The Impact of Moderately High Preconception Thyrotropin Levels on Ovarian Reserve Among Euthyroid Infertile Women Undergoing Assisted Reproductive Technology

Thyroid function tests and serum anti-Müllerian hormone in various populations, is there any association? A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the association between anti-Müllerian hormone (AMH) as a biomarker of ovarian reserve and various thyroid function tests, including thyroid-stimulating hormone (TSH), free T3 (FT3), free T4 (FT4), T3, T4, and thyroid autoantibodies, such as thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb), in various female populations.

METHODS

A comprehensive literature search was conducted across six electronic databases and original observational studies examining the correlation between AMH levels and at least one TFT, TPOAb, or TgAb.

RESULTS

Forty studies with 14,009 participants were included in the quantitative synthesis. The pooled results showed that AMH levels were not significantly correlated with TSH levels in the overall population or diverse subgroups. However, after adjusting for publication bias, a small, but significant, positive correlation was observed. Meta-regression analyses identified estradiol, FT3, and follicle-stimulating hormone (FSH) as significant moderators of AMH-TSH association in various populations. AMH was significantly positively correlated with FT3 (r = 0.177) and FT4 (r = 058), negatively correlated with T3 (r = - 0.202) and T4 (r = - 0.216) in the overall population, and significantly positively correlated with TPOAb in the normal population (r = 0.348). AMH levels were not significantly correlated with TgAb levels. Meta-regression revealed body mass index and FT4 as moderators in AMH-FT4 and AMH-TPOAb correlations.

CONCLUSION

These findings highlight the complex relationship between AMH and thyroid function markers with potential moderators influencing these associations. Further well-controlled longitudinal studies are required to clarify the underlying mechanisms and clinical implications of these associations across reproductive stages and metabolic profiles.

Should we routinely assess ovarian reserve in girls and young women with autoimmune thyroid disease?

Background and aims

Some studies report that reproductive aged women with autoimmune thyroid disease (ATD) have a significantly higher risk of diminished ovarian reserve (OR). What is the best time to assessed OR in females with ATD? To answer this question, we assessed OR in girls and young women with ATD and reviewed the current literature regarding on the topic.

Methods

The study included 70 patients with ATD, mean 14.4 ± 3.3 years, and 29 age-matched controls. Follicle-stimulating hormone (FSH), luteinizing hormone, estradiol, prolactin, thyroid stimulating hormone, free thyroxin, thyroid peroxidase antibody, thyroglobulin antibody and Anti-Mullerian Hormone (AMH), and Inhibin-B were measured in all participants, if possibly on day 3-5 of the menstrual cycle.

Results

Most ATD patients were euthyroid. All participants have normal OR. We found a significantly positive correlation between AMH and Inhibin-B in ATD patients and between Inhibin-B and FSH in both groups.

Conclusions

The results of our study and the literature review indicate that euthyroid adolescents with ATD do not have impaired OR. Routine evaluation of OR in adolescents with ATD does not seem necessary. But OR should be assessed in everyone with ATD and hypothyroidism, because not the presence of ATD but euthyroidism matters to OR.

The use of breast milk iodine concentration in the first week of lactation as a biomarker of iodine status in breast-feeding women

Breast milk iodine concentration (BMIC) is a promising indicator of iodine status in lactating women. However, there are limited data on its usefulness to reflect maternal iodine deficiency. Therefore, the aim of our study was to assess iodine concentration in breast milk and urine samples in exclusively breast-feeding women. Eligible pregnant women undergoing routine antenatal care in a large hospital in Shaanxi Province, China, were followed up from the third trimester of pregnancy until the first week of lactation. Urine samples (20 ml) were collected during pregnancy and lactation. Iodine concentration in samples was measured based on Sandell-Kolthoff reaction. Breast milk samples (5 ml) were provided during lactation. A receiver operating curve (ROC) was constructed to determine the diagnostic performance of BMIC. An iodine-specific FFQ was completed twice during pregnancy and lactation. A total of 200 women completed the study. The overall median BMIC was 89 μg/l, indicating iodine sufficiency (i.e. BMIC reference range between 60 and 465 μg/l). Women reported similar median urinary iodine concentration (UIC) during pregnancy and lactation (112 and 113 μg/l, respectively), but their iodine status differed - mild-to-moderate iodine deficiency during pregnancy and iodine sufficiency during lactation. The ROC for BMIC using UIC as a reference standard was 0·755 (95 % CI: 0·644, 0·866). In conclusion, this study demonstrated that women were iodine sufficient in the first week of lactation as assessed by UIC, which was consistent with BMIC. These findings suggested that BMIC is a useful biomarker to assess iodine status in lactating women.