Clinical Scenario

I have been snoring for years but now that I am 6 months pregnant, I wake up gasping a few times a night. Why is this happening?

Q. What causes snoring?

A. Snoring occurs when tissues in the nose and throat relax in sleep and vibrate causing noise. Snoring is commonly experienced in people with obstructive sleep apnea (OSA) but can also affect people who do not have OSA.

Q. What is Sleep Apnea?

A. Sleep apnea is a condition in which a person repeatedly stops and starts breathing during their sleep. During the time that a person is not breathing their oxygen level declines; when they resume breathing, they may wake up slightly, interrupting their sleep.

Q. What is Obstructive Sleep Apnea (OSA)?

A. There are different types of sleep apnea, but obstructive sleep apnea (OSA) is the most common. OSA is a condition where the throat muscles relax in sleep and briefly block (obstruct) the flow of air. This can cause disrupted sleep and decreased oxygen levels in the blood.

Symptoms of obstructive sleep apnea may include:

• waking up gasping, choking, or with shortness of breath

• waking frequently in the night for unknown reasons

• waking with headaches in the morning

• feeling that sleep is not refreshing or feeling very tired during the day

• bed-partner noticing snoring, gasping, or breathing pauses

Q. What is the difference between OSA and snoring? Do people with OSA always snore?

A. Snoring does not always mean that someone has OSA, but it is a symptom more common among people with OSA. Women are more likely to snore more quietly than men, so it can go unnoticed; in fact, it is more common for women to have less typical symptoms of OSA. Even if someone does not snore, they can still have OSA.

Q. Does snoring get worse in pregnancy?

A. Snoring can get worse in pregnancy. There are several reasons why this can happen:

• being tired and more fatigued

• pregnancy weight gain

• higher levels of estrogen can cause swelling in the nose and nasal passages.

If snoring is getting significantly worse or you feel increasingly tired, discuss this with your healthcare provider.

Q. How is OSA diagnosed?

A. OSA requires a sleep study to diagnose. Sleep studies are often done in a sleep lab, although many provinces also have “at home” options

Q. Who is at a higher risk of getting OSA in pregnancy?

A. About 15% of pregnant individuals will develop OSA in their 2nd to 3rd trimester. Risk factors for developing OSA during pregnancy are:

• older age – there is no defined age cut-off, but the risk increases with age

• having physical features such as a larger neck, smaller airway, or smaller jaw

• higher weight, such as being overweight (body mass index [BMI] ≥ 25) or obese (BMI > 30) pre-pregnancy

• having medical conditions such as high blood pressure (hypertension) or diabetes in pregnancy

Q. Who should be screened for OSA?

A. Screening for OSA is suggested for pregnant individuals with:

• BMI>30, measured during the 1^st or 2^nd trimester

• a hypertensive disorder of pregnancy in the current or previous pregnancy

• diabetes in the current or previous pregnancy

Screening for OSA is recommended in the 1^st or 2^nd trimester (6 weeks to 28 weeks + 6 days).  Note that some screening questionnaires commonly used for OSA in the general population (e.g. STOP-BANG and Epworth Sleepiness Scale) may still be used in pregnancy but may not perform as well. Patients with new symptoms of OSA during pregnancy should be considered for sleep medicine assessment, regardless of the score from screening questionnaires.

Q. Does OSA get worse in pregnancy?

A. OSA can get worse during pregnancy for several reasons:

• the growing uterus which increases the pressure in the abdomen, decreasing the space that the lungs can expand. This leads to shallower breathing

• the increased use of oxygen during pregnancy can results in oxygen levels dropping faster than when not pregnant

• higher levels of estrogen can cause swelling in the nose and nasal passages

Q. Do snoring and/or OSA in pregnancy result in any risks to the baby?

A. Most pregnancies result in healthy babies, but there are chances of complications and unexpected outcomes. These chances are called baseline risks. For example, in Canada, the baseline risk of major birth defects is 3-5%. This means that 3-5 out of 100 babies born in the general population in Canada will be born with a major birth defect. There are also baseline risks for other outcomes.  

Snoring itself is not usually a concern, although sometimes it can disrupt sleep. Poor sleep has been shown to be associated with a higher risk of adverse effects on the pregnancy. Please see Sleep during Pregnancy health topic for more details.

Studies have shown that OSA during pregnancy may increase the risk of:

• low birth weight

• small and large for gestational age (birthweight that is lower/higher than expected at the time of delivery)

• preterm birth

• birth defects

Q. Does OSA in pregnancy increase the risk of any other harmful outcomes?

A. OSA may increase the risk of developing:

• high blood pressure during pregnancy

• preeclampsia (pregnancy related high blood pressure condition)

• diabetes during pregnancy

• rare heart (cardiovascular) complications

Q. How can snoring and/or OSA be managed during pregnancy?

A. Patients with OSA should be seen by a sleep specialist. Treatment depends on the features and severity of the sleep apnea.

Options to manage snoring and OSA include:

• sleeping on the side, not the back. During pregnancy, especially in the 3^rd trimester, side sleeping on the left side is suggested regardless of snoring or OSA. Pillows behind the back can help in getting more comfortable on the side

• treating nasal congestion with nasal rinses or nasal spray. Discuss with your healthcare provider which medications are safe for use in pregnancy

• using devices, such as a dental “snore guard” or nasal strips or nasal dilators for snoring, or a mandibular advancement device for OSA, which is made by a dentist with specific sleep dentistry training

• continuous positive airway pressure (CPAP) machine for OSA. If a CPAP was used before pregnancy, a sleep specialist should be consulted on whether CPAP pressure adjustment is needed

Q. Where to get more information?

Resources for the Public:

American Thoracic Society-Sleep-disordered Breathing in Pregnancy: Part 1

American Thoracic Society-Preventing Sleep Problems and Treatment of Sleep-disordered Breathing in Pregnancy: Part 2