I work for a Stop Smoking Service and have really mixed feelings about this. I suppose I have concerns that the same women who do not admit to smoking in pregnancy will miss antenatal appointments, or will feel that their relationship with their midwife is damaged. I suppose that smoking in pregnancy will become even more stigmatised.
as for the mechanics of it, any woman can opt out. Nobody will be forced to take a test, as with all antenatal tests and screening opportunities.
Regarding the oft-quoted 'Pregnant women know smoking is bad' line: that is not always true. Women come through our service with a lot of misconceptions about smoking, along the lines of 'My mum smoked with me and it didn't do my any harm' or 'the smoke doesn't go to my baby as it only goes in my lungs', and many pregnant women think they will have an easier birth if they smoke, as the baby will be lighter.
For these women, a frank discussion about the effects of smoking can be a real eye-opener. Additionally, only 10% of people wanting to give up smoking know how to access stop smoking services, where their chance of giving up smoking is increased by 4X.
On a personal note, i was able to give up smoking when I found out I was pregnant with my first (unplanned) child and never looked back. But I recognise not everyone can do this. My DSis really struggledto give up smoking in her pregnancy and didn't get a lot of support from her midwife