Sleep apnea in pregnancy: risks, screening and CPAP

Sleep apnea in pregnancy is more common than many people expect, and it tends to increase as the pregnancy goes on. It matters because it's linked to preeclampsia, high blood pressure in pregnancy and gestational diabetes. The reassuring part is that screening is simple, and CPAP, the standard treatment, is considered low risk in pregnancy. If you snore loudly, gasp at night or feel exhausted beyond normal pregnancy tiredness, mention it to your midwife, obstetrician or other obstetric provider.

How common is sleep apnea in pregnancy?

Sleep apnea in pregnancy is fairly common and becomes more frequent with each trimester. How common depends on who is studied and how. Studies that test the same women early and late in pregnancy consistently find more sleep apnea later on, as weight, fluid and hormones change the airway.

In a 2014 study from the University of Pennsylvania, 105 pregnant women had full overnight sleep studies in the first and third trimesters. Obstructive sleep apnea was found in 10.5% of them in the first trimester and 26.7% by the third. The average AHI, a count of breathing events per hour, rose from about 2 to nearly 4. Higher body mass index and older maternal age in early pregnancy predicted third-trimester sleep apnea.

The largest study, nuMoM2b, tested 3,705 first-time mothers at home. Sleep-disordered breathing (an AHI of 5 or more) was found in 3.6% in early pregnancy, at 6 to 15 weeks, and 8.3% in midpregnancy, at 22 to 31 weeks.

Rates are higher in people who start pregnancy with risk factors. In a study of 128 high-risk women, including those with obesity, chronic high blood pressure, diabetes, past preeclampsia or twins, mild sleep-disordered breathing rose from 21% in early pregnancy to 35% in the third trimester. About 1 in 5 developed it new during pregnancy, and most of those new cases were mild.

Why does pregnancy raise the risk?

Pregnancy raises the risk of sleep apnea because the changes that support a growing baby can also narrow the airway at night. Weight gain is one factor, and the Pien study found that higher body mass index in early pregnancy was one of the main predictors of sleep apnea by the third trimester. Older maternal age was the other.

Nasal congestion plays a part too. The 2023 consensus guideline from the Society of Anesthesia and Sleep Medicine and the Society for Obstetric Anesthesia and Perinatology notes that nasal congestion is common in pregnancy. Our guide to a stuffy nose during pregnancy covers why it happens and what's safe to try. Snoring often rises for the same reasons, which our article on snoring during pregnancy explains.

Is sleep apnea linked to preeclampsia and gestational hypertension?

Sleep apnea in pregnancy is linked to preeclampsia and other high blood pressure problems of pregnancy. In nuMoM2b, sleep-disordered breathing was associated with nearly twice the odds of preeclampsia in both early pregnancy (adjusted odds ratio 1.94) and midpregnancy (1.95), after accounting for other factors.

The same study found a link with hypertensive disorders of pregnancy as a group, which includes preeclampsia and gestational hypertension. That link was statistically significant in midpregnancy (adjusted odds ratio 1.73). The researchers also saw an exposure-response pattern, meaning higher AHI went along with higher rates of these problems.

These are associations, not proof that sleep apnea causes preeclampsia. But they're one reason sleep symptoms are worth mentioning. Preeclampsia itself needs prompt care. The NHS lists warning signs including a severe headache that doesn't go away with simple painkillers, vision problems such as blurring or flashing lights, pain below the ribs, and sudden swelling of the face, hands or feet. It says to get urgent medical help if you have them. Our article on sleep apnea and high blood pressure covers the link outside pregnancy.

Is sleep apnea linked to gestational diabetes?

Sleep apnea in pregnancy is linked to gestational diabetes. In nuMoM2b, sleep-disordered breathing was tied to about three and a half times the odds of gestational diabetes in early pregnancy (adjusted odds ratio 3.47) and nearly three times in midpregnancy (2.79).

A 2013 meta-analysis in Diabetes Care pooled nine studies with 9,795 pregnant women. Women with sleep-disordered breathing had more than three times the odds of gestational diabetes, with a pooled odds ratio of 3.06 after adjusting for body mass index. The authors said the link held even after considering obesity and called for earlier recognition of sleep-disordered breathing in pregnancy. The 2023 consensus guideline adds that studies suggest sleep apnea is more common among people with gestational diabetes.

Who should be screened for sleep apnea in pregnancy?

Screening for sleep apnea in pregnancy is suggested for people with higher risk, ideally in the first or second trimester. The 2023 consensus guideline says higher risk means a BMI over 30, chronic high blood pressure, diabetes before pregnancy, or gestational diabetes in this or a previous pregnancy. It rates this screening as reasonable, with moderate strength.

The check itself is about symptoms. The guideline suggests asking about loud snoring, gasping at night or pauses in breathing that someone else has noticed, and daytime sleepiness or excessive fatigue. Those are easy things to bring up at a routine appointment.

Some common tools don't work well in pregnancy. The guideline recommends against using the STOP-BANG questionnaire as a screening tool in pregnancy, because its own meta-analysis found it was a poor predictor. It also advises against overnight pulse oximetry alone to diagnose sleep apnea in pregnancy. Some pregnancy-specific screening tools exist, but the guideline says they need more validation.

How is sleep apnea diagnosed in pregnancy?

Sleep apnea in pregnancy is diagnosed with a sleep study, either in a lab or with a portable home device. The 2023 guideline says portable devices are particularly helpful in pregnancy for convenience and practicality, and studies have shown good agreement with in-lab results.

There are limits. The guideline notes that portable monitoring has mostly been validated in people with obesity late in pregnancy, and is generally less sensitive than in-lab testing in pregnant people. In early pregnancy without obesity, it suggests portable testing may be reasonable only when there's a clinical suspicion of severe disease.

Is CPAP safe during pregnancy?

CPAP is considered low risk in pregnancy. The 2023 consensus guideline says CPAP safety hasn't been studied regularly in pregnant people, but there is no evidence that CPAP therapy is harmful in pregnancy. It describes the safety profile of sleep apnea treatment in pregnancy as thought to be favorable, with minimal risk.

The guideline is also honest about what CPAP has and hasn't shown. Studies of CPAP's effect on blood pressure, blood sugar and other pregnancy outcomes have been small and short. So the guideline suggests telling patients that treatment is aimed at symptoms, the sleep study numbers and quality of life, not at changing pregnancy-specific outcomes. It still judges the potential benefit to outweigh the expected risk.

A few points are specific to pregnancy. The guideline suggests starting with an auto-adjusting CPAP machine set to a wide range, because pressure needs can rise slightly as pregnancy goes on, and reviewing the machine data two or three times during pregnancy and after birth. Our comparison of CPAP, APAP and BiPAP explains the auto-adjusting type. Nasal congestion can make CPAP harder to use, so tell your sleep team if your nose is blocked. Our guide to getting used to CPAP covers mask fit, humidity and the first few weeks.

The guideline also suggests avoiding alcohol and stopping smoking as part of treatment, which are already standard advice in pregnancy.

What should you ask your obstetric provider?

Ask your obstetric provider whether your symptoms or risk factors mean you should be checked for sleep apnea. Useful details to bring include how loudly and how often you snore, whether anyone has seen you stop breathing or gasp, how sleepy you feel during the day, and any history of high blood pressure, diabetes or preeclampsia.

If you're already on CPAP from before pregnancy, ask whether your settings should be reviewed as the pregnancy goes on. If you're diagnosed during pregnancy, ask who will follow up after the birth. Your obstetric provider and sleep specialist should work together on the plan.

Does sleep apnea go away after pregnancy?

Sleep apnea that appears in pregnancy often improves after birth, but it doesn't always go away. The 2023 guideline says it persists in nearly 50% of people diagnosed in pregnancy. It recommends that people with symptoms in the third trimester be evaluated by a specialist after delivery, and suggests repeat testing may be considered, though the best timing is unknown.

The guideline also has a practical tip for new parents on CPAP: plan where the machine will sit if the baby sleeps in your room, and disconnect it when you wake for night feeds. Our article on snoring after pregnancy covers what to expect in the months after birth.

Can mouth tape help snoring in pregnancy?

Mouth tape is not a first step for snoring in pregnancy. We don't recommend mouth tape in pregnancy without checking with your midwife or doctor first. Snoring in pregnancy can be a sign of sleep apnea, which needs testing, and mouth tape doesn't treat sleep apnea. It could also hide the snoring that would prompt someone to get checked.

Pregnancy also brings a stuffy nose for many people, and mouth tape only makes sense if you can breathe easily through your nose. If your midwife or doctor has ruled out sleep apnea and your nose is clear, they can help you decide whether it's reasonable. Our guide to mouth tape and pregnancy goes through the details. We don't recommend mouth tape for children.

This article is general information, not medical advice. Your midwife, obstetrician or sleep doctor can advise on your own pregnancy.

Read next

• Snoring during pregnancy
• Snoring after pregnancy
• Sleep apnea in women

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.