Overt and subclinical thyroid dysfunction among Indian pregnant women and its effect on maternal and fetal outcome

Subclinical hypothyroidism during pregnancy and the impact of levothyroxine therapy on pregnancy outcomes in women

Aims

The purpose of this study is to investigate the impact of subclinical hypothyroidism (SCH) during pregnancy and levothyroxine (LT4) therapy on pregnancy outcomes.

Methods

Among 6,510 pregnant women who came to The Fourth Hospital of Shijiazhuang for pregnancy examination and delivery, 266 pregnant women with SCH and treated with LT4 were selected as the SCH group and 672 pregnant women without SCH were selected as the non-SCH group, and the incidence rates of adverse pregnancy outcomes in pregnant women and newborns of the two groups were compared using Chi-square test and logistic regression. According to the therapeutic effect, pregnant women treated with LT4 were categorized into sustained euthyroid status (SES) and suboptimal thyroid status (STS) groups and compared with the non-SCH group using chi-square test. The correlation of thyroid stimulating hormone (TSH) levels at different stages of pregnancy was explored using Spearman's rank test.

Results

The incidence of hypertensive disorders of pregnancy (HDP), premature rupture of membranes (PROM), and neonatal outcomes were ventricular or atrial septal defect (V/ASD), hyperbilirubinemia, and pneumonia were higher in the SCH group (SCH pregnant women) than in the non-SCH group (non-SCH pregnant women) (p < 0.05). The incidence of multiple maternal and neonatal complications was higher in the SCH-STS group (SCH in two or three gestational trimesters) compared to the SCH group. With a tendency for TSH levels to increase as the pregnancy progressed.

Conclusion

SCH during pregnancy is associated with a high incidence of various pregnancy complications, and LT4 therapy that controls serum TSH levels at normal levels throughout pregnancy can reduce these risks.

THRA1/PGC-1α/SIRT3 pathway regulates oxidative stress and is implicated in hypertension of maternal hypothyroid rat offspring

Many epidemiologic and animal studies have shown that maternal hypothyroidism is associated with an increased risk of hypertension in offspring in later life. In this study, we established a maternal hypothyroidism rat model to explore the underlying mechanism that contributes to elevated blood pressure in adult male offspring of hypothyroid mothers. The levels of thyroid hormones (THs) in the offspring were measured using ELISA kits. Blood pressure (BP) and depressor response were recorded in conscious, freely moving rats. Vascular reactivity was conducted in isolated mesenteric arteries (MAs) using a myograph. We used real-time quantitative PCR (RT-qPCR) and Western blots to examine the mRNA and protein expression of relevant molecules in MAs. The A7r5 cells were transfected with small interfering RNA (siRNA) to further investigate the gene functions. The following findings were observed: Basal systolic BP and diastolic BP was significantly increased, accompanied by attenuated depressor response and decreased vascular sensitivity to sodium nitroprusside (SNP). Reactive Oxygen Species (ROS) levels in the MAs were enhanced, along with decreased expression of the THRA1/PGC-1α/SIRT3 pathway. In A7r5 cells, triiodothyronine (T3) pretreatment improved the PGC-1α/SIRT3 pathway and reduced ROS levels after H2O2-induced oxidative stress. In contrast, the knockdown of THRA1 or SIRT3 diminished the above effects of T3. Down-regulation of THRA1 contributed to a decline in the PGC-1α/SIRT3 pathway, which causes an increased production of ROS. This indicates that the T3-THRA1/PGC-1α/SIRT3 pathway plays a protective role in the regulation of BP and may be a potential therapeutic strategy against hypertension.

A retrospective analysis on maternal and neonatal outcomes in pSS/AITD pregnancies

The combined impact of concurrent primary Sjögren's syndrome (pSS) and autoimmune thyroid disease (AITD) on pregnancy outcomes remains underreported. A retrospective analysis was conducted on 115 pregnant patients diagnosed with pSS and delivering at the Third Affiliated Hospital of Guangzhou Medical University from January 2009 to July 2023. The effects of AITD on maternal and neonatal outcomes were examined and compared to a control group without AITD. In the group with pSS and AITD, the pregnancy loss rate was significantly higher than in the non-AITD group (P = 0.015), primarily reflected in the increased rate of neonatal death (P = 0.029). The proportion of term births and vaginal deliveries in the AITD group was notably reduced compared to the non-AITD group (54% vs. 81.5%; 16.0% vs. 41.5%; P = 0.001 and P = 0.003, respectively). No significant differences were observed in other maternal pregnancy outcomes, including induced abortion, spontaneous abortion, therapeutic abortion, and premature delivery (P > 0.05). The average birth weight of newborns in the pSS with AITD group was significantly lower than in the pSS without AITD group (2587.70 ± 720.50 g vs. 2812.54 ± 495.30 g, P < 0.001). Additionally, the rate of low-birth-weight infants in the pSS with AITD group was higher than in the pSS without AITD group (39.0% vs. 19.7%, P = 0.032). However, no significant differences were found between the two groups in the rates of fetal death, neonatal live birth, and fetal distress (P > 0.05). These results emphasize the importance of monitoring and managing thyroid health during pregnancy to optimize maternal and neonatal outcomes. Further exploration is essential to unravel the precise mechanisms through which AITD impacts fetal growth and to identify potential interventions to mitigate these effects.

Ovarian response in preimplantation genetic testing for myotonic dystrophy type 1

PURPOSE

To evaluate ovarian stimulation response in couples undergoing preimplantation genetic testing (PGT-M) for myotonic dystrophy type 1 (DM1) METHODS: Retrospective, observational, multicentric study. Parameters of ovarian response and PGT-M outcomes were compared according to the DM1-affected patient (female or male). A total of 229 couples underwent at least one controlled ovarian hyperstimulation cycle for the PGT-M procedure. Overall, 678 COS cycles were started, leading to 560 cycles with oocyte retrievals and subsequent PGT-M analysis.

RESULTS

At the time of the first PGT-M attempt, affected DM1 females were 1 year older and their serum AMH level was significantly lower than that of the healthy partner of affected DM1 males. After higher starting and total doses of exogenous gonadotropins, the number of mature oocytes was not statistically different between both groups (9 [6-13] vs 9 [6-13] mature oocytes, p=0.73). The FORT index was similar in both groups (35.2% [19.2-52.8] vs 33.3% [19.6-50.0], p=0.09), suggesting that antral follicle responsiveness to FSH is not altered. The live birth rate per fresh embryo transfer was 23.8% in the affected females group and 27.6% for the affected males.

CONCLUSION

After adapted controlled ovarian stimulation protocol and starting dose, a similar response (number of mature oocytes) and sensitivity (FORT index) was observed in DM1 females when compared to healthy partners of DM1 males undergoing PGT-M.

Impact of maternal thyroid dysfunction on fetal and maternal outcomes in pregnancy: a prospective cohort study

BACKGROUND

Thyroid dysfunction in pregnancy can adversely impact maternal and fetal outcomes. However, the association between thyroid status and specific adverse outcomes needs clarity, especially in understudied regions.

OBJECTIVE

This prospective cohort study aimed to illuminate the multifaceted associations between maternal thyroid dysfunction and feto-maternal outcomes in Gujarat, India.

METHODS

This hospital-based cohort study recruited and monitored 500 euthyroid, 250 hypothyroid, and 150 hyperthyroid pregnant women until delivery. Maternal thyroid status was determined by serum thyroid stimulating hormone (TSH) and free thyroxine (fT4) levels. Adverse fetal outcomes included preterm birth, neonatal intensive care unit (NICU) admission, respiratory issues, and low APGAR scores. Maternal outcomes included preeclampsia, haemorrhage, hypertension, postpartum thyroiditis, and thromboembolism. Relative risks quantified associations between thyroid dysfunction and outcomes.

RESULTS

Compared to euthyroid women, hypothyroid women had a higher RR for preterm birth (RR 1.8, 95% CI 1.1-3.0), low APGAR score (RR 2.5, 95% CI 1.5-4.1), preeclampsia (RR 3.0, 95% CI 1.9-4.8), postpartum haemorrhage (RR 1.6, 95% CI 1.2-2.1), and venous thromboembolism (RR 3.1, 95% CI 1.7-5.7). Hyperthyroid women had over twice the risk of low APGAR score (RR 1.8, 95% CI 0.9-3.5), neonatal hypoglycemia (RR 1.5, 95% CI 0.5-4.3), respiratory distress (RR 1.4, 95% CI 0.7-2.8), and postpartum thyroiditis (RR 2.3, 95% CI 1.1-4.8).

CONCLUSION

Maternal thyroid dysfunction escalates risks for adverse fetal and maternal outcomes. Thyroid monitoring and management during pregnancy are critical to mitigate complications.

Evaluation and Management of Thyrotoxicosis During Pregnancy

This review summarizes the diagnosis and management of thyrotoxicosis in pregnancy. The diagnostic clinical and biochemical considerations used to distinguish the various etiologies of hyperthyroidism from appropriate physiologic changes during pregnancy will be outlined. Finally, the review will discuss the risks and benefits of available options for the treatment of thyrotoxicosis during pregnancy, to mitigate the risks of fetal hyperthyroidism.

Comparison of Factors Influencing Gestational Outcomes in Healthy Versus Hypothyroid Women from Karachi, Pakistan

BACKGROUND

Gestational outcomes are known to be negatively correlated with hypothyroidism. This study was designed to compare the maternal factors affecting gestational outcomes in women with and without hypothyroidism.

METHODS

This retrospective analysis was carried out in a tertiary hospital in Karachi, Pakistan, between 2008 and 2016. A standardized form was used to collect information on the age of the mother, gestational duration at the prenatal appointment, gestational diabetes mellitus (GDM), hypertension, and past records of miscarriages in hypothyroid and healthy pregnant women. Gestational outcomes were recorded as live birth or pregnancy loss. Statistical analysis was performed to examine overt versus sub-clinical hypothyroidism and among those diagnosed before versus during gestation.

RESULTS

A collective of 708 women were enlisted in the hypothyroid pregnant group and 759 were recruited in healthy controls. Pregnancy loss was 9.9% (n=70) in hypothyroid women, whereas it was 14.3% (n=108) in the control group. The age of the mother, gestational duration at the prenatal appointment, and past records of miscarriages were discovered to be related to a higher chance of pregnancy loss in a multivariable analysis, but GDM (OR 0.04, CI 0.06-0.32, P=0.002) and hypothyroidism (OR 0.62, CI 0.43-0.89, P=0.01) exhibited a protective effect.

CONCLUSION

This study found the age of the mother, gestational duration at a prenatal appointment, and past records of miscarriages to be associated with negative outcomes in hypothyroidism. These factors remained significant in overt as well as subclinical hypothyroid women.

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

PURPOSE

The purpose of this study was to determine the association between maternal subclinical hypothyroidism (SCH) and gestational diabetes mellitus (GDM) risk.

METHODS

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.

RESULTS

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).

CONCLUSIONS

Maternal SCH in pregnancy is related to an increased risk of GDM.

Early treatment will prevent feto-maternal complications in thyroid disorders during pregnancy: A prospective study

Context

Associations between adverse maternal complications and fetal outcomes are known entity in thyroid disorders during pregnancy. Thus, prompt identification of thyroid disorders and timely initiation of treatment is essential. Universal screening and early treatment of pregnant women for thyroid disorder should be considered especially in a resource-limited country like India with a high prevalence of undiagnosed thyroid disorders and adverse feto-maternal outcomes.

Aims

Early treatment will prevent feto-maternal complications in thyroid disorders in pregnant females visiting outpatient department in tertiary care hospital in rural settings.

Settings and Design

This study was conducted in a tertiary care rural-based medical college with participation from departments of Obstetrics and Gynaecology, Medicine, and ENT.

Methods and Material

Expectant mothers in first trimester who had urine pregnancy test positive in outpatient clinic were included after a written informed consent. Detailed history and examination was done. TSH was done if abnormal-FT3 and FT4 were done. All thyroid disorders were treated according to American Thyroid Association (ATA) 2017 guideline. All pregnancies were followed up for maternal complications and fetal outcomes.

Statistical Analysis Used

Data from the performa were entered in Office Excel and analysis was performed using STATA (14.2). Descriptive statistics (mean [standard deviation], Frequency [%], etc.) were used to depict profile of study participants, prevalence of thyroid dysfunction, and outcome measures. Chi-square test was employed to assess the association between thyroid dysfunction and various maternal and fetal outcomes. A P value less than. 05 was considered statistically significant.

Results

Of 350 pregnant females, 83 (23.5%) pregnant females had thyroid disorder. Of which, 33 (9.4%) had subclinical hypothyroidism, 37 (10.5%) had overt hypothyroidism, 11 (3.1%) had subclinical hyperthyroidism, and two (0.5%) had hyperthyroidism. The prevalence of hypothyroidism in pregnancy increases with increasing age (P value. 001) and not associated with parity, abortion, and consumption of iodized salt. Total patients with feto-maternal outcome follow-up were 241. Pre-eclampsia (P value. 004) was a significant complication in hypothyroid mothers. There was no significant difference in the rate of cesarean section and preterm delivery in hypothyroid and euthyroid mothers. Neonatal outcomes showed more trends of abortion, fetal demise, and IUFD in the hypothyroid group, although not statistically significant. (P value. 07).

Conclusions

Due to the high prevalence of thyroid disorders during pregnancy, universal screening of thyroid disorders should be done in early pregnancy instead of high-risk screening. Early detection and early treatment in the first 10 weeks of pregnancy help to prevent maternal and fetal complications of thyroid disorders in pregnancy. Pre-eclampsia is to be monitored in treated pregnant females with hypothyroidism.

Maternal and fetal outcomes of SLE in pregnancy: a literature review

Systemic Lupus Erythematosus (SLE) is an auto-immune disease in which the immune system assaults its tissues. We aimed to analyse the maternal and foetal outcomes during pregnancy in SLE mothers. A literature search was conducted by two investigators to assess SLE's outcomes on maternal and foetal during pregnancies. We searched PubMed/Medline, Embase, and Google scholar to collect evidence from different research studies, draw the conclusion, and report it. In our investigation, we found out that SLE could cause a spectrum of complications during pregnancy, not only for the mother but also for the foetus. It could affect fertility and cause difficult pregnancies for the couple as well which includes certain complications such as: preterm labour and delivery, high blood pressure (preeclampsia), placental insufficiency, miscarriage or stillbirth, whereas in the foetus SLE can cause mortality, preterm birth, and neonatal lupus (a temporary condition in the baby caused by SLE-related antibodies) and structural abnormalities. The literature suggests that SLE could prove fatal for the foetus and induce many complications in the mother. However, this could be avoided if pregnancy is planned right from the start and proper management is provided to the mother during pregnancy and delivery.p.

Maternal hypothyroidism in rats impairs placental nutrient transporter expression, increases labyrinth zone size, and impairs fetal growth

INTRODUCTION

Hypothyroidism during pregnancy is associated with fetal growth restriction (FGR). FGR is commonly caused by placental insufficiency and yet the role of hypothyroidism in placental regulation of fetal growth is unknown. This study aimed to investigate the effects of maternal hypothyroidism on placental nutrient transporter expression, placental morphology, and placental metabolism.

METHODS

Hypothyroidism was induced in female Sprague-Dawley rats by adding methimazole (MMI) to drinking water at moderate (MOD, MMI at 0.005% w/v) and severe (SEV, MMI at 0.02% w/v) doses from one week prior to pregnancy and throughout gestation. Maternal and fetal tissues were collected on embryonic day 20 (E20).

RESULTS

Hypothyroidism reduced fetal weight (PTrt<0.001) despite causing fetal hyperglycaemia (PTrt = 0.016). Placental weight was not affected by hypothyroidism however placental efficiency was reduced (PTrt<0.001), as was the junctional zone (JZ):labyrinth zone (LZ) weight ratio (PTrt = 0.005). LZ glycogen content was increased (PTrt = 0.029) and while mRNA expression of glucose transporters was reduced by hypothyroidism, only GLUT1 protein expression was reduced in male LZs. Maternal hypothyroidism reduced mitochondrial content (PTrt = 0.031), particularly in SEV males relative to CON males (P = 0.004). Protein expression of Complex V (P < 0.001) and Complex III (P = 0.002) of the electron transport chain were also reduced in males. Maternal hypothyroidism reduced LZ (PTrt<0.001) and fetal plasma triglycerides (P = 0.019) while fetal free fatty acids and the expression of LZ lipid transporters was not affected.

DISCUSSION

Overall, maternal hypothyroidism may lead to FGR through reduced maternal T4 availability, changes to placental morphology, altered nutrient transporter expression and sex-specific effects on placental metabolism. Changes to LZ glycogen and triglyceride stores as well as mitochondrial content suggest a metabolic shift from oxidative phosphorylation to anaerobic glycolysis in males. These changes also likely impact fetal substrate availability and therefore fetal growth.

Serum lipid profile in relation to free thyroxine and the effect of levothyroxine treatment on lipids in patients with isolated hypothyroxinemia during pregnancy: a single-center retrospective study

BACKGROUND

Thyroid function is widely considered a lipid metabolism regulator. However, studies on lipid metabolism in pregnant women with low free thyroxine (FT₄) levels are limited and inconclusive. Furthermore, the association between maternal FT₄ deficiency and adverse lipid metabolic parameters is unknown. Therefore, we aimed to investigate this association and the effects of levothyroxine (L-T₄) treatment on these metabolic indicators.

METHODS

This retrospective study included 164 patients with isolated hypothyroidism (IH) (FT₄ levels below the 5^th percentile with normal thyroid stimulating hormone levels according to the gestational-specific reference range) and 407 euthyroidism patients (control group who had regular antenatal examinations at Zhejiang Provincial People's Hospital, Hangzhou, China) between January 1, 2019, and December 31, 2020. Patients with IH were divided into levothyroxine (L-treatment group, n = 77) and dietary iodine supplement treatment groups (dietary treatment group, n=87) according to the hospital's treatment policy and clinical experience. The intervention lasted for at least 8 weeks. Metabolic indicators, including thyroid function and lipid parameters, were collected at least twice before and after the intervention. Other data collected included maternal age, history of abortion, prepregnancy BMI, and gestational weight gain (Fig. 1).

RESULTS

Compared with the control group, Patients with IH had a higher degree of dyslipidemia, reflected in elevated total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo B) levels. In IH patients, an inverse correlation was found between FT₄ and TG levels, which remained after adjusting for prepregnancy BMI. The L-treatment group demonstrated a significantly slower rate of hypercholesterolemia progression during pregnancy than the dietary treatment group. In addition, there was a relationship between the therapeutic effect and the degree of disease, with the main factors being FT₄, TSH and TG levels prior to starting treatment.

CONCLUSIONS

Low FT₄ levels were associated with elevated blood lipid levels. Serum FT₄ and lipid levels in patients could be improved by medical intervention.

Maternal subclinical hyperthyroidism and adverse pregnancy outcomes considering the iodine status: Tehran thyroid and pregnancy study

BACKGROUND

Unlike overt thyroid diseases, the impacts of subclinical thyroid dysfunction, especially subclinical hyperthyroidism (SH), on adverse pregnancy outcomes are inconclusive.

OBJECTIVE

We aimed to investigate the effect of maternal SH on adverse maternal and neonatal outcomes based on urinary iodine concentration (UIC).

METHODS

A secondary analysis was run on data collected in the Tehran Thyroid and Pregnancy study (TTPs). We used the data of 131 women with SH and 1650 cases of euthyroid. Serum levels of thyroid-stimulating hormone (TSH), thyroxine (T4), free thyroxine index (FT4I), and thyroid peroxidase antibody (TPOAb) were assessed at the first prenatal visit. A generalized linear regression model was applied to identify the effect of SH on the pregnancy outcomes based on UIC, and the effects were estimated with a 95% confidence interval.

RESULTS

Preterm delivery was observed in 12.3% of women with SH and 6.7% of those with euthyroid (P = 0.03). Women with TSH< 0.3 mIU/L had a higher odds of preterm delivery than those with TSH≥ 0.3 regardless of urine iodine cut-off [OR= 2.27; 95% CI: (1.15, 4.48), p = 0.02]. Among those with UIC levels≥ 150 μg/L, the odds ratio of preterm delivery was 4.61 folds higher in the SH group compared to those with euthyroid [95%CI: (1.36, 15.71), p = 0.01)]. No significant difference between these two study groups was found in Neonatal Intensive Care Unit admission. Moreover, the results revealed no statistically significant difference in the means of neonatal anthropometric parameters in the SH and euthyroid groups in none of the subgroups of UIC (<150 or ≥150 µg/l).

CONCLUSIONS

According to our results, maternal SH appears to be a risk factor for preterm delivery. This effect is more pronounced in women with higher UIC than those with lower UIC.

Pregnancy in lupus: an updated consensus to guide best practice strategies

Background

Systemic lupus erythematosus is a multifaceted chronic relapsing autoimmune disease of unknown etiology. The disease has always been a serious diagnosis in women being a multisystem pathology that is classically encountered during the childbearing age posing serious systemic comorbidities with a potential impact on the functional performance, psychosocial status, and survival. In this article, we review critical issues related to the decision to conceive in female with lupus highlighting the impact of the diagnosis and disease activity status on the mother and the fetus, attempting to suggest a consensus to guide safe decision making for pregnancy with SLE.

Main body

The pleomorphic dysregulated immune nature of lupus in the presence of uncontrolled disease carries a higher risk of complicated pregnancy. Therefore, SLE pregnancies should be well planned and are usually encouraged if the disease is inactive (at least 6 months prior to conception) to ensure immune quiescence towards a safer outcome.

Conclusion

With the proper implementation of preconception counseling strategy, choice of the correct timing of conception, close monitoring of SLE flares with tight control, and the appreciation of the value of multidisciplinary management to best practice most young women with SLE can carry on successful pregnancies with favorable outcome.

Reduced Birth Weight and Exposure to Per- and Polyfluoroalkyl Substances: A Review of Possible Underlying Mechanisms Using the AOP-HelpFinder

Prenatal exposure to per- and polyfluorinated substances (PFAS) may impair fetal growth. Our knowledge of the underlying mechanisms is incomplete. We used the Adverse Outcome Pathway (AOP)-helpFinder tool to search PubMed for studies published until March 2021 that examined PFAS exposure in relation to birth weight, oxidative stress, hormones/hormone receptors, or growth signaling pathways. Of these 1880 articles, 106 experimental studies remained after abstract screening. One clear finding is that PFAS are associated with oxidative stress in in vivo animal studies and in vitro studies. It appears that PFAS-induced reactive-oxygen species (ROS) generation triggers increased peroxisome proliferator-activated receptor (PPAR)γ expression and activation of growth signaling pathways, leading to hyperdifferentiation of pre-adipocytes. Fewer proliferating pre-adipocytes result in lower adipose tissue weight and in this way may reduce birth weight. PFAS may also impair fetal growth through endocrine effects. Estrogenic effects have been noted in in vivo and in vitro studies. Overall, data suggest thyroid-damaging effects of PFAS affecting thyroid hormones, thyroid hormone gene expression, and histology that are associated in animal studies with decreased body and organ weight. The effects of PFAS on the complex relationships between oxidative stress, endocrine system function, adipogenesis, and fetal growth should be further explored.

Evaluating thyroid function in pregnant women

Thyroid hormones are primarily responsible for regulating the basal metabolic rate but also make important contributions to reproductive function and fetal development. Both hyper- and hypothyroidism in pregnancy have been associated with increased risks of complications that include preeclampsia and low birth weight, among others. Furthermore, thyroid hormone deficiency in the developing fetus results in neurodevelopmental delay. As the fetus is exclusively reliant on maternal thyroid hormone for most of the first trimester and requires continued maternal supply until birth, identifying maternal thyroid dysfunction is critically important. However, evaluating thyroid function in pregnancy is challenging because of the many physiological changes that affect concentrations of thyroid-related analytes. Increasing plasma human chorionic gonadotropin (hCG) concentrations in the second half of the first trimester elicit a corresponding transient decrease in thyroid-stimulating hormone (TSH), and continually increasing estradiol concentrations throughout pregnancy cause substantial increases in thyroxine-binding globulin (TBG) and total thyroxine (T4) relative to the nonpregnant state. Lastly, free T4 concentrations gradually decrease with increasing gestational age. For these reasons, it is essential to interpret thyroid function test results in the context of trimester-specific reference intervals to avoid misclassification of thyroid status. This review summarizes the effects of thyroid dysfunction prior to conception and during pregnancy and describes considerations for the laboratory assessment of thyroid function in pregnant women.

Higher Thyroid fT3-to-fT4 Ratio Is Associated with Gestational Diabetes Mellitus and Adverse Pregnancy Outcomes

Aim: To determine the association between thyroid function and the risk of developing gestational diabetes mellitus (GDM) and adverse pregnancy outcomes. Methods: This case−control study was a sub-analysis of the BEDIP-N study, in which 199 GDM women were matched for age and body mass index with 398 controls. Thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and thyroid peroxidase (TPO) antibodies were measured at 6−14 weeks and 26−28 weeks during pregnancy. TSH and fT4 were also measured in early postpartum in GDM women. Results: The fT3-to-fT4 ratio at 26−28 weeks was positively associated with GDM risk with an adjusted odds ratio (aOR for smoking, education, parity, ethnicity, gestational weight gain, and (family) history of diabetes or GDM) of 2.12 (95% CI 1.07; 4.23), comparing the highest with the lowest tertile. Higher fT3 levels and a higher fT3-to-fT4 ratio were associated with a less favorable metabolic profile with higher BMI and more insulin resistance during pregnancy and postpartum. Women in the upper fT3 tertile and the upper fT3-to-fT4 ratio had a higher rate of preeclampsia [4.6% (10) vs. 1.0% (2), p = 0.040, and 4.4% (9) vs. 0.5% (1), p = 0.020], gestational hypertension [8.3% (18) vs. 3.1% (6), p = 0.034 and 8.9% (18) vs. 2.0% (4), p = 0.003], and caesarean sections [29.4% (63) vs. 16.1% (31), p = 0.002 and 32.2% (65) vs. 12.7% (25), p < 0.001]. Conclusion: A higher fT3-to-fT4 ratio late into pregnancy was associated with GDM, adverse pregnancy outcomes, and an adverse metabolic profile in early postpartum.

Maternal Subclinical Hyperthyroidism and Adverse Pregnancy Outcomes: A Systematic Review and Meta-analysis of Observational Studies

CONTEXT

Findings from studies evaluating adverse pregnancy outcomes in pregnant women with subclinical hyperthyroidism are conflicting and inconclusive.

OBJECTIVES

In this systematic review and meta-analysis, our aim was to evaluate the pooled odds ratio (OR) of adverse pregnancy outcomes in women with subclinical hyperthyroidism, compared to euthyroid women.

DATA SOURCES

Scopus, PubMed (including Medline), and Web of Science databases were systemically searched for regaining published studies to January 2022 examining adverse pregnancy outcomes in women with subclinical hyperthyroidism.

STUDY SELECTION

Outcomes of interest were classified into seven composite outcomes, including hypertensive disorders, preterm delivery, macrosomia/large for gestational age (LGA), pregnancy loss, adverse maternal outcomes, adverse neonatal outcomes, and adverse fetal outcomes.

DATA EXTRACTION

In this meta-analysis, both fixed and random effect models were used. Publication bias was also evaluated by Egger test and the funnel plot, and the trim and fill method was conducted in case of a significant result, to adjust the bias.

RESULTS

Of 202 records retrieved through searching databases, 11 studies were selected for the final analyses. There were no significant differences in pooled ORs of hypertensive disorders, preterm delivery, macrosomia/LGA, and pregnancy loss in pregnant women with subclinical hyperthyroidism, compared to the euthyroid controls. The pooled OR of adverse maternal, neonatal, and fetal outcomes in pregnant women with subclinical hyperthyroidism was not statistically significantly different from that of the euthyroid control group.

CONCLUSIONS

The current meta-analysis demonstrated that subclinical hyperthyroidism in pregnancy is not related with adverse maternal and fetal outcomes. Therefore, clinicians should be avoided unnecessary treatments for pregnant women with subclinical hyperthyroidism.

Effects of thyroid hormones in women with gestational diabetes

PURPOSE

This study aims to determine the effect of serum free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH) and fT3/fT4 ratio on the gestational diabetes.

METHODS

This multicenter study was conducted by analyzing retrospectively 495 pregnant women who admitted to the Tepecik training and Research Hospital, and Kocaeli Derince training and Research Hospital between January 2017 and December 2019. Seventy-eight pregnant women diagnosed with Gestational Diabetes Mellitus (GDM) and 82 pregnant women without GDM diagnosis were included in the study. The relationship between thyroid markers (TSH, fT3, fT4 and fT3/fT4) and gestational diabetes was determined using logistic regression analysis.

RESULTS

Advanced age, low fT4 and high TSH levels were higher in GDM group, p < .05. Results of the logistic regression analysis revealed that the gestational week (OR 20.291, 95% CI 3.132-131-449, p = .002], fasting plasma glucose (OR 48,551, 95% CI 9.223-255.582, p < .001), HbA1c (OR 13,671, 95%CI 2.977-62.781, p =.001) and fT3/fT4 (OR 29.934, 95% CI 3.558-251836, p = .002) were the risk factors of GDM.

DISCUSSION

Advanced gestational week, fasting blood glucose, HbA1c and fT3/fT4 ratio are among the risk factors for the development of the gestational diabetes.

Gestational Diabetes Mellitus with autoimmune subclinical hypothyroidism in pregnancy in relation to gravida

Introduction

Gestational diabetes mellitus (GDM) and hypothyroidism are the most common endocrinological abnormalities associated with pregnancy. The association of gravida with incidence of autoimmune subclinical hypothyroidism (SCH) and GDM in pregnancy has not been studied extensively with availability of very limited data in this context. So, this study was done to find out the association between GDM and autoimmune SCH in pregnancy as per gravida status of the study population.

Materials and Methods

382 antenatal cases, both primi and multigravida, were screened for thyroid dysfunction and GDM in their first ANC coming to a tertiary level health care institution. 75 gm GCT was used for diagnosis of GDM and serum TSH, fT4, and anti-TPO antibody were measured for assessment of thyroid dysfunction. Prevalence of SCH was evaluated taking the ATA 2011 guidelines. Data obtained was also compared with ATA 2017 recommendations. Anti-TPO antibody level more than 60 U/L was considered to be raised value.

Observation

The percentage of GDM was higher in autoimmune SCH participants compared to euthyroid cases with raised anti-TPO Ab Titer. GDM, SCH, and raised anti-TPO Ab titer were overall more prevalent in multigravida cases compared to primigravida participants.

Conclusion

GDM and SCH with high anti-TPO Ab titer were more prevalent in multigravida participants compared to primigravida cases though not statistically significant. As occurrence of SCH varies with nutritional and geographical factors, hence internal trimester specific range should be calculated and used in practice as recommended by ATA 2017 guidelines.

Maternal Hypothyroidism in Rats Reduces Placental Lactogen, Lowers Insulin Levels, and Causes Glucose Intolerance

Hypothyroidism increases the incidence of gestational diabetes mellitus (GDM) but the mechanisms responsible are unknown. This study aimed to assess the pathophysiological mechanisms by which hypothyroidism leads to glucose intolerance in pregnancy. Hypothyroidism was induced in female Sprague-Dawley rats by adding methimazole (MMI) to drinking water at moderate (MOD, MMI at 0.005% w/v) and severe (SEV, MMI at 0.02% w/v) doses from 1 week before pregnancy and throughout gestation. A nonpregnant cohort received the same dose for the same duration but were not mated. On gestational day 16 (GD16), or nonpregnant day 16 (NP16), animals were subjected to an intraperitoneal glucose tolerance test. Tissues and blood samples were collected 4 days later. Hypothyroidism induced a diabetic-like phenotype by GD16 in pregnant females only. Pregnant MOD and SEV females had reduced fasting plasma insulin, less insulin following a glucose load, and altered expression of genes involved in insulin signaling within skeletal muscle and adipose tissue. Hypothyroidism reduced rat placental lactogen concentrations, which was accompanied by reduced percentage β-cell cross-sectional area (CSA) relative to total pancreas CSA, and a reduced number of large β-cell clusters in the SEV hypothyroid group. Plasma triglycerides and free fatty acids were reduced by hypothyroidism in pregnant rats, as was the expression of genes that regulate lipid homeostasis. Hypothyroidism in pregnant rats results in a diabetic-like phenotype that is likely mediated by impaired β-cell expansion in pregnancy. This pregnancy-specific phenomenon is likely due to reduced placental lactogen secretion.

Effect of Hyperthyroidism Control During Pregnancy on Maternal and Fetal Outcome: A Systematic Review and Meta-Analysis

CONTEXT

Although the overt hyperthyroidism treatment during pregnancy is mandatory, unfortunately, few studies have evaluated the impact of treatment on reducing maternal and fetal outcomes.

OBJECTIVE

This study aimed to demonstrate whether treatment to control hyperthyroidism manifested during pregnancy can potentially reduce maternal-fetal effects compared with euthyroid pregnancies through a systematic review with meta-analysis.

DATA SOURCE

MEDLINE (PubMed), Embase, Cochrane Library Central, LILACS/BIREME until May 2021.

STUDY SELECTION

Studies that compared, during the gestational period, treated women with hyperthyroidism versus euthyroid women. The following outcomes of this comparison were: pre-eclampsia, abruptio placentae, fetal growth retardation, gestational diabetes, postpartum hemorrhage, low birth weight, stillbirth, spontaneous abortions, premature birth.

DATA EXTRACTION

Two independent reviewers extracted data and performed quality assessments. Dichotomous data were analyzed by calculating risk differences (DR) with fixed and random effect models according to the level of heterogeneity.

DATA SYNTHESIS

Seven cohort studies were included. The results of the meta-analysis indicated that there was a lower incidence of preeclampsia (p=0.01), low birth weight (p=0.03), spontaneous abortion (p<0.00001) and preterm birth (p=0.001) favouring the euthyroid pregnant group when compared to those who treated hyperthyroidism during pregnancy. However, no statistically significant differences were observed in the outcomes: abruptio placentae, fetal growth retardation, gestational diabetes mellitus, postpartum hemorrhage, and stillbirth.

CONCLUSIONS

Our findings demonstrated that treating overt hyperthyroidism in pregnancy is mandatory and appears to reduce some potential maternal-fetal complications, despite there still being a residual risk of negative outcomes.

Prevalence of Subclinical Hypothyroidism in Pregnancy and Its Association With Anti-thyroperoxidase Antibody and the Occurrence of Gestational Diabetes Mellitus

Introduction Subclinical hypothyroidism (SCH) and gestational diabetes mellitus (GDM) are common endocrinological abnormalities associated with pregnancy. The presence of a raised anti-thyroperoxidase (anti-TPO) antibody titer increases the risk of progression of subclinical hypothyroidism to overt hypothyroidism. Subclinical hypothyroidism and GDM are known to affect maternal and fetal outcomes adversely. A few studies have shown an increased risk of GDM with autoimmune hypothyroidism. However, data regarding this association between GDM, SCH, and anti-TPO Ab are scarce. This study aimed to find the prevalence of autoimmune subclinical hypothyroidism and its association with GDM in pregnancy. Materials and methods In a cross-sectional study, 382 pregnant women at their first antenatal checkup (ANC) were enrolled in the study. Serum thyroid-stimulating hormone (TSH), free T4 (FT4), anti-TPO Ab, and the 75 g oral glucose tolerance test (OGTT) were evaluated. The results obtained were analyzed in Systat Version 13.2 (SPSS Inc., Chicago, IL). Observations Results showed an SCH prevalence of 37.69% with a raised anti-TPO Ab titer in 49.31% of the diagnosed SCH cases, pointing towards an autoimmune etiology. Our study revealed a GDM prevalence of 12.04%. Out of the 46 GDM cases, 16 were found to have SCH and 3 cases had raised anti-TPO Ab titers. In our study, 27.73% of euthyroid pregnant women had a raised anti-TPO Ab titer. Our study revealed no significant association between GDM, SCH, and raised anti-TPO Ab titer. Conclusion Anti-TPO antibody subsequently leads to hypothyroxinemia, for which it is necessary that cases with high titer of anti-TPO antibody though euthyroid should be meticulously followed up and screened for to detect development of hypothyroidism or SCH, particularly in future pregnancies. However, GDM prevalence was at par with the national figure, but with no significant association of SCH and a high anti-TPO ab titer was found with GDM in our study. Further studies with a larger cohort may establish a causal association between the two most common endocrinological disorders observed in pregnancy.

Relationship Between Subclinical Hypothyroidism in Pregnancy and Hypertensive Disorder of Pregnancy: A Systematic Review and Meta-Analysis

OBJECTIVE

Studies have shown a high incidence of subclinical hypothyroidism in pregnancy, but the adverse pregnancy outcomes caused by it are not clear. Therefore, we conducted a systematic review and meta-analysis to evaluate the relationship between subclinical hypothyroidism in pregnancy and hypertensive disorders of pregnancy(HDP) to guide clinical practice.

METHOD

We searched the MEDLINE (PubMed), Cochrane Central, EMBASE, Web of Science, and SCOPUS databases and screened all studies evaluating the relationship between subclinical hypothyroidism in pregnancy and hypertensive disorders of pregnancy. Two researchers independently evaluated the quality of all eligible original studies using the Newcastle-Ottawa Scale (NOS). We also performed a meta-analysis using STATA15.1. Sensitivity analyses were also performed by examining the effects of individual studies as well as using different effect models and detecting any publication bias using the harbord test.

RESULTS

Twenty-two studies were included in the final meta-analysis. Our results indicated that pregnant women with subclinical hypothyroidism had an increased risk of HDP (OR = 1.54(95% CI: 1.21-1.96) I²=67.1%), compared with euthyroidism. Subclinical hypothyroidism in pregnancy was not associated with hypertensive disorders of pregnancy at TSH diagnostic cut-off of less than 3.0 mIU/L (P = 0.077). Curiously, the risk of HDP increases when the TSH diagnostic cut-off value is higher or lower than 4 mIU/L. Although only 9 studies were above the threshold, the risk of developing HDP was still 1.69 times, which was highest in all subgroup analyses. This is consistent with the newly recommended diagnostic cut-off value of 4 mIU/L for TSH by the ATA. Our results consider that the risk of hypertensive disorder complicating pregnancy is increased regardless of the diagnosis of subclinical hypothyroidism at any stage of pregnancy. Unfortunately, there is insufficient evidence to support that patients can benefit from treatment with levothyroxine.

CONCLUSION

The results of this meta-analysis indicate that subclinical hypothyroidism in pregnancy is associated with an increased risk of developing HDP, and this association exists regardless of the gestational period. However, the available evidence cannot support these patients receiving thyroxine intervention can benefit from it, so routine screening is only recommended for pregnant women with risk factors for hypothyroidism. Further research is needed to validate more scientific and rigorous clinical studies to clarify the relationship between subclinical hypothyroidism and HDP to improve patient prognosis.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42021286405).

Association of thyroid disorders with gestational diabetes mellitus: a meta-analysis

PURPOSE

The current meta-analysis aimed to evaluate the association of thyroid dysfunction and autoimmunity with gestational diabetes mellitus (GDM).

METHODS

A comprehensive search from PubMed, Embase, MEDLINE, and Cochrane databases until November 2020 was conducted. Fixed-effect model was used to combine the results when I² was <50%. Random-effect model was used to summarize the results when I² was >50%.

RESULTS

A total of 44 studies were included in the meta-analysis. Low FT4 levels were closely related with GDM in the first and second trimesters of gestation. Hypothyroxinemia (OR: 1.45; 95% CI: 1.25, 1.68; P < 0.00001), overt (OR: 1.80; 95% CI: 1.73, 1.86; P < 0.00001), and subclinical (OR: 1.54; 95% CI: 1.03, 2.30; P = 0.03) hypothyroidism, overt hyperthyroidism (OR: 1.49; 95% CI: 1.09, 2.04; P = 0.01), and positive thyroid antibodies (OR: 1.49; 95% CI: 1.07, 2.07; P < 0.00001) were observed significantly associated with the risk of GDM. Pregnant women with subclinical hyperthyroidism were less likely to develop GDM (OR: 0.62; 95% CI: 0.39, 0.97; P = 0.04).

CONCLUSIONS

Thyroid dysfunction and positive thyroid antibodies were associated with the risk of GDM. Our findings suggest that pregnant women with these thyroid diseases may be offered screening for GDM comprehensively.

The Study of Prevalence and Pattern of Thyroid Disorder in Pregnant Women: A Prospective Study

Background The most frequent thyroid disorder in pregnancy is maternal hypothyroidism. The geographical variation in the prevalence of hypothyroidism during pregnancy is very wide and ranges from 2.5% to 11%. The prevalence of hypothyroidism is more in Asian countries as compared to western countries. Thus, this study was conducted to find out the prevalence of thyroid disorder in pregnancy at our center. Methods The present study was conducted in the Department of Physiology in collaboration with the Department of Obstetrics & Gynecology, Index Medical College, Hospital and Research Center, Indore, MP, India over a period of one and a half years from October 2018 to March 2020. It was a cross-sectional study including 865 pregnant women. The patients' demographic profile was noted in all cases. A detailed history and thorough examination were done in all cases. Serum thyroid-stimulating hormone (TSH), Free T3, and Free T4 (FT3 and FT4) were done along with routine blood investigations as per The Federation of Obstetric and Gynaecological Societies of India-Indian College of Obstetricians and Gynaecologists (FOGSI-ICOG) good clinical practice recommendation. Results In this study, the prevalence of thyroid dysfunction was 10.4%. Of these 90 patients with thyroid dysfunction, subclinical and overt hypothyroidism was found in 5.50% and 0.92%, respectively, whereas subclinical and overt hyperthyroidism was observed in 3.12% and 0.81% pregnant females, respectively. A significant association was found between thyroid dysfunction and maternal age, BMI, parity, and education. Conclusions The prevalence of thyroid dysfunction was 10.4% in this study. Hypothyroidism was more common than hyperthyroidism and subclinical thyroid disorders were more common than overt thyroid disorders in pregnancy. Therefore, we should include thyroid function tests with other routine investigations during pregnancy to detect thyroid dysfunction.

The effects of hypothyroidism and hyperthyroidism on placental Hofbauer cells of pregnant rats

We investigated the effects of maternal thyroid disorders on Hofbauer cells of both the placenta and the fetus in pregnant rats. We divided 21 rats into three groups: control group, induced hypothyroidism (hypo) group and induced hyperthyroidism (hyper) group. Hypothyroidism was induced using propylthiouracil and hyperthyroidism was induced using L-thyroxine. We measured maternal weight, maternal free thyroxine, fetal weight, fetal viability and placental morphology. At the end of the experiment, fetuses of the hypo and hyper groups were less developed than those of the control group. In the hypo and hyper groups, the thickness of the labyrinth zone was decreased, but thickness of the basal zone and decidua basalis was increased. The number of Hofbauer cells was increased in both the hypo and hyper groups. Vascular endothelial growth factor expression was increased in both the hypo and hyper groups compared to controls. Our findings indicate that maternal thyroid disorders exert a negative effect on fetal growth and placental development.

Impact of maternal thyroid hormone in late pregnancy on adverse birth outcomes: A retrospective cohort study in China

The purpose of this study was to explore the impact of maternal thyroid hormone dysfunction in late pregnancy on birth outcomes in a Chinese population. We retrospectively examined hospitalisation records and laboratory data between April 2016 and March 2017 and obtained results from 11,564 consecutive pregnant women with singleton births in which serum thyroid hormone had been examined together with birth outcomes. We assessed the association between maternal thyroid level and dysfunction with adverse birth outcomes based on regression analysis. Hyperthyroidism was associated with an increased risk of preterm birth (PTB, adjusted OR: 2.41, 95% CI: 1.83-3.17) and hypothyroidism was associated with an increased risk of small for gestational age (SGA, adjusted OR: 1.56, 95% CI: 1.10-2.22), while hyperthyroxinaemia was associated with a decreased risk of large for gestational age (LGA, adjusted OR: 0.64, 95% CI: 0.45-0.90). In addition, compared to women with normal FT3 and TSH (≥the 5^th and ≤the 95^th percentiles), women with high free triiodothyronine (FT3 >the 95^th percentile) and low thyroid-stimulating hormone (TSH <the 95^th percentile) had a 4.02- fold higher risk of PTB (95% CI: 2.05-7.88), and women with low FT3 and high TSH had a 4.22- fold greater risk of SGA (95% CI: 1.59-11.23). Our study supports associations between multiple types of maternal thyroid dysfunction in late pregnancy and adverse birth outcomes.

Do maternal urinary iodine concentration or thyroid hormones within the normal range during pregnancy affect growth parameters at birth? A systematic review and meta-analysis

CONTEXT

Iodine, an essential constituent of thyroid hormones, is required for proper growth and development.

OBJECTIVE

To investigate whether growth parameters at birth are associated with maternal urinary iodine concentration (UIC) or normal ranges of thyroid hormones during pregnancy.

DATA SOURCES

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, electronic databases (namely, MEDLINE, Web of Science, the Cochrane Library, Scopus, and Google Scholar) were searched between January 1988 and November 2018 to identify relevant articles.

DATA EXTRACTION

Data from the studies included were independently extracted by 2 investigators using standardized forms developed for this review.

DATA ANALYSIS

The pooled mean birth weight, length, and head circumference values, and 95% confidence intervals were estimated in newborns born to women with UIC < 150 and UIC ≥150 μg/L during pregnancy. Possible linear or nonlinear associations between maternal UIC and the aforementioned anthropometric measures were evaluated. A narrative synthesis of the data was performed for thyroid hormones with levels within the normal range.

RESULTS

Of the 123 studies identified, 11 were eligible for inclusion in the meta-analysis. The pooled mean birth weight, length, and head circumference in newborns whose mothers had UIC < 150 μg/L vs UIC ≥150 μg/L were 2898 g vs 2900 g (P = 0.970), 49.6 cm vs 49.4 cm (P = 0.880), and 34.0 cm vs 34.1 cm (P = 0.933), respectively. Dose-response meta-analyses revealed no significant linear or nonlinear associations between maternal UIC during pregnancy and anthropometric measures at birth. Among the different thyroid function parameters evaluated, high-normal values of maternal free thyroxine and thyrotropin during pregnancy were inversely associated with neonatal birth weight.

CONCLUSION

This systematic review showed that birth weight may be affected by even mild variations in the normal concentrations of maternal thyroid hormones. However, in the current meta-analysis, birth anthropometric measures were not associated with maternal UIC during pregnancy.

Prevalence of Hypothyroidism in Pregnant Women in India: A Meta-Analysis of Observational Studies

INTRODUCTION

This meta-analysis was conducted to estimate the prevalence of hypothyroidism among pregnant women in India.

METHODS

We searched PubMed, Web of Science, Scopus, Google Scholar, and Shodhganga (Indian thesis repository) for observational studies, providing prevalence of hypothyroidism among pregnant women in India. Systematic study selection and data extraction procedures were followed. Quality assessment of each study was done using JBI critical appraisal checklist. The random effects model was used for pooling the effect sizes. Publication bias was assessed using the funnel plot and rank correlation test. I 2 statistics was used to measure heterogeneity across the studies. Heterogeneity in the pooled estimates was further explored with subgroup analyses and meta-regression analysis.

RESULTS

Sixty-one studies were found eligible and included in this review. The pooled estimate of the prevalence of hypothyroidism in pregnant women was 11.07% (95% CI: 8.79-13.84, I 2 = 99%). Pooled prevalence estimates of subclinical and overt hypothyroidism are 9.51% (95% CI: 7.48-12.04, I 2 = 98%) and 2.74% (95% CI: 2.08-3.58, I 2 = 94%).

CONCLUSION

We documented 11.07% pooled prevalence of hypothyroidism in pregnant women in India.

KK, Horo M, Shumayla S, Mehra S. Generating evidence on screening, diagnosis and management of non-communicable diseases during pregnancy; a scoping review of current gap and practice in India with a comparison of Asian context

BACKGROUND

Children born to high-risk pregnancies are more likely to experience adverse health outcomes later in life. As estimated, 15% of all pregnancies are at risk of various life-threatening conditions leading to adverse maternal and foetal outcomes. Millennium Development Goal resulted in the global reduction of maternal death from 390,000 to 275000 in 1990-2015). Similarly, to keep this momentum, the current United Nations Sustainable Development Goal (SDG: 3.1) aims at reducing the global maternal mortality ratio to less than 70 per 100,000 live births by 2030, and this can be achieved by addressing high-risk pregnancy contributing to significant mortality and morbidity. In India, gestational diabetes, gestational hypertension, and gestational hypothyroidism were identified as factors contributing to the high-risk pregnancy. This review summarises the commonly used approach for screening, diagnosis, and management of these conditions in the Asian population. It draws a comparison with the current protocols and guidelines in the Indian setting.

METHODS

Electronic search in PubMed and Google Scholar, reference snowballing, and review of current guidelines and protocols were done between January 2010 to October 2019. Published studies reporting Screening, diagnosis, and management of these conditions were included. Articles selected were then screened, appraised for quality, extract relevant data, and synthesised.

RESULTS

Screening, diagnosis, and management of these three conditions vary and no single universally accepted criteria for diagnosis and management exist to date. In India, national guidelines available have not been evaluated for feasibility of implementation at the community level. There are no national guidelines for PIH diagnosis and management despite the increasing burden and contribution to maternal and perinatal morbidity and mortality. Criteria for diagnosis and management of gestational diabetes, gestational hypertension, and gestational hypothyroidism varies but overall early screening for predicting risk, as reported from majority of the articles, were effective in minimizing maternal and foetal outcome.

CONCLUSION

Existing National guidelines for Screening, Diagnosis, and Management of Gestational Diabetes Mellitus (2018) and Gestational Hypothyroidism (2014) need to be contextualized and modified based on the need of the local population for effective treatment. Findings from this review show that early screening for predicting risk to be an effective preventive strategy. However, reports related to a definitive diagnosis and medical management were heterogeneous.

Prevalence of Thyroid Disorder in Pregnant Women Visiting a Tertiary Care Teaching Hospital: A Descriptive Cross-sectional Study

Introduction:

The function of the thyroid gland is altered during pregnancy. Thyroid disorders during pregnancy are associated with serious maternal and fetal outcomes. Universal screening for thyroid disorders is recommended in the first trimester of pregnancy. This study aims to determine the prevalence of thyroid disorder during pregnancy in women attending a tertiary care hospital.

Methods:

A descriptive cross-sectional study was conducted in the Department of Obstetrics and Gynaecology of Kathmandu Medical College and Teaching Hospital from March 2020 to August 2020 after obtaining ethical approval from the Institutional Review committee with reference number 20032020. The pregnant women >18 years of age, irrespective of their gestational age and gravida status, were included in the study by convenience sampling method. The participants were screened by estimation of thyroid function test. Data were collected, and statistical analysis was done in Statistical Packages for Social Services version 20.0.

Results:

A total of 329 pregnant women were included in this study. The prevalence of thyroid disorders in the present study is 24.62%. The most common thyroid disorder observed was subclinical hypothyroidism comprising 65 (19.75%) cases followed by overt hypothyroidism 8 (2.43%) cases.

Conclusions:

There is a high prevalence of thyroid disorders during pregnancy in our settings. Timely screening of pregnant women helps in the early diagnosis and management of complications related to thyroid disorders.

Influence of maternal region of birth on neonatal outcomes of babies born small

AIM

To compare neonatal outcomes of small for gestational age (SGA) infants born to South Asian (SA)-born women and Australian/New Zealand (ANZ)-born women.

METHODS

Retrospective cohort study at a hospital network in Australia. Maternal and neonatal data were collected for infants born SGA between 2013 and 2017 to SA- or ANZ-born women. Rates of perinatal mortality and neonatal morbidities were analysed between groups.

RESULTS

A total of 1018 SA and 959 ANZ SGA infants were included. SA SGA babies were older (median [IQR] 39 [38-40] weeks) and heavier (2590 [2310-2780] grams) compared to ANZ SGA babies (38 [37-40] weeks and 2480 [2059-2740] grams; P < .001 for both). After adjustment for differences in demographics, SA SGA babies were 1.5 times more likely to develop hypothermia (CI: 1.16-1.88, P = .001), but 60% less likely to be born with a major congenital malformation (CI: 0.24-0.67, P = .001) and 36% less likely to need gavage feeding (CI: 0.43-0.93, P = .02) compared to ANZ SGA babies.

CONCLUSION

Small for gestational age babies of SA-born women have different neonatal outcomes as compared to those born to ANZ-born women. Further research into influence of maternal region of birth on placental function, organogenesis and body composition of SGA babies is warranted.

Consequences of Iodine Deficiency and Excess in Pregnancy and Neonatal Outcomes: A Prospective Cohort Study in Rio de Janeiro, Brazil

Background: Insufficient or excessive iodine intake during gestation may compromise adaptive mechanisms in maternal thyroid function and lead to adverse pregnancy outcomes. In this context, we aimed to study the effects of maternal iodine status in the first and third trimesters of gestation on obstetric and neonatal outcomes in an iodine-sufficient population in Rio de Janeiro, Brazil. Methods: A total of 214 pregnant women in the first trimester of gestation were enrolled and prospectively followed until delivery between 2014 and 2017. All participants were ≥18 and ≤35 years, had a spontaneous single pregnancy, and had no history of thyroid or other chronic diseases, nor were they taking iodine-containing supplements at enrollment. In the first trimester, we obtained clinical information and determined thyroid function and the urinary iodine concentration (UIC) of the participants. Thyroid function and UIC were reassessed in the third trimester. Iodine status was determined by the median of UIC obtained from six urine spot samples by the inductively coupled plasma mass spectrometry method. Pregnancy and neonatal outcomes and delivery information were obtained from medical records. Results: The median UIC in the whole population was 219.7 μg/L. The prevalence of UIC <150 μg/L was 17.2%, and 38.7% had UIC ≥250 μg/L. Gestational diabetes (GDM) was higher in the group with UIC 250-499 μg/L (n = 77) compared with the group with UIC 150-249 μg/L (n = 94) (20.3% vs. 9.7%, p < 0.05). Ultimately, UIC ≥250 μg/L was an independent risk factors for GDM (relative risk [RR] = 2.9 [confidence interval, CI = 1.1-7.46], p = 0.027) and hypertensive disorders of pregnancy (HDP) (RR = 4.6 [CI = 1.1-18.0], p = 0.029). Among 196 live-born newborns, lower birth length was observed in infants whose mothers had UIC <150μg/L (n = 37) in the first trimester compared with those with UIC 150-249 μg/L (n = 86) (median interquartile range: 48.0 [2.2] vs. 49.0 [4.0] cm, p = 0.01). Maternal UIC <150 μg/L was negatively associated with birth length of newborns (Exp (B) = 0.33 [CI = 0.1-0.9], p = 0.03). Conclusions: In a population whose median iodine intake is sufficient, extensive individual variation occurs. Such abnormalities are associated with increased GDM and HDP when UIC is ≥250 μg/L, and lower infant birth length when UIC is <150 μg/L.

New Insights into Mechanisms of Endocrine-Disrupting Chemicals in Thyroid Diseases: The Epigenetic Way

In recent years, the presence in the environment of chemical compounds with thyroid-disrupting effects is progressively increased. This phenomenon has risen concern for human health as the preservation of thyroid system homeostasis is essential for fetal development and for maintaining psychological and physiological wellbeing. An increasing number of studies explored the role of different classes of toxicants in the occurrence and severity of thyroid diseases, but large epidemiological studies are limited and only a few animal or in vitro studies have attempted to identify the mechanisms of chemical action. Recently, epigenetic changes such as alteration of methylation status or modification of non-coding RNAs have been suggested as correlated to possible deleterious effects leading to different thyroid disorders in susceptible individuals. This review aims to analyze the epigenetic alterations putatively induced by chemical exposures and involved in the onset of frequent thyroid diseases such as thyroid cancer, autoimmune thyroiditis and disruption of fetal thyroid homeostasis.

Management of overt hypothyroidism during pregnancy

Overt hypothyroidism is a common endocrine disorder affecting 1-2% of women of reproductive age. Optimizing treatment in pregnant women with overt hypothyroidism can reduce adverse fetal and maternal outcomes. Ideally, women who are known to have a history of hypothyroidism or those with risk factors for becoming hypothyroid, should have adequate preconception care to ensure euthyroidism from the onset of pregnancy, with a TSH target of below 2.5mIU/L. On women who are already on levothyroxine, an empirical dose increase of 30-50% as soon as pregnancy is confirmed may be considered. During pregnancy, levothyroxine doses should be titrated against TSH, which have trimester-specific ranges. In women who are known to be hypothyroid but are inadequately treated, we recommend a doubling of levothyroxine dose on at least three days a week to rapidly achieve euthyroidism. In newly diagnosed overt hypothyroidism in pregnancy, starting doses of either 100 or 150 mg daily may be considered safe.

Universal screening for thyroid disease during pregnancy should be performed

Thyroid disease can significantly impact the pregnant woman and her child. Human and animal studies have firmly linked overt hypothyroidism and overt hyperthyroidism to miscarriage, preterm delivery and other adverse pregnancy outcomes. Overt hypothyroidism and overt hyperthyroidism affect 1% of all pregnancies. Treatment is widely available, and if detected early, results in decreased rates of adverse outcomes. Universal screening for thyroid disease in pregnancy can identify patients with thyroid disease requiring treatment, and ultimately decrease rates of complications. Universal screening is cost-effective compared to the currently accepted practice of targeted screening and may even be cost-saving in some healthcare systems. Targeted screening, which is recommended by most professional associations, fails to detect a large proportion of pregnant women with thyroid disease. In fact, an increasing number of providers are performing universal screening for thyroid disease in pregnancy, contrary to society guidelines. Limited evidence concerning the impact of untreated and treated subclinical disease and thyroid autoimmunity has distracted from the core rationale for universal screening - the beneficial impact of detecting and treating overt thyroid disease. Evidence supporting universal screening for overt disease stands independently from that of subclinical and autoimmune disease. The time to initiate universal screening is now.

Maternal, cord, and three-year-old child serum thyroid hormone concentrations in the Health Outcomes and Measures of the Environment study

PURPOSE

Maternal thyroid function during pregnancy may influence offspring thyroid function, though relations between maternal and child thyroid function are incompletely understood. We sought to characterize relations between maternal, cord and child thyroid hormone concentrations in a population of mother-child pairs with largely normal thyroid function.

METHODS

In a prospective birth cohort, we measured thyroid hormone concentrations in 203 mothers at 16 gestational weeks, 273 newborns and 159 children at 3 years among participants in the Health Outcomes and Measures of the Environment (HOME) Study. We used multivariable linear regression to estimate associations of maternal thyroid hormones during pregnancy with cord serum thyroid hormones and also estimated associations of maternal and cord thyroid hormones with child thyroid-stimulating hormone (TSH).

RESULTS

Each doubling of maternal TSH was associated with a 16.4% increase of newborn TSH (95% CI: 3.9%, 30.5%), and each doubling of newborn TSH concentrations was associated with a 10.4% increase in child TSH concentrations at 3 years (95% CI: 0.1%, 21.7%). An interquartile range increase in cord FT4 concentrations was associated with an 11.7% decrease in child TSH concentrations at 3 years (95% CI: -20.2%, -2.3%).

CONCLUSIONS

We observed relationships between maternal, newborn and child thyroid hormone concentrations in the HOME Study. Our study contributes to understandings of interindividual variability in thyroid function among mother-child pairs, which may inform future efforts to identify risk factors for thyroid disorders or thyroid-related health outcomes.

Obstetric complications in bipolar disorder: Psychiatric factors and the risk of caesarean section

Bipolar Disorder (BD) is a chronic psychiatric condition with somatic morbidity that requires continuous mood stabilizing treatment to prevent relapses. Pregnant women with BD have shown an increased rate of caesarean section (C-Section) in comparison with women without BD. Because specific differentiated profiles between mothers with BD that require C-Section and those that do not require C-Section have not been largely discussed, we aim to explore the risk factors associated with the type of delivery in pregnant women with BD. A prospective cohort study was conducted at the Perinatal Mental Health Unit. 100 pregnant women with BD were followed throughout their pregnancy by obstetric and psychiatric services at the same hospital. The cohort was developed in order to compare psychiatric and obstetric outcomes between women with BD that required C-Section (N = 40) versus women that did not require C-Section (N = 60). Final regression models showed an increased risk for obstetric complications during labour (OR 4,52, 95% CI 1,66-12,29), higher rates of hypothyroidism (OR 3,73, 95% CI 1,04-13,73) and treatment with lithium + antidepressant (OR 4,24, 95% CI 1,34-13,40) amongst the C-Section group when compared to the non-C-Section group. In our sample, women with BD treated with lithium plus antidepressant, with hypothyroidism and without obstetric complications have a 70,5% probability of C-Section. In conclusion, psychopharmacology and thyroid function might help understanding which women with BD will have more probability of C-Section. The implementation of more targeted interventions in selected patients might be useful to avoid complications during delivery.

Association between thyroid hormone parameters during early pregnancy and gestational hypertension: a prospective cohort study

Objective

Thyroid dysfunction may play a role in the development of gestational hypertension. However, this relationship remains unclear. This study was performed to evaluate the association between thyroid hormone parameters during early pregnancy and gestational hypertension.

Methods

Women with singleton pregnancies were recruited into this prospective cohort study at 9 to 13 gestational weeks, and their serum thyroid-stimulating hormone, free thyroxine, and free triiodothyronine concentrations were measured using electrochemiluminescence immunoassays. In total, 1226 participants were included in the final analysis.

Results

Of the 1226 participants, 81 subsequently developed gestational hypertension (overall incidence of 6.6%). Compared with women with euthyroidism, both pregnant women with hypothyroidism and those with subclinical hypothyroidism had an increased risk of gestational hypertension (adjusted odds ratio [OR], 3.61; 95% confidence interval [CI], 1.52–8.57 and OR, 2.24; 95% CI, 1.06–4.72, respectively). When the thyroid-stimulating hormone and free thyroxine concentrations were analyzed by quintiles, the women in the highest thyroid-stimulating hormone quintile had a higher risk of gestational hypertension (adjusted OR, 4.22; 95% CI, 1.78–9.05) than the women in the middle quintile.

Conclusion

Our results suggest that hypothyroidism, subclinical hypothyroidism, and a high thyroid-stimulating hormone concentration during early pregnancy are risk factors for gestational hypertension.

Association between thyroid dysfunction and perinatal outcomes in women with gestational hypertension: a retrospective study

Background

Previous studies showed that thyroid dysfunction in women with gestational hypertension could negatively affect maternal and fetal outcomes. In this study, we aimed to investigate whether thyroid dysfunction assessed in the second half trimester contributed to neonatal outcomes of pregnancy in different subtypes of gestational hypertension disease.

Methods

We performed a retrospective case-control study and collected data from 135 singleton pregnant women with gestational hypertension disease and their offspring who delivered in Renmin Hospital of Wuhan University from January 2015 to June 2017. We classified the patients based on the severity of the preeclampsia into three groups: pregnant induced hypertension (PIH), mild preeclampsia (MPE) and severe preeclampsia (SPE). Based on the onset time of preeclampsia, we classified the patients into PIH, early onset preeclampsia (EPE) and late onset preeclampsia. Demographic data and levels of thyroid hormones, as well as the adverse maternal and neonatal outcomes were collected from Electronic Medical Records. Logistic regression was used to estimate the associations between thyroid dysfunction and neonatal outcomes in these patients.

Results

Gestational weeks and neonatal birthweight were significantly lower, while incidence of preterm birth was significantly higher in the SPE and EPE groups than those in the PIH group (P < 0.001). Thyroid dysfunction was more frequent in the SPE group than in the MPE group (P = 0.01). Incidences of both preterm birth and low birth weight were significantly higher in patients with thyroid dysfunction (P = 0.008, P = 0.047 respectively). After adjustment, both severity of gestational hypertension (OR = 4.360, 95%CI [2.050, 9.271], P < 0.001; OR = 4.023, 95%CI [1.933, 8.372], P < 0.001) and thyroid dysfunction (OR = 3.011, 95%CI [1.248, 7.262], P = 0.014; OR = 11.306, 95%CI [1.040, 122.889], P = 0.046) were associated with higher risk of preterm birth and low birth weight, while the onset time of preeclampsia (OR = 0.031, 95%CI [0.009, 0.110], P < 0.001; OR = 0.097, 95%CI [0.033, 0.282], P < 0.001) was negatively associated with the risk of preterm birth and low birth weight.

Conclusion

Severe and early onset preeclampsia, as well as thyroid dysfunction are associated with higher risk of preterm birth and low neonatal birth weight. Therefore, our data suggest that monitoring thyroid hormones in women with preeclampsia might help to predict adverse neonatal outcomes.

Pregnancy Outcomes among Obese Pregnant Women with Hypothyroidism: Medical Record Review of a Single Tertiary Center in Saudi Arabia

Background Thyroid disorder is common among pregnant women. Hashimoto thyroiditis is the most common etiology of hypothyroidism among pregnant women. Many studies showed that hypothyroidism during pregnancy has been associated with negative outcomes for the mother and for child as well including miscarriage, intrauterine growth retardation, preterm delivery and cognitive impairment in the offspring. Objectives To assess the adverse maternal and neonatal outcome among hypothyroidism obese pregnant women. Methods This is a retrospective study conducted among obese pregnant women diagnosed with hypothyroidism attending King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia between January 1, 2013, and December 31, 2018. For analysis, we used (1) descriptive statistics, (2) Chi-square test, Pearson correlation, independent t-test, and one-way ANOVA to test the difference in thyroid stimulating hormone (TSH) levels and adverse pregnancy outcomes. A p-value of <0.05 is used to calculate statistical significance. Results A total of 9095 pregnant women had delivered in the last five years, 65 of these pregnant women had been diagnosed with hypothyroidism and 57 were enrolled in our study. Out of 65, 44 (77.2%) were Saudi, and 13 (22.8%) non-Saudis. Mean age at the time of delivery was 32.9 ± 5.6 years, while BMI means were 35.7 ± 4.6. A total of 35 (61.4%) were from class 1, 14 (26.2%) were from class 2 and eight (12.3%) were from class 3. Out of 57, 16 (28.1%) developed undesired antepartum outcomes, while 14 (21.5%) had postpartum outcomes. Preterm labor, gestational diabetes mellitus, and urinary tract infections were significantly associated with abnormal TSH levels (P < 0.05). Conclusion As demonstrated earlier, hypothyroidism during pregnancy leads to unfavorable outcomes. Therefore, screening for thyroid function tests in prenatal and antenatal periods is vital to avoid potential adverse outcomes.

Impact of an integrated nutrition, health, water sanitation and hygiene, psychosocial care and support intervention package delivered during the pre- and peri-conception period and/or during pregnancy and early childhood on linear growth of infants in the first two years of life, birth outcomes and nutritional status of mothers: study protocol of a factorial, individually randomized controlled trial in India

Background

The period from conception to two years of life denotes a critical window of opportunity for promoting optimal growth and development of children. Poor nutrition and health in women of reproductive age and during pregnancy can negatively impact birth outcomes and subsequent infant survival, health and growth. Studies to improve birth outcomes and to achieve optimal growth and development in young children have usually tested the effect of standalone interventions in pregnancy and/or the postnatal period. It is not clearly known whether evidence-based interventions in the different domains such as health, nutrition, water sanitation and hygiene (WASH) and psychosocial care, when delivered together have a synergistic effect. Further, the effect of delivery of an intervention package in the pre and peri-conception period is not fully understood. This study was conceived with an aim to understand the impact of an integrated intervention package, delivered across the pre and peri-conception period, through pregnancy and till 24 months of child age on birth outcomes, growth and development in children.

Methods

An individually randomized controlled trial with factorial design is being conducted in urban and peri-urban low- to mid-socioeconomic neighbourhoods in South Delhi, India. 13,500 married women aged 18 to 30 years will be enrolled and randomized to receive either the pre and peri-conception intervention package or routine care (first randomization). Interventions will be delivered until women are confirmed to be pregnant or complete 18 months of follow up. Once pregnancy is confirmed, women are randomized again (second randomization) to receive either the intervention package for pregnancy and postnatal period or to routine care. Newborns will be followed up till 24 months of age. The interventions are delivered through different study teams. Outcome data are collected by an independent outcome ascertainment team.

Discussion

This study will demonstrate the improvement that can be achieved when key factors known to limit child growth and development are addressed together, throughout the continuum from pre and peri-conception until early childhood. The findings will increase our scientific understanding and provide guidance to nutrition programs in low- and middle-income settings.

Trial registration

Clinical Trial Registry – India #CTRI/2017/06/008908; Registered 23 June 2017, http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=19339&EncHid=&userName=society%20for%20applied%20studies

Maternal Thyroid Dysfunction and Gestational Anemia Risk: Meta-Analysis and New Data

Background: Previous studies indicate the effects of thyroid dysfunction on adverse obstetric outcomes and fetal neurodevelopment, of which the results on gestational anemia are controversial. Here, we evaluated the influence of thyroid dysfunction on gestational anemia via published epidemiological articles and a new prospective study conducted by our team, respectively. Methods: We searched studies on the PubMed, Embase, MEDLINE, and Cochrane databases as of November 2019, and conducted a prospective study in which participants underwent thyroid function and blood routine testing throughout pregnancy. Results: The meta-analysis showed that pregnancies with overt hypothyroidism [OH; odds ratio (OR) = 3.74, 95% confidence interval (CI): 1.95-7.15] or that were thyroid peroxidase antibody (TPOAb)-positive (OR = 1.97, 95%CI: 1.19-3.26) had increased anemia risk, but similar results were not found in pregnancies with subclinical hypothyroidism (SCH) and hyperthyroidism. In the prospective study from our new data, the hypothyroid group had significant reductions in hemoglobin (Hb) (P = 0.048) and increased anemia risk (OR = 6.384, 95%CI: 2.498-16.311) during the second half of pregnancy. From the first to second half of pregnancy, the longitudinal reductions in Hb, erythrocyte (RBC), and hematocrit (Hct) levels were significantly increased in hypothyroid group. Conclusions: Our meta-analysis indicates that untreated OH or TPOAb-positive pregnant women have increased risk of anemia. In addition, our new data showed that treated hypothyroidism is also a risk factor for anemia in the second half of pregnancy rather than in the first half. The results may guide strengthening of Hb monitoring in pregnancies with thyroid dysfunction.

Maternal characteristics and outcomes affected by hypothyroidism during pregnancy (maternal hypothyroidism on pregnancy outcomes, MHPO-1)

BACKGROUND

Hypothyroidism in pregnancy is an arena of ongoing research, with international conflicts regarding screening, management, and outcomes. Various studies have described the outcomes depending on geographical and international diagnostic criteria. No study has been conducted in this regard from the region of Pakistan. Therefore, we aim to report the clinical features and maternal outcomes of hypothyroid pregnancies and compare the maternal outcomes between uncontrolled and controlled TSH levels in the preconception as well as the gestational period.

METHODS

We conducted a cross-sectional retrospective study on 718 cases in the Aga Khan University Hospital after ethical approval. We collected information on pregnant females who have diagnosed hypothyroidism before conception or during their antenatal period. We noted the maternal characteristics and maternal comorbidities. Laboratory data were recorded for thyroid stimulating hormone levels before conception and during gestation. We recorded maternal outcomes as pregnancy loss (including miscarriage, stillbirth/intrauterine death, medical termination of pregnancy and ectopic pregnancy), gestational hypertension, pre-eclampsia, postpartum hemorrhage, placental abruption, and modalities of delivery. Data analysis was performed on Statistical Package for the Social Sciences version 20.0.

RESULTS

Among 708 hypothyroid women 638 had live births. Postpartum hemorrhage was the most frequent maternal outcome (38.8%). The emergency cesarean section occurred in 23.4% of cases. We determined TSH levels in 53.2, 56.7, 61.7 and 66.6% of cases in preconception, 1st, 2nd, and 3rd trimester periods. A significant association existed between cesarean section and preconception thyrotropin levels > 2.5 mIU/L, whereas postpartum hemorrhage was significantly associated with thyrotropin levels > 2.5 mIU/L in the preconception and third trimester.

CONCLUSION

Successful live births in our patients were complicated by maternal postpartum hemorrhage and a frequent number of emergency cesarean section.

Subclinical hypothyroidism in pregnancy

PURPOSE OF REVIEW

Subclinical hypothyroidism (SCH) is a common diagnosis among women of reproductive age. The importance of sufficient maternal thyroid supply during pregnancy is well known. Nevertheless, the effects of SCH during pregnancy and the efficacy of its treatment on maternofetal outcomes are not well established. This review discusses the recent evidence on SCH in pregnancy and how this evidence is reflected in current clinical care.

RECENT FINDINGS

Recent observational studies have found a positive association between SCH during pregnancy and adverse maternal, neonatal and offspring outcomes, mainly in thyroid peroxidase autoantibody positive women. Although interventional studies have shown a benefit of levothyroxine (LT4) treatment on selected pregnancy outcomes, there was no effect on offspring neurodevelopment.

SUMMARY

Current evidence strengthens the association between SCH with both maternofetal and offspring adverse outcomes. An earlier and more individualized diagnostic assessment taking into consideration predictors of thyroid dysfunction and major risk factors for complications could result in better management of SCH during pregnancy. The effectiveness of LT4 on improving maternofetal and long-term offspring outcomes is still not fully elucidated.