Effect of thyroxine treatment on pregnancy outcomes in infertile Japanese women with TSH levels between 2.5 μIU/mL and the upper reference limit: a retrospective study

Levothyroxine Treatment in Pregnant Women with Thyrotropin Levels Ranging Between 2.5 and 10 mIU/L: A Propensity Score Matched Analysis

Objective: To clarify the association between levothyroxine (LT4) treatment and various adverse pregnancy outcomes in pregnant women with thyrotropin (TSH) levels ranging between 2.5 and 10.0 mIU/L in the first trimester, stratified according to thyroid peroxidase antibody (TPOAb) positivity and TSH level. Methods: This retrospective analysis of retrospectively and prospectively collected cohort data included Chinese pregnant women with TSH levels of 2.5-10 mIU/L and normal free thyroxine levels (11.8-18.4 pmol/L) in the first trimester. All participants were followed up until the completion of pregnancy, and information on LT4 treatment, pregnancy complications, and pregnancy outcomes was recorded. A 1:1 nearest-neighbor propensity score matching (PSM) between the LT4-treated and - untreated groups with a caliper distance of 0.02 was performed using a multivariable logistic regression model. Multivariable-adjusted modified Poisson regression was used to estimate the relative risk (RR) and 95% confidence interval (CI) of LT4 treatment for adverse pregnancy outcomes. Subgroup analyses were also performed in four subgroups simultaneously stratified by TPOAb status (negative or positive) and TSH levels (2.5-4.0 mIU/L as high-normal group and 4.0-10.0 mIU/L as SCH group). The study was registered in the Chinese Clinical Trial Registry (ChiCTR2100047394). Results: Among the 4,370 pregnant women in the study, 1,342 received LT4 treatment and 3,028 did not. The 1:1 PSM yielded 668 pairs of individuals and revealed that LT4 treatment was significantly associated with a decreased risk of pregnancy loss (RR = 0.528, 95% CI: 0.344-0.812) and an increased risk of small-for-gestational-age infants (RR = 1.595, 95% CI: 1.023-2.485). Subgroup analyses suggested that the above effects of LT4 treatment were mainly from TPOAb-negative participants. LT4 treatment was associated with an increased risk of preterm birth (RR = 2.214, 95% CI: 1.016-4.825) in TPOAb-positive pregnant women with high-normal TSH levels. Conclusion: LT4 treatment was significantly associated with a lower risk of pregnancy loss and a higher risk of small-for-gestational-age infants in pregnant women with TSH levels of 2.5-10 mIU/L. An increased risk of preterm birth was observed in the LT4-treated group among TPOAb-positive participants with TSH levels of 2.5-4.0 mIU/L.

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.

The impact of levothyroxine therapy on pregnancy and neonatal outcomes in euthyroid pregnant women with thyroid autoimmunity: A systematic review, meta-analysis and trial sequential analysis

Background: At present, only one systematic review has investigated the effect of levothyroxine (LT4) in the treatment of euthyroid pregnant women with thyroid autoimmunity, but some problems [such as merging different types of research for meta-analysis, lacking neonatal outcomes, and so on] exist in this study, satisfactory results can not be provided. So, this systematic review was performed to investigate the effect of LT4 in euthyroid pregnant women with thyroid autoimmunity, in the hope of providing more comprehensive evidence for clinical use. Methods: Medline (Ovid), Embase (Ovid), and Cochrane Central Register of Controlled Trials were electronically searched from database inception to March 2022. We included cohort studies and RCTs that evaluated the impact of LT4 therapy on pregnancy and neonatal outcomes in euthyroid pregnant women with thyroid autoimmunity. Meta-analyses of different types of studies were performed separately, and meta-analyses were further performed by only including researches with low and moderate risk of bias. We used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach to evaluate the quality of evidence, and used TSA to test the sufficiency of the evidence. Results: Finally, 2,901 euthyroid pregnant women with thyroid autoimmunity in six RCTs and five cohort studies were included. In all outcomes, no statistically significant differences were found between LT4 group and control group, including miscarriage [RR = 0.85, 95%CI (0.69,1.05), p = 0.14, I ² = 1%], preterm birth [RR = 0.80, 95%CI (0.59,1.08), p = 0.14, I2 = 0%], preeclampsia [RR = 0.68, 95%CI (0.12, 3.91), p = 0.66, I ² = 0%], placenta abruption [Peto' OR = 0.14, 95%CI (0.00, 6.94), p = 0.32, I ² = 0%], birth weight [MD = -36.00, 95%CI (-170.41, 98.41), p = 0.60, I ² = 0%], gestational age at delivery [MD = -0.10, 95%CI (-0.61, 0.41), p = 0.70, I ² = 0%] and neonatal admission [RR = 1.33, 95%CI (0.21, 8.58), p = 0.76, I ² = 0%]. The results for all outcomes were insufficient and inconclusive as demonstrated by TSA. The GRADE assessments showed that the quality of evidence of 4 outcomes (miscarriage, preterm birth, birth weight and gestational age at delivery) were moderate, and 3 outcomes (preeclampsia, placenta abruption and neonatal admission) were low or very low. Conclusion: For pregnancy and neonatal outcomes in euthyroid pregnant women with thyroid autoimmunity, we did not find benefit of LT4 treatment in this study. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022346745, identifier CRD42022346745.

Evaluation of the relationship between serum TSH levels and pregnancy outcomes of IVF/ICSI patients in follicular phase long-acting long protocol

ObjectiveTo investigate whether TSH levels are associated with the pregnancy outcomes of patients in the follicular phase long-acting long protocol of IVF/ICSI.MethodsThis was a single-central, retrospective study which was conducted in the Reproductive Medicine Center, Renmin Hospital of Wuhan University from February 2019 to April 2021. A total number of 773 patients underwent the follicular phase long-acting long protocol during in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment were divided into Group A (0.5 mIU/L ≤ TSH ≤2.5 mIU/L, n = 463) and Group B (2.5 mIU/L < TSH≤ 4.5 mIU/L, n = 310) according to their serum TSH levels. The clinical data and pregnancy outcomes were compared between the two groups. The possible relationship between TSH levels and pregnancy outcomes in people who performed follicular phase long-acting long protocol was investigated.ResultsThe proportion of patients with infertility due to ovulation disorders was significantly greater in Group B than in Group A (p = 0.036). The duration of Gn of Group B was significantly longer than that of Group A (p = 0.001). The Gn dose of Group B was significantly larger than that of Group A (p = 0.002). Besides, the implantation rate and miscarriage rate of embryos transferred on D3 were significantly higher in Group B than that of Group A (p = 0.033, p = 0.026 respectively).ConclusionsThe higher implantation and miscarriage rates of D3 of IVF/ICSI in the follicular phase long-acting long protocol may be related to higher serum TSH levels.