Fertility and birth experts based at Southampton's university hospitals have found women who stop smoking as late as when pregnancy is confirmed can dramatically boost the health of their baby.

In the largest study of its kind, Professor Nick Macklon, a consultant gynaecologist and medical director of the Complete Fertility Centre at the Princess Anne Hospital, and his team studied the outcomes of 50,000 pregnancies.

They found that women who gave up smoking at the time of conception or when their pregnancy was confirmed - the periconceptional period - gave birth to babies with a similar weight to those born to mothers who had never smoked, cutting the risk of complications associated with low birth weight.

Healthy development during pregnancy without exposure to smoke also helps to limit the chances of premature birth, which can cause brain damage and congenital defects such as cleft lip and lead to other illness in later life.

"Not only was birth weight much better in this group than it was in the groups where the mothers had continued to smoke, but we also found that the babies reached the same gestational age and head circumference as those born to women who had never smoked," said Prof Macklon, chair of the department of obstetrics and gynaecology at the University of Southampton.

"Mothers who smoke are encouraged to stop smoking when they become pregnant but, to date, there was little evidence that giving up at this late stage could have a positive effect on birth weight, so we can now give couples hard proof that making the effort to stop smoking once pregnancy is confirmed is beneficial for their baby."

The team studied clinical, lifestyle, and socio-economic data collected from pregnancies registered at Southampton University Hospitals NHS Trust between 2002 and 2010 and analysed seven groups of women, including non-smokers, those who stopped more than a year prior to conceiving, those who stopped less than a year prior to conceiving, smokers who stopped once the pregnancy was confirmed and those who continued to smoke.

Prof Macklon also warned of the worrying trend of women who continue to smoke because they want to give birth to a smaller baby - despite overwhelming evidence of the consequences.

"It is important that people who believe that a smaller baby means an easier birth take into account the increased risks of complicated deliveries in smokers as well as the risk of disease later in life which goes with low birth weight."

Prof Macklon, who launched Complete Fertility Centre in Southampton in May, reported the findings today (Wednesday) at the annual conference of the European Society of Human Reproduction and Embryology in Stockholm.


1) The Complete Fertility Centre Southampton is a new initiative by Southampton University Hospitals NHS Trust which, in collaboration with internationally recognised fertility experts and the University of Southampton, offers both NHS and private patients a university teaching hospital fertility service.

2) Southampton University Hospitals NHS Trust is one of the largest acute trusts in England and operates at three sites across the city of Southampton. It provides local hospital services to half a million people living in Southampton and SW Hampshire and specialist services including neurosciences, cardiac care and specialist children's services to more than three million people in central southern England and the Channel Islands.

3) Every year more than 7,500 staff at the trust see 420,000 people at outpatient appointments, deal with 110,000 attendances at the Emergency Department and treat 115,000 inpatients and day patients. Providing these services costs £1.3 million per day.

4) In January, independent watchdogs from the Care Quality Commission carried out a planned review of compliance against the requirements of the 16 essential standards of quality and safety at Southampton General Hospital and found the hospital compliant with all 16.

5) Southampton University Hospitals NHS Trust has over 20,000 members - ranging from patients, local residents and staff - who have registered an interest in the development and progress of their hospitals.

6) Southampton University Hospitals NHS Trust now has a Twitter page. Twitter is a form of microblogging which enables you to keep up-to-date with the people or organisations in which you are interested in headlines of 140 characters or fewer. Sign up to follow us on Twitter at http://twitter.com/suht to make sure you know about all our latest news.

7) As well as fundraising for ward and department charity projects across SUHT, a major fundraising Red & White Appeal has been launched by Southampton Hospital Charity to raise £2.2 million to create the transplant treatment centre of choice for patients with leukaemia and other blood disorders from Hampshire, the Isle of Wight, Wiltshire, Dorset, West Sussex and the Channel Islands.

Southampton University Hospitals NHS Trust