than in isolation. The nexus of dual endocrinopathy is being explored in this study. The aim of the study is to determine the prevalence of hypothyroidism in pregnant women with gestational diabetes mellitus (GDM) in India as well as the association between GDM and hypothyroidism
. MATERIALS AND METHODS
The study subjects were pregnant women attending the Divakars Speciality Hospital Bengaluru, India. They were recruited on their first antenatal visit; excluded were women known to have hypothyroidism as well as those who were taking thyroid medication. GDM testing was carried out according to the Diabetes in Pregnancy Study group India (DIPSI) as per FIGO guidelines and serum TSH estimation was carried with the ADVIA Centaur XL Siemens kit using the CLIA technique. Hypothyroidism was diagnosed if the serum TSH levels were >2.5 µIU/L while GDM was diagnosed if the blood glucose levels were >140 mg/dL.
Thirty-eight of the 315 subjects recruited to take part in the study (12.1%) were diagnosed with GDM, while 277 exhibited a normal glucose tolerance. TSH levels were only available for 251 of the subjects in this study, 87 of whom were diagnosed with hypothyroidism. Of the 251 subjects for whom TSH and blood glucose data were available, only 29 subjects had GDM (12%). Of the 29 subjects who were diagnosed with GDM, 24 (82.7%) were also hypothyroid. A Mantel-Haenszel common odds ratio estimate showed that a weak association existed between TSH levels greater than 2.5 µIU/L and blood plasma glucose levels greater than 140 mg/dL (OR=12.11; 95% CI: 4.42-33.15).
There is a considerably high prevalence of hypothyroidism in pregnant women who have been diagnosed with GDM. This study adds to the growing literature regarding the dual endocrinopathy of hypothyroidism and GDM in pregnant women and makes a case for increased observation of pregnant women diagnosed with either endocrinopathy.