Smoking Exposure in Pregnancy Could Increase Risks of Infertility in Sons

Researchers have identified some of the main factors that contribute widely to male infertility.

Roger Hart, Professor of Reproductive Medicine at the University of Western Australia, and colleagues found that exposure to nicotine while in the womb, increases a boy's risk of having low sperm count at adulthood.

The study included nearly 2900 mothers and their babies, part of the 1989-1991 Western Australian Pregnancy Cohort. Researchers collected information about maternal smoking habits, measured and recorded the babies' growth regularly during childhood. 

After 20 years, 423 men from the cohort underwent testicular assessment- measurement of testicular volume, determination of semen quality and hormone production. Researchers also noted down body composition of each of the participants.

Researchers found that a significant number of the participants didn't meet the standard level of normal sperm parameters or sperm appearance prescribed by the World Health Organization.

Men who had a relatively slow and poor growth at childhood and who were exposed to smoke while in their mother's womb (18.6 percent) were found to be at a greater risk of having a low sperm count at adulthood. They also added that factors like poor fetal growth, obesity during teenage, drug addiction and smoking during adulthood could lead to low sperm count in males.

"The main message from our study is that to reach adulthood with the best possible testicular function a man should not be exposed to his mother's smoking, should have good fetal growth and, in childhood and through adolescence, should be 'appropriately grown' - that is, neither underweight nor overweight, and as an adult should not smoke or take drugs." Professor Hart said, in a news release.

The study was scheduled to be presented at the annual meeting of European Society of Human Reproduction and Embryology (ESHRE), July 8.

Smoking during pregnancy is known to cause many health problems in children. Premature birth, low birth weight, cot death, asthma, infections, obesity, gestational diabetes, stillbirth and autism are some of the risks. Health experts have always advised pregnant women, or those planning to conceive, to abstain from smoking. However, nearly 14 percent of women in the U.S. continue smoking even after a pregnancy confirmation.