Female smokers usually show less interest in breastfeeding as they believe that formula food is a safer alternative. Infants born to women smokers have shown to be prone to lung infections, SIDS (sudden infant death syndrome), and asthma.

Credit: Sata Production/ Shutterstock.com

Breastfeeding plays a vital role in an infant’s health. Breast milk is an essential and complete food for infants as it supplies growth nutrients such as proteins, fats, minerals, and carbohydrates. Breastfeeding lends huge benefits to both the baby and the mother. In babies, it decreases the risk of cancer, diabetes, and respiratory problems while in the mother it avoids the risk of breast cancer and aids in postpartum weight loss.

Effects of smoking on lactation

Low milk secretion

The effects of smoking by the mother during breastfeeding were first described in 1950 by Mills. Studies show that female smokers have less secretion of milk (approximately 200–300 ml) than nonsmokers.                  

Smoking impacts the secretion of dopamine, a prolactin inhibitor hormone. This hormone decreases prolactin production, leading to inhibition of the lactating capacity and mammary development. Smoking causes lower milk volume and lower fat concentration in the milk, all of which reduce the course of breastfeeding.

Low iodine level

A few researchers declare that, as an aftereffect of smoking, breast milk contains low iodine levels, which leads to iodine deficiency and induces brain damage in children. In such cases, iodine supplements are advised for mothers while breastfeeding.

Transfer of cigarette substance from mother to baby

Transfer through bloodstream

During breastfeeding, high amounts of nicotine and other harmful chemicals like cotinine (nicotine metabolite) in tobacco are transferred to the child through breast milk. The amount of nicotine in breast milk depends on the number of cigarettes the mother smokes per day. The accumulated amount of nicotine in breast milk is double the amount of nicotine that is transferred through the placenta during pregnancy.

Nicotine is absorbed rapidly from the mother’s respiratory tract and flows into the bloodstream, before diffusing into the breast milk and blood serum.

Absorption of nicotine by the infant

Nicotine is slowly adsorbed by breast milk after being transferred from the bloodstream. During breastfeeding, the infant ingests the nicotine along with other by-products such as ammonia, tar, arsenic, and carbon monoxide from the cigarette. Hence the bloodstream of the infant becomes contaminated with nicotine.

Effects of cigarette smoking and nicotine on the infant

The American Academy of Pediatrics has declared nicotine to be a contraindicated drug during lactation. While smoking, nicotine enters the breast in high concentrations, and after 2 hours, the concentration is reduced to half. Nicotine takes about 10 hours to leave the bloodstream and from breast milk completely, without any traces.

Nicotine and its metabolites, such as cotinine, remain for 24 hours in the bloodstream of a female smoker who smokes the entire day, non-stop. Infants who are breastfed by such mothers can be impacted by the nicotine:

• Nicotine is a drug that can suppress the appetite and acts as a flavoring agent for milk. When a mother tries to breastfeed immediately after smoking a cigarette, the baby may refuse to be fed because of the flavor of nicotine in the milk.
• Nicotine acts as a stimulant, causing sleeping problems in infants.
• There is high risk of SIDS or cot death due to insufficient oxygen supply to the infant.
• Baby shows fussiness when it is time for nursing, because the smell of tobacco and cigarette from the mother may cause irritation.
• Other symptoms like vomiting, tachycardia, restlessness, abdominal cramps, diarrhea, and gastrointestinal disease can occur in the infant.
• Infants generally experience colic, in addition to ear and lung infections like bronchiolitis.
• Babies have lower birth weight (200gm) and show no weight gain for a year.
• In the future, the infants of smoking mothers become obese and might get thyroid malfunctions.

Reasons for early weaning off breastfeeding

An important effect during breastfeeding is that, mothers who smoke wean their children earlier from breastfeeding compared to nonsmoking mothers. The reasons for early weaning are as follows:

• Smoking more than 10 cigarettes a day can reduce the amount of milk secretion and the fat components in the milk. The quality of milk is then affected and the baby dislikes the taste. This leads to early weaning.
• Smokers are less likely to breastfeed as they think their supply of milk is inadequate.
• The breastfeeding mother who smokes more than 5 cigarettes a day contributes to infantile colic and an upset stomach. This also results in early weaning.

Withdrawal from smoking is highly recommended during breastfeeding, as this will stop infants from exposure to nicotine. Nicotine replacement therapy products such as skin patches and nicotine gum, and medications like chantix or zyban may be considered, which can lower the effects of smoking on infants.