Congenital Hypothyroidism: A Review of the Risk Factors

  • Setila Dalili Mail Guilan Health Center, Guilan University of Medical Sciences, Guilan, Iran.
  • Seyed Mahmood Rezvany Guilan Health Center, Guilan University of Medical Sciences, Guilan, Iran.
  • Arsalan Dadashi Guilan Health Center, Guilan University of Medical Sciences, Guilan, Iran.
  • Abdolreza Medghalchi Guilan Health Center, Guilan University of Medical Sciences, Guilan, Iran.
  • Hamid Mohammadi Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Iran.
  • Hosein Dalili Department of Pediatrics, Breastfeeding Research Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran.
  • Mostafa Mirzanejad Guilan Health Center, Guilan University of Medical Sciences, Guilan, Iran.
  • Hajar Gholamnezhad Guilan Health Center, Guilan University of Medical Sciences, Guilan, Iran.
  • Anis Amirhakimi Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Iran.
Keywords:
Congenital hypothyroidism, Low birth weight, Macrosomia, Postdate delivery

Abstract

This study was aimed to evaluate the situation of congenital hypothyroidism (CH) in Guilan using the screening program and determine the correlation of CH with birth weight, gestational age and seasonality. During 2006 to 2010, in Guilan province, neonatal screening for CH by measurement of serum TSH level was performed in 3-5 days after birth. All neonates with TSH level ≥ 5mu/l were referred to endocrinologists and serum TSH, T3 and T4 were measured. Based on public health data and profiles, total number of newborns, gestational age, route of delivery, birth season and birth weight in all screened neonates was reviewed and for ones with CH, their TSH measurements was also recorded. During 5 years, 119701 neonates were screened and CH was confirmed in 10.8% (221) of the referral cases (prevalence=1:542). No significant statistical difference was seen between gender and birth season among patients with CH and the rest of the population. Interestingly, low birth weight (LBW) (31% vs. 4.9%, P<0.01), postdate delivery (1.4% vs. 0.2%, P<0.01) and macrosomia were more prevalent in CH versus normal population (Odds ratio for post-date delivery was 6.9 and for LBW was 3.2). Rate of normal vaginal delivery (NVD) was significantly higher in neonates with CH compared to normal population (39.2% vs. 29.2%, P=0.01). LBW, postdate delivery and macrosomia are risk factors for CH. No association between sex, birth season or caesarian section delivery was seen.

References

Alm J, Hagenfeldt L, Larsson A, Lundberg K. Incidence of congenital hypothyroidism: retrospective study of neonatal laboratory screening versus clinical symptoms as indicators leading to diagnosis. Br Med J (Clin Res Ed),1984; 89(6453):1171-5.

Alm J, Larsson A, Zetterström R. Congenital hypothyroidism in Sweden: Incidence and age at diagnosis. Acta Paediatr Scand 1978; 67(1):1-3.

Wiebel J. [Hypothyroidism in newborn infants and children]. Med Monatsschr 1977; 31(7):295-300.

Olney RS, Grosse SD, Vogt RF. Prevalence of congenital hypothyroidism--current trends and future directions: workshop summary. Pediatrics 2010; 125 Suppl 2:S31-6.

Brown AL, Fernhoff PM, Milner J, McEwen C, Elsas LS. Racial differences in the incidence of congenital hypothyroidism. J Pediatr 1981; 99(6):934-6.

Hashemipour M, Hovsepian S, Kelishadi R, Iranpour R, Hadian R, Haghighi S, Gharapetian A, Talaei M, Amini M. Permanent and transient congenital hypothyroidism in Isfahan-Iran. J Med Screen 2009; 16(1):11-6.

Karamizadeh Z, Dalili S, Sanei-far H, Karamifard H, Mohammadi H, Amirhakimi G. Does Congenital Hypothyroidism Have Different Etiologies in Iran? Iran J Pediatr 2011; 21(2):188-92.

Yarahmadi SH, Ali Mohammadzadeh KH, Tabibi SJ, Maleki MR. Presenting Mathematics Model of Cost- Benefit Calculation of Screening for Congenital Hypothyroidism in Iran. Int Math Forum 2011; 6(13-16):681-97.

Mao HQ, Yang RL, Liu ZH. [Correlation of congenital hypothyroidism with birth weight and gestational age in newborn infants]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2007; 36(4):378-81.

American Academy of Pediatrics, Rose SR; Section on Endocrinology and Committee on Genetics, American Thyroid Association, Brown RS; Public Health Committee, Lawson Wilkins Pediatric Endocrine Society, Foley T, Kaplowitz PB, Kaye CI, Sundararajan S, VarmaSK. Update of newborn screening and therapy for congenital hypothyroidism. Pediatrics 2006; 117(6):2290-303.

Azizi F, Sheikholeslam R, Hedayati M, Mirmiran P, Malekafzali H, Kimiagar M, Pajouhi M. Sustainable control of iodinedeficiency in Iran: beneficial results of the implementation of the mandatory law on salt iodization. J Endocrinol Invest 2002; 25(5):409-13.

Fagela-Domingo C, Padilla CD. Newborn screening for congenital hypothyroidism in early discharged infants. Southeast Asian J Trop Med Public Health 2003; 34 Suppl 3:165-9.

Mikelsaar RV, Zordania R, Viikmaa M, Kudrjavtseva G. Neonatal screening for congenital hypothyroidism in Estonia. J Med Screen 1998; 5(1):20-1.

Silva SA, Chagas AJ, Goulart EM, Silva GA, Marçal LV, Gomes MN, Alves VM. Screening for congenital hypothyroidism in extreme premature and/or very low birth weight newborns: the importance of a specific protocol. J Pediatr Endocrinol Metab 2010; 23(1-2):45-52.

Bijarnia S, Wilcken B, Wiley VC. Newborn screening for congenital hypothyroidism in very-low-birth-weight babies: the need for a second test. J Inherit Metab Dis 2011; 34(3):827-33.

Waller DK, Anderson JL, Lorey F, Cunningham GC. Risk factors for congenital hypothyroidism: an investigation of infant's birth weight, ethnicity, and gender in California, 1990-1998. Teratology 2000; 62(1):36-41.

Hinton CF, Harris KB, Borgfeld L, Drummond-Borg M, Eaton R, Lorey F, Therrell BL, Wallace J, Pass KA. Trends in incidence rates of congenital hypothyroidism related to select demographic factors: data from the United States, California, Massachusetts, New York, and Texas. Pediatrics 2010; 125 Suppl 2:S37-47.

How to Cite
1.
Dalili S, Rezvany SM, Dadashi A, Medghalchi A, Mohammadi H, Dalili H, Mirzanejad M, Gholamnezhad H, Amirhakimi A. Congenital Hypothyroidism: A Review of the Risk Factors. Acta Med Iran. 50(11):735-739.
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