Cord Blood Thyroid Stimulating Hormone Research Articles

Diagnostic Utility of Cord Thyroid-Stimulating Hormone (TSH) in Congenital Hypothyroidism and Its Association With Perinatal Factors: A Study From a Tertiary Referral Centre in Hyderabad, India.

Introduction Congenital hypothyroidism (CH) is one of the most common, easily treatable, causes of long-term neurodevelopmental complications in children. The prevalence of CH in India is much higher compared to other countries. Although developed countries have well-established neonatal screening programs, a uniform nationwide screening program at birth is still not established in India. Cord blood thyroid-stimulating hormone (TSH) screening is crucial in diagnosing congenital hypothyroidism even with advancements in expanded newborn screening programs. The aim of this study was to determine the prevalenceof elevated cord blood TSH levels and factors associated with it among newborns and to analyze the false positive rates ofelevated cord blood TSH levels among the study population and factors associated with it. Methods This retrospective cross-sectional studywas conducted among 51,251 live newborn babies born at Fernandez Hospital, Hyderabad, India, over a period of five years from January 2019 to December 2023.The data of all the mothers and newborns was retrieved from medical records and details of maternal age, parity, co-morbidities, mode of delivery, gestational age of the newborn at delivery, gender, number of babies, APGAR score, and birth weight were obtained. As per hospital policy, 5 ml of cord blood sampleof all newborn babies was collected from the umbilical cord at the time of birth. Samples were analysed for cord TSH batchwise by the enzyme-linked immunosorbent assay (ELISA) method. As per the manufacturer, the normal biological reference intervals are <20 uIU/mL. All the cord TSH values > 20 uIU/ mL were considered abnormaland advised a repeat serum TSH test within 14 days of life. Cord TSH values that were higher than the biological reference range after retesting were considered positive for CH. All the initial and repeat results were retrieved from the neonatal digital database. Results Out of 51,251 live newborn babies, 71 (0.14%) were confirmed with a diagnosis of congenital hypothyroidism.The prevalenceof CH in our study population was 1.4 per 1000 live births. Anaemia was found to be a statistically significant predictor of true positive cases (p<0.05).In our study, while evaluating risk factors for elevated cord TSH levels, we found that the babies born by vaginal delivery had higher cord TSH levels than babies born by lower segment caesarean section (LSCS) (p<0.001). The other variables considered in the study which include maternal age, BMI, parity of mother, gender of the baby, birth weight, gestation age and APGAR score were not statistically significant for CH. Conclusion The prevalence of congenital hypothyroidism was 1.4 in 1000 in our study. Mode of delivery and maternal anaemia had an impact on elevated cord TSH levels. These factors should be considered while interpreting cord TSH values.Cord TSH testing is an effective screening tool for CH.It helps in the early detection of thyroid dysfunction in newborns, enabling timely intervention and treatment to prevent developmental delays and other complications. This study presents evidence supporting the inclusion of cord blood TSH as a predictive factor in CH screening programs.

CONGENITAL HYPOTHYROIDISM IN NEWBORN AND ASSOCIATION WITH SOCIODEMOGRAPHIC PARAMETERS AMONG NEONATE DELIVERED AT MILITARY HOSPITAL IN A CITY OF CENTRAL INDIA

Objectives: The present study aims to assess the incidence of congenital hypothyroidism (CH) among neonates in a tertiary care hospital in central India, examining its association with various sociodemographic parameters. Methods: This cross-sectional study, conducted between January and December 2022, included all live births at a tertiary care center in Jabalpur, Madhya Pradesh. Cord blood thyroid-stimulating hormone (TSH) levels were measured for all newborns as part of routine screening. Sociodemographic data, including maternal age, gestational age, birth order, and newborn sex, were collected. Universal sampling was employed, encompassing all consenting parents and their neonates. Results: Among 388 live births, TSH values ranged from 0.23 to 35.59 mIU/L, with a mean TSH of 8.76±5.92 mIU/L. Of the neonates, 95.9% had normal TSH levels, while 4.1% exhibited elevated levels. Subsequent follow-up identified CH in two neonates (5.2 per thousand live births). Analysis revealed no significant association between elevated TSH levels and maternal age or newborn sex. However, a significant association was observed with gestational age. Birth order also displayed significance, with the third birth order having a higher proportion of neonates with raised TSH levels. Conclusion: This study highlights the importance of CH screening in preventing long-term complications and the various sociodemographic factors linked to CH, such as maternal age, gestational age, and birth order.

Congenital hypothyroidism screening by umbilical cord blood thyroid stimulating hormone: a cross sectional study

Background: Congenital hypothyroidism is one of the most important and common preventable cause of intellectual disability. The objective of the study is to determine the proportion of congenital hypothyroidism among newborn babies delivered at ESIC-MC and PGIMSR Hospital, Bangalore. Methods: Present study was a cross sectional study conducted in the Department of Paediatrics, ESICMC and PGIMSR over a period of 18 months from march 2021 to august 2022. All babies wherein the cord blood TSH was found to be over 20 mIU/l will be intimated within 24 hrs of the test. The babies were advised to give fresh samples TSH on day 3. Results: In the present study, of the 1900 deliveries, cord blood was available for 1669 newborns. Of the 1669 newborns, 3.1% (N=51) newborns had cord blood TSH more than 20 mIU/l and remaining 96.9%(n=1618) had cord blood TSH levels of less than 20 mIU/l. Out of 51 newborn who were screened positive for congenital hypothyroidism were subjected to futher testing by serum TSH on day 3. Serum TSH on day 3 levels was high (&gt;20 mIU/l) 11.7% (N=6) neonates and serum TSH (&lt;20 mIU/l) 88.2% (N=46) neonates. In this study, the proportion of congenital hypothyroidism was 0.4% (N=6) which was 1 in 278 babies delivered. Conclusions: The present study adds emphasis on the need for continuing screening for congenital hypothyroidisn, one of the preventable cause for intellectual disability. In developing countries, incidence is very high, the need for screening programs is the need of the hour.

A Detailed Analysis of the Various Perinatal Factors Influencing Neonatal TSH: Results from a 6 Months Congenital Hypothyroidism Screening Program.

Abstract Background: The aims of this study are to analyse various perinatal factors influencing neonatal cord blood thyroid stimulating hormone (TSH) level and to find out incidence of congenital hypothyroidism in neonates. Material and Methods: A total of 800 newborns whose mother not having any thyroid medications during her pregnancy period were enrolled for the study. Cord blood samples of the neonates were collected for estimation of TSH level at the Laboratory Services of GMERS Medical College, Junagadh. TSH levels above 20mIU/L were considered as having congenital hypothyroidism. The data were compared with other similar international as well as national studies. Result: In present study, there was no significant difference in cord blood TSH level when compared for various mode of delivery of newborn, as well as according to birth weight and gender of newborn. There was a statistically significant higher mean cord blood TSH level in newborns whose mother had a history of pregnancy induced hypertension (PIH). One newborn was found to have congenital hypothyroidism. Conclusions: It was evident from the present study that newborns whose mother having history of PIH had significantly higher cord blood TSH level. Though incidence of congenital hypothyroidism was rare, routine congenital hypothyroidism screening program was advisable. Keywords: Congenital hypothyroidism, TSH, PIH, Cord blood TSH.

Effect of perinatal factors on cord blood thyroid stimulating hormone levels

Background: Screening for congenital hypothyroidism (CH) is a routine practice in most developed countries of the world. This can be done by measuring cord blood thyroid stimulating hormone (CBTSH). Apart from foetal thyroid status and iodine nutrition status of the population, many perinatal factors may also affect CBTSH. The influence of these perinatal factors may affect the sensitivity of CBTSH as a screening tool for CH. The present study was carried out to study the influence of various perinatal factors on CBTSH level. Methods: It was a cross sectional study conducted in tertiary care centre in North Maharashtra. 793 new-borns were included in study. Effects of perinatal factors like maternal age, parity, gender of the baby, birth weight, mode of delivery, gestational age, birth asphyxia on CBTSH was analysed with appropriate scientific method. Results: The mean TSH level in the study group was 7.56±3.9 mIU/l. Among the associated factors vaginal delivery, low gestational age, low birth weight and birth asphyxia were significantly associated with elevated CBTSH values. Hence, any rise in cord blood TSH should be seen in the light of these factors. Conclusions: Among all the associated factors, primi-parity, vaginal delivery, low gestational age, low birth weight and birth asphyxia were significantly associated with elevated CBTSH values. However, no association was observed between CBTSH values and gender of the baby and maternal age.

Prenatal exposure to perfluorooctane sulfonate alternatives and associations with neonatal thyroid stimulating hormone concentration: A birth cohort study

BackgroundChlorinated polyfluorinated ether sulfonic acids (Cl-PFESA) and perfluorobutane sulfonate (PFBS), used as perfluorooctanesulfonate (PFOS) alternatives, were indicated as thyroid hormone disruptive toxicants in experimental studies. However, it is unclear whether prenatal exposure to Cl-PFESA and PFBS affects neonatal thyroid stimulating hormone (TSH) in human. ObjectiveTo disclose the relationships between prenatal Cl-PFESAs and PFBS exposure and neonatal thyroid-stimulating hormone (TSH) levels based on a perspective cohort study. MethodsA total of 1015 pairs of mother and newborn were included from an ongoing birth cohort study in Wuhan, China, between 2013 and 2014. Six PFASs in cord blood sera and TSH concentration in neonatal postpartum heel sticks blood were quantified. Mixed linear and weighted quantile sum (WQS) regression models were applied to assess the individual and combination effects of PFASs exposure on neonatal TSH levels with multiple covariates adjustments. ResultsAfter adjusting for potential confounders and other five PFASs, for each 1-ng/mL increase of PFBS or 8:2 Cl-PFESA, was negatively associated with 25.90% (95%CI: 37.37%, −12.32%; P < 0.001) and 27.19% (95%CI: 46.15%, −1.55%; P = 0.033) change in TSH in male but not female infants, respectively. No significant association was found between other PFASs exposure and neonatal TSH. Higher PFAS mixture in cord blood was significantly associated with decrease TSH concentration in all newborns (β = −0.36; 95%CI: 0.58, −0.13; P = 0.001) identified by WQS regression model. PFBS, PFOS and 6:2 Cl-PFESA were the major contributors to the neonatal TSH decrement with the weights of 56.50%, 18.71%, 12.81% among PFAS mixture, respectively.Conclusions: our prospective cohort study suggested a negative association of cord serum PFBS and 8:2 CI-PFESA with TSH concentration in newborns, especially for boys. Additional studies are required to elaborate on the underlying biological mechanisms, especially for PFBS.

Reference Interval of Thyroxine and Thyroid Stimulating Hormone in Cord Blood in Tertiary Care Hospital, Kerala

Introduction: Even though Congenital hypothyroidism (CH) is one of the most common causes of preventable mental retardation, diagnosis at birth is difficult due to absent or delayed clinical manifestations, owing to the transplacental transfer of maternal thyroid hormones. Delayed diagnosis and treatment can cause irreversible damage to the developing brain. The occurrence of cognitive dysfunction due to CH has reduced significantly in countries where Newborn Screening (NBS) is routinely practiced. Cord blood screening is considered to be an effective method to diagnose congenital hypothyroidism. Aim: To establish reference interval for thyroxine (T3 and T4) and Thyroid Stimulating Hormone (TSH) in cord blood Medical College, Thrissur. Materials and Methods: In the present cross-sectional observational hospital based study, the cord blood samples from 252 deliveries collected over a period of three months from May 2011 at in Government Medical College, Thrissur, Kerala, India. A 5 mL of cord blood samples were collected in a plain non vacuum tube with clot activator from umbilical cord incised 15-20 cm at the time of birth. T3, T4 and TSH was estimated by Enzyme Linked Immuno-sorbent Assay (ELISA) using kits of ELISA reader and Washer. Normality check done by visual inspection of histogram, Q-Q plot, box plot and Kolmogorov-Smirnov test. Results: In total of 153 cord blood samples considered, and final analysis was done on 151 samples (69 males and 82 females) after excluding the samples of babies delivered by Lower Segment Cesarean Section (LSCS). The gestational age was mean 38.48 weeks and mean age of mothers was 24.22 years. More than 90% of the values for TSH is less than 12 mIU/mL and 90% of T4 values is less than 20 µg/dL. Reference interval determined by non parametric ascending rank order. Reference interval established is 0.63-17.033 mIU/L and 9.45-27.173 for TSH and T4 respectively, lower than those reported from studies in other parts of India. The mean value of TSH was 5.084 mIU/L and 87.5% of babies are having TSH values &lt;10 mIU/L. Conclusion: The study was conducted to establish reference intervals for cord blood TSH, T4 and T3 and confirms to the use of cut off values for the screening of CH for TSH as &gt;20 mIU/L.

Optimizing Cord Blood Thyroid Stimulating Hormone Cutoff for Screening of Congenital Hypothyroidism-Experience from Screening 164,000 Newborns in a Tertiary Hospital in India.

Background and Objectives:In our institution, we have an ongoing newborn thyroid screening (NBS) program since July 2001. In the initial 9 months, we used cord blood thyroid-stimulating hormone (TSH) (CBTSH) cutoff of 20 mIU/L and thereafter the cutoff was increased to 25 mIU/L. Our objective was to evaluate whether a CBTSH cutoff of 25 mIU/L is sensitive and cost-effective in NBS of congenital hypothyroidism (CH).Materials and Methods:All in-born babies are screened and those with CBTSH ≥25 mIU/L are recalled for confirmatory TSH/T4/FT4 tests. CH is confirmed with elevated TSH and low T4/FT4. Those with CBTSH 20–24.99 mIU/L were recalled for confirmatory tests in initial period of our NBS and prospectively between January and August 2017. Statistical analysis was done to derive positive predictive value and sensitivity to diagnose CH for each CBTSH between 20 and 30 mIU/L.Results:A total of 164,163 neonates were screened from July 2001 to August 2017. Of the 2352 babies with CBTSH ≥25–30 mIU/L, 1763 returned for retesting and 5 confirmed as CH (4 gland-in-situ and 1 absent uptake on nuclear scan). Of the 14,742 screened during the study period, 195 of the 293 babies with CBTSH 20–24.99 mIU/L returned for retesting and none diagnosed as CH. A CBTSH of 25 mIU/L has 99.2% sensitivity and 97.5% specificity. A lower screen TSH cutoff 20 mIU/L would result in recall of additional 300 babies/year with no definite improvement in sensitivity.Conclusions:Our data justify the continuation of using screen TSH cutoff of 25 mIU/L while using cord blood for NBS in our population. With a diverse and large population, it is important that we use feasible regional screen cutoffs for optimal use of our resources.

Congenital hypothyroidism screening with umbilical cord blood thyroid-stimulating hormone at birth and peripheral venous blood thyroid-stimulating hormone after 72 h at a hospital in suburban area of Chhattisgarh

Background: Primary congenital hypothyroidism (CH) is the most common cause of hypothyroidism in infancy and early childhood. Neonatal screening programs for the detection of CH in the neonatal period are widespread and in most screening programs, blood samples are collected at 5–6 days age. Objective: The objective of the study was to obtain cord blood (CB) samples at birth and the peripheral venous blood sample of thyroid-stimulating hormone (TSH) at 72 h. Materials and Methods: This cross-sectional observational study was done at a tertiary suburban center and a total of 1470 newborn delivered was enrolled after satisfying the inclusion criteria. Umbilical CB TSH sample was taken at birth and peripheral venous sample for TSH was taken at 72 h. TSH values more than 20 ?IU/mL, in both groups, were taken as an upper limit of normal. Results: Out of 1470 samples collected, among those with umbilical cord sample, 31 (2%) had a value &gt;20 ?IU/mL, while only one baby had a value of TSH &gt;20 ?IU/mL at 72 h of life and was diagnosed as CH. Conclusion: The incidence of CH is 1 out of 1470 neonates. Female gender, maternal age, and lower socioeconomic status of parents have a significant impact on umbilical cord TSH Levels.

Effect of Mode of Delivery on Cord Blood Thyroid Stimulating Hormone Levels- A Cross-sectional Study

Introduction: Cord Blood Thyroid Stimulating Hormone (CBTSH) level estimation is an accepted screening tool for Congenital Hypothyroidism (CH). CBTSH levels are affected by many perinatal factors including mode of delivery. Previous studies have shown conflicting results on effect of mode of delivery of CBTSH levels. Aim: To study CBTSH profile in neonates born at tertiary care referral centre and to analyse the influence of mode of delivery (vaginal vs caesarean) on CBTSH levels. Materials and Methods: This was a cross-sectional study conducted at Mahatma Gandhi Medical College and Hospital from February 2014 to August 2015. Study population included 856 neonates (males=437, females=419). The CBTSH levels were estimated using Electrochemiluminescence Immunoassay ‘ECLIA’ on the Elecsys 2010 analyser. CBTSH levels between vaginally delivered and caesarean section born babies were compared. The values were tabulated as mean and statistically analysed using Statistical Package for the Social Sciences (SPSS) software version 21. Results: Mean CBTSH level of vaginally born neonates were 9.59 (median 7.0) in comparison to 9.11 (median 7.15) in caesarean born babies, this difference was not statistically significant. Conclusion: As per the present study finding mode of delivery did not have any significant effect on CBTSH levels.

Newborn screening for congenital hypothyroidism

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 &gt;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.

Association of Cord Blood Thyroid-Stimulating Hormone Levels with Maternal, Delivery and Infant Factors

This study examined maternal, delivery and infant factors associated with cord thyroid-stimulating hormone (TSH) concentrations in an Asian population. The Growing Up in Singapore Towards healthy Outcomes (GUSTO) study is a mother-offspring birth cohort from 2 major hospitals in Singapore. Cord serum TSH was measured using the Abbott ARCHITECT TSH Chemiluminescent Microparticle Immunoassay and the ADVIA Centaur TSH-3 Immunoassay. After excluding infants with a maternal history of thyroid disease, screening cord TSH results from 604 infants were available for multivariable regression analysis in relation to the factors of interest. Babies born by vaginal delivery had significantly higher cord serum TSH concentrations than babies born by caesarean section. Cord serum TSH concentrations differed significantly by measurement method. There was no association of cord TSH concentrations with ethnicity, sex, birth weight, gestational age, maternal body mass index, gestational weight gain, gestational diabetes mellitus status and other maternal, delivery and infant factors studied. Interpretation of cord serum TSH results may need to take into account mode of delivery and measurement method.

Association of urinary bisphenols during pregnancy with maternal, cord blood and childhood thyroid function

BackgroundMost pregnant women are exposed to bisphenols, a group of chemicals that can interfere with various components of the thyroid system. ObjectivesTo investigate the association of maternal urinary bisphenol concentrations during pregnancy with maternal, newborn and early childhood thyroid function. MethodsThis study was embedded in Generation R, a prospective, population-based birth cohort (Rotterdam, the Netherlands). Maternal urine samples were analyzed for eight bisphenols at early (<18), mid (18–25) and late (>25 weeks) pregnancy. Maternal serum thyroid stimulating hormone (TSH), free thyroxine (FT4) and total thyroxine (TT4) were measured in early pregnancy and child TSH and FT4 were measured in cord blood and childhood. ResultsThe final study population comprised 1,267 mothers, 853 newborns and 882 children. Of the eight bisphenols measured, only bisphenol A (BPA) was detected in >50% of samples at all three time-points and bisphenol S (BPS) at the first time-point. There was no association of BPA or the bisphenol molar sum with maternal thyroid function. Higher BPS concentrations were associated with a higher maternal TT4 (β [95% CI] per 1 (natural-log) unit increase: 0.97 [0.03 to 1.91]) but there was no association with TSH or FT4. Furthermore, higher BPS was associated with an attenuation of the association between maternal FT4 and TSH (Pinteraction = 0.001). There was no association of early or mid-pregnancy BPA or early pregnancy BPS with cord blood or childhood TSH and FT4. A higher late pregnancy maternal BPA exposure was associated with a higher TSH in female newborns (Pinteraction = 0.06) and a higher FT4 during childhood in males (Pinteraction = 0.08). DiscussionOur findings show that exposure to bisphenols may interfere with the thyroid system during pregnancy. Furthermore, the potential developmental toxicity of exposure to bisphenols during pregnancy could affect the thyroid system in the offspring in a sex-specific manner.

Primary Thyroid Stimulating Hormone Screening for Congenital Hypothyroidism in King Abdullah Hospital, Bisha, Saudi Arabia.

BackgroundThyroid stimulating hormone (TSH) concentration in cord blood measured at birth has been proposed as an indicator of congenital hypothyroidism (CH). Elevated TSH levels at birth were associated with cognitive and psychomotor disorders among young children.ObjectivesThe purpose of this study is to investigate the epidemiology of CH using cord blood TSH screening among 2501 newborn infants in the period from January to November 2016 in Bisha Province, Saudi Arabia.MethodologyThis cross-sectional, hospital-based study was conducted at King Abdullah Hospital, Bisha, which is a secondary care referral district general hospital with 400 beds. All neonates born in the designed period were included and screened according to the standard CH screening protocol. Data was collected from all neonates born in the designed period. The screening was performed according to the standard CH screening protocol. After birth, cord blood specimens were used. TSH was measured by Perkin Elmer ELISA machine. The data were analyzed using the Statistical Package for the Social Sciences (SPSS) version 24.0 (IBM Corp., Armonk, NY). A p-value of less than or equal to 0.05 was considered significant.Main resultsA total of 1308 (52.3%) neonates were males, while 1193 (47.7%) were females. Serum TSH levels were ranged from 0.01-73.9 µU/ml. The mean ± SD was (7.60 ± 6.02 µU/ml); the cutoff point was 25 µU/ml.ConclusionThe prevalence of congenital hypothyroidism among Saudi neonates in Bisha Province is 1:834, which is the highest in the rejoin. The prevalence of hypothyroidism from the total screened population was (0.12%). We recommended screening with special consideration to those with high TSH in the primary screening.

Unfolding the perinatal factors that affect cord blood thyroid stimulating hormone levels- an experience from a rural centre in southern India

Objective: To evaluate the incidence of congenital hypothyroidism using cord blood thyroid stimulating hormone (CB-TSH) levels and examining the influence of maternal and perinatal factors on these levels in our cohort of babies. Design: A cross-sectional study. Setting: Tertiary care teaching hospital, China Kakani, A.P. Methods: CB-TSH levels were measured in 2012 live-born neonates using electro chemiluminescence immunoassay. The effect of various maternal and perinatal factors on CB-TSH levels was analyzed statistically by multivariate analysis. Results: The mean CB-TSH was 8.86 micro IU/ml (ranged between 0.23 to 100micro IU/ml). The incidence of high CB-TSH (>20microIU/ml) was 4.82%. CB-TSH levels were significantly raised in neonates delivered in 1st and 2nd birth order, assisted vaginal deliveries, need for emergency section, and who were born with low APGAR scores (p

Maternal and neonatal iodine status in Dakshina Kannada district of Karnataka, India.

This study was designed to assess iodine status of mother-fetus dyad by estimation of spot urine iodine concentration (UIC) in the study district. It is a cross-sectional study of 250 pregnant women with euthyroid status and their term neonates residing in Dakshina Kannada district. Neonates with foetal growth restriction or requiring intensive care were excluded. Median UIC was quantified using modified Sandell-Kolthoff reaction by microplate method. World Health Organization (WHO) classification was used to categorise the iodine status of pregnant women. Among 250 pregnant women, the majority were primigravida (38%). Median maternal thyroid stimulating hormone (TSH) was 1.54 mIU/l, and median UIC was 352 mcg/l. Urine iodine levels were insufficient (<150 mcg/l) in 1.2% (n = 3), adequate (150-249 mcg/l) in 9.2% (n = 23) and above requirement (250-499 mcg/l) in 89.6% (n = 224); none had excess (> 500 mcg/l). Median birth weight was 3,000 g and head circumference was 34 cm. Median cord blood TSH was 8.1 mIU/l, and median UIC 344.5 mcg/l. All the newborns had adequate (> 100 mcg/l) iodine status, including those born to mothers with insufficient values. Maternal and newborn median UIC showed positive correlation (r = 0.139; p = 0.028). Iodine statuses were above requirement or adequate in pregnant women from the study district and their neonates, respectively, indicating successful salt iodisation.

Organophosphate pesticides exposure in pregnant women and maternal and cord blood thyroid hormone concentrations

BackgroundAnimal studies suggest that organophosphate (OP) pesticides exposure affects thyroid function, but evidence in humans remains sparse and inconclusive. Gestational exposure is of particular interest, since thyroid hormone is essential for fetal brain development. OP pesticides are able to cross the placental and blood-brain barrier and may interfere with fetal development processes regulated by thyroid hormone. ObjectiveTo investigate the association of gestational OP pesticides exposure during pregnancy with maternal and cord blood thyroid hormone concentrations. MethodsThis study was embedded within Generation R (Rotterdam, the Netherlands), a prospective population-based birth cohort. Mother-child pairs with OP pesticides assessment and maternal (N = 715) or cord blood (N = 482) thyroid hormone measurements were included. OP pesticides exposure was assessed at <18, 18–25, and >25 weeks gestation by measuring six urinary dialkylphosphate (DAP) metabolites. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) were measured in maternal and cord blood. Maternal measures also included total thyroxine (TT4) and TPO antibodies (TPOAbs). To study the association of creatinine-adjusted DAP metabolite concentrations with thyroid function and TPO antibodies, multivariable linear regression models including relevant confounders were used. ResultsThere was no association of DAP metabolites with maternal TSH, FT4, TT4 or TPOAb concentrations during pregnancy. Similarly, there was no association of DAP metabolites with cord blood TSH or FT4. Results did not change when DAP concentrations were analyzed at individual time points or as mean gestational exposure. ConclusionGestational OP pesticides exposure, as assessed by repeatedly measured urinary DAP metabolite concentrations in an urban population, was not associated with maternal or cord blood thyroid hormone concentrations. These findings do not support a mediating role for serum thyroid hormone availability in the relation of early life exposure to low levels of OP pesticides with child neurodevelopment. However, disruption of the thyroid system at tissue level cannot be excluded. In addition, this is one of the first studies on this subject and measurement error in DAP metabolites might have resulted in imprecise estimates. Future studies should use more urine samples to increase precision and should investigate specific OP pesticide metabolites.

Hypothyroidism in pregnancy: Prevalence, associated factors and biochemical monitoring

Animal studies suggest that organophosphate (OP) pesticides exposure affects thyroid function, but evidence in humans remains sparse and inconclusive. Gestational exposure is of particular interest, since thyroid hormone is essential for fetal brain development. OP pesticides are able to cross the placental and blood-brain barrier and may interfere with fetal development processes regulated by thyroid hormone.To investigate the association of gestational OP pesticides exposure during pregnancy with maternal and cord blood thyroid hormone concentrations.This study was embedded within Generation R (Rotterdam, the Netherlands), a prospective population-based birth cohort. Mother-child pairs with OP pesticides assessment and maternal (N = 715) or cord blood (N = 482) thyroid hormone measurements were included. OP pesticides exposure was assessed at <18, 18–25, and >25 weeks gestation by measuring six urinary dialkylphosphate (DAP) metabolites. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) were measured in maternal and cord blood. Maternal measures also included total thyroxine (TT4) and TPO antibodies (TPOAbs). To study the association of creatinine-adjusted DAP metabolite concentrations with thyroid function and TPO antibodies, multivariable linear regression models including relevant confounders were used.There was no association of DAP metabolites with maternal TSH, FT4, TT4 or TPOAb concentrations during pregnancy. Similarly, there was no association of DAP metabolites with cord blood TSH or FT4. Results did not change when DAP concentrations were analyzed at individual time points or as mean gestational exposure.Gestational OP pesticides exposure, as assessed by repeatedly measured urinary DAP metabolite concentrations in an urban population, was not associated with maternal or cord blood thyroid hormone concentrations. These findings do not support a mediating role for serum thyroid hormone availability in the relation of early life exposure to low levels of OP pesticides with child neurodevelopment. However, disruption of the thyroid system at tissue level cannot be excluded. In addition, this is one of the first studies on this subject and measurement error in DAP metabolites might have resulted in imprecise estimates. Future studies should use more urine samples to increase precision and should investigate specific OP pesticide metabolites.

Evaluation of thyroid function in a sample of newborns through different modes of delivery

Background and objective: Congenital hypothyroidism is the most common preventable cause of mental retardation detected during early childhood. Its early diagnosis is crucial for a better outcome. Many factors are contributed to this problem including maternal, fetal and others. This study aimed to assess thyroid hormone status in relation to certain obstetrical especially mode of delivery and neonatal factors Methods: A descriptive cross-sectional study conducted in postnatal care and delivery room (operative and vaginal) of Maternity teaching hospital in Erbil city. Ninety-two babies were included and subdivided into three groups according to their route of delivery. A thyroid stimulating hormone cut off value of 10 was selected as the upper normal level for the purpose of the study. Results: A significant proportion of babies with cord thyroid stimulating hormone concentration more than 10 mIU/L (25 out of 92) were noticed, and this is near to many previous studies used the same cut off value. Mean of This hormone is relatively increased among newborns of the elective cesarean section while maternal total triiodothyronine and total thyroxine were higher within the elective group. Prenatal evidence of placental calcification and first born babies were associated with higher thyroid stimulating hormone levels. Conclusion: Emergency cesarean section is less likely to be associated with elevated cord blood thyroid stimulating hormone level compared to other routes of delivery/but this is not confirmatory and recall test is recommended to exclude hypothyroidism.

Cord blood thyroid-stimulating hormone as a screening tool for congenital hypothyroidism: A single-center 5-year experience

Cord blood thyroid-stimulating hormone as a screening tool for congenital hypothyroidism: A single-center 5-year experience