Cord blood Thyroid Stimulating Hormone Level - and the influence of perinatal and other factors on it

Abstract

Background: Thyroid hormone is essential for growth and development especially the brain. Deficiency of thyroid hormone i.e. congenital hypothyroidism (CH) is the commonest cause of preventable mental retardation. As it is difficult to diagnose CH with clinical symptoms at birth, most patients with CH are diagnosed by laboratory results. Early detection is important, either by Thyroid Stimulating Hormone (TSH) or T4 estimation or both by newborn screening. Cord blood TSH (CB-TSH) estimation has high sensitivity, but various maternal and perinatal factors affect the CB-TSH levels, which may interfere with the interpretation.

Cord Blood TSH and Free T4 Correlation with Maternal and Neonatal Factors and Heel-Stick TSH For the Early Detection of Congenital Hypothyroidism: A Cross-sectional Study in Iran

“…Cortés-Castell et al (31) have reported the risk of high neonatal TSH without congenital hypothyroidism is higher in males. Although paralleled results have been extracted by other studies (13,32), several reports emphasized on no signi cant association of mean cord blood TSH and sex (1,24,25,33). However, the exact mechanism is not clear yet.…”

“…Umbilical cord blood TSH measurement has shown several advantages, including non-invasive, easy sampling, and recheck enabling even before the mother leaves the hospital. However, some studies have demonstrated that the values for CBTSH can be affected by a variety of maternal neonatal factors, while these reports were accompanied by paradoxical and different results (1,3,13,19). In this study, the data of effect of maternal and neonatal factors on cord blood Free T4 and TSH were demonstrated, which were studied in neonates born at Amir-Al-Momenin, Semnan, Iran.…”

“…A growing body of evidence indicates that delivery mode has the strongest and most consistent relationship with CBTSH (34). Previous investigators found that CBTSH is elevated in neonates born vaginally compared to C-section (3,13,17,34). It is postulated that vaginal deliveries resulted in increasing of catecholamine secretion and induction of stress condition which in turn, can elevate CBTSH levels (25,34,35).…”

“…Neonatal CBTSH has been shown to be associated to maternal and perinatal factors, including gestational hypertension, preeclampsia, gestational diabetes mellitus (GDM) (11), presence of labor, mode of delivery (3), and birth weight (7,12). It was believed that these factors induce intrapartum stress experienced by the fetuses and in uence the CBTSH (13). Increasing the rate of cesarean section (Csection) on request, as reported more than 50% of overall deliveries ( 14), rising the delayed child bearing in Iran, and the change in reproductive behaviors lead to the enhancement of perinatal stress events (15).…”

Congenital hypothyroidism in India: A systematic review and meta-analysis of prevalence, screen positivity rates, and etiology

“…Seventy-nine studies were included in the systematic review, and 70 studies in the meta-analysis. 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 The flow...…”