Causes

Snoring in the Third Trimester

Snoring that starts in pregnancy is common, and it is also the version linked to gestational hypertension and preeclampsia. That makes it worth raising at an appointment rather than waiting it out.

By Renee Alvarez, Editor 4 min read

Snoring gets worse as pregnancy progresses, and the third trimester is where most people notice it. That part is ordinary. The part worth five minutes of your attention is that snoring which begins during pregnancy is not the same thing, clinically, as snoring you have always done.

The distinction that matters

A prospective cohort of 1,719 pregnant women found 34% reported snoring, and 25% reported pregnancy-onset snoring — snoring that had started during the pregnancy rather than predating it (O'Brien et al., American Journal of Obstetrics and Gynecology, 2012).

After adjusting for confounders, pregnancy-onset snoring — but not chronic snoring — was independently associated with gestational hypertension (odds ratio 2.36; 95% CI, 1.48–3.77; P < .001) and preeclampsia (odds ratio 1.59; 95% CI, 1.06–2.37; P = .024) [O'Brien 2012]. It was not associated with gestational diabetes.

Two things follow, and they point in opposite directions depending on which group you are in.

If you snored before you were pregnant and it has simply got louder, this study found no independent association with those outcomes. That is genuinely reassuring.

If the snoring started during this pregnancy, it belongs in a conversation with your midwife or obstetrician. The authors' own conclusion is that new-onset snoring is a strong risk factor for gestational hypertension and preeclampsia, and that simple screening of pregnant women may have clinical utility [O'Brien 2012].

An association is not a cause, and this is observational. Snoring may be a marker of something else — airway narrowing, fluid retention, weight gain — rather than the mechanism itself. But it is a cheap, visible marker, which is exactly what makes mentioning it worthwhile. Tier 1 for the association; the mechanism is less settled. How we grade evidence.

Why the third trimester is the peak

Four things compound, and all of them are at their maximum late on.

Nasal congestion. Pregnancy rhinitis is driven by oestrogen-related vascular changes in the nasal lining and affects a substantial minority of pregnancies. A blocked nose forces mouth breathing, and mouth breathing snores. Nasal congestion and snoring.

Fluid. Total body water rises through pregnancy, and lying down redistributes some of it into the neck and airway tissues. Late pregnancy is where this is largest.

Weight. Normal, necessary pregnancy weight gain still adds tissue around the upper airway. Weight and snoring.

Mechanics. An elevated diaphragm reduces lung volume, and lower lung volume reduces the tethering that helps hold the upper airway open. This is the least discussed and the most specific to late pregnancy.

None of these is a fault, and none is avoidable by trying harder.

What is appropriate to try

Side sleeping, ideally left. Already recommended in late pregnancy for circulation, and it happens to be the most effective positional measure for snoring. A full-length body pillow makes it sustainable when nothing else is comfortable. Position and snoring.

Elevate the head of the bed. Helps airway patency and reflux at the same time, which is a common late-pregnancy combination.

Humidify the bedroom if the air is dry, since dry air worsens nasal congestion. Target 40–50% and measure it rather than guessing. Humidifiers.

Nasal strips are the reasonable product here. They are drug-free and purely mechanical, holding the nasal valve open from outside, which means no systemic exposure. Many providers regard them as low risk in pregnancy — but the correct move is still to ask yours rather than to take that from a website. Nasal strips and pregnancy.

Saline rinses or spray. Drug-free and often the most useful thing for pregnancy rhinitis.

What to avoid

Mouth tape. Not in pregnancy. Nausea and vomiting can occur at any stage, and anything impeding the mouth is the wrong idea when that is a live possibility. This is one of the clearest contraindications on this site. Who should not use mouth tape.

Decongestant sprays and tablets, unless your provider has specifically approved one. Oral decongestants have vascular effects, and topical sprays cause rebound congestion beyond about three nights, which is how a short problem becomes a long one. Strips versus spray.

Anything sedating, including over-the-counter sleep aids and antihistamines taken for sleep. Sedatives relax the airway dilator muscles and make snoring worse, aside from the pregnancy question. Sedatives that worsen snoring.

Alcohol. Covered elsewhere, and not a pregnancy question.

The symptoms that are not about snoring

Some of these overlap with normal late pregnancy, which is precisely why they get dismissed. Contact your maternity team the same day for:

  • Severe or persistent headache
  • Visual changes — blurring, flashing, spots
  • Pain under the ribs or in the upper abdomen
  • Sudden swelling of the face, hands or feet
  • Nausea or vomiting newly appearing in late pregnancy

Those are possible signs of preeclampsia, and given what the evidence links new-onset snoring to, they deserve a lower threshold than usual if you have started snoring this pregnancy [O'Brien 2012].

Separately, witnessed breathing pauses, gasping or choking awake, or daytime sleepiness beyond ordinary pregnancy tiredness point at obstructive sleep apnea, which is more common in pregnancy and is treatable. No consumer product treats it. Snoring versus sleep apnea · What to tell the doctor.

Afterwards

Pregnancy-onset snoring usually settles in the weeks after birth as fluid, weight and hormones shift back. Snoring that is still there several months postpartum is worth investigating rather than accepting as permanent — and sleep deprivation with a newborn will make any residual snoring feel worse than it is. Snoring and new parents.

Common questions

Is snoring in the third trimester normal?
Common, yes — around a third of pregnant women in one cohort of 1,719 reported snoring. Whether it is worth raising depends on when it started: snoring that began during the pregnancy is the version linked to gestational hypertension and preeclampsia.
Why does snoring get worse in late pregnancy?
Pregnancy rhinitis blocks the nose, rising total body water redistributes into the neck when lying down, weight gain adds tissue around the airway, and an elevated diaphragm reduces the lung volume that helps hold the airway open.
Should I tell my midwife I have started snoring?
Yes. New-onset pregnancy snoring was independently associated with gestational hypertension (odds ratio 2.36) and preeclampsia (1.59) in a prospective cohort, and the authors suggested simple screening may be clinically useful.
Can I use nasal strips while pregnant?
They are drug-free and purely mechanical, with no systemic exposure, and are often regarded as low risk — but ask your own provider rather than relying on a website.
Can I use mouth tape while pregnant?
No. Nausea and vomiting can occur at any stage of pregnancy, and anything obstructing the mouth is contraindicated when that is possible.

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