Smoking is known to cause harm in pregnancy.1 It has been found to be associated with miscarriage, ectopic pregnancy, low birthweight, placental abruption and birth defects.

Introduction 

Smoking is known to cause harm in pregnancy.1 It has been found to be associated with miscarriage, ectopic pregnancy, low birthweight, placental abruption and birth defects.2 Despite widespread campaigns promoting smoking cessation in the preconception period and during pregnancy, up to 14% of pregnant women report smoking tobacco.3  

 

A recent systematic review showed that the risk of sporadic miscarriage was increased in both active (risk ratio [RR] 1.23, 95% confidence interval [CI] 1.16 to 1.30, n = 50 studies) and passive (RR 1.32, 95% CI 1.21 to 1.44, n = 25 studies) smokers.3 In addition, a prospective study of 526 men identified an association between heavy paternal smoking and early pregnancy loss.4 It remains unclear whether smoking is linked specifically to a higher risk of recurrent pregnancy loss (RPL).2  

 

Nicotine replacement therapy, in the form of patches or gum, has not been shown to be harmful in pregnancy and does not increase the risk of miscarriage.5 In recent years, the use of electronic cigarettes (EC) among pregnant women has also increased significantly, although it remains unclear whether EC can cause harm to the fetus.6  

 

Bullet point guidance 

  • Women and men with a history of RPL should be advised that smoking could increase the risk of miscarriage, and hence smoking cessation should be encouraged.1,2 
  • Women seeking nicotine replacement therapy (NRT) products should be informed that these are safe in pregnancy.7
  • Women with RPL who use EC should be advised about the lack of safety evidence on these devices.8
  • Clinicians caring for women and men with a history of RPL and ongoing issues with smoking should signpost patients to smoking cessationservices, or contact their general practitioners for onward referral to NHS smoking cessation services.
  • Advice on smoking cessation can be found in the following resources:
  • https://www.nhs.uk/live-well/quit-smoking/nhs-stop-smoking-services-help-you-quit/
  • Smokefree National Helpline (0300 123 1044).

References 

  1. Quenby, S., et al., Miscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss. Lancet 2021. 397(10285): p. 1658-1667.
  2. Bender Atik, R., et al., ESHRE guideline: recurrent pregnancy loss. Hum Reprod Open, 2018. 2018(2): p. hoy004.
  3. Pineles, B.L., E. Park, and J.M. Samet, Systematic review and meta-analysis of miscarriage and maternal exposure to tobacco smoke during pregnancy. American journal of epidemiology 2014. 179(7): p. 807-823.
  4. Venners, S.A., et al., Paternal Smoking and Pregnancy Loss: A Prospective Study Using a Biomarker of Pregnancy. American Journal of Epidemiology 2004. 159(10): p. 993-1001.
  5. Taylor, L., et al., Fetal safety of nicotine replacement therapy in pregnancy: systematic review and meta-analysis. Addiction 2020.
  6. McDonnell, B.P., P. Dicker, and C.L. Regan, Electronic cigarettes and obstetric outcomes: a prospective observational study. British Journal of Obstetrics and Gynaecology 2020. 127(6): p. 750-756.
  7. Dhalwani, N.N., et al., Stillbirth Among Women Prescribed Nicotine Replacement Therapy in Pregnancy: Analysis of a Large UK Pregnancy Cohort. Nicotine & Tobacco Research 2018. 21(4): p. 409-415.
  8. Wagner, N.J., M. Camerota, and C. Propper, Prevalence and Perceptions of Electronic Cigarette Use during Pregnancy. Maternal and Child Health Journal 2017. 21(8): p. 1655-1661.