The relation between umbilical cord coiling index and thyroid function disorders

Several articles have demonstrated an association between specific pregnancy-related medical issues and the prevalence of the umbilical coiling index.The objective: to determine the potential impact of the aberrant coiling index of the human umbilical cord on thyroid function content and its potential deleterious effects on infant health.Materials and methods. Umbilical cord samples were taken from 105 practically healthy pregnant women. Umbilical cords were collected immediately after delivery and stored in formalin (10%) based on the type of coil. Umbilical cords were divided into three categories of 35 samples for each experimental group – normocoiled, hypercoiled, and hypocoiled. This division was performed according to the umbilical cord index.Thyroid hormones (thyroid-stimulating hormone – TSH), triiodothyronine – T3 and thyroxine – T4) were determined using the enzyme immunoassay method in maternal venous blood serum and umbilical cord blood.Results. There was no significant difference in the concentration of TSH, T3 and T4 hormones in the blood serum of mothers between the three different study groups (P>0.05). There was also no statistically significant difference (P>0.05) when comparing the levels of TSH and T3 in the umbilical cord in all three study groups.Regarding concentration of T4, the data showed a significant difference in the obtained values (P<0.01) when comparing venous blood samples in normocoiled cords compared to hypercoiled and hypocoiled cords. In addition, comparison of thyroid hormone levels in maternal venous blood and umbilical cord blood demonstrated that in all study groups there was a significant difference (P<0.05) in TSH levels between maternal and umbilical cord blood serum.The concentration of T3 did not differ significantly (P>0.05) in maternal blood serum compared to umbilical cord blood. In the statistical analysis, the levels of T4 in venous blood samples from normocoiled and hypocoiled umbilical cords differ significantly from the level of this hormone in the mother’s blood (P<0.01, P<0.05). There was no significant difference in the concentration of T4 in hypercoiled umbilical cord blood samples (P>0.05) compared to maternal blood serum.Conclusions. The concentration of T4 increases in the fetal circulation with normocoiled umbilical cord, since this form of coiling is the best situation for proper feto-maternal exchange function of this hormone.