What are the effects of nicotine replacement therapy (NRT) on pregnancy?

From the Guidelines

Nicotine replacement therapy (NRT) is not recommended during pregnancy due to potential risks of nicotine exposure to the fetus. However, for pregnant persons who are unable to quit smoking with behavioral counseling alone, NRT may be considered under close supervision, as the benefits of quitting smoking may outweigh the risks of NRT 1.

Key Considerations

• The evidence to support the use of NRT for smoking cessation in pregnant women is limited, with few clinical trials evaluating its effectiveness 1.
• Potential adverse maternal events reported in studies of NRT include slightly increased diastolic blood pressure and skin reactions to the patch 1.
• NRT may be safer than smoking during pregnancy, given that cigarette smoke contains harmful substances in addition to nicotine 1.

Treatment Approach

• If NRT is prescribed, it should be used at a low dose, such as 2mg every 1-2 hours as needed, for a limited duration of 12-16 weeks.
• Healthcare providers should closely monitor pregnant persons using NRT for any potential adverse effects.
• Alternative non-nicotine medications, such as bupropion or varenicline, may also be considered for smoking cessation during pregnancy, but only under the guidance of a healthcare provider 1.

Important Notes

• Quitting smoking early in pregnancy can reduce or eliminate the adverse effects of smoking on fetal growth 1.
• Smoking during pregnancy reduces fetal growth, increases the risk of preterm birth, and doubles the risk for delivering an infant with low birth weight 1.

From the Research

Effects of Nicotine Replacement Therapy on Pregnancy

• The effects of nicotine replacement therapy (NRT) on pregnancy were studied in a Cochrane review 2, which found that NRT can help pregnant women quit smoking, with a statistically significant benefit of NRT on abstinence close to the time of delivery.
• The review found that the risk ratio (RR) of abstinence for any form of NRT relative to control was 1.32 (95% confidence interval (CI) 1.04 to 1.69) in a subset of six trials conducted in pregnant women.
• However, the review also noted that the result was no longer statistically significant (RR 1.29,95% CI 0.90 to 1.86) in the four trials that followed up participants post-partum.
• Another study 3 compared the nicotine pharmacokinetics of an oral nicotine pouch and two NRT products, but did not specifically examine the effects of NRT on pregnancy.
• A systematic review 4 examined the effectiveness and safety of alternative tobacco and nicotine products, including NRT, for smoking reduction and cessation, but did not focus specifically on pregnancy.
• A randomized controlled trial 5 compared the effectiveness of NRT, varenicline, and combination therapy for smoking cessation, but did not examine the effects of NRT on pregnancy.
• A policy statement from the American Heart Association 6 discussed the potential adverse effects of smokeless oral nicotine products on cardiovascular disease, but did not specifically address the effects of NRT on pregnancy.

Adverse Events

• The Cochrane review 2 found that adverse events from using NRT were related to the type of product, and included skin irritation from patches and irritation to the inside of the mouth from gum and tablets.
• The review also found that attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing, and duration of symptoms.
• The review noted that chest pains and palpitations were rare in both groups, and serious adverse events were extremely rare.