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Snoring During Pregnancy: Why It Happens and Why It Matters

About 40% of women who don't normally snore start snoring in late pregnancy. For most, it's an annoying but harmless side-effect of being pregnant. For some, it signals a condition — gestational sleep apnea — that's worth treating because it's associated with elevated blood pressure complications. Here's what's going on and what to do about it.

Why pregnancy causes snoring

Four physiological changes converge to narrow the upper airway during pregnancy:

• Hormonal nasal congestion. Elevated estrogen and progesterone cause the lining of the nasal passages to swell — a condition called "pregnancy rhinitis" that affects about 30% of pregnant women. The narrower nose forces more mouth breathing, which is much more prone to snoring.
• Increased blood volume. Blood volume increases by ~50% during pregnancy. The extra volume contributes to soft-tissue swelling in the upper airway as well as the nose.
• Weight gain. Normal pregnancy weight gain (25-35 pounds) deposits fat in the neck and abdomen — both of which narrow the airway, especially when supine.
• Diaphragm compression. The growing uterus pushes the diaphragm up, reducing lung volume and forcing higher airflow velocity through a narrower upper airway. Faster airflow through a narrower tube = more turbulence = more snoring sound.

Why it matters medically

New-onset snoring during pregnancy is associated with significantly higher rates of:

• Gestational hypertension (~2x risk)
• Preeclampsia (~1.6-2x risk)
• Gestational diabetes (~1.5x risk)
• Cesarean delivery (~1.3x risk)
• Lower infant birth weight

The mechanism appears to be related to gestational obstructive sleep apnea — the snoring is a marker of subclinical or clinical apnea, which itself drives cardiovascular stress. Treating the apnea (typically with CPAP for diagnosed cases) can normalize these risks.

This isn't a reason to panic if you snore in pregnancy — most women who snore don't develop these complications. But it IS a reason to mention it at your prenatal visits.

When to talk to your OB

• You've started snoring during pregnancy and didn't before
• You snore loudly or your partner reports witnessed breathing pauses
• You wake up gasping, choking, or with a headache
• You're chronically exhausted beyond typical pregnancy fatigue
• You have any blood pressure elevation, swelling, or protein in your urine
• You have high BMI entering pregnancy (apnea risk is elevated)

Your OB may refer you for a home sleep apnea test (HSAT) — a simple at-home study you wear for 1-3 nights. If it shows OSA, treatment is typically CPAP, which is safe and effective during pregnancy. The diagnosis and treatment can substantially reduce the cardiovascular risks above.

What helps right now

Most of these are gentle interventions appropriate during pregnancy:

• Sleep on your left side. Side sleeping reduces snoring (see our positions guide), and left-side specifically improves circulation to the placenta. Most prenatal guidance recommends left-side sleeping in the second and third trimesters anyway.
• Use a pregnancy pillow. Body-length or C-shaped pillows make side sleeping comfortable when nothing else does. Bonus: they help prevent rolling onto your back.
• Elevate the head of your bed (or use a wedge pillow) 30-45°. Helps with both snoring and the acid reflux that's common in pregnancy.
• Treat nasal congestion gently. Saline rinses, humidifier in the bedroom, breathing strips. Most decongestant medications should be avoided during pregnancy — check with your OB before taking anything oral or medicated nasal sprays.
• Stay well-hydrated. Counterintuitively, dehydration thickens nasal mucus and worsens congestion.
• Avoid alcohol (you're already doing this) — but also be aware that pregnancy makes you more sensitive to anything that worsens snoring.

After delivery

For most women, pregnancy-related snoring resolves within weeks to a few months of delivery as hormones normalize, weight comes off, and blood volume returns to baseline. If snoring persists beyond about 6 months postpartum, or if you had a sleep apnea diagnosis during pregnancy, follow up with a sleep specialist — chronic OSA needs different management than gestational OSA.

Related reading

SnoreCam is not a medical device. This article is for informational purposes only and does not constitute medical advice. Pregnancy-related health concerns should be discussed with your obstetrician or midwife.