Maternal Subclinical Hypothyroidism Research Articles

Impact of levothyroxine therapy for maternal subclinical hypothyroidism on infant’s neurodevelopment

Impact of levothyroxine therapy for maternal subclinical hypothyroidism on infant’s neurodevelopment

The Benefit of Levothyroxine Replacement in Maternal Subclinical and Overt Hypothyroidism on Early Child Neurodevelopment

The Benefit of Levothyroxine Replacement in Maternal Subclinical and Overt Hypothyroidism on Early Child Neurodevelopment

Impact of levothyroxine therapy for maternal subclinical and overt hypothyroidism on early child neurodevelopment: A prospective cohort study.

Treatment indication of maternal subclinical hypothyroidism (SCH) is undetermined, despite the wide administration of levothyroxine for maternal overt hypothyroidism (OH). This study aimed to evaluate the therapeutic effect of levothyroxine for maternal SCH and OH in real-world practice, with a focus on early child neurodevelopment. Prospective cohort study. Pregnant women diagnosed with SCH at the first antenatal visit were enroled and compared to those diagnosed with OH. Thyroid follow-ups were conducted during pregnancy. Early child neurodevelopment was assessed using the Gesell Development Diagnosis Scale (GDDS) at 1, 3, 6, 12and 24 months of age. From January 2012 to December 2013, a total of 442 pregnant women were included in final analysis, among whom 194 and 248 were assigned to the SCH and OH groups, respectively. The percentage of levothyroxine therapy at the first antenatal visit was significantly lower in the SCH group than that in the OH group (91.24% vs. 97.58%, p < .01), with a similar treatment rate at delivery (99.4% vs. 100%, p > .05). Notably, GDDS scores were lower in the SCH group than those in the OH group at 6 months to 2 years of age, which was confirmed by subgroup analyses and sensitivity analyses. Children born with maternal SCH demonstrated slightly lower neuropsychological scores at 6 months to 2 years of age compared to those with maternal OH in the clinical practice. The therapeutic effect of maternal SCH on the child neurodevelopment requires further exploration.

Expressions of mitochondria-related genes in pregnant women with subclinical hypothyroidism, and expressions of miRNAs in maternal and cord blood

BackgroundSubclinical hypothyroidism in pregnancy and definition by upper thyrotropin (TSH) cutoff are controversial. As mitochondria are influenced by thyroid hormones, the purpose in this study was to measure expression of mitochondria-related genes in euthyroid and subclinical hypothyroid pregnant women to obtain more knowledge of potential metabolic consequences of maternal subclinical hypothyroidism. In addition, we wished to test if applied TSH-cutoff significantly changed our results of expressed gene-levels. Moreover, we aimed to identify potential microRNA-biomarkers for subclinical hypothyroidism – markers that could be traced to offspring as well.MethodsFrom a cohort of at-term pregnant women undergoing planned cesarean section, 77 women had expression levels of the mitochondria-related genes Peroxisome Proliferator-activated Receptor-γ coactivator-1β (PGC-1β), mitochondrial Transcription Factor A (TFAM), Superoxide Dismutase 2 (SOD2) and Nuclear Respiratory Factor 2 (NRF-2) determined by qPCR from blood sampled in prior to delivery. Two TSH-cutoff levels defining subclinical hypothyroidism (> 3.0 and > 3.7 mIU/L) were applied for the procession of results, generating two data analyses of the same cohort. In 22 pairwise maternal-cord samples (subclinical hypothyroid/euthyroid-rate 0.5, TSH-cutoff > 3.0 mIU/L), microRNA-expressions (miRNA) were analyzed.ResultsAll gene expressions were lower in the subclinical hypothyroid group regardless of applied TSH-cutoff, but insignificant except for PGC-1β at TSH cutoff > 3.0 mIU/L. Two miRNAs (hsa-let-7d-3p and hsa-miR-345-5p) were upregulated in blood from women and offspring (cord blood) with subclinical hypothyroidism.ConclusionsA trend towards decreased mitochondrial gene expressions in subclinical hypothyroidism were demonstrated. The miRNAs hsa-let-7d-3p and hsa-miR-345-5p might be potential markers of maternal subclinical hypothyroidism. However, larger studies are needed to verify the findings.

Association between levothyroxine treatment for maternal subclinical hypothyroidism with negative TPOAb and early child neurodevelopment: A prospective real-world clinical trial.

Subclinical hypothyroidism (SCH) during pregnancy is reported to have detrimental impact on pregnancy and child development. However, its treatment indications require further investigation in different thyroid peroxidase antibody (TPOAb) status. This was a secondary analysis of a Chinese prospective cohort in a real-world setting. Pregnant women with gestational SCH were enrolled at the first antenatal visit and grouped by TPOAb positivity. Child neurodevelopment was assessed by the Gesell development diagnosis scale (GDDS) at one, three, six, 12, and 24 months of age. Subgroup analyses and sensitivity analyses were also conducted. ClinicalTrials.gov NCT01744743. From January 2012 to December 2013, a total of 171 participants were enrolled, including 116 of SCH with TPOAb negative (SCH-TPOAb [-]) and 55 of SCH with TPOAb positive (SCH-TPOAb [+]). Compared to women in the SCH-TPOAb (+) group, those in the SCH-TPOAb (-) group had lower thyroid-stimulating hormone (TSH) levels at enrollment and 12-16+6 gestational weeks, and unexpectedly higher TSH levels at 30-34+6 gestational weeks and delivery, with a correspondingly lower levothyroxine dosage throughout pregnancy (all p < 0.05). Offspring in the SCH-TPOAb (-) group displayed lower GDDS scores at one year old than did their counterparts (adjusted p < 0.05), which was possibly related to the worse thyroid function control of maternal SCH-TPOAb (-). No statistically significant difference was found in the GDDS assessments of children at one, three, six, and 24 months of age. These results were also confirmed in subgroup analyses stratified by maternal thyroid characteristics at enrollment, namely TSH levels, free levothyroxine (T4 ) levels, and anti-thyroglobulin antibody (TgAb) status, as well as in sensitivity analyses excluding participants with no levothyroxine treatment at enrollment. In the current clinical practice, infants born to mothers with SCH-TPOAb (-) displayed slightly lower neurodevelopmental scores at one year old than did those born to mothers with SCH-TPOAb (+) but this difference was not seen at two years.

The risk of developing gestational diabetes mellitus in maternal subclinical hypothyroidism: a systematic review and meta-analysis.

The purpose of this study was to determine the association between maternal subclinical hypothyroidism (SCH) and gestational diabetes mellitus (GDM) risk. This study is a systematic review and meta-analysis. Following PubMed, Medline, Scopus, Web of Science, and Google Scholar database search up to April 1 2021, a total of 4597 studies were identified. Studies published in English, with full text available, related to subclinical hypothyroidism in pregnancy, reporting or mentioning the incidence of GDM were included in the analysis. Following exclusion of studies, a total of 16 clinical trial were analyzed. For the risk of GDM, odds ratios (ORs) were calculated. Subgroup analyzes were performed according to gestational age and thyroid antibodies. Pregnant women with SCH were at increased risk of GDM compared to women with euthyroidism, overall (OR = 1.339, 95% CI 1.041-1.724; p = 0.023). Additionally, SCH without thyroid antibodies has no significant effect on GDM risk (OR = 1.173, 95% CI 0.88-1.56; p = 0.277) and pregnant women with SCH in the first trimester were not found to be at increased risk of GDM compared to women with euthyroidism regardless of thyroid antibodies (OR = 1.088, 95%CI 0.816-1.451; p = 0.564). Maternal SCH in pregnancy is related to an increased risk of GDM.

Maternal Subclinical and Clinical Hypothyroidism Effects on Rat Offspring: A Story of the Skin and its Derivatives

Abstract Epidermis stem cells have a crucial role through the processes of proliferation and differentiation, to replace cells that are constantly lost during tissue turnover or following injury. On the other hand, thyroid hormones regulate the proliferation and differentiation of epidermal cells and thus significantly influence the homeostasis of the skin. It is well known that maternal hypothyroidism during pregnancy leads to impaired development of many organ systems in their offspring. However, there is a lack of data about the influence of maternal subclinical hypothyroidism during pregnancy and lactation on the development of the skin and its derivatives in the litter. The aim of this study was to investigate the effects of maternal thyroid dysfunction on the development of the skin and its derivatives in their offspring in the early postnatal period. Antithyroid substance 6-n-propyl-2-thiouracil was added into the drinking water to female Albino Oxfords rats from the beginning of pregnancy and during lactation, with the aim to induce subclinical and overt form of hypothyroidism. Skin samples were taken from male pups within twenty-four hours and seven days after birth. The main findings of this investigation were that both forms of maternal hypothyroidism lead to serious damage of the epidermis in pups in terms of pronounced hyperkeratosis and reduction of the germinal layer along with a reduced number of hair follicles and their delayed morphogenesis. Epidermal impairments were more pronounced in pups with the overt form of hypothyroidism while offspring with the subclinical form had impairments that were less pronounced and delayed in occurrence.

Exploring the Impact of Maternal Subclinical Hypothyroidism on First-trimester Screening Results

Exploring the Impact of Maternal Subclinical Hypothyroidism on First-trimester Screening Results

Late offspring effects of antenatal thyroid screening.

Thyroid dysfunction in pregnancy is associated with adverse offspring outcomes and recent birth-cohort studies suggest that even mild degrees of thyroid dysfunction may be linked with a range of late cognitive and behavioural effects in childhood and adolescence. This review summarizes recent literature of observational studies and critically appraises randomized controlled trials (RCTs) of antenatal thyroid screening and Levothyroxine intervention. Overt hypothyroidism and hyperthyroidism carry significant risks for unfavourable offspring outcomes and should be appropriately corrected in pregnancy. The significance of subclinical hypothyroidism and hypothyroxinaemia is still unclear. Meta-analyses of birth-cohort studies show associations of maternal subclinical hypothyroidism and hypothyroxinaemia with intellectual deficits, attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders, while hyperthyroidism and high-normal FT4 were linked with ADHD. RCTs have shown no benefits of screening on neurodevelopmental outcomes although Levothyroxine could have been initiated too late in pregnancy in these trials. A small number of studies have shown inconsistent associations of maternal thyroid dysfunction with offspring cardiometabolic indices including blood pressure and body weight. Correction of maternal thyroid dysfunction was, however, associated with favourable long-term metabolic profiles in mothers, including lipid profiles, fat mass and body mass index. Antenatal thyroid screening may therefore present opportunities for optimizing a wider range of outcomes than envisaged. Future trials with early antenatal thyroid screening and intervention are necessary to clarify the impact of screening on late offspring and maternal effects.

Under and overtreatment with thyroid hormone replacement during pregnancy.

Among pregnant women on thyroid hormone replacement therapy undertreatment is common, while overtreatment is rare. Both deficient and excessive maternal thyroid hormone have been related to adverse maternofetal and long-term offspring outcomes, although studies' results are inconsistent. This review aims to discuss recent evidence regarding the effects of under- and overtreatment with thyroid hormone replacement during pregnancy and how current practices could be improved. Whether or not thyroid hormone therapy needs to be initiated for maternal subclinical hypothyroidism remains unclear, but recent meta-analyses have confirmed associations between adverse maternal, neonatal, and offspring outcomes in both overt and subclinical hypothyroidism. Subclinical hyperthyroidism in pregnancy is related to fewer adverse outcomes. Current adherence to levothyroxine during pregnancy and medication counseling by healthcare providers are suboptimal. Undertreatment of maternal hypothyroidism may increase risks for adverse maternofetal and offspring effects more than overtreatment does. If thyroid hormone replacement therapy is indicated and initiated in pregnancy, frequent thyroid function monitoring is required to avoid under- or overtreatment. Effective communication between clinicians and patients is imperative to increase medication adherence.

Effect of Maternal Subclinical Hypothyroidism on Congenital Hypothyroidism Screening Results: A Retrospective Cohort Study.

This study aimed to evaluate the results of congenital hypothyroidism screening (CHS) in neonates born to women with subclinical hypothyroidism (SHT) during pregnancy and to identify maternal and neonatal characteristics associated with recall rate in CHS. This retrospective cohort study included nonrefugee pregnant women and newborn pairs who underwent thyroid function tests during prenatal follow-up between 2014 and 2017 and had neonatal CHS records. The women were evaluated overall and divided into euthyroidism (ET) and SHT groups according to their thyroid function tests. The groups were compared in terms of CHS results. Neonates with thyroid-stimulating hormone (TSH) levels <5.5 mIU/L were considered "normal," while those with values ≥5.5 mIU/L were "recall." The antenatal thyroid function data of a total of 22,383 pregnant women were analyzed. Of these, 71.6% were ET and 16.3% were diagnosed as SHT. Overall, the recall rate accounted for 5.34% of all CHS results and the recall rate was higher in the SHT group (7.10%) compared with the ET group (5.54%; p = 0.001). Being low birth weight (LBW) or large for gestation age (LGA), maternal TSH above the 97.5th percentile, and cesarean delivery increased the risk of recall in CHS (p ˂ 0.05). The recall rate was higher among the neonates of mothers with SHT. Being LBW or LGA, maternal TSH above the 97.5th percentile and cesarean delivery increased the risk of recall in CHS. · SHT is the most common form of hypothyroidism in pregnancy.. · TSH elevation is higher among the neonates of mothers with SHT.. · Being LBW or LGA, and cesarean delivery also increase the risk of TSH elevation in infants..

Subclinical hypothyroidism in pregnancy rats impaired offspring's spatial learning and memory and the cerebellar development

Subclinical hypothyroidism (SCH) is a very common preclinical condition during pregnancy. The adverse effect of maternal clinical hypothyroidism (CH) on the nervous system development of offspring is beyond doubt, but it is still controversial in SCH. The aim of this study was to investigate whether spatial learning and memory ability of offspring is inhibited in SCH rat model and its possible mechanism. 45 Wistar female rats were randomly divided into SCH, CH and control (CON) groups, which were induced by semi-thyroid electrocauterization, total thyroidectomy and sham operation, respectively. Rat pups were sacrificed at embryonic day 14 (E14), E18, postnatal day 1 (P1), P3, and P10, and pups' cerebellar tissues were collected. The proliferation, differentiation and migration of cerebellar cells were observed, and RNA level of the thyroid hormone receptor α (TRα) and TRβ in the cerebellum was detected by real-time PCR, respectively. Morris Water Maze (MWM) test was performed to detect the spatial learning and memory ability of pups at P40. Our data indicated that maternal SCH will significantly extend the offspring's escape latency time, and pups perform worse in the spatial probe test compared with the CON group. Except for E14, the proliferation of pups' cerebellar granule cells (GCs), and the migration of pups' Purkinje cells (PCs) in the SCH group was significantly inhibited compared with that in the CON group at other time points (P < 0.05 or P < 0.01), and the differentiation of cerebellar astrocytes (As) in SCH group was higher than that in CON group at P3 and P10. Except for E14, the expression of TRα mRNA in SCH group was significantly lower than that in CON group (P < 0.05 or P < 0.01). And the difference of the differentiation of As and the spatial learning and memory between SCH and CH groups was not statistically significant. Our findings suggested that SCH during pregnancy nuisances the offspring's spatial learning and memory. It may be related to the decrease of the expression of TRα in cerebellum, which may further inhibit the proliferation of GCs and the migration of PCs, and increase the differentiation of As.

Outcomes in Pregnant Patients with Subclinical Hypothyroidism and Thyroid Autoimmunity: A Critical Appraisal of Recent Randomized Controlled Trials

The management of subclinical hypothyroidism (SCH) and thyroid autoimmunity (TAI) in pregnancy is still uncertain. Over the years, several scientific societies published guidelines on the management of thyroid dysfunction before, during, and after pregnancy, the most recent ones being published by the American Thyroid Association (ATA) in 2017. This study aimed to review the published literature in the field from 2017 onward to investigate whether new findings can change ATA recommendations. A literature search was conducted in PubMed between March 2017 (date of the publication of the ATA guidelines) and March 2020. The research was restricted to randomized controlled trials (RCTs), having pregnancy-related complications in patients with SCH and TAI as the main focus. A total of 5 RCTs were retrieved, 2 of which investigated pregnant women with SCH and 3 with TAI. Selected studies displayed proofs against treating maternal SCH and hypothyroxinemia because no benefit from LT4 was demonstrated in offspring intelligence quotient and in pregnancy outcomes; moreover, they reported proofs against treating TAI patients because no benefit from LT4 was demonstrated in improving pregnancy rate or live birth rate or reducing miscarriage rate.RCTs published from 2017 to 2020 might have a significant impact on current ATA guidelines. In particular, they suggested that isolated hypothyroxinemia and SCH should not be treated and that considering treatment in antibodypositive women, especially those with TSH of 2.5-4.0 mIU/L, would not be justified; they suggested that infertility and miscarriage rates are not decreased by LT4 treatment in euthyroid antibody-positive women seeking pregnancy.

Study on thyroid function test in pregnancy in a tertiary care hospital

Thyroid disorder is a very common endocrine problem encountered by pregnant women. Maternal thyroid dysfunction is associated with adverse outcome both in mother and fetus.&#x0D; The aim of the study: to find out the prevalence of various thyroid disorders in pregnant women attending antenatal clinic.&#x0D; Materials and methods. This prospective cross-sectional study was carried out in the Department of Obstetrics and Gynecology, F.M. Medical College &amp; Hospital, Balasore, Odisha from June 2020 to May 2021. 220 women with uncomplicated singleton pregnancy were included. Serum Thyroid-stimulating hormone (TSH), free T4 (FT4) and free T3 (FT3) were estimated by using electro-chemiluminescence immunoassay technique.&#x0D; Results. Out of 220 pregnant women screened for thyroid dysfunction, 68 were found to have thyroid disorders. 27.3 % of pregnant women had subclinical hypothyroidism, 1.4 % had overt hypothyroidism, 1.8 % had subclinical hyperthyroidism and 0.5 % had overt hyperthyroidism. Prevalence of subclinical hypothyroidism was 6.36 % when the upper reference limit of TSH level taken as 4 mIU/L. Prevalence of thyroid disorder among pregnant women in the age groups 18–25 years, 26–30 years and 31–40 years were 28.9 %, 32.1 % and 38.9 % respectively. There were 35.5 %, 28 % and 26 % pregnant women with thyroid disorders in the first, second and third trimester respectively. Prevalence of both subclinical and overt hypothyroidism were more in multigravida compared to primigravida.&#x0D; Conclusion. Our study revealed high prevalence of thyroid disorders in pregnant women and maternal subclinical hypothyroidism was the most common pattern.

Maternal Subclinical Hypothyroidism in Rats Impairs Spatial Learning and Memory in Offspring by Disrupting Balance of the TrkA/p75NTR Signal Pathway

Maternal subclinical hypothyroidism (SCH) during pregnancy can adversely affect the neurodevelopment of the offspring. The balance of nerve growth factor (NGF)-related tropomyosin receptor kinase A/p75 neurotrophin receptor (TrkA/p75NTR) signaling in the hippocampus is important in brain development, and whether it affects cognitive function in maternal SCH’s offspring is not clear. In this study, we found that compared with the control (CON) group, expression of proliferation-related proteins [NGF, p-TrkA, phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2) and phospho-cAMP response element-binding protein (p-CREB)] decreased in the hippocampus of the offspring in the SCH group, overt hypothyroidism (OHT) group, and the group with levothyroxine (L-T4) treatment for SCH from gestational day 17 (E17). In contrast, expression of apoptosis-related proteins [pro-NGF, p75NTR, phospho-C-Jun N-terminal kinase (p-JNK), p53, Bax and cleaved caspase-3] was increased. The two groups with treatment with L-T4 for SCH from E10 and E13, respectively, showed no significant difference compared with the CON group. L-T4 treatment enhanced relative expression of NGF by increasing NGF/proNGF ratio in offspring from maternal SCH rats. In conclusion, L-T4 treatment for SCH from early pregnancy dramatically ameliorated cognitive impairment via TrkA/p75NTR signaling, which involved activation of the neuronal proliferation and inhibition of neuronal apoptosis in SCH rats’ offspring.

Impact of maternal subclinical hypothyroidism on the neurocognitive development of children; a systematic review

Impact of maternal subclinical hypothyroidism on the neurocognitive development of children; a systematic review

Impact of Early Pregnancy Subclinical Hypothyroidism on Gestational Diabetes Mellitus: A Retrospective Study of 7,536 Cases.

Background: Maternal subclinical hypothyroidism (SCH) has been associated with adverse pregnancy outcomes. This study aimed to explore whether SCH in the first trimester contributed to the development of gestational diabetes mellitus (GDM). Materials and Methods: A total of 8,777 pregnant women who first visited before 13 weeks and 6 days of gestation and accepted routine prenatal service at the Third Affiliated Hospital of Sun Yat-Sen University from January 2015 to September 2018 were recruited in this study. Thyroid functions (thyroid stimulating hormone [TSH], free T4, and thyroid peroxidase antibody [TPOAb]) were measured before 13 weeks and 6 days of gestation and data of 7,536 subjects with TSH ≥0.1 mIU/L were analyzed. A 2-hour 75-g oral glucose tolerance test was performed between 24 and 28 gestational weeks. Chi-square test and multivariate logistic regression analysis were applied to evaluate the relationship between SCH and GDM. Results: The prevalence of SCH in this population was 7.53%. After stratifying the relationship between SCH and GDM according to TSH concentrations (slightly elevated TSH: ≥2.5, <4.0 mIU/L; moderately elevated TSH: ≥4.0, <10.0 mIU/L) and TPOAb status, a moderately elevated TSH combined with positive TPOAb (23.9% vs. normal 13.0%, chi-square = 6.317, p = 0.012) was found to increase the incidence of GDM. Furthermore, after adjusting for confounders (maternal age, educational levels, parity, and pregestational body mass index [preBMI]), the SCH group still exhibited a higher risk of GDM (relative risk [RR] 1.867, 95% confidence interval [CI] 1.018-3.424). Conclusion: Our findings indicated that SCH during early pregnancy, in the presence of moderately elevated TSH levels and positive TPOAb, might lead to an increased risk of GDM.

Impact of TPOAb-negative maternal subclinical hypothyroidism in early pregnancy on adverse pregnancy outcomes.

Purpose:To investigate the effect of subclinical hypothyroidism on pregnancy outcomes of women early in their pregnancy with different thyroid-stimulating hormone levels and thyroid peroxidase antibody–negative status and to explore reasonable thyroid-stimulating hormone levels for subclinical hypothyroidism in early pregnancy.Methods:A total of 2378 women early in their pregnancy were studied retrospectively. The baseline characteristics were collected from medical records. Pregnancy outcomes were compared between the euthyroidism and subclinical hypothyroidism groups that were diagnosed by 2011 or 2017 American Thyroid Association guidelines. In addition, the effect of different maternal thyroid-stimulating hormone levels on adverse pregnancy outcomes was analyzed using binary logistic regression.Results:According to the 2011 American Thyroid Association diagnostic criteria of subclinical hypothyroidism, the prevalence of pregnancy outcomes was not significantly higher in the subclinical hypothyroidism group than in the euthyroidism group. However, pregnant women with subclinical hypothyroidism identified by the 2017 American Thyroid Association criteria had a higher risk of premature delivery (odds ratio = 3.93; 95% confidence interval = 1.22–12.64), gestational diabetes mellitus (odds ratio = 2.69; 95% confidence interval = 1.36–5.32), and gestational anemia (odds ratio = 3.28; 95% confidence interval = 1.60–6.75). Moreover, no differences in the prevalence of adverse pregnancy outcomes were observed between the mildly elevated thyroid-stimulating hormone group (2.5 < thyroid-stimulating hormone ⩽4.0 mIU/l) and the normal thyroid-stimulating hormone group (0.27 < thyroid-stimulating hormone ⩽2.5 mIU/l). The significantly elevated thyroid-stimulating hormone group (4.0 < thyroid-stimulating hormone < 10.0 mIU/l) had a higher prevalence of premature delivery, gestational diabetes mellitus, and gestational anemia than the normal thyroid-stimulating hormone group, even after controlling for potential confounding factors.Conclusion:A mildly elevated thyroid-stimulating hormone level or maternal subclinical hypothyroidism diagnosed by 2011 American Thyroid Association guidelines during early pregnancy in thyroid peroxidase antibody–negative women was not associated with adverse pregnancy outcomes. However, maternal subclinical hypothyroidism identified by the 2017 American Thyroid Association guidelines increased the risks of several adverse pregnancy outcomes in women untreated with levothyroxine. The 2017 American Thyroid Association guidelines could be more reasonable for the diagnosis of subclinical hypothyroidism in southern China.

Hearing outcome in infants following correction of maternal hypothyroidism during pregnancy

PurposeThere is significant prevalence of overt and subclinical hypothyroidism in pregnant women in rural areas. Maternal hypothyroidism is known to cause congenital hypothyroidism resulting in sensorineural hearing loss. Anti-Thyroperoxidase antibodies are known to cross placental barrier. There is no literature on hearing assessment in infants born to women whose hypothyroidism was corrected during pregnancy. Do these infants suffer hearing loss? Our study addresses this question. Methods140 infants born to women on treatment for hypothyroidism during pregnancy and 140 infants born to euthyroid women were evaluated for hearing by Brainstem Evoked Response Audiometrry at 1 and 4 months age. Anti-TPO antibodies were estimated at 4 months of age. ResultsThere was no clinical hearing deficit or delay in neurological development in infants born to women undergoing treatment for hypothyroidism during pregnancy. However wave V latency on BERA was slightly prolonged in them compared to infants born to euthyroid women. There was absence of wave V when maternal subclinical hypothyroidism persisted till parturition. However within 6–8months of age the wave V latencies corrected to normal. Anti-TPO antibodies were within normal range at 4months age. ConclusionMaternal hypothyroidism when corrected before parturition does not affect hearing in the infants clinically. The mild delay in wave V on BERA corrects within first year of life. However larger studies to assess hearing in infants born to women having overt hypothyroidism during first trimester of pregnancy may be desirable to assess whether hearing is adversely affected in them.

Insignificant Effect of Isolated Hypothyroxinemia on Pregnancy Outcomes During the First and Second Trimester of Pregnancy.

Objective: Adverse maternal outcomes and perinatal complications are associated with overt and subclinical maternal hypothyroidism. It is not clear whether these complications also occur in women with isolated hypothyroxinemia during pregnancy. The aim of this study was to evaluate the effects of isolated hypothyroxinemia on maternal and perinatal outcomes during pregnancy.Methods: This study included data from 2,864 pregnant women in the first trimester (67 women with isolated hypothyroxinemia, 784 euthyroid women) and the second trimester (70 women with isolated hypothyroxinemia, 1,943 euthyroid women) of pregnancy. Maternal serum samples were collected in the first and second trimesters to examine thyroid hormone concentration. Hypothyroxinemia was defined as a normal maternal thyroid-stimulating hormone concentration with a low maternal free thyroxine concentration and negative thyroid autoantibodies. The following maternal outcomes were recorded: gestational hypertension, gestational diabetes mellitus, placenta previa, placental abruption, prelabor rupture of membranes, and premature delivery. Perinatal outcomes, including fetal growth restriction, fetal distress, low birth weight, intrauterine fetal death, and malformation. The incidence of adverse pregnancy outcomes and perinatal complications was compared between women in the first trimester and second trimester with isolated hypothyroxinemia.Results: There were no significant differences in the incidence rates of adverse maternal outcomes and perinatal complications between patients in the first and second trimesters with isolated hypothyroxinemia.Conclusion: The results of this study indicate that isolated hypothyroidism does not increase the incidence of adverse maternal outcomes and perinatal complications.