Abnormal Shape of Placenta as a Consequence of Maternal Thyroid Disorders-Does It Leave Any Microscopic Changes?

Abstract

Introduction: Thyroid disorders are common in the reproductive age group of women and these can cause significant perinatal outcomes.Though the effect of abnormal thyroid hormones on the foetus and its development is established, their effect on the placenta and its contribution towards the effect is not elaborately studied. Aim: To compare the microscopic features of euthyroid placentae with those of mothers with thyroid dysfunction. Materials and Methods: This is prospective observational study wherein placentae received from October 1 ,2017 to March 31, 2019 in the Department of pathology, Karnataka Institute of Medical Sciences, Hubballi, Karnataka, India, were collected, processed and analysed. A total of 539 cases were received for histopathological examination during this period, of these 64 cases had abnormal antenatal thyroid profile. These were compared grossly and microscopically with the control group of 64 euthyroid cases. Results: The total sample of the study comprised of case group(n=64) and control group(n=64), mean age: mean age of the women 26.91±4.1 years. The case group samples included 3 hyperthyroid cases and 61 hypothyroid cases.In the control group, 3 (2.3%) foetuses were dead as compared to 6 (4.7%) foetuses in hypothyroid group and 3 (2.3% of total, 100% of hyperthyroid group) foetuses in hyperthyroid group (p< 0.001). Abnormal shape of the placenta was seen in 1 (0.8%) case in normal group as compared to 3 (2.3%) in hypothyroid group and 1 (0.8%) case in hyperthyroid group (p=0.018). However, there weren’t any significant microscopic changes. Conclusions: Maternal thyroid disorders result in abnormal shape of placenta and hence resulting in foeto-maternal insufficiency and subsequent foetal growth restriction and adverse foetal outcome.