Smoking during pregnancy is known to increase the risk of stillbirth and pregnancy complications. To assist in smoking cessation, nicotine replacement therapy (NRT) is commonly prescribed but there is little information about the effects of NRT on a pregnant woman and her baby. New research to be published in BJOG: An International Journal of Obstetrics and Gynaecology examines whether NRT is safe to use during pregnancy.

87, 032 singleton pregnancies from the Danish National Birth Cohort (DNBC) over the period 1996 - 2002 were selected for the study. The types of NRT products used by the women were: chewing gum, patches or inhalers. Lifestyle and demographic characteristics, smoking habits of participants (whether they never smoked, continued smoking or stopped smoking during pregnancy; including amounts consumed), and the use of NRT were recorded and analysed. The number of stillbirths which occurred in the sample population was also recorded.

The study confirms that smoking during pregnancy was associated with an increased risk of stillbirth regardless of whether NRT was used. 2% of women in the study used NRT. Researchers found that women using NRT during pregnancy tended to be older (35 years and above), were first-time mothers and had normal weight (BMI below 25).

Out of the whole group, 495 pregnancies ended in stillbirth (stillbirth rate: 5.7/1000 births). Eight women who were users of NRT had stillbirths (stillbirth rate: 4.2/1000 births). Researchers note that the lower stillbirth rate among users of NRT could be because these women were healthier during their pregnancy than those who continued to smoke heavily. From the findings of their study, the researchers conclude that NRT use during pregnancy has no serious impact on the risk of stillbirth.

Karine Strandberg-Larsen, from the National Institute of Public Health at the University of Southern Denmark, who co-authored the study, said "Use of nicotine replacement therapy (NRT) during pregnancy is controversial, because NRT contains one of the toxins in tobacco smoke and not much is known about the safety of NRT use during pregnancy.

"Our study suggests that NRT-assisted smoking cessation or smoking reduction in early pregnancy provides some protection from stillbirth among women who continue to smoke during pregnancy. More research on a range of smoking-associated health outcomes is needed if we are to understand the overall safety of NRT use in pregnancy."

Professor Philip Steer, BJOG editor-in-chief, said, "Most women tend to be sensible when they are pregnant and work hard at adopting healthier lifestyles.

"Giving up on tobacco can be difficult as it is addictive but there are ways to manage the cravings during this period. A slow weaning-off from tobacco and a combination of NRT and behavioural therapy is advised.

"The best result from this is the birth of a healthy baby. However, the long-term aim for the mother should be to stop smoking."

Notes

An abstract of the paper is available by clicking here.

BJOG: An International Journal of Obstetrics and Gynaecology is owned by the Royal College of Obstetricians and Gynaecologists (RCOG) but is editorially independent and published monthly by Wiley-Blackwell. The journal features original, peer-reviewed, high-quality medical research in all areas of obstetrics and gynaecology worldwide. Please quote 'BJOG' or 'BJOG: An International Journal of Obstetrics and Gynaecology' when referring to the journal.

Reference

Strandberg-Larsen K, Tinggaard M, Nybo Andersen M, Olsen J, Grønbæk M. Use of nicotine replacement therapy during pregnancy and stillbirth: a cohort study. BJOG 2008; DOI: 10.1111/j.1471-0528.2008.01867.x.

Royal College of Obstetricians and Gynaecologists

Tag Cloud