Women know the risks to babies, but they are being let down by a lack of supports
The evidence is overwhelming and the message has been given loud and clear for many decades now.
Smoking in pregnancy is harmful to the developing baby.
The statistics - based on self-reported figures - indicate that warnings are being heeded by many and rates among mothers-to-be are falling.
But maybe they are not telling the full story, so are we really getting the true picture?
Why are so many continuing to light up and smoke so heavily?
Clearly the stronger the habit, the more difficult it is to break.
Pregnancy itself is a huge motivation to stop smoking, but women also need support to help them tackle the cravings for a cigarette.
One of the reasons contributing to why so many women are continuing to smoke heavily during pregnancy may be linked to the inadequate supports that are being provided by maternity services at this crucial time.
All 19 maternity hospitals and units now routinely ask a pregnant woman at her first antenatal visit if she smokes.
Midwives rely on the patient to be upfront and truthful.
But as with any self-reporting quiz, some people will not come clean.
Just one maternity unit in the country validates the response by asking the woman to take a carbon monoxide test.
Yet this kind of test is now routine in Scotland.
It is a golden opportunity to advise a woman on the dangers of smoking and the risks of preterm delivery or having a small baby.
Although all units give advice verbally, it can range from as little as 15 minutes to just 10 seconds.
Only one-third of midwives are trained in stop-smoking counselling, the UCD Centre for Human Reproduction found.
Only half of maternity units have quit smoking services on site.
One of the many weaknesses is the lack of follow up by the hospital to see how the woman progressed in their efforts to quit.
It is known that just giving a woman details of where to go to get support is less successful that making an appointment for them.
A proper programme to help pregnant women quit, which is implemented across all maternity units, is not costly. But it needs to be urgently introduced to avoid needless risk to babies and complications that can last a lifetime.