Pregnant teenagers are "six times as likely to smoke" while expecting, compared to women over the age of 35. Regional differences show "much higher" rates in poorer areas, said Prof Russell Viner from the Royal College of Paediatrics and Child Health. Smoking during pregnancy causes an estimated 5,000 miscarriages in the UK each year, along with still and premature births. But when Newsbeat asked you to text in your experiences, opinion was divided.
Dr David James, a trainee doctor specialising in paediatric care, explains the truth behind some of your concerns, questions and beliefs. "Well done for actually managing to cut down. We certainly know that it's not good to be stressed during pregnancy either for the mother or for the unborn baby but we know it's more dangerous to smoke. The risks that we know really well around miscarriages, stillbirths, premature births and small babies probably vastly outweigh the risk coming from stress. We know there are increased risks of infections, particularly things like glue ear and upper respiratory tract infections in babies born to women who smoke. Unlike alcohol, we know there is no safe amount a woman can smoke. Every cigarette is potentially harmful to that baby. The less you smoke, the better. It's a bit of a worry because although it might be less painful to give birth to a smaller baby, we know that small babies have lots of problem," says Dr James.
"Small babies often stay in hospital longer because they have problems around feeding and maintaining their temperature. There's really good evidence out there now which suggests small babies, in the long term, have a higher chance of getting things like diabetes and issues with being overweight later in life. Giving birth can be painful but there are plenty of ways midwives and obstetricians can manage to alleviate that pain. Giving up at any point is a real achievement," says Dr James.
"It's important for the health of the mother. And it's really important for the children. We know that babies who are in smoky houses have got a far higher instance of respiratory problems like wheeze and asthma and all those infections like glue ear.""All the data we have is population data so it talks about risk overall. It doesn't tell you that you're definitely going to have a small baby or your definitely going to have a miscarriage. All it says is that you're more likely to have that than someone who doesn't. We all have to recognise it's really hard to give up smoking," says Dr James.
"It's one of the most addictive substances that there is. What we need to be focusing on is how do we give support to those people." Newsbeat had some questions as well "We know that people who live in a household with another smoker find it much harder to give up," says Dr James. "So if you both smoke and you both quit, there's a much higher chance of them staying off cigarettes. When the baby's born, it's much healthier for that baby not to be exposed to smoke. Even when they're inside [the womb] we know that the effects of second-hand smoke can be damaging as well. No-one currently knows that it's safe," says Dr James. "From what we can tell, it's still harmful to the baby so people shouldn't have e-cigarettes when they're pregnant."