Snoring during pregnancy is extremely common, affecting roughly one in four pregnant women, but it can signal real health risks depending on when it starts and how severe it becomes. Mild, occasional snoring is usually harmless. However, snoring that begins during pregnancy (rather than snoring you’ve always had) is linked to a significantly higher chance of developing high blood pressure and preeclampsia, two conditions that can threaten both your health and your baby’s.
Why Pregnancy Causes Snoring
Pregnancy changes your body in ways that make snoring far more likely, even if you never snored before. Rising hormone levels dilate blood vessels and cause the mucous membranes inside your nose to swell. That congestion narrows your nasal passages and pushes you toward mouth breathing during sleep, which is the primary setup for snoring.
Weight gain compounds the problem. As pregnancy progresses, extra tissue around the neck and throat can put pressure on the upper airway. Your growing uterus also pushes the diaphragm upward, reducing lung capacity and making it harder to breathe deeply while lying down. The combination of nasal congestion, weight gain, and reduced lung volume explains why snoring tends to get louder and more frequent in the third trimester.
The Link to Preeclampsia and High Blood Pressure
A prospective study of over 1,700 pregnant women found that about 25% developed new snoring during pregnancy. Those women who started snoring during pregnancy, not those who had always snored, faced more than double the odds of developing gestational hypertension (2.36 times the risk) and roughly 60% higher odds of preeclampsia compared to non-snorers. These numbers held up even after researchers accounted for other risk factors like weight and age.
Preeclampsia involves dangerously high blood pressure and potential organ damage, most commonly to the liver and kidneys. It can restrict blood flow to the placenta and, in severe cases, lead to seizures or premature delivery. The fact that new-onset snoring specifically predicts these complications suggests that the breathing disruptions of pregnancy are doing something physiologically different from longstanding snoring.
Snoring and Gestational Diabetes Risk
The connection extends to blood sugar. A Harvard-affiliated study found that women who snored frequently (“most or all of the time”) had 2.5 times the odds of developing gestational diabetes compared to women who never snored. Even women at a healthy pre-pregnancy weight who snored had about double the risk. For women who were overweight before pregnancy and also snored frequently, the odds of gestational diabetes jumped to five times higher than lean non-snorers.
The likely explanation involves what happens when your breathing repeatedly gets disrupted at night. Each partial airway collapse triggers small spikes in stress hormones and brief drops in blood oxygen. Over time, these repeated disruptions can impair how your body processes insulin, nudging blood sugar levels higher.
How It Can Affect Your Baby
When snoring crosses into obstructive sleep apnea, where breathing actually stops and restarts throughout the night, the risks to the baby become more concrete. Sleep apnea during pregnancy has been associated with fetal growth restriction (a baby measuring below the 10th percentile for weight), low birth weight, preterm delivery, and higher rates of admission to neonatal intensive care.
These outcomes are tied to the same mechanism that drives the maternal risks. Repeated drops in blood oxygen and spikes in blood pressure can reduce the efficiency of the placenta over time. A placenta that isn’t delivering oxygen and nutrients optimally produces a smaller, potentially more vulnerable baby.
When Snoring Becomes a Warning Sign
Not all pregnancy snoring is equal. Soft, occasional snoring that doesn’t wake you or your partner is generally nothing to worry about. The red flags that suggest something more serious include gasping or choking during sleep, long pauses in breathing that your partner notices, excessive daytime sleepiness that goes beyond normal pregnancy fatigue, and morning headaches that weren’t part of your routine before.
If your snoring started during pregnancy and is getting progressively louder or more frequent, that pattern itself is worth mentioning to your provider. The research consistently shows that pregnancy-onset snoring carries more risk than chronic snoring, so a change in your sleep breathing matters more than whether you’ve always been a light snorer.
What You Can Do About It
Sleeping on your side, particularly your left side, is one of the simplest interventions. The supine position (lying on your back) worsens sleep-disordered breathing because gravity pulls the tongue and soft tissues backward, partially blocking the airway. Side sleeping keeps the airway more open and also improves blood flow to the placenta. A body pillow or a wedge behind your back can help you stay off your back through the night, though a pilot trial using a specialized belt for this purpose found that while women did stay on their sides more, measurable improvements in breathing patterns were modest.
Other practical steps include elevating the head of your bed slightly (an extra pillow or a foam wedge under the mattress), using saline nasal spray or nasal strips to open congested passages, and keeping your bedroom humidity up with a humidifier. Staying within recommended weight gain guidelines also helps, since excess weight is one of the strongest drivers of airway narrowing.
If your snoring is severe or you’re showing signs of sleep apnea, CPAP therapy is the standard treatment. A CPAP machine delivers a gentle stream of air through a mask that keeps your airway from collapsing during sleep. It is considered safe during pregnancy. In non-pregnant patients, CPAP reliably lowers blood pressure, though researchers are still studying whether it can prevent complications like preeclampsia or gestational diabetes when started during pregnancy.
Risks That Can Linger After Delivery
For most women, pregnancy-related snoring fades within weeks of delivery as hormone levels normalize and weight decreases. But for some, it doesn’t fully resolve. A study funded by the National Heart, Lung, and Blood Institute found that women who had sleep apnea during pregnancy and continued to have it in the two to seven years afterward faced more than three times the risk of developing hypertension and more than double the risk of metabolic syndrome compared to women with normal sleep studies.
This makes postpartum follow-up important if you were diagnosed with sleep apnea during pregnancy or had significant snoring. Persistent sleep-disordered breathing after delivery isn’t just a nuisance; it’s an independent cardiovascular risk factor that’s worth addressing on its own terms, separate from the pregnancy that brought it to your attention.