Pregnancy and fertility in thyroid disorders

These hormones influence several organs, including the testis, and are crucial for sperm production. A healthy thyroid gland supports overall male reproductive health by ensuring normal sperm count and sperm motility. When thyroid dysfunction occurs, whether it’s an overactive thyroid (hyperthyroidism) or an underactive thyroid gland (hypothyroidism), it can negatively impact semen parameters, leading to lower sperm quality and fertility outcomes. In hyperthyroidism, increased T4 levels, altered LH and FSH responsiveness, disrupt the endocrine regulation upon development and functioning of male reproductive tissues and germ cells resulting in distortions in tissues such as the reduced diameter of seminiferous tubule and impaired or delayed spermatogenesis.

• For men who are treated with antithyroid drugs, there are no risks attached to fathering a child.
• However, the authors claimed there was some improvement in sperm count and its motility59.
• Among these hormones, thyroxine (T4) and triiodothyronine (T3) are essential for maintaining normal reproductive function.
• These patients did not show a change in serum LH, FSH, testosterone, BioT, progesterone, estradiol and SHBG levels.

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In the UK all babies have a heel-prick blood test to screen for hypothyroidism shortly after birth and treatment can be started very quickly if your baby needs levothyroxine. Hypothyroidism is rare in newborn babies in the UK – only about one baby in every 2,000-3,000 is born with hypothyroidism. Moreover, alterations in thyroid hormones signaling could also have detrimental effects on the placenta, possibly even causing abortion; however, the molecular mechanisms involved have not been completely understood 21. In this article, we will interchangeably use the terms “hyperthyroidism” or“thyrotoxicosis” to identify thyroid hormone excess. If you are on antithyroid drugs, you can breastfeed provided the dose is low, but check first with your doctor.

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• When low thyroid hormone levels occur, sperm may struggle to mature and gain the motility needed to reach an egg.
• Regular thyroid function tests should be an essential part of any fertility evaluation, especially in cases of unexplained infertility.
• If you have an untreated (or undertreated) underactive thyroid gland (hypothyroidism) you are likely to find it more difficult to conceive.
• However, prior work has demonstrated a relationship between thyroid autoantibodies and sexual dysfunction in women.

A simple blood test to measure the TRAb level in the mother can help predict whether the baby will be affected in this way. If the levels of antibodies are high it is likely that you and your baby will be monitored more closely. There is, unfortunately, an increased risk of miscarriage in the early stages of pregnancy if your hyperthyroidism is not under control. If you are taking antithyroid drugs there is a very slight increased risk of the baby having developmental abnormalities so some patients choose to have definitive treatment for Graves’ disease with radioactive iodine or surgery to allow them to have a pregnancy without needing to take antithyroid drugs. Also, if the dose of antithyroid drugs is too high, the baby’s thyroid may become underactive and the baby may develop a goitre.

• Two randomized studies showed a significant reduction in miscarriages with levothyroxine treatment 83, 84, while one other, very large, did not find any significant difference in live birth rates upon treatment with a fixed dose of 50 mcg levothyroxine started before pregnancy 85.
• Women may have longer or heavier periods, which can cause anaemia, or your periods may stop completely.
• Clinical manifestations of SDs included erectile and ejaculatory dysfunction, impaired spermatogenesis, and disruption of the hypothalamic-pituitary-gonadal axis.

They calculated a decrease in free testosterone to free estradiol ratio suggesting an increased aromatization of testosterone. However, we66 reported an increase in calculated bioT and an unaltered total estradiol to testosterone ratio in hyperthyroid patients. Thus, there is conflicting information on whether hyperthyroidism affects female sexual function, with two studies finding a relationship and one failing to find a relationship (Table 5). Several studies have investigated the relationship between male sexual dysfunction and hyperthyroidism. Researchers have sought to examine this relationship both by looking for sexual dysfunction in hyperthyroid men as well as looking for hyperthyroidism in men with sexual dysfunction. To investigate the associations between thyroid hormones and sexual dysfunction in women and men.

They have noticed that hypothyroidism had adverse effects on male spermatogenesis, though the sperm morphology was the only parameter that was affected significantly, sperm motility was also affected but the differences were not statically significant62 (Table 1). Viewed together, the treatment of hypothyroidism in men shows some emerging trends in its effect on sexual function. In all studies, the rate of ED decreased after treatment.17, 27, 28 In studies using IIEF scores, total IIEF scores increased significantly.17, 28 However, there was difference in which IIEF domain scores improved with treatment.

Furthermore, the ratio of the conversion of androstenedione to estrone, as well as of testosterone to estradiol, increases 22. These hormonal alterations result in menstrual cycle disturbances 2.5 times more frequent than in the general population 22 (Fig.1). These conditions result in different thyroid-stimulating hormone (TSH) and free T4 (fT4) reference range than in the period out of gestation. In fact, TSH level decreases in the first trimester of pregnancy by 20–50%, due to hCG stimulatory effect on TSH receptor, leading to an fT4 increase in the same trimester, reaching maximum concentrations by 16 weeks of gestation, and consequently TSH increasing and fT4 lowering throughout the rest of gestation. In 15% of pregnant women during the first trimester, TSH level is below the lower limit of reference range of 0.4 mU/L 5.

Men with hypothyroidism may notice fatigue, weight gain, dry skin and cold intolerance, while those with hyperthyroidism may experience weight loss, heat intolerance, irritability and an increased heart rate. In both cases, fertility issues like reduced sperm count and poor sperm quality are common, which is why seeking medical advice for these symptoms is important. Further research is needed to investigate (1) whether hyperthyroidism orhypothyroidism affects nonconventional sperm parameters (2) whether subclinicalthyroid dysfunction influences male fertility.

SEXUAL FUNCTIONS

For men who are treated with antithyroid drugs, there are no risks attached to fathering a child. To date, no studies are available investigating the effect of hyperthyroidism on IVF outcomes. Probably, this is because patients with hyperthyroidism should postpone IVF techniques after normalization of thyroid function 27. We herein aimed to review the new insights on the relationship between impaired thyroid function and male and female fertility, spacing from spontaneous pregnancy to ART, with the objective of providing an updated narrative revision of the literature. 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.

Therefore, LT4 significantly reduced sperm necrosis and lipid peroxidation ameliorating chromatin compactness. These effects of LT4 were evident at a concentration of 2.9 pmol L-1, close to the physiological free-thyroxine (FT4) concentrations in the seminal fluid of euthyroid subjects. We showed a beneficial role of thyroid hormones on sperm mitochondrial function, oxidative stress and DNA integrity.

However, more research is needed to determine exactly how normalization of thyroid hormone levels affects other aspects of sexual functioning. Thyroid hormones and their impacts on male reproduction have been reported in numerous studies in past few decades. They are the crucial players synthroid acb in the regulation of male gonadal developments and reproductive functions. An excess or deficit of thyroid hormones not only alter the testicular functions but also interrupts neuroendocrine axis through the crosstalk between hypothalamic-pituitary-thyroid (HPT) axis and hypothalamic-pituitary-gonadal (HPG) axis. These changes result in decreased testosterone level and altered seminal plasma components which affect semen quality.