Smoking in Pregnancy

Men and women who smoke are less likely to conceive. Smoking reduces sperm count and motility in men and hormonal imbalance in women, reducing pregnancy rates in smoking couples.

Risks

125,000 spontaneous miscarriages occur each year in the United Kingdom, with one fifth of these occurring in women who smoke. This makes smoking during pregnancy the single most preventable cause of foetal death alongside causing low birth weight and increased perinatal mortality.

Nicotine can freely cross the placenta along with toxic constituents of tobacco smoke, for example carbon monoxide. Second-hand smoke can also result in reduced birthweight.

One estimate is that 24% of infant killed by sudden death syndrome are a result of mothers smoking during pregnancy.

There are also links between smoking during pregnancy and intellectual and behavioural deficits through childhood and into adulthood. Although the risks from smoking to the child appear to be dose dependent, light smokers still put their child at significant risk.

It should therefore constantly be reiterated by healthcare professionals to women who continue to smoke during pregnancy; smoking is the best thing for both the mother and the baby through pregnancy and beyond. Cessation should occur prior to conceiving for the best possible outcome for the child.

 

Prevalence

In 2011, 11% of UK mothers were recorded as smoking at the time of delivery in 2015, with a range in all areas from 2% to 26%.

Most women who become pregnant and fail to quit smoking during the first trimester will not succeed in quitting through to term.

The prevalence of smoking through pregnancy is higher in those from lower socio-economic backgrounds, lower educational levels, those who started younger and those who have partners who smoker.

Partners who are openly pro-cessation to the pregnant mother are more likely to be successful in encouraging complete cessation.

There is perception amongst low income, teenage smokers that by smoking, and reducing the birth weight of the foetus, they will reduce the pain of delivery.

Of the pregnant women who do manage to quit, 63% relapse within 6 months of birth.

Interventions

In the UK, the most effective intervention for reducing smoking in pregnant women has been increasing the price of cigarettes through taxation. However, this has a downside; individuals from low socioeconomic backgrounds can be driven into poverty as they are unable to quit.

The most effective intervention in pregnant women centres around ‘behavioural support.’ These are effective at promoting smoking cessation in pregnant women, however they are underused.

Nicotine replacement therapies (NRTs) can also be used in assisting smoking cessation, however there is discussion as to whether these are completely safe or a harm reduction strategy.

As previously stated, nicotine can cross the placenta and may affect the developing foetus. However, studies have shown no adverse effects to the child from wearing a nicotine patch for up to four days. The NHS currently advises that licenced NRTs are safe for pregnant women to use during pregnancy.

Electronic cigarettes are the newest smoking cessation aid which healthcare professionals must give advice about. Unfortunately, confusion and misconceptions about electronic cigarettes may prompt women who are pregnant to utilise an electronic cigarette without knowing all potential risks.

It must be stressed that electronic cigarettes during pregnancy do not remove all risks and does still expose the unborn baby to nicotine and other inhalants from the electronic cigarette liquid. Some ingredients in the electronic cigarette liquid are toxic and liquid production is not regulated. 

Bibliography & Further Reading
Augood C, Duckitt K, Templeton AA. Smoking and female infertility: a systematic review and meta-analysis. Hum Reprod 1998; IQ: 1532±39.
Bader P, Boisclair D, Ferrence R. Effects of tobacco taxation and pricing on smoking behavior in high risk populations: a knowledge synthesis. International journal of environmental research and public health. 2011 Oct 26;8(11):4118-39.
Baeza-Loya S, Viswanath H, Carter A, Molfese DL, Velasquez KM, Baldwin PR, Thompson-Lake DG, Sharp C, Fowler JC, De La Garza R. Perceptions about e-cigarette safety may lead to e-smoking during pregnancy. Bulletin of the Menninger Clinic. 2014;78(3):243.
Das TK, Moutquin JM, Lindsay C, Parent JG, Fraser W. Effects of smoking cessation on maternal airway function and birth weight. Obstet Gynecol 1998; WP: 201±205.
Faden VB, Graubard BI. Maternal substance use during pregnancy and developmental outcome at age three. J Subst Abuse 2000; IP: 329±40.
Foy A. Cigarette smoking in pregnancy [editorial] Med J Aust 1988, 148:377-8
Harris JE. Cigarette smoke components and disease: cigarette smoke is more than a triad of tar, nicotine, and carbon monoxide. National Cancer Institute. The FTC cigarette test method for determining tar, nicotine, and carbon monoxide yields of US cigarettes. National Cancer Institute Smoking and Tobacco Control Monograph. 1996;7
Hegaard HK, Kjaergaard H, Moller LF, Wachmann H, Ottesen B. The effect of environmental tobacco smoke during pregnancy on birth weight. Acta Obstet Gynecol Scand 2006;85:675–81.
HSCIC Smoking Status at Time of Delivery Collection 2016
Jurkovic D, Overton C, Bender-Atik R. Diagnosis and management of first trimester miscarriage. BMJ2013;346:f3676.
Lawson EJ. The role of smoking in the lives of low-income pregnant adolescents: a ®eld study. Adolescence 1994; PW: 61±79.
Lerner CA, Sundar IK, Yao H, Gerloff J, Ossip DJ, McIntosh S, Robinson R, Rahman I. Vapors produced by electronic cigarettes and e-juices with flavorings induce toxicity, oxidative stress, and inflammatory response in lung epithelial cells and in mouse lung. PloS one. 2015 Feb 6;10(2):e0116732.
Lindqvist R, Aberg H. Who stops smoking during pregnancy? Acta Obstet Gynecol Scand 2001; VH: 137±41.
Lumley J, Oliver S, Waters E. Interventions for promoting smoking cessation during pregnancy. Cochrane Database Syst Rev 2002; I: CD001055.
Meier KJ, Licari MJ. The effect of cigarette taxes on cigarette consumption, 1955 through 1994. Am J Public Health 1997; VU: 1126±30.
Mullen PD, Quinn VP, Ershoff DH. Maintenance of nonsmoking postpartum by women who stopped smoking during pregnancy. Am J Public Health 1990; VH: 992±94.
Ogburn PL Jr, Hurt RD, Croghan IT, Schroeder DR, Ramin KD, Offord KP, et al. Nicotine patch use in pregnant smokers: nicotine and cotinine levels and fetal effects. Am J Obstet Gynecol 1999; IVI: 736±43.
Owen L, McNeill A, Callum C. Trends in smoking during pregnancy in England, 1992±97: quota sampling surveys [see comments]. Br Med J 1998; QIU: 728.
Pollack HA. Sudden infant death syndrome, maternal smoking during pregnancy, and the cost- effectiveness of smoking cessation intervention. Am J Public Health 2001; WI: 432±36.
Taylor T, Hajek P. Smoking cessation services for pregnant women. London: Health Develop- ment Agency; 2001.
West R. Smoking cessation and pregnancy. Fetal and Maternal Medicine Review. 2002 Aug 1;13(03):181-94.
Zinaman MJ, Brown CC, Selevan SG, Clegg ED. Semen quality and human fertility: a prospective study with healthy couples. J Androl 2000; PI: 145±53.
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