Histomorphometry of thyroid gland in different weeks of gestation

Abstract

Aim: In human beings, the thyroid gland is one of the earliest endocrine organs to differentiate; it has an important hormonal role in embryonic development. Objective: 50 stillborn foetus obtained within time to avoid post-mortem changes. The gestational age, sex, weight, crown-rump lengths were studied in detail. The gestational age ranges from 12th week to 36th week. Weight measured in grams, crown-rump length by plastic tape and scale divider. Methods and Material: 50 stillborn, normal fetuses 30 male, 20 female. Gestational age, sex, weight, crown-rump length. Weight measured on the digital weighing machine. Plastic tape, scale and divider to measure crown-rump length. Fetuses were dissected and thyroid gland was removed. On calculation, 1 division of micrometre eyepiece was 4μm. By using this scale diameter of follicles were calculated at 10xs by 40xs. Size of follicles was measured from early to late fetal period, nature of epithelium, appearance, amount of colloid content, capsular and vascular development was studied. Result: The size of follicles & colloid increased gradually 12wks to 24 wks Conclusion: As size of follicles and colloid increases which increase the weight of thyroid gland in human fetuses seems to be directly proportional to the increase in the body weight, crown-rump length and estimated gestational age of fetuses. The weight of thyroid at 12th week was 0.0717gms. It increased gradually up to 0.517gms at 28th week of gestation. The weight at 38th-week gestation was 1.25gms.