title: Effect of perinatal factors on cord blood thyroid stimulating hormone levels.
abstract: OBJECTIVE
  To study the influence of perinatal factors on cord blood (CB) TSH levels.
  
  
  METHODS
  In a prospective cross-sectional study, CB TSH levels were measured in 1,590 live-born infants using IRMA. The effect of various perinatal factors on the CB TSH levels was analyzed statistically.
  
  
  RESULTS
  The mean TSH level in the study group was 10.6 +/- 6.7 microU/ml (range 0.01-66.4 microU/ml). A significant fall in CB TSH levels was noted with increasing gestational age. A similar decline was noted in TSH levels with increase in birth weight. No significant difference in TSH levels was noted between males and females, or AGA and SGA (n = 296) infants. Infants with birth asphyxia (Apgar score < 4 at 5 min) had significantly higher CB TSH levels (mean 31 microU/ml, n = 18) as compared to those without (mean 10.4 microU/ml) (p < 0.01). The highest TSH levels were noted in neonates delivered by forceps extraction (mean 29.4 microU/ml, n = 17) and lowest levels in infants born by elective Caesarian section (mean 8.7 microU/ml, n = 149).
  
  
  CONCLUSIONS
  CB TSH levels fall with increase in gestational age while birth asphyxia and difficult deliveries tend to elevate them.
authors.affiliation: Department of Pediatrics, Lady Hardinge Medical College, Timarpur, India.
authors.lastname: Rashmi
authors.forename: Anju
authors.initials: A
authors.lastname: Seth
authors.forename: Tarun
authors.initials: T
authors.lastname: Sekhri
authors.forename: Abha
authors.initials: A
authors.lastname: Agarwal
mesh_terms: D001034:Apgar Score; D001238:Asphyxia Neonatorum / Q000097:blood / Q000150:complications; D001724:Birth Weight; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric; D005260:Female; D005312:Fetal Blood / Q000737:chemistry* / Q000378:metabolism; D005865:Gestational Age; D006801:Humans; D007037:Hypothyroidism / Q000175:diagnosis; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D013972:Thyrotropin / Q000097:blood* / Q000378:metabolism
chemical_list: D013972:Thyrotropin