Endocrine Abstracts

Introduction: Isolated maternal hypothyroxinemia leads to higher prevalence of children autism, attention-deficit/hyperactivity disorder and mild cognitive deficiency. Frequency of hypothyroxinemia among women with gestational diabetes mellitus (GDM) is unclear and routine screening is not well established.

Objective: Find prevalence of maternal isolated hypothyroxinemia in women with GDM and assess relations with necessity of insulinotherapy.

Methods: Retrospective observational open study. Four hundred and eighty-five women with GDM were enrolled. In all women were measured free thyroxin (fT₄), thyroid stimulation hormone (TSH) and thyroid peroxidase antibodies by RIA. Women with pre-existent or newly discovered thyroidal illness or with elevated thyroid-peroxidase antibodies or with other autoimmune disease were excluded. All subjects had common iodine supplementation (multivitamins with iodine). Statistical analysis was performed using Mann–Whitney test and Spearman correlation test.

Results: Serum fT₄ levels were below 10th percentile according to normal values in 173 women, below 5th percentile in 65 women. In this three groups – below 5th percentile, below 10th percentile and above 10th percentile – were observed no differences in initial metabolic (TSH, serum total cholesterol, serum triglycerides, fasting plasma glucose, glycosylated haemoglobin, manifestation of GDM) and anthropometric (age, weight, BMI) parameters. Insulinotherapy was needed significantly frequently in the group below 10th percentile (62 women – 35.8%) than in the group above 10th percentile (59 women – 18.9%).

Conclusion: In our patients with gestational diabetes mellitus we observed higher frequency of isolated maternal hypothyroxinemia in comparison with literary data (1–5%). Women with lower fT₄ needed significantly more often insulinotherapy (approx. twice).