One of the persistent problems in sleep medicine is that obstructive sleep apnoea is culturally and clinically associated with a particular kind of patient: male, middle-aged, overweight, and audibly snoring. This association is not wrong — those factors do increase risk — but it has had the effect of systematically underdiagnosing the condition in women, who present differently, often without the same classic profile, and who consequently wait years longer for diagnosis on average.
The clinical cost of that diagnostic gap is considerable. Women with OSA have higher rates of cognitive impairment, more severe depression, greater cardiovascular risk elevation for equivalent disease severity, and a range of reproductive and hormonal consequences that are rarely connected to their airway in clinical practice. This page is about that evidence, with every statistic explained in plain terms.
PCOS and Sleep Apnoea: A Hidden Connection
Polycystic ovary syndrome affects roughly 1 in 10 women of reproductive age. It is characterised by hormonal imbalance, often with elevated androgens (male-type hormones), irregular menstrual cycles, and the metabolic consequences of insulin resistance. What most women with PCOS are not told is that the condition comes with a dramatically elevated risk of obstructive sleep apnoea.
A 2025 systematic review and meta-analysis found that women with PCOS are 9.52 times more likely to have OSA than women without PCOS. To put that in plain terms: roughly 6 per cent of women without PCOS have sleep apnoea — that is about 1 in 17. For women with PCOS, around 37 to 40 per cent have it — that is closer to 2 in 5. This is not a small or marginal difference. It is one of the most dramatic associations in the entire women's health literature, and almost no one knows about it.
The mechanism runs in both directions. Hyperandrogenism — elevated male-type hormones, which is a core feature of PCOS — directly increases upper airway collapsibility, making the airway more prone to collapse during sleep. Insulin resistance, also central to PCOS, is both a cause and a consequence of OSA. The two conditions are biologically intertwined in a way that makes each worse than it would be alone.
OSA in women with PCOS is also associated with significantly worse metabolic profiles. Women who have both conditions simultaneously have considerably wider waist circumference, higher blood pressure, worse lipid profiles, and more severe insulin resistance than women with PCOS but without OSA. Reduced sex hormone-binding globulin (SHBG) — a protein that controls how much active hormone circulates in the blood — is lower in women with both conditions, which amplifies androgen effects and worsens the symptoms most associated with PCOS: acne, unwanted hair growth, and irregular cycles.
Around 37 per cent of women with PCOS have obstructive sleep apnoea. Only 6 per cent of women without PCOS do. This is one of the most underreported connections in women's health.
Treating OSA in women with PCOS improves the metabolic profile. CPAP is associated with improved insulin sensitivity, reduced blood pressure, and better lipid regulation in this group. For a condition already associated with elevated lifetime cardiovascular risk, that treatment signal matters enormously.
Pregnancy: A High-Risk Period That Is Largely Unrecognised
Sleep apnoea affects approximately 15 to 20 per cent of pregnant women, rising through the trimesters as weight gain and physiological changes increase upper airway resistance. Yet it is almost never screened for in routine antenatal care in the UK.
A meta-analysis — a study that pools results from many separate pieces of research to get the most reliable overall picture — covered 120 studies involving 58 million pregnant women. This is one of the largest bodies of evidence in obstetric research. It found that sleep disturbances including OSA are associated with a 2.80-fold increased risk of pre-eclampsia. To make that concrete: pre-eclampsia normally affects roughly 1 in 14 pregnancies in the UK. With sleep apnoea, that rises to roughly 1 in 5. Pre-eclampsia is a serious condition involving high blood pressure in pregnancy that can threaten the life of both the mother and the baby if not managed carefully.
A 2025 study using a method called Mendelian randomisation gave us stronger evidence about whether this link is causal. Mendelian randomisation uses people's genetic makeup as a kind of natural experiment — because we inherit our genes randomly, like a coin toss, genetic variants that predispose to OSA are distributed at random across the population. When researchers test whether those who are genetically more likely to have OSA also have higher rates of pregnancy complications, they are essentially testing causation rather than just correlation. This approach confirmed that sleep apnoea independently causes gestational diabetes and pre-eclampsia — meaning OSA is not simply tagging along with other risk factors, but is genuinely driving the increased risk.
| Pregnancy Complication | Risk with OSA | What This Means in Practice |
|---|---|---|
| Pre-eclampsia | 2.80 times more likely | Rises from roughly 1 in 14 pregnancies to roughly 1 in 5 |
| Gestational hypertension | 1.74 times more likely | Rises from roughly 1 in 10 pregnancies to roughly 1 in 6 |
| Gestational diabetes | 1.59 times more likely (confirmed causal) | Rises from roughly 1 in 16 pregnancies to roughly 1 in 10 |
| Caesarean section | 1.47 times more likely | Substantially elevated odds |
| Preterm birth | 1.38 times more likely | Meaningful increase in an already significant outcome |
| Stillbirth | 1.25 times more likely | 25% higher risk — a small relative increase in an uncommon outcome, but with profound consequences |
Infants born to mothers with OSA also face elevated risks: lower birth weight, higher rates of admission to the neonatal intensive care unit, and emerging evidence of effects on placental function. For women undergoing IVF, sleep-disordered breathing is associated with fewer eggs retrieved, lower fertilisation rates, and poorer embryo quality in cohort studies — meaning the sleep problem may be affecting the chances of the fertility treatment working.
CPAP during pregnancy has been shown to reduce blood pressure in women with OSA-related hypertension and pre-eclampsia risk, and improves oxygen levels during sleep. Adherence during pregnancy is a challenge, partly because of physical discomfort, but the stakes for both maternal and fetal outcomes are high enough to justify actively pursuing treatment rather than taking a wait-and-see approach.
Menopause: The Compounding Cycle
Before menopause, women have substantially lower rates of OSA than men of equivalent age and BMI. Oestrogen and progesterone both have protective effects on the upper airway: oestrogen maintains muscle tone in the muscles that keep the pharynx (throat) open, and progesterone is a respiratory stimulant that increases the sensitivity of the airway to collapse. When these hormones fall at menopause, the airway loses these protective effects and OSA risk rises substantially.
Post-menopausal women who also experience weight gain — which is common due to metabolic changes at this life stage — face a compound problem: the hormonal protection is gone and the mechanical pressure on the airway is simultaneously increasing. By their 60s, women's rates of OSA approach those of men. But because the classic male presentation is what clinicians are trained to recognise, women in this age group are systematically less likely to be referred for sleep studies.
The clinical complication is that OSA then worsens the symptoms of menopause. Hot flushes, insomnia, mood disturbances, and cognitive changes are all driven in part by disrupted sleep architecture. OSA fragments sleep further, amplifying these symptoms and creating a cycle where menopause worsens sleep, OSA worsens sleep further, and the whole constellation is attributed to the menopause rather than to its additive components. Treating the OSA in this group consistently improves sleep quality, mood, and cognitive performance, though the hormonal symptoms of menopause itself require separate management.
Female Sexual Dysfunction
Women with OSA are 2.56 times more likely to experience female sexual dysfunction. To put that in real terms: female sexual dysfunction is estimated to affect roughly 1 in 3 women at some point in their lives. With OSA, the evidence suggests that proportion rises to more than 1 in 2. The association covers all domains of the Female Sexual Function Index: desire, arousal, lubrication, orgasm, satisfaction, and pain.
The mechanisms include the effects of chronic fatigue and non-restorative sleep on libido and arousal, hormonal disruption affecting oestrogen and sex hormone-binding globulin levels, and endothelial dysfunction (impaired blood vessel response) affecting genital blood flow in ways that mirror the erectile dysfunction seen in men with OSA. Importantly, these findings hold up in studies that have controlled for relationship factors, meaning the sexual dysfunction is at least partly a direct consequence of the OSA biology rather than simply a downstream effect of being unwell and tired.
Why Women Are Underdiagnosed
Women with OSA are less likely to report the classic symptom of loud snoring. They more commonly present with insomnia, morning headaches, fatigue, mood disturbances, and depression. These are symptoms that can be attributed to anxiety, menopause, thyroid disease, or stress, and frequently are. Sleep studies are consequently ordered less often, and when they are ordered, the referral tends to come years later in the disease course than for men with equivalent severity.
The cognitive evidence specifically highlights post-menopausal women as a group with disproportionately severe cognitive consequences for equivalent OSA severity compared with men. The diagnostic gap is not only affecting quality of life in the short term. It is allowing damage to accumulate over years in a group that is already at elevated risk simply from the hormonal changes of menopause.
References
[1] Abdul Jafar NK et al. Obstructive sleep apnea syndrome in polycystic ovary syndrome: a systematic review and meta-analysis. Frontiers in Endocrinology. 2025. 8 cross-sectional studies, 942 participants; pooled OSA prevalence 37% in PCOS vs 6% in non-PCOS; OR 9.52 for composite OSA (95% CI 3.90-23.26).
[2] Jafar NKA et al. Sex hormones, sex hormone-binding globulin and sleep problems in females with polycystic ovary syndrome: a systematic review and meta-analysis. Clinical Endocrinology. 2025. 24 studies; SHBG significantly lower in PCOS women with OSA versus without (SMD -0.62).
[3] Kahal H et al. The association between obstructive sleep apnea and metabolic abnormalities in women with PCOS: a systematic review and meta-analysis. Sleep. 2018. 6 studies, 252 participants; PCOS+OSA associated with 6 kg/m2 higher BMI, 10.93 cm wider waist circumference, significantly worse insulin resistance, blood pressure, and lipid profiles.
[4] Lu Q et al. Sleep disturbances during pregnancy and adverse maternal and fetal outcomes: a systematic review and meta-analysis. Sleep Medicine Reviews. 2021. 120 studies, 58,123,250 pregnant women; OSA associated with OR 2.80 for pre-eclampsia, OR 1.59 for gestational diabetes, OR 1.38 for preterm birth.
[5] Liu L et al. The prevalence of obstructive sleep apnea and its association with pregnancy-related health outcomes: a systematic review and meta-analysis. Sleep and Breathing. 2018. 33 studies; pooled OSA prevalence 15% in pregnancy; OSA associated with substantially elevated odds of gestational hypertension, gestational diabetes, and pre-eclampsia.
[6] Chen P et al. Sleep apnea and risk of gestational diabetes and preeclampsia: a Mendelian randomization study. Sleep. 2025. One-sample MR using genetic instruments for OSA; OSA causally associated with gestational diabetes (OR 1.43) and pre-eclampsia (OR 1.48); no horizontal pleiotropy detected, supporting causal interpretation.
[7] Habibi F et al. Relationship between sleep disturbances and in vitro fertilization outcomes in infertile women: a systematic review and meta-analysis. Brain and Behavior. 2025. 9 studies; significant association between sleep quality and IVF outcomes.
[8] Zhou P et al. A possible important regulatory role of estrogen in obstructive sleep apnea hypoventilation syndrome. Frontiers in Medicine. 2025. Narrative review of oestrogen's protective role in upper airway tone and its reduction at menopause.
[9] Qin S et al. Association between obstructive sleep apnea and female sexual dysfunction: a systematic review and meta-analysis. Sexual Medicine Reviews. 2025. Meta-analysis; OR 2.56 for female sexual dysfunction in OSA patients across all FSFI domains (95% CI 1.38-4.75).
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