The dangers of cigarette smoke in pregnancy

2 mins to read

Naturopath Stephanie Hamilton highlights the serious risks of smoking in pregnancy and discusses new evidence on the risk of “thirdhand” smoking on your unborn baby.

Pregnancy and preconception

According to Australian data, 17% of women still smoke in pregnancy despite the increasing awareness of the risks to both mother and baby. In July 2011, the first ever comprehensive systematic review of all studies that examined the risks of birth defects associated with smoking in pregnancy over the past 50 years was published. The conclusion? Smoking in pregnancy increases the risk of a range of serious birth defects.

While the exact mechanism of how smoking might cause such damage is still being established, it is understood that nicotine restricts important blood flow to the placenta resulting in poor nutrition and oxygen supply to the developing foetus. Carbon monoxide also interferes with the baby’s oxygen supply in the womb and if this occurs during organ development, defects may occur.

Birth defects

The review found that maternal smoking was associated with the following deformities in the new born:

Cardiovascular/heart defects
Musculoskeletal defects
Limb reduction defects
Missing/extra digits
Clubfoot
Craniosynostosis
Facial defects, eye defects and orofacial clefts
Gastrointestinal defects
Gastroschisis
Anal atresia
Hernia
Undescended testes

Birth outcomes

Tobacco smoke contains 7000 chemicals, many of which can easily cross from the mother’s blood stream into the placenta. In addition to the deformities listed above, smoking in pregnancy is also an established risk factor for miscarriage, stillbirth, labour complications, low birth weight, premature birth, and sudden infant death syndrome (SIDS).

Reduced protection against heart disease

Australian research has suggested that children born to mothers who smoked in pregnancy had lower levels of the ‘good’ high-density lipoprotein (HDL) cholesterol by the age of 8 years. The authors suggest that this could have a serious impact on health later in life as HDL cholesterol plays an important role in protecting against atherosclerosis.

New evidence: Thirdhand smoke just as dangerous

Thirdhand smoke is aged second hand smoke that remains on a variety of surfaces such as skin, hair, clothes, furniture, curtains, walls, bedding, carpets, dust, and vehicles long after the smoking has stopped. Residual nicotine and other chemicals react with common indoor pollutants to create a toxic mix which poses a potential health hazard to anyone who comes in contact with it, especially children.

A recent study, the first of its kind, found prenatal exposure to thirdhand smoke can have a serious or an even more negative impact on an infants’ lung development than postnatal or childhood exposure to smoke.

Thirdhand smoke is composed of smaller, ultra-fine particles with a greater molecular weight which pose a greater asthma hazard than firsthand or secondhand smoke. Since infants tend to ingest twice the amount of dust than adults, they are especially vulnerable to the effects of thirdhand smoke.

When to quit

Evidence suggests that smoking has adverse effects on male and female fertility.

In males, smoking negatively affects sperm production, motility and morphology and is associated with an increased risk of DNA damage.

In females, smoking can interfere with hormone levels and therefore the menstrual cycle. Sperm penetration of the female egg may be hindered in a woman who smokes, and the chemicals and heavy metals contained in cigarette smoke, such as cadmium, have been found in the fluid that surrounds the developing follicle.

Stopping smoking well before conception will improve your chances of a healthy conception and reduce the likelihood of birth defects in your baby.

Giving your body enough time to eliminate the toxins from your body before conception and addressing any nutritional deficiencies smoking may have caused are also important. There are many programs available to support you on giving up smoking, and be sure to seek out advice from a healthcare professional on how to best prepare you for pregnancy.

Quitline 131 848
www.quitnow.gov.au

I Can Quit
www.icanquit.com.au

References available upon request.