Nasonex During Pregnancy: Is It Safe?

What does the evidence say about nasonex during pregnancy?

1. Studies of inhaled corticosteroids as a medication class have found no overall increased chance of birth defects, and these medicines are absorbed into the body in lower amounts than medication taken by mouth, with research suggesting only a small amount, if any, reaches the pregnancy. 1
2. A clinical review of intranasal corticosteroids found broad expert consensus supporting their effectiveness, but identified budesonide as the only intranasal corticosteroid with established safety in pregnancy, without comparable pregnancy-specific data for mometasone or other options in the class. 2
3. A systematic review and meta-analysis of mometasone furoate nasal spray studies found that none of the included trials, despite studying adults 18 and older, reported on its effects in pregnant women specifically, and the authors called for dedicated research given how common nasal symptoms are during pregnancy. 3
4. Mometasone furoate has a reported systemic bioavailability under 1 percent, since it is poorly absorbed into the bloodstream and undergoes extensive first-pass processing by the liver, and in laboratory research no drug was detected reaching the blood in the hours after nasal administration. 4
5. The amount of an inhaled corticosteroid that passes into breast milk after use is likely small and not expected to cause problems for a breastfeeding infant. 1

Is nasonex safe in each trimester?

• First trimester. Nasal congestion often starts early as blood volume rises, but pregnancy-specific research on mometasone itself is limited: even a recent safety review found no studies that looked at its use in pregnant women specifically, so this is a good spray to discuss with your provider before starting.
• Second trimester. Congestion commonly peaks in the second trimester. Mometasone's systemic absorption is very low, under 1 percent, since the drug is poorly absorbed into the bloodstream and undergoes extensive processing by the liver, which is reassuring at the mechanism level even without pregnancy-specific outcome data.
• Third trimester. If a steroid nasal spray is still needed late in pregnancy, ask whether budesonide (Rhinocort) makes sense as an alternative, since it is the one intranasal steroid described as having an established pregnancy safety record, backed by a large early-pregnancy registry.