Risk of defective childbirth increases with smoking during pregnancy, warn researchers, adding that pregnant mothers who smoke also lay the lives of their unborn babies on the line.

A peer-reviewed study conducted under the aegis of University College London has revealed that women who smoke during pregnancy are likely to give birth to babies with congenital deformities, such as missing or defective limbs.

While reports of miscarriage caused because of smoking are common, the latest data show that 17 out of 100 pregnant women smoke in the UK and Wales and approximately 3,700 babies are born with a physical deformity every year. Worse still, many soon-to-be-moms are completely in the dark about the dangers of smoking in the pre-partum period.

Led by Professor Allan Hackshaw, a team of doctors at UCL thoroughly checked 172 research papers published over the last five decades and concluded that smoking during pregnancy increases the risk of a baby being born with a cleft lip by 28%. The study estimated that 26 out of 100 babies born of mothers who smoked during pregnancy are likely to have missing or mal-shaped limbs.

Maternal smoking also increases the risk of talipes equinovarus (club foot) by 28%, vision problems by 25%, skull deformities by 33%, and gastrointestinal defects by 27%. Any of these damages caused to the newborn can be irreversible, which is why a pregnant mother must quit smoking before she conceives, advise experts.