By Samantha Smolinski, PharmD Student
Approximately 50% of women who smoke before pregnancy continue to smoke after pregnancy. Smoking during pregnancy has been shown to cause some adverse effects on the baby. These adverse effects include lifelong decreases in lung function, an increased risk for asthma, low birth weight, shortened pregnancy terms, miscarriage, and infant mortality.1,2 The standard of care for pregnant women who smoke is to suggest that they quit.3
Many women have difficulty quitting smoking. Research has shown that when women join smoking cessation programs like Freedom From Smoking through the American Lung Association or FreshStart from the American Cancer Society to help them quit smoking, they are more likely to quit due to social support and encouragement.4,5 Women have reported that when they were living with another person who smoked, it was much harder for them to quit smoking and remain a non-smoker. In addition to this, many women claim that they found quitting easier when their significant other was supportive of their decision.6 Another common option to aid the mother in her journey to quit smoking is nicotine replacement therapy. Nicotine replacement therapy involves substituting cigarettes with pure nicotine, so that the patient maintains the same level of nicotine in the blood to reduce withdrawal symptoms. The amount of nicotine the patient receives is gradually reduced overtime until the patient can comfortably quit smoking. The forms for this replacement therapy can come in patches, gums, lozenges (dissolved in mouth), inhalators, nasal sprays, and microtabs. Nicotine replacement therapy increases the chances for someone to quit smoking by approximately 80%.4 However, this therapy may cause some adverse pregnancy outcomes and potential malformations. Although malformations may occur, studies have shown that this side effect may be less harmful than those adverse effects that result from smoking during pregnancy.3 In addition to the potential side effects, nicotine is absorbed faster in pregnant women than in non-pregnant women, which means that standard uses of this therapy may not be applicable to pregnant women.4
Recently, a randomized, double-blind trial was conducted with one hundred fifty-nine newborns of pregnant smokers and seventy-six newborns of pregnant non-smokers. Smoking pregnant women were randomly placed in groups where sixty-three received vitamin C 500 mg and eighty-three received a placebo.1 Vitamin C was chosen for this study because there have been multiple studies that have shown that it has a protective effect on lung function.7 After the women had their babies, pulmonary function tests were performed on the babies within seventy-two hours after birth and again a year later. The tests that were conducted a year later were only for the babies of the smoking pregnant due to institutional review board regulations. The first outcome included the measured pulmonary function tests within seventy-two hours of birth and the second outcome included pulmonary function tests at one year as well as the incidence of wheezing. Results suggested that women who smoked while they were pregnant and taking vitamin C 500 mg improved their newborn pulmonary function and decreased the chance of wheezing within one year when compared to the offspring of women who were pregnant and smoking in the placebo group. This study was conducted because of a prior study that had been done on pregnant rhesus monkeys.1 This study had shown that the offspring of the pregnant monkeys with nicotine treatment and vitamin C supplementation had increased pulmonary functions when compared to the offspring of the pregnant monkeys who were only treated with nictotine.7 Thus, vitamin C can be an inexpensive and simple approach to decrease the adverse effects smoking has on pregnancy.4
Vitamin C supplementation can bring additional benefit to women who are smoking and pregnant. This can help the adverse effects that smoking has on the baby’s lung function after birth. Although quitting is still the best choice for pregnant women and their babies, vitamin C supplementation can be useful by helping the baby if the mother smokes intermittently (through part of the pregnancy or through the entire pregnancy.) My recommendation to patients would be to quit smoking as soon as possible and that the best way to do this is through the support of others. In addition to quitting, they should take a daily 500 mg vitamin C supplement which has shown benefits for the babies of women who smoke during pregnancy. Vitamin C can be found over the counter at a relatively low price.
What changes are you willing to make to help your baby?
- McEvoy CT, Schilling D, Clay N,et al. Vitamin c supplementation for pregnant smoking women and pulmonary function in their newborn infants: A randomized clinical trial.JAMA. 2014;311(20):2074-2082.
- Pollack H, Lantz PM, Frohna JG. Maternal smoking and adverse birth outcomes among singletons and twins.Am J Public Health. 2000;90(3):395-400.
- Forinash AB, Pitlick JM, Clark K, Alstat V. Nicotine replacement therapy effect on pregnancy outcomes.Ann Pharmacother. 2010;44(11):1817-1821.
- Coleman T. Recommendations for the use of pharmacological smoking cessation strategies in pregnant women.CNS Drugs. 2007;21(12):983-993.
- Lando HA, McGovern PG, Barrios FX, Etringer BD. Comparative evaluation of american cancer society and american lung association smoking cessation clinics.Am J Public Health. 1990;80(5):554-559.
- Flemming K, Graham H, Heirs M, Fox D, Sowden A. Smoking in pregnancy: A systematic review of qualitative research of women who commence pregnancy as smokers.J Adv Nurs. 2013;69(5):1023-1036.
- Proskocil BJ, Sekhon HS, Clark JA, Lupo SL,