Hormonal Causes of Pregnancy Rhinitis in Second Trimester

Feeling more stuffed up as your bump grows? If your nose has been blocked for weeks without an obvious cold or allergy, you’re likely dealing with pregnancy rhinitis. You’re not alone—and there’s a science-backed reason for it.

Key takeaway: Hormones in the second trimester—especially estrogen, progesterone, placental growth hormone (PGH), and vascular endothelial growth factor (VEGF)—can swell nasal tissues and increase mucus, causing persistent congestion. The good news: It usually fades soon after birth, and safe, effective relief is available.

Pregnancy rhinitis 101: what it is and how long it lasts

Pregnancy rhinitis is defined as nasal congestion lasting at least six weeks during pregnancy, without signs of a respiratory infection or an allergic cause. Many people notice symptoms in mid–late pregnancy, and they typically resolve within about two weeks after delivery (Cleveland Clinic; PMC review of rhinitis in pregnancy) Cleveland Clinic, PMC.

Common symptoms include:

Ongoing nasal blockage or stuffiness
Clear nasal discharge (rhinorrhea)
Postnasal drip and throat clearing
Snoring or sleep disruption from mouth breathing

How common is it in the second trimester?

Prevalence estimates vary widely—from about 18% up to 42% across studies—with many reports showing a higher incidence in the second and third trimesters. Individual studies in the second trimester have ranged from roughly 9% to nearly 40%, reflecting different definitions and study designs (PMC review; INAJOG review) PMC, INAJOG.

Why it matters: Beyond the discomfort, pregnancy rhinitis can disrupt sleep, increase daytime fatigue, and contribute to snoring—and in some cases may be linked to obstructive sleep apnea (OSA) symptoms that warrant attention (PMC review; Pregnancy, Birth and Baby) PMC, Pregnancy, Birth and Baby.

The hormone story: estrogen, progesterone, PGH, and VEGF

The leading explanation for pregnancy rhinitis centers on hormonal changes that peak in mid–late pregnancy. Key players include:

Estrogen: Rises substantially in the second trimester and can dilate blood vessels, increase vascular permeability, and upregulate histamine receptors in nasal tissues—amplifying swelling and sensitivity (PMC review) PMC.
Progesterone: Promotes smooth muscle relaxation and vasodilation and contributes to overall plasma volume expansion, which can translate to engorged nasal mucosa—sometimes called "progesterone rhinitis" (PMC review) PMC.
Placental growth hormone (PGH) and VEGF: These gestational hormones support vascular growth and remodeling. In the nose, they’re thought to promote angiogenesis and increased vascular surface area within the turbinates, adding to congestion (PMC review) PMC.

Together, these gestational rhinitis hormones help explain why nasal symptoms often begin or intensify in the second trimester.

What hormones do in your nose: vessels, glands, and nerves

How do these hormones create that stuffed-up feeling? Several mechanisms work in parallel (PMC review):

Vasodilation and engorgement: Estrogen and progesterone widen blood vessels and boost blood flow, plumping the nasal mucosa and narrowing airflow.
Increased vascular permeability (edema): Fluid seeps from vessels into nasal tissues, swelling the lining and turbinates.
Angiogenesis and remodeling: PGH and VEGF can increase the number and size of blood vessels in nasal tissues, making congestion more persistent.
Receptor changes and neurogenic effects: Estrogen may upregulate histamine receptors and alter nerve signaling, increasing secretomotor activity in nasal glands and producing more mucus—even without allergens present.

Result: a combination of swelling, extra mucus, and heightened sensitivity that causes persistent nasal obstruction during pregnancy (PMC review) PMC.

Pregnancy rhinitis vs allergies or a cold

Because treatment choices differ, it’s helpful to tell these apart:

Pregnancy rhinitis: Congestion ≥6 weeks, clear discharge, worse at night/lying down, no fever; often starts in the second trimester and resolves within two weeks postpartum (Cleveland Clinic; PMC) Cleveland Clinic, PMC.
Allergic rhinitis: Itchy eyes, sneezing fits, watery eyes, and clear discharge; often linked to identifiable triggers (pollen, pets, dust). May respond to antihistamines and allergen avoidance (ACOG; Mayo Clinic) ACOG, Mayo Clinic.
Cold or sinus infection: Fever, sore throat, body aches, thick yellow/green discharge, facial pain/pressure, or symptoms that worsen after initial improvement suggest infection. Seek care if symptoms persist >10 days or are severe (Cleveland Clinic) Cleveland Clinic.

If you’re unsure, check in with your clinician. An accurate diagnosis ensures you choose safe treatments during pregnancy.

Is pregnancy rhinitis harmful to you or the baby?

The reassuring news: pregnancy rhinitis is typically benign and not directly harmful to the fetus. The biggest impact is on your comfort and sleep. Congestion can lead to snoring, mouth breathing, and sleep fragmentation; in some cases, it may contribute to OSA symptoms that should be evaluated (PMC review) PMC.

Direct fetal risks from rhinitis alone haven’t been clearly demonstrated. However, indirect effects—like poor sleep, untreated OSA, or worsened asthma—can affect overall health during pregnancy. If you have asthma, coordinate care because uncontrolled rhinitis can make asthma harder to manage (Asthma & Pregnancy Toolkit) Asthma & Pregnancy Toolkit.

Drug‑free relief first: daily habits that help

Start with conservative, low-risk strategies. These are safe for most pregnant people and often provide meaningful relief (Cleveland Clinic; Verywell Health) Cleveland Clinic, Verywell Health.

Isotonic saline rinses or sprays: Use distilled or previously boiled and cooled water. Rinse daily and before bed to reduce swelling and wash out irritants.
Cool‑mist humidifier at night: Aim for indoor humidity around 40–50%. Clean the unit regularly to prevent mold.
Head elevation for sleep: Use an extra pillow or a wedge; side‑lying with the upper body elevated can reduce nighttime congestion.
Hydration: Drink water throughout the day to thin mucus.
Light, regular movement: Gentle walks or prenatal yoga (if cleared by your clinician) can improve nasal airflow.
Steam inhalation and warm compresses: Soothe dryness and relieve pressure. Take care to avoid burns.
Avoid irritants: Smoke, strong fragrances, cleaning chemicals, and dusty environments can worsen symptoms.
Nasal strips: External nasal dilator strips may help open nasal passages mechanically at night.

Medications that may help—and what’s considered safe

If symptoms remain disruptive, some medications have reassuring safety data in pregnancy. Always confirm choices with your obstetric clinician, especially if you have hypertension, glaucoma, thyroid disease, or are on other medications.

Corticosteroid nasal sprays (first‑line for persistent symptoms): Budesonide has the most pregnancy safety data and is often preferred. Fluticasone and mometasone are also considered acceptable. These act locally with minimal systemic absorption and can reduce swelling over several days to weeks (Cleveland Clinic; ACOG) Cleveland Clinic, ACOG.
Antihistamines (if itchy/teary symptoms suggest mixed allergic rhinitis): Non‑sedating options like cetirizine or loratadine are commonly recommended when needed; older options like chlorpheniramine can also be used but may be more sedating. Discuss dosing and timing with your clinician (ACOG; Mayo Clinic) ACOG, Mayo Clinic.
Topical decongestant sprays (short‑term only): Oxymetazoline may provide quick relief for special occasions or severe nights, but limit to ≤3 consecutive days to avoid rebound congestion (rhinitis medicamentosa) (Cleveland Clinic) Cleveland Clinic.

Tip: With steroid nasal sprays, technique matters. Aim slightly outward, away from the septum, and use after a saline rinse to improve effectiveness.

What to avoid or limit during pregnancy

Oral decongestants (e.g., pseudoephedrine): Generally avoided in the first trimester due to a small potential risk of abdominal wall defects and used with caution later in pregnancy; avoid entirely if you have high blood pressure. Always discuss with your clinician first (ACOG; Cleveland Clinic) ACOG, Cleveland Clinic.
Prolonged use of topical decongestants: More than 3 days can cause rebound congestion, making symptoms worse (Cleveland Clinic) Cleveland Clinic.
Unverified supplements or essential oils: Safety data are limited in pregnancy; consult your clinician before use.

A simple bedtime plan for better sleep

A consistent routine can reduce nighttime congestion and improve sleep quality.

1. Evening saline rinse to clear mucus and shrink swelling. 2. Apply your prescribed nasal steroid (if recommended) after the rinse and before bed. 3. Set a cool‑mist humidifier to 40–50% humidity; keep the room cool and well‑ventilated. 4. Side‑lying position with head elevated on a wedge or extra pillows; consider nasal strips. 5. Gentle stretches or a brief prenatal yoga flow to relax neck and chest muscles and encourage nasal airflow. 6. Allergen control: Fresh pillowcases, dust‑mite covers for pillows/mattress, and pet‑free sleeping space if allergies are suspected.

When to call your clinician

Reach out promptly if you notice:

Fever, facial pain/pressure, or thick yellow‑green discharge lasting more than 10 days
Frequent or heavy nosebleeds
Severe headaches, vision changes, or concerning sinus pain
Loud snoring with witnessed pauses, gasping at night, or extreme daytime sleepiness (possible OSA)
Worsening asthma symptoms or chest tightness
Symptoms that persist or worsen despite home measures and guideline‑supported medications

These can signal an infection, complications, or another diagnosis that needs targeted treatment (Cleveland Clinic; PMC review) Cleveland Clinic, PMC.

Support from partners and family

Small acts of support can make a big difference:

Keep the humidifier clean and refill it nightly.
Mix fresh saline or pick up sterile saline sprays from the pharmacy.
Reduce household irritants: Use unscented cleaners and fragrance‑free laundry products; vacuum with a HEPA filter; open windows when cooking (as weather allows).
Help with sleep setup: Arrange pillows/wedges and apply nasal strips.
Cover a few chores so the pregnant parent can prioritize rest.

The bottom line

Pregnancy rhinitis in the second trimester is common and largely driven by hormone‑related changes—especially estrogen, progesterone, PGH, and VEGF—that swell nasal tissues and boost mucus production. While usually benign, it can meaningfully affect sleep and daily comfort. Start with drug‑free strategies, and if needed, consider safe treatments like budesonide nasal spray or pregnancy‑compatible antihistamines under medical guidance (Cleveland Clinic; ACOG) Cleveland Clinic, ACOG.

If your congestion is severe, prolonged, or comes with red‑flag symptoms, connect with your clinician for a tailored plan. Share this guide with your partner so you can create a supportive routine that helps you breathe—and sleep—easier.

Disclaimer: This article is for education only and isn’t a substitute for personalized medical advice. Always consult your healthcare professional about medications and new or worsening symptoms.