|Ahead of print publication
Newborn screening for congenital hypothyroidism: A local perspective from Himachal Pradesh, India
Vinay Gupta, Ashwani Sood, Mangla Sood
Department of Pediatrics, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
|Date of Submission||03-Dec-2020|
|Date of Acceptance||10-Dec-2020|
|Date of Web Publication||19-Apr-2021|
Department of Pediatrics, Indira Gandhi Medical College, Shimla - 171 001, Himachal Pradesh
Source of Support: None, Conflict of Interest: None
Background: Incidence of congenital hypothyroidism (CH) varies across countries and different geographic regions.
Aims and Objectives: This study was conducted to find prevalence of CH in iodine-deficient district of North Indian hilly state Himachal Pradesh, India.
Materiala and Methods: A prospective analysis of cord blood thyroid-stimulating hormone (TSH) and T4 hormone values on 4057 neonates was done in the delivery hospital.
Results: No CH was detected among 3964 neonates; with limitation of losing 93 newborns with high cord blood TSH >20 uIU/l who could not be recalled for serum testing.
Conclusion: With known benefits of CH screening, a properly implemented neonatal screening program for CH at all levels of health care is definitely the need of the hour.
Keywords: Congenital hypothyroidism, infant, newborn, thyrotropin
|How to cite this URL:|
Gupta V, Sood A, Sood M. Newborn screening for congenital hypothyroidism: A local perspective from Himachal Pradesh, India. Thyroid Res Pract [Epub ahead of print] [cited 2021 Jun 22]. Available from: https://www.thetrp.net/preprintarticle.asp?id=314048
Newborn screening (NBS) for congenital hypothyroidism (CH) performed worldwide since the 1970s is one of the significant achievements in preventive medicine integrated into the health system of many countries around the world. Unfortunately, it has not been implemented nationwide in India due to lack of available facilities, lack of awareness among treating physicians, cost, and early discharge of neonates due to overburden in the government setups. In 2013, the Ministry of Health and Family Welfare launched child health screening and early intervention services in India as Rashtriya Bal Swasthya Karyakram (RBSK) program which calls for screening of all children from birth to 18 years of age for congenital disorders and developmental delays and specifically listed CH, sickle cell disease, congenital hearing loss, and heart disease as targeted birth defects.
| Introduction|| |
Iodine deficiency is an endemic health problem in Himachal Pradesh (HP) and leads to neonatal hypothyroidism (NH) with associated problems including mental retardation if present during pregnancy. A study conducted in Kangra district of HP on 613 umbilical cord blood samples of neonates and analyzed for thyroid-stimulating hormone (TSH) estimated by enzyme-linked immunosorbent assay method, found the prevalence of NH to be 4.4%. This finding suggested the need for the implementation of a neonatal screening program within state. Following instruction from the National Health Mission, HP to conduct NBS for CH as pilot to provide scientific evidence and identify issues for statewide implementation of NBS screening, this study was planned. 4057 live borns delivered in the Indira Gandhi Medical College Shimla from November 1, 2018 to October 31, 2019, were sampled in this prospective observational study after approval from institutional protocol review and ethics committee with consent from either parent. Participants demographics are summarized in [Table 1].
Three milliliter of cord blood was collected from placental site immediately after birth in a plain vacutainer and stored in refrigerator at 4°C, till transportation to the local biochemistry laboratory for analysis of TSH and T4 levels using electrochemiluminescence method on Access 2 Immunoassay System make Beckman Coulter machine. Cord blood TSH provides a suitable first-line diagnosis of CH, especially when a 72-h screen cannot be ensured, is logistically easier to collect, and has better parental acceptance than heel-prick samples. Results were calculated automatically by the instrument in relation to the calibration curve stored in memory (4-parameter logistic model). Newborns with cord blood TSH >20 uIU/l were recalled and further investigated with serum TSH and serum FT4 levels on venous sample after 72 h of age. Low birth weight, preterm, and sick neonates admitted to newborn unit were retested prior to discharge in order not to miss the delayed rise of TSH. The data obtained was analyzed with the help of Epi info software.
Among 3716 neonates with normal cord blood values, the mean TSH was 10.03 ± 7.35 uIU/l, cord blood T4 level was 0.74 ± 0.16 ng/dl (mean ± standard deviation). There were 341 (8.4%) newborns with cord blood TSH levels >20 uIU/l, i.e., who were screen positive. When recalled for repeat serum TSH and serum FT4 estimation after 72 h of birth, only 248/341 (72.7%) could be retested, with mean TSH level reported 5.24 ± 3.26 uIU/l and mean FT4 level was 1.25 ± 1.21 ng/dl. No neonate was detected with CH after repeat testing [Table 2]. Ninety-three (27.3%) screen positive neonates were lost to follow up and could not be retested. These included migrants who had left the place (n = 45), wrong contact number (n = 43), and population residing in far interior areas who refused repeat testing (n = 13). Because this was not a follow-up study, so outcome among neonates with increase cord blood TSH level who could not be retested is not known.
| Results|| |
|Table 2: Mean thyroid-stimulating hormone value at screening of neonatal hypothyroidism|
Click here to view
NBS and early treatment of infants with CH have largely eliminated intellectual disabilities such as mental retardation worldwide. The national program Janani Suraksha Yojna has very effectively moved deliveries from home to the institutions. RBSK program has included CH screening as one of the targets in the categories of deficiencies. Thus, we are likely to encounter more newborns with metabolic birth defects. Indian Council of Medical Research National Task Force Team on New Born Screening at AIIMS, New Delhi (2007–2012) results revealed incidence of CH all over India of 1 in 1172 live births. However, we could not find a single congenital hypothyroid among 3964 neonates.
| Discussion|| |
The study strength includes large sample size, representations of both urban as well as a rural cohort, and the use of both cord blood TSH and T4 values for NBS CH screening. As all preterm and low birth weight live neonates were also included, it is likely to be a true representation of the hilly state data considering the location of birthing facility with huge catering population. Majority of screen positive neonates with TSH values of >20 mIU/ml were recalled for serum TSH and FT4. Major limitation is lost to follow-up of 27.3% neonates with high TSH.
Early discharges within 24 h of age are happening in overburdened birth facilities to prevent infection as a sequelae of overcrowding. Hence, provision for heel-prick sampling 2–3 days after birth though more accurate is not applicable in most institutions. Large cohort studies are required to find the specificity and sensitivity of different TSH screening cut off points for local population to find the best cut off to decrease the recall rate. Recognized socio-cultural taboos, including the at-home births, early infant discharge, and lack of parental education about NBS are barriers to implementing a sustainable screening program. Despite not finding a high reported prevalence of CH in our study sample, with its known benefits, a properly implemented neonatal screening program for CH at all levels of health care is definitely the need of the hour. We recommend provision for online NBS data collection to ensure accountability of hospitals, peripheral health care providers, and parents. In government setup, it is important to counsel parents repeatedly, have adequate IEC, and ensure follow-up of all neonates with appropriate and adequate therapy so as not to miss CH.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Kapil U, Jain V, Kabra M, Pandey RM, Sareen N, Khenduja P. Prevalence of neonatal hypothyroidism in Kangra Valley, Himachal Pradesh. Eur J Clin Nutr 2014;68:748-9.
Anand MR, Ramesh P, Nath D. Congenital Hypothyroidism Screening with Umbilical Cord Blood: Retrospective Analysis. Indian Pediatr. 2015 May;52(5):435-6. doi: 10.1007/s13312-015-0652-8.
ICMR Task Force on Inherited Metabolic Disorders. Newborn screening for congenital hypothyroidism and congenital adrenal hyperplasia, Indian J Pediatr 2018;85:935-40.
[Table 1], [Table 2]