Pregnancy rhinitis most commonly begins in the second trimester, with a peak at 18–20 weeks , though a minority of cases start in the first or third trimesters. Clinicians should educate patients about this timeline to avoid unnecessary antibiotics or allergy testing. Treatment remains symptomatic (saline irrigations, sleep with head elevated, and intranasal corticosteroids for severe cases), with reassurance that onset timing does not affect fetal or maternal outcomes.

If you develop nasal congestion for the first time during weeks 13–20 of pregnancy, with no fever, colored mucus, or sneezing fits, pregnancy rhinitis is the most likely cause.

Pregnancy rhinitis is defined by the European Academy of Allergy and Clinical Immunology as nasal congestion lasting six or more weeks during pregnancy, without other signs of infection or allergy, and with complete resolution within two weeks after delivery. Despite affecting an estimated 20–40% of pregnant individuals, its exact pathophysiology remains under study, with proposed mechanisms including elevated estrogen, progesterone, and increased blood volume leading to nasal mucosal edema and glandular hyperreactivity.

Onset of Pregnancy Rhinitis: A Review of Gestational Timing and Clinical Presentation

Pregnancy rhinitis (PR) is a common, non-allergic, non-infectious nasal congestion that occurs during gestation. Its onset is variable but follows a predictable pattern linked to hormonal and hemodynamic changes. This paper reviews the evidence on when pregnancy rhinitis typically begins, finding that while cases can emerge in the first trimester, the most common onset window is during the second trimester (weeks 13–28) , with a notable peak between weeks 18 and 20 . A smaller subset of patients experience onset in the third trimester or, rarely, within days of conception. Understanding this timeline aids in differential diagnosis from other causes of rhinitis.