Does Fatty Liver Affect Fertility?

Fatty liver disease and fertility are more closely connected than many people realise. Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease, can disrupt the hormonal environment needed for conception in both women and men. Through mechanisms including insulin resistance, impaired sex hormone metabolism and chronic low-grade inflammation, fatty liver may reduce the chances of getting pregnant. This article explains how fatty liver affects reproductive health, what lifestyle changes can help, and when to seek medical advice.

Can fatty liver disease affect your chances of getting pregnant?

Fatty liver disease is associated with reduced fertility in both sexes by disrupting hormonal balance, impairing ovulation in women and reducing sperm quality in men, largely through insulin resistance and impaired liver metabolism of sex hormones.

Fatty liver disease is associated with reduced fertility in both women and men, with evidence suggesting that metabolic liver disease disrupts the hormonal and physiological conditions needed for conception. Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is closely linked to insulin resistance, obesity and type 2 diabetes, all of which are independently associated with reduced fertility.^[1][3] In women, these metabolic disturbances may impair ovulation and reduce egg quality. MASLD and polycystic ovary syndrome (PCOS) frequently co-exist through shared metabolic risk factors, including insulin resistance and obesity, and PCOS is itself a leading cause of female infertility.^[5][6] In men, fatty liver disease has been associated with lower testosterone levels, reduced sperm quality and impaired sperm motility, though much of this evidence is observational.^[7][8]

The relationship between fatty liver and fertility is not simply coincidental. The liver plays a central role in metabolising sex hormones, including oestrogen and testosterone. When liver function is compromised by fat accumulation and inflammation, this metabolic processing may become less efficient, potentially contributing to hormonal imbalances that can interfere with reproductive function.

Fatty liver disease is increasingly common in the UK. The NHS and British Liver Trust note that MASLD affects a substantial proportion of the adult population, with estimates varying by diagnostic method and population studied. Recognising the link between liver health and fertility is an important first step. Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support, which may be relevant for those whose fertility concerns are connected to metabolic health.

How does fatty liver disrupt hormones linked to fertility?

Fatty liver impairs the liver's ability to clear sex hormones and lowers SHBG, increasing free androgens in women and reducing testosterone in men, both of which can disrupt ovulation and sperm production.

Fatty liver disease may disrupt fertility-related hormones primarily by impairing the liver's ability to metabolise and clear sex hormones. When hepatic fat accumulation triggers inflammation and reduces liver cell efficiency, hormonal processing may be compromised, potentially creating an environment of hormonal imbalance that undermines reproductive health. The magnitude of these effects varies between individuals and is often confounded by the degree of adiposity.

In women, relative excess of oestrogen compared with progesterone may disrupt the menstrual cycle, impair the luteal phase and reduce the likelihood of successful implantation. Insulin resistance, which frequently accompanies fatty liver disease, is associated with ovarian androgen excess, contributing to the hormonal profile seen in PCOS. The established mechanisms in PCOS involve hyperandrogenism and insulin resistance rather than oestrogen excess alone. Elevated insulin is also associated with suppression of sex hormone-binding globulin (SHBG), a protein that regulates the availability of active sex hormones in the bloodstream. Lower SHBG means more free androgens may circulate, potentially disrupting ovulation.

In men, fatty liver disease is associated with reduced SHBG and lower total testosterone, which may impair sperm production and libido. Adipose tissue, which is often increased in people with fatty liver, can convert testosterone to oestradiol via a process called aromatisation, potentially lowering the testosterone-to-oestrogen ratio. This hormonal shift has been associated with reduced sperm count and motility, though the evidence is largely observational.

Chronic low-grade inflammation associated with MASLD raises levels of pro-inflammatory cytokines such as tumour necrosis factor-alpha and interleukin-6. These inflammatory mediators may interfere with the hypothalamic-pituitary-gonadal axis, the hormonal signalling pathway that governs reproductive function in both sexes, though direct causal evidence in humans remains limited and this area continues to be studied.

What lifestyle changes can improve both liver health and fertility?

A Mediterranean-style diet, modest weight loss of 5 to 10 per cent of body weight, at least 150 minutes of weekly aerobic activity and alcohol avoidance can improve hepatic steatosis, insulin sensitivity and hormonal balance.

Adopting a balanced, nutrient-dense diet and achieving a modest reduction in body weight are among the most effective lifestyle changes for improving both liver health and fertility simultaneously. NICE guidance on NAFLD (NG49) recommends weight loss as a key management strategy, with greater degrees of weight loss (in the region of 7 to 10 per cent of body weight) associated with greater histological and metabolic benefit. Modest weight loss of around 5 per cent has been shown to reduce hepatic steatosis and improve insulin sensitivity, though more substantial loss is generally needed to reduce liver inflammation and fibrosis.^[1] Both improvements support hormonal balance and may benefit reproductive function.

Dietary changes that benefit the liver also tend to support fertility. A Mediterranean-style diet, rich in vegetables, wholegrains, legumes, oily fish and olive oil, has evidence supporting its role in reducing hepatic steatosis and may support fertility outcomes, though direct evidence on ovarian function specifically is limited. Reducing intake of ultra-processed foods, refined carbohydrates and added sugars is particularly important, as these drive insulin resistance, a key mechanism linking fatty liver to impaired fertility. Alcohol should be minimised or avoided entirely, as it directly contributes to liver fat accumulation and can disrupt sex hormone metabolism. For those who are trying to conceive, avoiding alcohol altogether is the safest approach, in line with NHS guidance.

Regular physical activity is independently beneficial for both liver health and fertility. UK Chief Medical Officers and NHS guidance recommends at least 150 minutes of moderate-intensity aerobic activity per week for adults, and evidence suggests that resistance training alongside aerobic exercise is particularly effective at reducing visceral fat and improving insulin sensitivity.^[10][11] Smoking cessation is also advisable, as smoking is associated with reduced ovarian reserve in women and poorer sperm parameters in men.^[12]

For those whose weight is a significant contributing factor, a structured weight-management programme may be appropriate. NHS weight-management services can provide support, and your GP can advise on referral. Addressing sleep quality and managing psychological stress are also worthwhile, as both poor sleep and chronic stress can elevate cortisol, which may further disrupt the hormonal axis governing reproduction.

When should you see a doctor about fatty liver and fertility concerns?

See your GP after 12 months of unsuccessful conception (or 6 months if over 35), sooner if you have a known diagnosis of fatty liver, PCOS or insulin resistance, as these warrant earlier fertility investigation and liver assessment.

You should see your GP if you have been trying to conceive for 12 months without success (or 6 months if you are over 35), particularly if you have a known diagnosis of fatty liver disease, obesity, insulin resistance or PCOS, as these conditions warrant earlier investigation. NICE guidance (CG156) recommends that GPs offer initial fertility investigations to both partners at this stage. A diagnosis of MASLD should be disclosed as part of that assessment, as it may influence the investigations requested and the management plan offered.

If you have been diagnosed with fatty liver disease and are planning a pregnancy, it is sensible to discuss this with your GP before trying to conceive. For women, NICE CG156 recommends mid-luteal serum progesterone as the first-line test to confirm ovulation.^[2] Tests such as AMH, FSH, LH and oestradiol are not routinely recommended in primary care for predicting natural fertility, though your GP may consider TSH and prolactin if there are clinical reasons to do so.^[2] For men, a semen analysis is a standard first-line investigation. Your GP may also arrange liver function tests, a fasting glucose or HbA1c, and a lipid profile to assess the extent of metabolic liver disease. In line with NICE NG49, your GP may use a FIB-4 score (a calculation based on age, liver enzyme levels and platelet count) to assess the risk of liver fibrosis and determine whether referral to a hepatologist is appropriate.^[1]

You should seek prompt medical advice, rather than waiting for a routine appointment, if you experience symptoms that may indicate worsening liver disease, such as persistent right upper abdominal discomfort, unexplained fatigue, or jaundice (yellowing of the skin or whites of the eyes). You should contact NHS 111 or seek urgent medical attention if you develop symptoms that may suggest decompensated liver disease, including significant abdominal swelling, confusion or disorientation, vomiting blood, or passing very dark or tarry stools, as these require prompt assessment.

Referral to a hepatologist, endocrinologist or reproductive medicine specialist may be appropriate depending on the findings. Your GP is best placed to coordinate this, and early engagement with the right specialist team can meaningfully improve outcomes for both liver health and fertility.

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