In an obstetrics and gynecology clinic, a woman nearing 30 burst into tears upon hearing the news that she would have difficulty conceiving and her chances of having children were significantly reduced.
Having smoked more than a pack of cigarettes daily for many years, she only realized the consequences after getting married and undergoing a reproductive health check-up. The results showed a very low AMH (Anti-Müllerian Hormone) level, indicating severely diminished ovarian reserve, which means natural conception would be incredibly challenging.
A low AMH level signifies a serious decline in ovarian function, making natural conception extremely difficult. Her case is clear evidence that cigarette smoke rapidly depletes the quality and quantity of eggs, directly limiting fertility, even at a very young age.
“Tobacco brings long-term health consequences for both smokers and those exposed to secondhand smoke. It is one of the significant causes negatively affecting reproductive health, increasing the risk of infertility for both husband and wife,” shared Dr. Nguyen Huu Trung, Head of Obstetrics and Gynecology Department, University Medical Center HCMC – Campus 2, with Dân trí.
A woman in a smoky environment, symbolizing the hidden impact of smoking on female fertility.
Impact on Conception Ability
Cigarette smoke contains over 7,000 chemical substances, hundreds of which are harmful to health, such as nicotine, carbon monoxide (CO gas), tar, benzene, formaldehyde, ammonia, acetone, arsenic, hydrogen cyanide, small particles in cigarette smoke, and carcinogens. These substances attack and weaken important reproductive cells (sperm and eggs).
For men, cigarette smoke is one of the leading causes of declining reproductive health. Specifically, exposure to oxidative radicals from cigarette smoke leads to a reduction in both sperm count and quality, while significantly increasing the proportion of abnormally shaped sperm.
For women, the impact of cigarette smoke on eggs is equally severe. Harmful substances directly affect egg quality and reduce ovarian reserve, seriously impacting the ability to conceive.
Furthermore, nicotine in cigarette smoke also negatively affects the uterine lining, making it difficult for the embryo to implant. Additionally, this hinders the embryo’s journey into the uterus, leading to a higher risk of ectopic pregnancy.
“When sperm and egg quality are affected, coupled with an unfavorable uterine environment, it will reduce the chances of conception and increase the risk of infertility for both husband and wife,” Dr. Trung analyzed.
Increased Risk of Fetal Malformations and Miscarriage
In addition to affecting the ability to conceive, Dr. Trung also emphasized that when a mother smokes or lives in a smoky environment, the fetus is at risk of delayed development.
Nicotine in tobacco is a powerful vasoconstrictor. When it passes through the placenta, nicotine constricts blood vessels in the uterus and placenta, thereby reducing blood flow to the fetus. Meanwhile, when CO gas enters the blood, it combines with hemoglobin to form carboxyhemoglobin (COHb).
Both of these substances reduce the oxygen-carrying capacity to the fetus, affecting the baby’s cardiovascular, digestive, and nervous systems. The fetus may face premature birth, delayed development, low birth weight, and long-term health problems.
Moreover, severely abnormal embryos may fail to develop in the early stages, leading to miscarriage, especially during the first trimester of pregnancy.
Another equally dangerous factor is that cigarette smoke also increases chromosomal abnormalities, thereby raising the likelihood of congenital malformations.
“Some birth defects include neural tube defects (hydrocephalus, spina bifida), craniofacial defects (cleft lip, cleft palate), and bone defects,” the doctor listed.
According to the World Health Organization, fetuses exposed to cigarette smoke, whether directly or passively, are at risk of birth defects, stillbirth, and premature birth. Mothers who smoke during pregnancy can double the risk of sudden infant death syndrome and congenital malformations.
Exposure to secondhand smoke during pregnancy also increases the risk of stillbirth by 23% and the risk of birth defects by 13%.
Dr. Trung further noted that passive smoking (regular exposure to cigarette smoke) is equally harmful as direct smoking.
“Both forms introduce the same types of toxins into the body. These harmful components are still capable of impairing the quality of reproductive cells, thereby reducing the chances of conception and increasing the risk of infertility for both husband and wife,” the doctor emphasized.
Therefore, given the serious harms of cigarette smoke to the reproductive health of both sexes, quitting smoking is paramount to protecting and enhancing fertility. When planning to conceive, couples should undergo health check-ups for specific advice.
