Overt and subclinical hypothyroidism complicating pregnancy

Association between antinuclear antibodies and pregnancy prognosis in recurrent pregnancy loss patients

STUDY QUESTION

Can antinuclear antibodies (ANA) affect the subsequent live birth rate (LBR) in patients with unexplained recurrent pregnancy loss (RPL) in the absence of antiphospholipid antibodies (aPL)?

SUMMARY ANSWER

Women with unexplained RPL have a high probability of live birth following a positive pregnancy test (>70%), being similar between those with positive and negative ANA testing, regardless of the cut-off value.

WHAT IS KNOWN ALREADY

The RPL guidelines of the ESHRE state that 'ANA testing can be considered for explanatory purposes'. However, there have been a limited number of studies on this issue and sample sizes have been small, and the impact of ANA on the pregnancy prognosis is unclear.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study was conducted at Nagoya City University Hospital between 2006 and 2019. The study included 1021 women with RPL without known cause.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Hysterosalpingography or 3D-ultrasound, chromosome analysis for both partners, blood tests for aPL, ANA, hypothyroidism, and diabetes mellitus were performed before a subsequent pregnancy. ANAs were measured by indirect immunofluorescence on Hep-2 cell slides. The cutoff dilution used was 1:40. In addition, patients were classified according to the ANA pattern on immunofluorescence staining: homogeneous, speckled, nucleolar, centromeric, peripheral, cytoplasmic, and others. LBRs were compared between ANA-positive and ANA-negative patients after excluding patients with antiphospholipid antibody syndrome, an abnormal chromosome in either partner and a uterine anomaly.

MAIN RESULTS AND THE ROLE OF CHANCE

Considering the cut-off value = 1:40 dilution, the subsequent LBRs were 72.5% (256/353) for the ANA-positive group and 73.2% (489/668) for the ANA-negative group; odds ratio (OR) = 0.97, 95% CI = 0.72-1.29. After excluding the miscarriages occurring from embryonic aneuploidy, the biochemical pregnancy losses, and the ectopic pregnancies, LBRs were 92.8% (256/276) for the ANA-positive group and 93.0% (489/526) for the ANA-negative group: OR = 0.97 (95% CI = 0.55-1.70). Considering the cut-off value = 1:80 dilution, the subsequent LBRs were 75.0% (87/116) for the ANA-positive group and 72.7% (658/905) for the ANA-negative group; OR = 1.13 (95% CI = 0.72-1.76). After excluding the miscarriages occurring from embryonic aneuploidy, the biochemical pregnancy losses, and the ectopic pregnancies, LBRs were 89.7% (87/97) for the ANA-positive group and 93.3% (658/705) for the ANA-negative group: OR = 0.62 (95% CI = 0.30-1.27). Considering the cut-off value = 1:160 dilution, the subsequent LBRs were 82.4% (28/34) for the ANA-positive group and 72.6% (717/987) for the ANA-negative group; OR = 1.76 (95% CI = 0.72-4.29). After excluding the miscarriages occurring from embryonic aneuploidy, the biochemical pregnancy losses, and the ectopic pregnancies, LBR were 93.3% (28/30) for the ANA-positive group and 92.9% (717/772) for the ANA-negative group: OR = 1.07 (95% CI = 0.25-4.63). There was no difference in LBR between the 2 groups before or after adjustment for age and BMI, but ANA-positive patients were significantly older than ANA-negative patients when using the 1:40 dilution, and ANA-positive patients had significantly lower BMIs than ANA-negative patients when using the 1:80 dilution.

LIMITATIONS, REASONS FOR CAUTION

A healthy control group was not established, making it impossible to compare ANA positivity rates between healthy controls and RPL patients. There were significant differences in age (1:40 dilution) and BMI (1:160 dilution) between the ANA-positive and ANA-negative groups.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that ANA testing is not useful to predict future pregnancy loss in women with RPL without known cause.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by MEXT Promotion of Distinctive Joint Research Center Program, Grant Number JPMXP0621467963 and used for English proofreading costs. There are no competing interests for all authors.

TRIAL REGISTRATION NUMBER

N/A.

Impact of Hypothyroidism in Pregnancy on Feto-Maternal Outcomes: A Prospective Observational Study

Introduction Hypothyroidism represents an endocrine disorder marked by the insufficient production of hormones by the thyroid gland, with significant effects on bodily functions. Its occurrence during pregnancy is of particular concern due to its profound effects on both maternal and fetal health outcomes. Aim To study the impact of hypothyroidism in pregnancy and its correlation with feto-maternal outcomes. Methodology The present study is a two-year prospective observational study carried out at a tertiary care hospital from July 2022 to June 2024. A total of 350 antenatal women with singleton pregnancies and without any pre-existing medical disorder were screened. Serum thyroid stimulating hormone (TSH) was evaluated with a cut-off value of 4.0 mIU/L. If serum TSH was abnormal, free thyroxine (FT4) and free triiodothyronine (FT3) levels were assessed. The participants were categorized into three groups designated as euthyroid, overt hypothyroidism, and subclinical hypothyroidism. TSH was periodically re-evaluated at 16 weeks, 20 weeks, and 32 weeks. All patients were monitored up to the point of delivery, allowing for comparison of outcomes across the three groups. Results The prevalence of hypothyroidism in the present study was 11.14% (n=39). Eight percent (n=28) of the cases had subclinical hypothyroidism whereas 3.14% (n=11) of cases had overt hypothyroidism. Hypothyroidism was more common in the 26-30 years age group. There was a higher incidence of hypothyroidism in multigravida patients. Lower segment caesarean section (LSCS) was the most common mode of delivery in the women with hypothyroidism. Maternal outcomes included preeclampsia, eclampsia, anemia, gestational hypertension, gestational diabetes mellitus (GDM), spontaneous miscarriage, preterm labor, oligohydramnios, etc. The fetal outcomes included intrauterine growth restriction (IUGR), low birth weight (LBW) and fetal distress. Conclusion Early diagnosis and adequate treatment of maternal hypothyroidism leads to successful pregnancy outcomes. Therefore, universal thyroid screening in pregnancy is recommended in order to prevent maternal and fetal complications.

Causal association between thyroid function and the risk of infertility: a Mendelian randomization study

Objectives

Thyroid dysfunction is commonly associated with the risk of infertility in both females and males. However, recent randomized controlled trials have demonstrated that thyroid function levels in females are not significantly related to infertility, and evidence on the association between male thyroid function and infertility is limited. We aim to investigate the association between thyroid function levels and infertility in both females and males.

Method

A two-sample Mendelian randomization study was conducted using four methods, with the inverse variance weighted method (IVW) as the primary approach. Data on thyroid function as the exposure were obtained from the ThyroidOmics Consortium and UK Biobank, including over 700,000 individuals from a large meta-analysis of genome-wide association studies for thyroid function and dysfunction. The outcome data for infertility in both sex encompassed more than 70,000 individuals from the FinnGen Consortium. All participants were adults of European ancestry. The MR Egger regression intercept and Cochran's Q test were employed to evaluate directional pleiotropy and heterogeneity.

Results

The results indicated no causal effect of thyroid-stimulating hormone (TSH) and free tetraiodothyronine (fT4) on female and male infertility. Furthermore, no causal association between hypo- and hyperthyroidism and infertility were identified. Notably, we observed a causal relationship between high TSH and endometriosis-related infertility (OR=0.82, 95% CI: 0.74-0.91, P = 1.49E-04).

Conclusions

This study did not find evidence for casual relationship between thyroid function levels and risk of infertility. The findings suggest that overall thyroid function levels may not be a significant predictor of infertility risk.

Exposure to Macrolides During Pregnancy and the Risk for Spontaneous Abortions: A Population-Based Retrospective Cohort Study

Previous studies evaluating the risk of spontaneous abortions following exposure to macrolides reported controversial results. The goal of the current study was to examine the risk for spontaneous abortions following exposure to macrolides during pregnancy. We conducted a population-based retrospective cohort study by linking three computerized databases: Clalit Health Services drug dispensation database, Soroka Medical Center (SMC) birth database, and SMC hospitalizations database. Multivariate time-varying Cox regressions were performed and adjusted for suspected confounders and known risk factors for spontaneous abortions. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated. A secondary analysis was performed to assess the association between exposure to macrolides in terms of the defined daily dose dispensed and spontaneous abortions. The study cohort included 65,457 pregnancies that ended at Soroka Medical Center between 2004 and 2009, of which 6508 (9.9%) resulted in a spontaneous abortion. A total of 825 (1.26%) pregnancies were exposed to macrolides during the exposure period. Exposure to macrolides was not associated with spontaneous abortions as a group (adjusted HR 1.00 95% CI 0.77-1.31) or as specific medications. There was no evidence of a dose-response relationship between exposure to macrolides and spontaneous abortions. In conclusion, this population-based retrospective cohort study did not detect an increased risk for spontaneous abortion following exposure to macrolides during the first trimester of pregnancy.

Investigating the complications of frequent pregnancy loss in patients referred to obstetrics and gynecology clinics at King Khalid University Hospital

Background

Recurrent pregnancy loss (RPL) is a common problem affecting many women. This study aimed to investigate the baseline characteristics of 400 women with RPL and to examine any differences in baseline characteristics of the recruited women with RPL throughout the years.

Methods

This study used retrospective data, which included the records of patients with RPL who visited King Khalid University Hospital's obstetric clinic between 2019 and 2022. The records of 400 patients who met the inclusion criteria were reviewed and analyzed.

Results

The mean age of enrolled women was 36.5 ± 5.4 years, and the mean RPL was 3.8 ± 2.5. The study also revealed that there were significant statistical differences in obesity and vitamin D deficiency among women with RPL based on year (P = 0.013 and P = 0.036, respectively), whereas no significant statistical differences were found between women with RPL in terms of age, parity, diabetes, hypothyroidism, hyperprolactinemia, antiphospholipid antibodies (APLs), uterine malformation, or consanguinity.

Conclusion

Advanced maternal age, number of previous miscarriages, parity, diabetes, hypothyroidism, APLs, uterine malformations, first-degree consanguinity, and vitamin D deficiency were found to be significant risk factors associated with RPL among women in Saudi Arabia.

A Review of Autoimmune Thyroid Diseases and Their Complex Interplay with Female Fertility

Hashimoto thyroiditis and Graves' disease are autoimmune thyroid disorders that are common in women of reproductive age and have a complex relationship with female fertility and health of the maternal-fetal dyad. Both hyperthyroidism and hypothyroidism, whether subclinical or overt in severity, directly or indirectly affect nearly every level of the hypothalamic-pituitary-ovary axis, uterine and ovarian function, as well as fetal development from implantation through delivery. Autoimmunity itself also appears to negatively impact both spontaneous and assisted fertility, as well as miscarriage risk, although the mechanism remains unclear, and the presence and magnitude of risk is variable in published literature. While treatment of overt hyperthyroidism and hypothyroidism is unequivocally recommended by professional societies, the impact of treatment on fertility outcomes, and the role of treatment in subclinical thyroid disease is more controversial. Unfortunately, levothyroxine has not been shown to abrogate the risk of subfertility and miscarriage observed in euthyroid thyroid autoantibody positive women.

Overt hypothyroidism in pregnancy and language development in offspring: is there an association?

PURPOSE

Overt hypothyroidism during pregnancy is linked to various obstetric complications, such as premature birth and fetal death. While some studies have shown that maternal hypothyroidism can impact a child's Intelligence Quotient (IQ) and language development, findings are controversial. The aim of this study was to explore the connection between treated maternal hypothyroidism during pregnancy and offspring neurodevelopment, focusing on learning and language and examining related maternal obstetric complications.

METHODS

Group 1 included 31 hypothyroid women with elevated thyroid stimulating hormone (TSH) (> 10 mU/L, > 10 µIU/mL) during pregnancy, and Group 2 had 21 euthyroid women with normal TSH levels (0.5-2.5 mU/L, 0.5-2.5 µIU/mL). Children underwent neuropsycological assessments using the Griffiths-II scale.

RESULTS

Pregnancy outcome showed an average gestational age at delivery of 38.2 weeks for hypothyroid women, compared to 40 weeks for controls, and average birth weight of 2855.6 g versus 3285 g for controls, with hypothyroid women having children with higher intrauterine growth restriction (IUGR) prevalence and more caesarean sections. The 1-min APGAR score was lower for the hypothyroid group's children, at 8.85 versus 9.52. Neuropsychological outcomes showed children of hypothyroid mothers scored lower in neurocognitive development, particularly in the learning and language subscale (subscale C), with a notable correlation between higher maternal TSH levels and lower subscale scores.

CONCLUSION

Fetuses born to hypothyroid mothers appeared to be at higher risk of IUGR and reduced APGAR score at birth. Neurocognitive development seemed to affect language performance more than the developmental quotient. This alteration appeared to correlate with the severity of hypothyroidism and its duration.

HDAC1/2/3-mediated downregulation of neurogranin is involved in cognitive impairment in offspring exposed to maternal subclinical hypothyroidism

Subclinical hypothyroidism (SCH) in pregnancy is the most common form of thyroid dysfunction in pregnancy, which can affect fetal nervous system development and increase the risk of neurodevelopmental disorders after birth. However, the mechanism of the effect of maternal subclinical hypothyroidism on fetal brain development and behavioral phenotypes is still unclear and requires further study. In this study, we constructed a mouse model of maternal subclinical hypothyroidism by exposing dams to drinking water containing 50 ppm propylthiouracil (PTU) during pregnancy and found that its offspring were accompanied by severe cognitive deficits by behavioral testing. Mechanistically, gestational SCH resulted in the upregulation of protein expression and activity of HDAC1/2/3 in the hippocampus of the offspring. ChIP analysis revealed that H3K9ac on the neurogranin (Ng) promoter was reduced in the hippocampus of the offspring of SCH, with a significant reduction in Ng protein, leading to reduced expression levels of synaptic plasticity markers PSD95 (a membrane-associated protein in the postsynaptic density) and SYN (synaptophysin, a specific marker for presynaptic terminals), and impaired synaptic plasticity. In addition, administration of MS-275 (an HDAC1/2/3-specific inhibitor) to SCH offspring alleviated impaired synaptic plasticity and cognitive dysfunction in offspring. Thus, our study suggests that maternal subclinical hypothyroidism may mediate offspring cognitive dysfunction through the HDAC1/2/3-H3K9ac-Ng pathway. Our study contributes to the understanding of the signaling mechanisms underlying maternal subclinical hypothyroidism-mediated cognitive impairment in the offspring.

Fertility issues in hypopituitarism

Women with hypopituitarism have lower fertility rates and worse pregnancy outcomes than women with normal pituitary function. These disparities exist despite the use of assisted reproductive technologies and hormone replacement. In women with hypogonadotropic hypogonadism, administration of exogenous gonadotropins can be used to successfully induce ovulation. Growth hormone replacement in the setting of growth hormone deficiency has been suggested to potentiate reproductive function, but its routine use in hypopituitary women remains unclear and warrants further study. In this review, we will discuss the clinical approach to fertility in a woman with hypopituitarism.

Dietary Intakes of Women with Gestational Diabetes Mellitus and Pregnancy Outcomes: A Prospective Observational Study

Purpose

Nutrient intake for pregnant women with gestational diabetes mellitus (GDM) is important to ensure satisfactory birth outcomes. This study aims to explore the dietary profiles of patients with GDM, compare the results with the Chinese dietary guidelines or Dietary Reference Intakes (DRIs) from China and investigate the relationship between maternal dietary intake and pregnancy outcomes.

Patients and Methods

A total of 221 patients with GDM in the second trimester were included in the cohort. Dietary intake data were collected using a 24-hour recall method for three consecutive days. The pregnancy outcomes of these participants were subsequently monitored. Both univariate logistic regression and multivariate logistic regression analyses were conducted to explore the associations between dietary intake variables or general characteristics variables and adverse pregnancy outcomes.

Results

Participants with adverse pregnancy outcomes showed a lower intake of iodine and vitamin D, a lower percentage of dietary energy intake from carbohydrates and a higher percentage of dietary energy intake from fats, compared to participants without adverse pregnancy outcomes. The gestational weight gain and family history of diabetes were associated with an increased risk of adverse pregnancy outcomes. Conversely, regular exercise, the intake of iodine and Vitamin D, and the percentage of dietary energy intake from carbohydrates were associated with a decreased risk.

Conclusion

The daily diet of pregnant women with GDM in China did not meet the dietary guidelines or DRIs. The low intake of Vitamin D and iodine, the low dietary carbohydrate ratio, family history of diabetes, lack of exercise, and high gestational weight gain were associated with increased risk of adverse pregnancy outcomes in pregnant women with GDM.

Subclinical hypothyroidism in the infertile female population: a guideline

There is controversy regarding whether to treat subtle abnormalities of thyroid function in infertile female patients. This guideline document reviews the risks and benefits of treating subclinical hypothyroidism in female patients with a history of infertility and miscarriage, as well as obstetric and neonatal outcomes in this population.

SARS-CoV-2 Infection in Pregnant Women With Hypothyroidism

Background Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) infection has been linked to increased maternal and fetal morbidity and mortality, as evidenced by numerous studies. Given the potential exacerbation of autoimmune diseases during viral infections, maternal and fetal complications such as preterm birth, low birth weight, or preeclampsia, often observed in pregnancies involving autoimmune thyroiditis with hypothyroidism, may be further aggravated. This study seeks to ascertain whether the association between viral infection and hypothyroidism contributes to an increase in adverse pregnancy outcomes. Methods This study included a cohort of 145 pregnant women with SARS-CoV-2 infection, who delivered in the Department of Obstetrics and Gynecology of the University Emergency Hospital in Bucharest, Romania, between January 1, 2020, and December 31, 2022. The participants were divided into two groups depending on the presence of autoimmune thyroiditis with hypothyroidism. We examined the maternal and fetal demographic parameters, paraclinical laboratory parameters, and outcomes, aiming to identify disparities between the two groups. Results Among the 145 SARS-CoV-2-positive pregnant women, the prevalence of hypothyroidism was 8.96%, with 13 cases reported. In the hypothyroidism group, the mean age of coronavirus disease 2019 (COVID-19) patients was higher (34.07 ± 5.18 years vs. 29.25 ± 6.23 years), as was the number of cases of investigated pregnancies, 12 (92.31%) vs. 91 (68.94%). There was no statistically significant correlation observed between fetal weight at birth, one-minute Apgar score, neonatal intensive care unit (NICU) admission, or intrauterine growth restriction between the two groups. Nevertheless, a case of stillbirth was recorded in the hypothyroidism group. The presence of thyroid pathology did not exacerbate the progression of the viral infection, as evidenced by the absence of cases of preeclampsia, ICU admission, or SARS-CoV-2 pneumonia. Conversely, the presence of hypothyroidism in pregnant women with SARS-CoV-2 infection was associated with lower uric acid levels and a slight decrease in international normalised ratio (INR) values. Additionally, there was a significant negative association between uric acid levels and the one-minute Apgar score in the hypothyroidism group, while no such correlations were observed in the other group. Furthermore, there was a statistically significant correlation between intrauterine growth restriction and uric acid values, as well as between the one-minute Apgar score and INR parameters, in both groups. Conclusion The link between SARS-CoV-2 infection and hypothyroidism does not appear to increase the risk of preterm birth, intrauterine growth restriction, or low fetal weight at birth. However, it may be associated with a higher risk of stillbirth. The presence of hypothyroidism in pregnant women with COVID-19 correlates with lower maternal uric acid levels and a slight decrease in INR values. The one-minute Apgar score correlates with the level of uric acid in pregnant women with SARS-CoV-2 infection and hypothyroidism.

Association of Serum Proteins Electrophoretic Pattern and Serum Hormones in Women with Spontaneous Pregnancy Loss

Background

Pregnancy is the state of carrying a developing embryo or fetus within a female body. Once pregnancy is established, a range of endocrinological events appear in its maintenance, finally helping in the successful pregnancy. The complications which are usually observed in pregnancy are gestational diabetes, preeclampsia, preterm labor, and spontaneous pregnancy loss or miscarriage, while 10%-15% of clinically recognized pregnancies terminate into spontaneous miscarriage. Thus, many attempts have been made by different researchers for the diagnosis of high-risk pregnancy on altered protein pattern using placental villous tissue or follicular fluid, but these are difficult to obtain and results of different studies are not constant.

Aim

This study was designed to identify the association (if any) among serum protein(s) electrophoretic pattern and different serum hormones in normal pregnant women (controls) and gestational age-matched women with spontaneous pregnancy loss (cases).

Materials and Methods

This study was carried out for 1½ year from October 2018 to March 2020 and included 120 participants (60 normal pregnant women and 60 women with spontaneous pregnancy loss) between 20 and 45 years of age with no mean age difference. The electrophoresis of serum was carried out using slab gel electrophoretic unit and serum thyroid-stimulating hormone (TSH), total tri-iodothyronine (TT3), total thyroxine (TT4), prolactin, and beta human chorionic gonadotropin (β-hCG) levels were analyzed using TSOSH AIA analyzer at Adesh University, Bathinda.

Results

Significant variations in the expression of proteins with molecular weight around ~150 kDa, ~50 kDa, and ~25 kDa were observed in normal pregnant women and women with spontaneous pregnancy loss. However, the protein band of ~50 kDa was found to be highly expressed in the serum of 1st and 2nd trimester women experiencing spontaneous pregnancy loss. Therefore, selected protein band of ~50 kDa was further processed by ECI-mass spectrophotometry QUAD time of flight and 365 different proteins were found, out of these; 34 proteins were found to be unidentified protein products (Verified using NCBI data base). Further, TT3, total proteins, β-hCG, and prolactin level were found to be low, whereas, TSH was found to be high in women experiencing spontaneous pregnancy loss. However, difference in the level of β-hCG in the 1st trimester and TT4 among normal pregnant women and women with spontaneous pregnancy loss was observed to be statistically insignificant.

Conclusion

This study indicated that the evaluation of serum protein variations along with hormonal profile may provide valuable information about high-risk pregnancy. Moreover, the differential expression of proteins in women with spontaneous pregnancy loss can be further explored to develop potential biomarker for the early identification of high-risk pregnancy and appropriate preventive measure.

Impact of Systemic Therapy on Fertility in Women with Early-Stage Breast Cancer

Purpose of Review

Fertility concerns are common among young women diagnosed with breast cancer, as systemic therapy increases the risk of premature ovarian insufficiency and delays family planning. Here, we review the impact of systemic therapies, including chemotherapy, endocrine therapy, HER-2 directed therapy, PARP inhibitors, and immunotherapy, on ovarian reserve.

Recent Findings

With an improved understanding of disease biology, fewer women are treated with gonadotoxic chemotherapy. There are limited data on the fertility impact of novel targeted treatments and immunotherapy, though preclinical and preliminary studies suggest an impact on fertility is possible. Notably, a recent study investigated the outcomes in women who interrupted adjuvant endocrine therapy to attempt pregnancy.

Summary

Further research is needed to characterize the fertility impact of novel therapies in breast cancer. Individualized fertility counseling should be offered to all women to discuss the possible impact of therapy on ovarian reserve and options for fertility preservation and timing of pregnancy.

Evaluation of the reliability and readability of ChatGPT-4 responses regarding hypothyroidism during pregnancy

Hypothyroidism is characterized by thyroid hormone deficiency and has adverse effects on both pregnancy and fetal health. Chat Generative Pre-trained Transformer (ChatGPT) is a large language model trained with a very large database from many sources. Our study was aimed to evaluate the reliability and readability of ChatGPT-4 answers about hypothyroidism in pregnancy. A total of 19 questions were created in line with the recommendations in the latest guideline of the American Thyroid Association (ATA) on hypothyroidism in pregnancy and were asked to ChatGPT-4. The reliability and quality of the responses were scored by two independent researchers using the global quality scale (GQS) and modified DISCERN tools. The readability of ChatGPT was assessed used Flesch Reading Ease (FRE) Score, Flesch-Kincaid grade level (FKGL), Gunning Fog Index (GFI), Coleman-Liau Index (CLI), and Simple Measure of Gobbledygook (SMOG) tools. No misleading information was found in any of the answers. The mean mDISCERN score of the responses was 30.26 ± 3.14; the median GQS score was 4 (2-4). In terms of reliability, most of the answers showed moderate (78.9%) followed by good (21.1%) reliability. In the readability analysis, the median FRE was 32.20 (13.00-37.10). The years of education required to read the answers were mostly found at the university level [9 (47.3%)]. Although ChatGPT-4 has significant potential, it can be used as an auxiliary information source for counseling by creating a bridge between patients and clinicians about hypothyroidism in pregnancy. Efforts should be made to improve the reliability and readability of ChatGPT.

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.

Recurrent MiscarriageGreen-top Guideline No. 17

In this guideline, recurrent miscarriage has been defined as three or more first trimester miscarriages. However, clinicians are encouraged to use their clinical discretion to recommend extensive evaluation after two first trimester miscarriages, if there is a suspicion that the miscarriages are of pathological and not of sporadic nature. Women with recurrent miscarriage should be offered testing for acquired thrombophilia, particularly for lupus anticoagulant and anticardiolipin antibodies, prior to pregnancy. [Grade C] Women with second trimester miscarriage may be offered testing for Factor V Leiden, prothrombin gene mutation and protein S deficiency, ideally within a research context. [Grade C] Inherited thrombophilias have a weak association with recurrent miscarriage. Routine testing for protein C, antithrombin deficiency and methylenetetrahydrofolate reductase mutation is not recommended. [Grade C] Cytogenetic analysis should be offered on pregnancy tissue of the third and subsequent miscarriage(s) and in any second trimester miscarriage. [Grade D] Parental peripheral blood karyotyping should be offered for couples in whom testing of pregnancy tissue reports an unbalanced structural chromosomal abnormality [Grade D] or there is unsuccessful or no pregnancy tissue available for testing. [GPP] Women with recurrent miscarriage should be offered assessment for congenital uterine anomalies, ideally with 3D ultrasound. [Grade B] Women with recurrent miscarriage should be offered thyroid function tests and assessment for thyroid peroxidase (TPO) antibodies. [Grade C] Women with recurrent miscarriage should not be routinely offered immunological screening (such as HLA, cytokine and natural killer cell tests), infection screening or sperm DNA testing outside a research context. [Grade C] Women with recurrent miscarriage should be advised to maintain a BMI between 19 and 25 kg/m2 , smoking cessation, limit alcohol consumption and limit caffeine to less than 200 mg/day. [Grade D] For women diagnosed with antiphospholipid syndrome, aspirin and heparin should be offered from a positive test until at least 34 weeks of gestation, following discussion of potential benefits versus risks. [Grade B] Aspirin and/or heparin should not be given to women with unexplained recurrent miscarriage. [Grade B] There are currently insufficient data to support the routine use of PGT-A for couples with unexplained recurrent miscarriage, while the treatment may carry a significant cost and potential risk. [Grade C] Resection of a uterine septum should be considered for women with recurrent first or second trimester miscarriage, ideally within an appropriate audit or research context. [Grade C] Thyroxine supplementation is not routinely recommended for euthyroid women with TPO who have a history of miscarriage. [Grade A] Progestogen supplementation should be considered in women with recurrent miscarriage who present with bleeding in early pregnancy (for example 400 mg micronised vaginal progesterone twice daily at the time of bleeding until 16 weeks of gestation). [Grade B] Women with unexplained recurrent miscarriage should be offered supportive care, ideally in the setting of a dedicated recurrent miscarriage clinic. [Grade C].

Thyroid dysfunction and female infertility. A comprehensive review

INTRODUCTION

Female infertility is defined as the inability to achieve pregnancy following one year of consistent, unprotected sexual intercourse. Among the various endocrine factors contributing to this complex issue, thyroid dysfunction assumes a pivotal and noteworthy role.

METHODS

A narrative review, encompassing 134 articles up to 2023, was conducted utilizing the PubMed/Medline, EMBASE, and Scielo databases. The primary focus of this review was to investigate the effects of thyroid dysfunction on female infertility.

RESULTS

Thyroid disorders exert a significant influence on folliculogenesis, fertilization, and implantation processes. Thyroid autoimmunity, although associated with diminished ovarian reserve, does not typically necessitate levothyroxine therapy. On the other hand, both subclinical and overt hypothyroidism often require levothyroxine treatment to enhance fertility and optimize obstetric outcomes. Hyperthyroidism warrants prompt intervention due to its heightened risk of miscarriage. Furthermore, thyroid dysfunction exerts notable effects on assisted reproductive technologies, underscoring the importance of achieving euthyroidism prior to ovarian stimulation.

CONCLUSION

Women presenting with thyroid dysfunction must undergo meticulous and individualized assessments since fertility outcomes, whether achieved through natural conception or assisted reproductive technologies, can be significantly influenced by thyroid-related factors.

Choosing the appropriate pharmacotherapy for breast cancer during pregnancy: what needs to be considered?

INTRODUCTION

Breast cancer is the most commonly diagnosed malignancy during pregnancy. Breast cancer during pregnancy is a challenging clinical condition requiring proper and timely multidisciplinary management.

AREAS COVERED

This review focuses on the management of breast cancer during pregnancy with a focus about the current state-of-the-art on the feasibility and safety of pharmacotherapy approaches in this setting.

EXPERT OPINION

Multidisciplinary care is key for a proper diagnostic-therapeutic management of breast cancer during pregnancy. Engaging patients and their caregivers in the decision-making process is essential and psychological support should be provided. The treatment of patients with breast cancer during pregnancy should follow the same recommendations as those for breast cancer in young women outside pregnancy but taking into account the gestational age at the time of treatment.Anthracycline-, cyclophosphamide-, and taxane-based regimens can be safely administered during the second and third trimesters with standard protocols, preferring weekly regimens whenever possible. Endocrine therapy, immune checkpoint inhibitors, and targeted agents are contraindicated throughout pregnancy, also due to the very limited data available to guide their administration in this setting. During treatment, careful fetal growth monitoring is mandatory, and even after delivery proper health monitoring for the children exposed in utero to chemotherapy should be continued.

Association between female circulating heavy metal concentration and abortion: a systematic review and meta-analysis

Objective

This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.

Methods

A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.

Results

Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, p = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, p <0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, p <0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, p = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with SA.

Conclusion

Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.

Impact of thyroid-stimulating hormone levels after controlled ovarian hyperstimulation on in vitro fertilization/intracytoplasmic sperm injection outcomes in women with fresh embryo transfer: a prospective cohort study

Objective

Maternal hypothyroidism before and during pregnancy is associated with an increased risk of adverse pregnancy outcomes; many studies have evidenced that controlled ovarian hyperstimulation (COH) triggers a significant increase in the levels of TSH; however, no large-scale prospective studies have evaluated the impact of TSH levels after COH on assisted reproductive technology outcomes. The aim of this prospective study was to investigate whether in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcomes are affected by TSH levels after COH in women with fresh embryo transfer (ET).

Methods

A total of 664 patients who underwent IVF/ICSI treatment and received fresh ET at the Peking University Third Hospital were included in this study. The rates of clinical pregnancy, miscarriage, live birth, and preterm delivery were analyzed.

Results

The patients were categorized into two groups based on serum TSH levels after COH (0.55 mIU/L < TSH < 2.5 mIU/L: n= 449, 2.5 mIU/L ≤ TSH ≤ 4.78 mIU/L: n= 215). There were no significant differences in the rates of clinical pregnancy, miscarriage, and live birth between the two groups, even after adjusting for age, body mass index (BMI), thyroid antibody positivity, and COH protocols. However, the preterm delivery rate was significantly higher in women with TSH < 2.5 mIU/L than in those with TSH ≥ 2.5 mIU/L, even after adjusting for relevant confounding factors. There was no significant difference in live birth weight between the two groups.

Discussion

Mildly elevated TSH levels (TSH ≥ 2.5 mIU/L) after COH did not affect IVF/ICSI outcomes, and strict control of TSH levels within 2.5 mIU/L after COH might not be necessary. Additionally, strictly controlled TSH levels (TSH < 2.5 mIU/L) may increase preterm delivery risk.

Maternal co-exposure to mercury and perfluoroalkyl acid isomers and their associations with child neurodevelopment in a Canadian birth cohort

BACKGROUND

Perfluoroalkyl acids (PFAAs) within the broader class of per- and polyfluoroalkyl substances (PFAS) are present in human serum as isomer mixtures, but epidemiological studies have yet to address isomer-specific associations with child development and behavior.

OBJECTIVES

To examine associations between prenatal exposure to 25 PFAAs, including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) isomers, and child neurodevelopment among 490 mother-child pairs in a prospective Canadian birth cohort, the Alberta Pregnancy Outcomes and Nutrition (APrON) study. To consider the influence of a classic neurotoxicant, total mercury (THg), based on its likelihood of co-exposure with PFAAs from common dietary sources.

METHODS

Maternal blood samples were collected in the second trimester and child neurodevelopment was assessed at 2 years of age using the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III). Linear or curvilinear multiple regression models were used to examine associations between exposures and neurodevelopment outcomes.

RESULTS

Select PFAAs were associated with lower Cognitive composite scores, including perfluoroheptanoate (PFHpA) (β = -0.88, 95% confidence interval (CI): -1.7, -0.06) and perfluorododecanoate (PFDoA) (β = -2.0, 95% CI: -3.9, -0.01). Non-linear relationships revealed associations of total PFOS (β = -4.4, 95% CI: -8.3, -0.43), and linear-PFOS (β = -4.0, 95% CI: -7.5, -0.57) and 1m-PFOS (β = -1.8, 95% CI: -3.3, -0.24) isomers with lower Language composite scores. Although there was no effect modification, including THg interaction terms in PFAA models revealed negative associations between perfluorononanoate (PFNA) and Motor (β = -3.3, 95% CI: -6.2, -0.33) and Social-Emotional (β = -3.0, 95% CI: -5.6, -0.40) composite scores.

DISCUSSION

These findings reinforce previous reports of adverse effects of maternal PFAA exposure during pregnancy on child neurodevelopment. The unique hazards posed from isomers of PFOS justify isomer-specific analysis in future studies. To control for possible confounding, mercury co-exposure may be considered in studies of PFAAs.

Role and Clinical Significance of Monocarboxylate Transporter 8 (MCT8) During Pregnancy

The review aims to summarize the available research focusing on the importance of monocarboxylate transporter (MCT8) in thyroid hormone trafficking across the placenta and fetal development. A systematic search was carried out in PubMed; studies available in English related to "monocarboxylate transporter", "adverse pregnancy", "fetal development," and "thyroid hormone" were identified and assessed. The references within the resulting articles were manually searched. MCT8 is a highly active and selective thyroid hormone transporter that facilitates the cellular uptake of triiodothyronine (T3), thyroxine (T4), reverse triiodothyronine (rT3), and diiodothyronine (T2) in different tissues. MCT8 is expressed in the placenta from the first trimester onwards, allowing the transport of thyroid hormone from mother to fetus. Mutations in MCT8 cause an X-linked disorder known as Allan-Herndon-Dudley syndrome (AHDS), characterized by severe psychomotor impairment and peripheral thyrotoxicosis. Hence, any maternal thyroid dysfunction may cause severe consequences for the fetus and newborn. Further research regarding MCT8 gene expression, polymorphic variation, and adverse pregnancy outcomes must be done to establish that MCT8 is a novel prognostic marker for the early detection of pregnancy-related complications.

First trimester sCD40L levels associated with adverse neonatal outcomes in euthyroid pregnant women with positive TPOAb

Backgrounds

It remained unclear whether isolated positive thyroid peroxidative antibodies (TPOAb) were associated with adverse maternal and neonatal outcomes. The purpose of this study was to observe adverse neonatal outcomes among euthyroid pregnant women with positive TPOAb and to investigate the underlying risk factors.

Methods

Euthyroid pregnant women with TPOAb positivity were enrolled and followed up in our study. Adverse neonatal outcomes such as preterm birth, low birth weight, and fetal macrosomia were observed. Clinical data in the first trimester were collected and compared between groups with or without adverse neonatal outcomes. Maternal serum soluble CD40 ligand (sCD40L) was also measured at the same time.

Results

A total of 176 euthyroid pregnant women with TPOAb positivity were finally enrolled and analyzed in our study. Thirty-nine (22.16%) euthyroid women with TPOAb positivity were found to have adverse neonatal outcomes. Thirteen participants received assisted reproductive technology (ART) in our study, and seven participants were in the adverse neonatal outcome group. Preterm birth, low birth weight, and fetal macrosomia were the most common comorbidities. The proportion of receiving ART and the levels of sCD40L and platelet were significantly higher in the adverse neonatal outcome group (all P < 0.05). Multivariate regression analysis showed that sCD40L and receiving ART were the independent risk factors for adverse neonatal outcomes. The odds ratio values of sCD40L higher than 5.625 ng/ml were 2.386 [95% confidence interval (CI) = 1.017 to 5.595; P = 0.046] for overall adverse neonatal outcome, 3.900 (95% CI = 1.194 to 12.738; P = 0.024) for preterm birth, and 3.149 (95% CI = 0.982 to 10.101; P = 0.054) for low birth weight.

Conclusions

Approximately one of the four euthyroid women with TPOAb positivity might have adverse neonatal outcomes. Measurement of sCD40L in first trimester might have a predictive value for adverse neonatal outcomes in euthyroid pregnant women with positive TPOAb.

Iodine and Thyroid Maternal and Fetal Metabolism during Pregnancy

Thyroid hormones and iodine are required to increase basal metabolic rate and to regulate protein synthesis, long bone growth and neuronal maturation. They are also essential for protein, fat and carbohydrate metabolism regulation. Imbalances in thyroid and iodine metabolism can negatively affect these vital functions. Pregnant women are at risk of hypo or hyperthyroidism, in relation to or regardless of their medical history, with potential dramatic outcomes. Fetal development highly relies on thyroid and iodine metabolism and can be compromised if they malfunction. As the interface between the fetus and the mother, the placenta plays a crucial role in thyroid and iodine metabolism during pregnancy. This narrative review aims to provide an update on current knowledge of thyroid and iodine metabolism in normal and pathological pregnancies. After a brief description of general thyroid and iodine metabolism, their main modifications during normal pregnancies and the placental molecular actors are described. We then discuss the most frequent pathologies to illustrate the upmost importance of iodine and thyroid for both the mother and the fetus.

Investigation and Management of Recurrent Pregnancy Loss: A Comprehensive Review of Guidelines

Importance

Recurrent pregnancy loss (RPL) is one of the most frustrating clinical entities in reproductive medicine requiring not only diagnostic investigation and therapeutic intervention, but also evaluation of the risk for recurrence.

Objective

The aim of this study was to review and compare the most recently published major guidelines on investigation and management of RPL.

Evidence Acquisition

A descriptive review of guidelines from the Royal College of Obstetricians and Gynaecologists, the European Society of Human Reproduction and Embryology, the American Society for Reproductive Medicine, the French College of Gynecologists and Obstetricians, and the German, Austrian, and Swiss Society of Gynecology and Obstetrics on RPL was carried out.

Results

There is consensus among the reviewed guidelines that the mainstays of RPL investigation are a detailed personal history and screening for antiphospholipid syndrome and anatomical abnormalities of the uterus. In contrast, inherited thrombophilias, vaginal infections, and immunological and male factors of infertility are not recommended as part of a routine RPL investigation. Several differences exist regarding the necessity of the cytogenetic analysis of the products of conception, parental peripheral blood karyotyping, ovarian reserve testing, screening for thyroid disorders, diabetes or hyperhomocysteinemia, measurement of prolactin levels, and performing endometrial biopsy. Regarding the management of RPL, low-dose aspirin plus heparin is indicated for the treatment of antiphospholipid syndrome and levothyroxine for overt hypothyroidism. Genetic counseling is required in case of abnormal parental karyotype. The Royal College of Obstetricians and Gynaecologists, the European Society of Human Reproduction and Embryology, and the French College of Gynecologists and Obstetricians guidelines provide recommendations that are similar on the management of cervical insufficiency based on the previous reproductive history. However, there is no common pathway regarding the management of subclinical hypothyroidism and the surgical repair of congenital and acquired uterine anomalies. Use of heparin for inherited thrombophilias and immunotherapy and anticoagulants for unexplained RPL are not recommended, although progesterone supplementation is suggested by the American Society for Reproductive Medicine and the German, Austrian, and Swiss Society of Gynecology and Obstetrics.

Conclusions

Recurrent pregnancy loss is a devastating condition for couples. Thus, it seems of paramount importance to develop consistent international practice protocols for cost-effective investigation and management of this early pregnancy complication, with the aim to improve live birth rates.

Impact of preconception thyrotrophin on obstetric outcomes in the fertile population

INTRODUCTION

There is evidence that subclinical hypothyroidism is associated with infertility, miscarriage and obstetric complications. However, there is controversy regarding the optimal TSH value in women seeking pregnancy. Current guidelines recommend that hypothyroid women with levothyroxine replacement who are planning pregnancy should optimise the dose of levothyroxine to achieve thyrotrophin (TSH) levels <2.5 mU/l, since these requirements increase in pregnancy, thus reducing the risk of TSH elevation during the first trimester. In women with infertility, who undergo highly complex treatments and have positive thyroid autoimmunity, values of TSH <2.5 mU/l prior to fertility treatment are suggested. Although this is a different population, these «optimal» TSH levels were also extended to euthyroid women without evidence of infertility, who are seeking pregnancy.

OBJECTIVES

Determine whether preconception TSH levels between 2.5 and 4.64 mIU/l are associated with adverse obstetric outcomes in euthyroid women.

MATERIALS AND METHODS

Retrospective cohort study. We evaluated 3265 medical records of pregnant women aged 18-40 years, euthyroid (TSH 0.5-4.64 mU/ml), with TSH measurement at least one year before gestation. 1779 met inclusion criteria. The population was divided according to categories: TSH 0.5-2.4 mU/l (optimal) and TSH 2.5-4.6 mU/l (suboptimal). Information on maternal and fetal obstetric outcomes was collected from each group.

RESULTS

We found no statistical difference in the occurrence of adverse obstetric events between the two groups. There was also no difference when adjusting for thyroid autoimmunity, age, body mass index, previous diabetes and previous arterial hypertension.

CONCLUSION

Our results suggest that the reference range of TSH used in the general population could be used in women seeking pregnancy, even in the presence of thyroid autoimmunity. Treatment with levothyroxine should be considered only in patients with special situations.

The impact of covid-19 on thyroid function tests in pregnancy

PURPOSE

To investigate the effects of laboratory-confirmed SARS-CoV-2 infection on thyroid function tests (TFTs) in pregnant women and to evaluate whether TFT changes are related to the severity and prognosis.

METHODS

Consecutive pregnant women tested for SARS-CoV-2 by RT-PCR at Ankara City Hospital were recruited between January 2021 and September 2021. Thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3), thyroid peroxidase antibody (anti-TPO), and thyroglobulin antibody (anti-TG) were measured on admission.

RESULTS

Among 747 eligible pregnant women with the same baseline characteristics, 369 RT-PCR-positive women in the patient group and 378 RT-PCR-negative women in the control group were included in the analyses. Pregnant women in the patient group had significantly lower TSH, FT4, FT3, Anti TPO, and Anti TG concentrations compared with those in the control group (p < 0.001). The proportion of patient groups with mild, moderate, severe, and critical diseases were 297 (80.4%), 40 (10.8%), 17 (4.6%), and 15 (4.2%), respectively, among which with the moderate, severe, and critical disease had significantly lower FT3 values (2.5 vs 2.19 pg/mL, p < 0.001) and higher nonthyroidal illness syndrome (NTIS) (29.2 vs. 8.4%, p < 0.001) than those with mild disease. Lower FT3 values increased the risk of ICU admission, NICU admission, and severe disease (p < 0.001). FT3 and TSH correlated positively with lymphocytes (p < 0.001) and negatively correlated with C-reactive protein (CRP) (p < 0.001, p = 0.005).

CONCLUSION

The SARS-CoV-2 infection seems to have an impact on the TFTs of pregnant women, and particularly FT3 level seems to be correlated with disease severity.

The role of thyroid function in female and male infertility: a narrative review

PURPOSE

We herein aimed to review the new insights into the impact of impaired thyroid function on male and female fertility, spacing from spontaneous pregnancy to ART, with the objective of providing an updated narrative revision of the literature.

METHODS

This narrative review was performed for all available prospective, retrospective and review articles, published up to 2021 in PubMed. Data were extracted from the text and from the tables of the manuscript.

RESULTS

Thyroid dysfunction is frequently associated with female infertility, whereas its link with male infertility is debated. Female wise, impaired function is detrimental to obstetric and fetal outcomes both in spontaneous pregnancies and in those achieved thanks to assisted reproduction technologies (ART). Furthermore, the reference range of TSH in natural pregnancy and ART procedures has recently become a matter of debate following recent reports in this field. On the other hand, the impact of thyroid function on the male reproductive system is less clear, although a possible role is suggested via modulation of Sertoli and Leydig cells function and spermatogenesis.

CONCLUSION

Thyroid function should be carefully monitored in both male and female, in couples seeking spontaneous pregnancy as well as ART, as treatment is generally immediate and likely to improve chances of success.

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.

Thyroid Function Rather Than Thyroid Antibodies Affects Pregnancy and Perinatal Outcomes: Results of a Prospective Study

CONTEXT

Thyroid autoantibody positivity has been associated with an increased rate of obstetrical complications.

OBJECTIVE

We aimed to evaluate the role of thyroid autoantibodies in adverse pregnancy outcomes.

METHODS

This prospective study was conducted in the Endocrinology Unit of Pisa Hospital. A total of 975 pregnant women were studied from 2012 to 2021; 572 (59%) were diagnosed with autoimmune thyroid (AT) diseases; 403 (41%) served as controls. Levothyroxine (LT4) treatment was introduced when TSH was > 2.5 mIU/L in the AT group and when TSH was > 4 mIU/L in the controls. Rates of obstetrical complications in each group were measured.

RESULTS

Although the frequency of miscarriage in the AT group was greater (4.8%) than in the controls (2.9%), no significant differences were detected (P = 0.181). There were no differences between the 2 groups concerning the other pregnancy complications, and no association with the titer of thyroid antibodies was observed. The frequency of congenital malformations was greater in the AT group than in the controls (P = 0.019), but no correlation with major congenital malformations was detected (P = 0.872). Given that thyroid hormone concentrations were strictly controlled in our population, we documented a tendency (not significant) toward an increase in miscarriage and preterm birth among women with TSH > 4 mIU/L.

CONCLUSION

If thyroid function is adequately controlled, the presence and titer of thyroid autoantibodies does not negatively influence gestation. Although not significant, suboptimal thyroid hormone status seems to affect pregnancy outcomes more than thyroid autoimmunity.

Association of maternal levothyroxine use during pregnancy with offspring birth and neurodevelopmental outcomes: a population-based cohort study

BACKGROUND

The influence of maternal levothyroxine treatment during pregnancy remains unclear. This study aimed to evaluate the associations of maternal levothyroxine treatment during pregnancy with the birth and neurodevelopmental outcomes in offspring.

METHODS

This population-based cohort study was conducted among pregnant women using the Hong Kong Clinical Data Analysis and Reporting System. Mother-child pairs in Hong Kong from 2001 to 2015 were included and children were followed up till 2020. We defined the exposure group as mothers who were exposed to levothyroxine during pregnancy. Preterm birth and small for gestational age (SGA) were included as birth outcomes. Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) were included as neurodevelopmental outcomes. Odds ratios (OR) or hazard ratios (HRs) with a 95% confidence interval (CI) were evaluated to assess the association of gestational levothyroxine use with offspring birth and neurodevelopmental outcomes respectively, using propensity score fine-stratification weighting and a Cox proportional hazards regression model.

RESULTS

Among 422,156 mother-child pairs, 2125 children were born from mothers exposed to levothyroxine during pregnancy. A significantly increased risk of preterm birth was observed in children with maternal levothyroxine exposure during pregnancy, when compared to mothers who had no history of thyroid-related diagnoses or prescriptions (weighted OR [wOR]: 1.22, 95% CI: 1.07, 1.39). Similarly, an increased risk of preterm birth was found among children of gestational levothyroxine users, when compared to children of mothers who had used levothyroxine before but stopped during pregnancy (wOR: 2.16, 95% CI: 1.09, 4.25). Sensitivity analysis, by excluding mothers exposed to psychotropic or antiepileptic medications before or during pregnancy, also indicated a similar increased risk of preterm birth regarding the gestational use of levothyroxine (wOR: 1.26, 95% CI: 1.10, 1.45). No significant association was observed for the risk of SGA, ADHD, and ASD.

CONCLUSIONS

There is no evidence that gestational use of levothyroxine is associated with SGA, ADHD, or ASD in offspring. Gestational levothyroxine treatment is associated with a higher risk of preterm birth. Such risk might be confounded by the underlying maternal thyroid disease itself, however, we cannot completely exclude the possible effect of gestational L-T4 treatment on offspring preterm birth. Our findings provided support to the current guidelines on the cautious use of levothyroxine treatment during pregnancy.

Under and overtreatment with thyroid hormone replacement during pregnancy

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

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.

Benefits of rescreening newborns of mothers affected by autoimmune hypothyroidism

Introduction

Infants of mothers with autoimmune hypothyroidism (AH) are at risk of developing late-onset hypothyroidism, often escaping at newborn screening. This condition might be caused both by the action of maternal antibodies and/or by maternal treatment.

Objectives

The aim of this study is to evaluate the prevalence of AH in the mothers of children born in Veneto region, Italy, and to define what is the most appropriate management for these newborns.

Methods

Newborns of six different hospitals with a mother suffering from AH and with negative neonatal screening for congenital hypothyroidism (CH) were included in the study. Between 15 and 20 days of life, we collected a serum sample for the evaluation of thyroid function (thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3)) and anti-thyroid antibodies. On the same occasion, a capillary blood sampling was performed for a second screening test.

Results

Maternal AH has a prevalence of 3.5%. A total of 291 newborns were enrolled from November 2019 to May 2021. Whereas the 11.4% of infants had a slight elevated serum TSH (>6 mU/L) and required a follow-up, only 2 children presented an elevated TSH level at the second screening test. One of these, with the gland in situ, showed persistently elevated serum TSH levels and required treatment with levothyroxine.

Conclusions

Maternal AH rarely caused neonatal thyroid dysfunction. We suggest to reassess newborns from mothers with AH 15 days after birth by means of a second neonatal screening test. This procedure avoids false negatives due to maternal thyroid status, is less invasive and cheaper than the serum TSH evaluation, and prevents a long follow-up.

Significance of levothyroxine treatment on serum lipid in pregnant women with subclinical hypothyroidism

BACKGROUND

There is no consensus reference range for serum lipid levels during pregnancy. The benefit of levothyroxine (L-T4) on serum lipid levels are unclear among pregnant women with subclinical hypothyroidism (SCH).

OBJECTIVE

To determine the recommended reference ranges for serum lipid concentrations during pregnancy and effects of L-T4 treatment on serum lipids in pregnant women with SCH.

DESIGN

Cohort study.

METHODS

A analysis of 20,365 women in the first trimester was conducted at Beijing Obstetrics and Gynecology Hospital, Capital Medical University during 2018-2020. After excluding women with adverse pregnancy outcomes, we determined the reference range of serum lipid in the first and third trimesters of pregnancy by using median and quartile to determine appropriate percentiles. Next, we divided into three groups as follows: SCH L-T4 treatment group (n = 319), SCH non-intervention group (n = 103) and the control group(n = 9598).

RESULTS

The recommended reference range for serum lipids in the first trimester of pregnancy should be: TC < 5.33 mmol/L, TG < 1.73 mmol/L, LDL-C < 3.12 mmol/L and HDL-C > 1.1 mmol/L, and in third trimester of pregnancy should be: TC < 8.47 mmol/L, TG < 4.86 mmol/L, LDL-C < 5.3 mmol/L and HDL-C > 1.34 mmol/L. There are significant differences in TC and LDL-C levels between SCH treatment group and SCH non-intervention Group (P = 0.043, P = 0.046; respectively).

CONCLUSIONS

We determine the recommended reference ranges for serum lipid concentrations during pregnancy. TC and LDL-C levels in pregnant women with SCH could improve after L-T4 treatment.

Can Thyroid Screening in the First Trimester Improve the Prediction of Gestational Diabetes Mellitus?

This study aimed to evaluate the clinical utility of the subclinical hypothyroidism (SCH) marker, elevated thyroid-stimulating hormone (TSH) and thyroid antibodies in their ability to predict subsequent gestational diabetes mellitus (GDM). In a prospective clinical trial, 230 pregnant women were screened for thyroid function during the first trimester of pregnancy. Increased TSH levels with normal free thyroxine (fT4) were considered SCH. The titers of thyroid peroxidase antibody (anti TPO Ab) at >35 IU/mL and thyroglobulin antibody (anti Tg Ab) at >115 IU/mL were considered as antibodies present. According to the OGTT results, the number of pregnant women with GDM showed the expected growth trend, which was 19%. Two groups of pregnant women were compared, one with GDM and the other without. Increased TSH levels and the presence of thyroid antibodies showed a positive correlation with the risk of GDM. TSH levels were significantly higher in pregnant women with GDM, p = 0.027. In this study, 25.6% of pregnant women met the diagnostic criteria for autoimmune thyroiditis. Hashimoto’s thyroiditis was significantly more common in GDM patients, p < 0.001. Through multivariate logistic regression, it was demonstrated that patient age, TSH 4 IU/mL, and anti TPO Ab > 35 IU/mL are significant predictors of gestational diabetes mellitus that may improve first-trimester pregnancy screening performance, AUC: 0.711; 95% CI: 0.629−0.793.

Management of Hypothyroidism and Hypothyroxinemia in Pregnancy

OBJECTIVE

To review the diagnosis and management of hypothyroidism in pregnancy, preconception, and the postpartum period.

METHODS

Literature review of English-language papers published between 1982 and 2022, focusing on the most recent literature.

RESULTS

During pregnancy, thyroid function laboratory tests need to be interpreted with regard to gestational age. Overt hypothyroidism, regardless of the TSH level, should always be promptly treated when it is diagnosed preconception or during pregnancy or lactation. Most women with preexisting treated hypothyroidism will require an increase in levothyroxine dosing to maintain euthyroidism during gestation. levothyroxine-treated pregnant patients need close monitoring with serum thyroid stimulating hormone (TSH) to avoid or- or under treatment. There is no consensus about whether to initiate levothyroxine in women with mild forms of gestational thyroid hypofunction. However, in light of current evidence it is reasonable to treat subclinically hypothyroid women with levothyroxine, particularly if the TSH is >10 mIU/L or the thyroperoxidase antibody is positive. Women who are not treated need to be followed to ensure that treatment is initiated promptly if thyroid failure progresses. Additional studies are needed to better understand the effects of the initiation of levothyroxine in early gestation in subclinically hypothyroid and hypothyroxinemic women and to determine optimal strategies for thyroid function screening in preconception and pregnancy.

CONCLUSION

The diagnosis and management of hypothyroidism in the peripregnancy period present specific challenges. In making management decisions, it is essential to weigh the risks and benefits of treatments not just for the mother but also for the fetus.

Short-Term Adverse Pregnancy Outcomes in Women with Subclinical Hypothyroidism: A Comparative Approach of Iranian and American Guidelines

Introduction

Subclinical hypothyroidism during pregnancy can be associated with numerous adverse outcomes. The purpose of this study was to compare short-term adverse pregnancy outcomes in treated versus nontreated patients who fall within the numerical range of thyroid-stimulating hormone (TSH) between the Iranian and American reference ranges.

Materials and Methods

Eighty pregnant women with a known level of antithyroid peroxidase (anti-TPO) and TSH levels of 2.5–3.9 mIu/L in the first trimester and 3–4.1 mIu/L in the second and third trimesters were enrolled in the study and randomly assigned into two groups including 41 patients in the intervention group and 39 in the control group. The intervention group was treated with levothyroxine at least 50 μg/day and the control group received no treatment. The data were analyzed by SPSS software version 23.

Results

The only significant findings were a correlation between pregnancy loss frequency (p − 0.011) and/or increased TSH level in the follow-up period (p = 0.008) with anti-TPO antibody positivity. Forty-four percent of mothers with positive anti-TPO Ab needed treatment initiation with levothyroxine, based on Iranian guidelines, due to increased TSH level during the follow-up period.

Conclusion

Untreated pregnant women with subclinical hypothyroidism, who were placed in the intermediate range of TSH, recommended by Iranian and American guidelines, did not show any significant difference in short-term adverse pregnancy outcomes compared to the treated patients. Positive anti-TPO Ab may play a role in the development of short-term complications in mothers with subclinical hypothyroidism or it may increase the likelihood of an increase in TSH level during pregnancy.

Thyroid Disease in Pregnancy: A Descriptive Review of Guidelines

Importance

Thyroid disorders represent one of the most frequent complications of pregnancy associated with adverse obstetric, fetal, and neonatal outcomes, especially in case of delayed diagnosis and suboptimal management.

Objective

The aim of this study was to review and compare the recommendations of the most recently published guidelines on the diagnosis and management of these common conditions.

Evidence Acquisition

A descriptive review of guidelines from the Endocrine Society, the European Thyroid Association, the Royal Australian and New Zealand College of Obstetricians and Gynecologists, the American Thyroid Association, and the American College of Obstetricians and Gynecologists on thyroid disease in pregnancy was carried out.

Results

There is an overall consensus regarding the diagnosis of overt and subclinical hypothyroidism and hyperthyroidism in pregnancy using the pregnancy-specific reference ranges and the definition of postpartum thyroiditis. The reviewed guidelines unanimously discourage universal screening for thyroid function abnormalities before and during pregnancy and support targeted screening of high-risk patients by measuring serum thyroid-stimulating hormone levels. Moreover, they all highlight the need of treating overt hypothyroidism and hyperthyroidism, not only during pregnancy, but also before conception, suggesting similar management policies and treatment targets. There is also agreement regarding the management of gestational transient hyperthyroidism with hyperemesis gravidarum, suspected fetal thyrotoxicosis, postpartum thyroiditis, and thyroid malignancy. Scanning or treating with radioactive iodine is contraindicated during pregnancy and breastfeeding. On the other hand, there is controversy on the management of subclinical thyroid disease, thyroid function surveillance protocols, and iodine nutrition recommendations. Of note, the American College of Obstetricians and Gynecologists makes some specific recommendations on the treatment of thyroid storm and thyrotoxic heart failure in pregnant women, whereas the American Thyroid Association makes a special reference to the management of women with thyroid cancer.

Conclusions

As the disorders of the thyroid gland affect a significant proportion of pregnant women, it is of paramount importance to develop uniform international evidence-based protocols for their accurate diagnosis and optimal management, in order to safely guide clinical practice and eventually improve perinatal outcomes.

Thyroid Status During Pregnancy in Women With Polycystic Ovary Syndrome and the Effect of Metformin

OBJECTIVE

Polycystic ovary syndrome (PCOS) and hypothyroidism are related conditions, and both are associated with adverse pregnancy outcomes. Knowledge is lacking about the complex interaction between thyroid status and PCOS during pregnancy. We investigated the thyroid status and its association with pregnancy complications in PCOS, and in relation to metformin treatment.

DESIGN

Post-hoc analyses of two randomized, double-blind, placebo-controlled trials.

METHODS

288 pregnant women with PCOS were randomized to treatment with metformin or placebo from first trimester to delivery. We measured serum levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) at gestational week (gw) 5-12, 19, 32 and 36 and related to metformin treatment and pregnancy complications. Thyroid peroxidase antibodies (TPO-ab) were analyzed at inclusion and at gw 36.

RESULTS

The overall prevalence of subclinical and overt hypothyroidism was 1.5% and 0%, respectively. The TSH level was not affected by metformin, whereas fT4 was significantly higher in the metformin group with less decrease throughout pregnancy compared to placebo, p<0.001. A lower decrease in fT4 during pregnancy correlated to less weight gain (r= -0.17, p=0.020) and tended to be associated with reduced odds ratio for gestational diabetes (OR 0.85 per 1 pmol/L, 95% CI 0.71;1.02).

CONCLUSIONS

In women with PCOS, metformin treatment during pregnancy was associated with less decrease in fT4 compared to placebo, while it did not affect TSH. A smaller decrease in fT4 correlated to less weight gain and tended to be associated with a lower risk of gestational diabetes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT00159536 (The PregMet study); identifier NCT03259919 (The pilot study).

Immunotherapy for cancer treatment during pregnancy

Immunotherapy has greatly improved outcomes for subgroups of patients with cancer. As indications keep expanding, there is an unmet need to gain a better understanding of the effect of these therapies on pregnancy and fertility. During pregnancy, substantial adaptations occur in the maternal immune system to maintain protection against pathogens while avoiding detrimental reactions to the semi-allogeneic fetus. The pathways involved in the establishment of this fetomaternal tolerance can be hijacked by cancers. Immunotherapies that target these inhibitory pathways, or that directly interact with the regulatory immune cells involved in tolerance mechanisms, might therefore result in complications during pregnancy. Similarly, by activating the patient's immune system with immunotherapy, a broad range of immune-related adverse events can occur that could negatively affect the fetus or impede a future desired pregnancy. This Review summarises preclinical and clinical data related to the use of immunotherapy during pregnancy, including all approved immune checkpoint inhibitors, recombinant cytokines, cell therapies, vaccines, and immunomodulatory drugs.

Iodine monitoring models contribute to avoid adverse birth outcomes related more than adequate iodine intake

BACKGROUND

Iodine plays an important role in pregnancy. How to maintain adequate iodine intake amongst pregnant women in each trimester of pregnancy to prevent adverse birth outcomes in central China is a challenge for clinical practice.

METHODS

870 pregnant women and their infants were enrolled in the study. Urinary iodine concentration (UIC) was measured using an inductively coupled plasma mass spectrometry (ICP-MS). Maternal and newborn information were obtained during follow-up. Multinomial logistic regression models were established.

RESULTS

Median UIC of pregnant women was 172 ± 135 μg/L which is currently considered to be sufficient. Multivitamin supplements containing iodine, iodized salt intake and frequent milk intake were significantly associated with higher UIC. Multivariate logistic regression analysis showed that multivitamin supplements containing iodine and milk consumption were risk factors for more than adequate iodine (UIC ≥ 250 μg/L). Iodine-rich diet was significantly related to heavier birthweight, larger head circumference and longer femur length of the newborns while more than adequate iodine intake (UIC ≥ 250 μg/L) was a risk factor for macrosomia. Logistic regression models based on potential risk factors involving iodine containing supplements and iodine-rich diet were established to predict and screen pregnant women with high risk of more than adequate iodine intake among local pregnant women in different trimesters and guide them to supplement iodine reasonably to prevent the risk.

CONCLUSIONS

Multivitamin supplements containing iodine and milk consumption were risk factors for maternal UIC ≥ 250 μg/L which was a risk factor for macrosomia. Iodine monitoring models were established to provide guidance for pregnant women to reduce the risk of more than adequate iodine intake, thereby contributing to reduce the risk of having a macrosomia.

Method-dependent variation in TSH and FT4 reference intervals in pregnancy: A systematic review

BACKGROUND

Gestational TSH and FT4 reference intervals may differ according to assay method, but the extent of variation is unclear and has not been systematically evaluated. We conducted a systematic review of published studies on TSH and FT4 reference intervals in pregnancy. Our aim was to quantify method-related differences in gestation reference intervals, across four commonly used assay methods, Abbott, Beckman, Roche and Siemens.

METHODS

We searched the literature for relevant studies, published between January 2000 and December 2020, in healthy pregnant women without thyroid antibodies or disease. For each study, we extracted trimester-specific reference intervals (2.5-97.5 percentiles) for TSH and FT4 as well as the manufacturer-provided reference interval for the corresponding non-pregnant population.

RESULTS

TSH reference intervals showed a wide range of study-to-study differences with upper limits ranging from 2.33 to 8.30 mU/L. FT4 lower limits ranged from 4.40 to 13.93 pmol/L, with consistently lower reference intervals observed with the Beckman method. Differences between non-pregnant and first trimester reference intervals were highly variable, and for most studies, the TSH upper limit in the first trimester could not be predicted or extrapolated from non-pregnant values.

CONCLUSIONS

Our study confirms significant intra- and intermethod disparities in gestational thyroid hormone reference intervals. The relationship between pregnant and non-pregnant values is inconsistent and does not support the existing practice in many laboratories of extrapolating gestation references from non-pregnant values. Laboratories should invest in deriving method-specific gestation reference intervals for their population.

Thyroid Laboratory Testing and Management in Women on Thyroid Replacement Before Pregnancy and Associated Pregnancy Outcomes

Background: Women with hypothyroidism before pregnancy often require an increase in their levothyroxine dosage to maintain a euthyroid state during pregnancy. The objectives of this study were to investigate: (i) the frequency and distribution of thyrotropin (TSH) testing and levothyroxine dosage adjustment by gestational age, (ii) the magnitude of levothyroxine increase by the underlying etiology of hypothyroidism, and (iii) the relationship of overtreatment or undertreatment during pregnancy with adverse pregnancy outcomes among women using thyroid replacement before pregnancy. Methods: A retrospective cohort study of pregnancies in women on thyroid replacement before pregnancy in Alberta, Canada, was performed. Women using thyroid replacement anytime during the two years before pregnancy who delivered between October 2014 and September 2017 were included. Delivery records, physician billing, and laboratory and pharmacy administrative data were linked. Outcomes included characteristics of TSH testing, levothyroxine dosing, and pregnancy outcomes. The frequency and gestational timing of TSH testing and levothyroxine adjustments were calculated. Multiple logistic regression was used to test whether pregnancies with TSH <0.10 mIU/L (overtreatment) or TSH ≥10.00 mIU/L (undertreatment) compared with control pregnancies (TSH 0.10-4.00 mIU/L) were associated with adverse pregnancy and neonatal outcomes. Results: Of the 10,680 deliveries, 8774 (82.2%) underwent TSH testing at least once during pregnancy, at a median gestational age of six weeks. An adjustment of levothyroxine dosage was made for 4321 (43.7%) during pregnancy. TSH in pregnancy below 0.10 mIU/L increased the odds of preterm delivery when compared with control pregnancies (adjusted odds ratio, 2.14 [95% confidence interval 1.51-2.78]). TSH ≥10.00 mIU/L during pregnancy was not associated with any adverse pregnancy or neonatal outcomes in the multivariable analysis. Conclusions: Although most women on thyroid replacement before conception had TSH measured at some point during pregnancy, it is concerning that 17.8% did not. Levothyroxine overtreatment in pregnancy was associated with preterm delivery. These findings suggest that clinicians should be careful to avoid overtreatment with levothyroxine in pregnancy.

Preconception Thyrotropin Levels and Risk of Adverse Pregnancy Outcomes in Chinese Women Aged 20 to 49 Years

IMPORTANCE

Maternal thyrotropin levels during gestation have a profound effect on pregnancy outcomes; however, few studies to date have evaluated the importance of preconception thyrotropin levels.

OBJECTIVE

To investigate the associations between preconception thyrotropin levels and pregnancy outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study enrolled Chinese women aged 20 to 49 years from the National Free Prepregnancy Checkups Project in China. Participants conceived within 6 months after the thyrotropin examination and completed follow-up for pregnancy outcomes between January 1, 2013, and December 31, 2017. Data were analyzed between May 1, 2019, and March 31, 2020.

EXPOSURES

Levels of thyrotropin within 6 months before pregnancy, measured as less than 0.10 mIU/L, 0.10 to 0.36 mIU/L, 0.37 to 2.49 mIU/L, 2.50 to 4.87 mIU/L, 4.88 to 9.99 mIU/L, and 10.00 mIU/L or greater.

MAIN OUTCOMES AND MEASURES

The association of maternal preconception thyrotropin levels with the 4 primary adverse pregnancy outcomes was assessed, including preterm birth (PTB), small for gestational age (SGA), birth defect, and perinatal infant death. Logistic regression analyses were used to evaluate the association between preconception maternal thyrotropin levels and risk of adverse pregnancy outcomes. The dose-response associations were assessed using restricted cubic spline regression.

RESULTS

This study enrolled 5 840 894 women (mean [SD] age, 26.30 [4.10] years) in the primary analysis. The median (interquartile range [IQR]) thyrotropin level was 1.60 (1.06-2.37) mIU/L. The cumulative incidences for the adverse pregnancy outcomes were as follows: PTB, 6.56%; SGA, 7.21%; birth defect, 0.02%; and perinatal infant death, 0.33%. Compared with the reference group (thyrotropin range, 0.37-2.49 mIU/L), both low (<0.10 mIU/L and 0.10-0.36 mIU/L) and high (4.88-9.99 mIU/L and ≥10.00 mIU/L) maternal preconception thyrotropin levels were associated with higher risk of PTB (low: odds ratio [OR], 1.23 [95% CI, 1.19-1.27] and OR, 1.15 [95% CI, 1.13-1.18] vs high: OR, 1.13 [95% CI, 1.10-1.15] and OR, 1.14 [95% CI, 1.08-1.20]), SGA (low: OR, 1.37 [95% CI, 1.33-1.40] and OR, 1.14 [95% CI, 1.12-1.17] vs high: OR, 1.05 [95% CI, 1.03-1.08] and OR, 1.17 [95% CI, 1.11-1.23]), and perinatal infant death (low: OR, 1.26 [95% CI, 1.10-1.43] and OR, 1.14 [95% CI, 1.05-1.24] vs high: OR, 1.31 [95% CI, 1.20-1.43] and OR, 1.47 [95% CI, 1.21-1.80]). J-shaped associations between preconception thyrotropin levels and PTB (χ2 = 1033.45; nonlinear P < .001), SGA (χ2 = 568.90; nonlinear P < .001), and perinatal infant death (χ2 = 38.91; nonlinear P < .001) were identified.

CONCLUSIONS AND RELEVANCE

In this cohort study, both low and high maternal thyrotropin levels were associated with a significantly increased risk of adverse pregnancy outcomes. Results suggest that the optimal preconception thyrotropin levels may be between 0.37 mIU/L and 2.50 mIU/L to prevent adverse pregnancy outcomes.

Testing, Monitoring, and Treatment of Thyroid Dysfunction in Pregnancy

Both hyperthyroidism and hypothyroidism can have adverse effects in pregnancy. The most common causes of thyrotoxicosis in pregnancy are gestational transient thyrotoxicosis and Graves' disease. It is important to distinguish between these entities as treatment options differ. Women of reproductive age who are diagnosed with Graves' disease should be counseled regarding the impact of treatment options on a potential pregnancy. Although the absolute risk is small, antithyroid medications can have teratogenic effects. Propylthiouracil appears to have less severe teratogenicity compared to methimazole and is therefore favored during the first trimester if a medication is needed. Women should be advised to delay pregnancy for at least 6 months following radioactive iodine to minimize potential adverse effects from radiation and ensure normal thyroid hormone levels prior to conception. As thyroid hormone is critical for normal fetal development, hypothyroidism is associated with adverse obstetric and child neurodevelopmental outcomes. Women with overt hypothyroidism should be treated with levothyroxine (LT4) to a thyrotropin (thyroid-stimulating hormone; TSH) goal of <2.5 mIU/L. There is mounting evidence for associations of maternal hypothyroxinemia and subclinical hypothyroidism with pregnancy loss, preterm labor, and lower scores on child cognitive assessment. Although there is minimal risk of LT4 treatment to keep TSH within the pregnancy-specific reference range, treatment of mild maternal thyroid hypofunction remains controversial, given the lack of clinical trials showing improved outcomes with LT4 treatment.