congenital hypothyroidism: a review of the risk factors

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