Sorry to butt in here..BUT in no way whatsoever does going cold turkey harm your baby.
Once you quit your baby's oxygen levels will go up,where as if you continue your restricting the baby's oxygen levels.
I smoke myself but managed to stop during my pregnancy,And i have smoked since i was 13 and still managed to stop for my baby and went completely cold turkey.
It's only for 9 months i dont understand why people try and justify the fact that they can continue smoking and it'll be fine.
I understand its an addiction and a hard one to break ect ect and try not to judge people who try their hardest to cut down ect ect but by quitting completely it will NOT harm your baby...
The lungs:
When you smoke, or inhale other people's secondhand smoke, the smoke goes into your lungs.
Chemicals from the smoke, such as carbon monoxide, are then absorbed into your bloodstream.
Some of the oxygen in your blood is replaced by carbon monoxide.
This means that the oxygen supply to your baby may be restricted.
Heart:
When you smoke you inhale over 4,000 chemicals from the cigarette. One of these is a dangerous chemical called carbon monoxide, which gets into your bloodstream.
This restricts the oxygen that's essential for your baby's healthy growth and development, and because cigarettes restrict their oxygen supply, their tiny heart has to beat harder every time you smoke.
Stop smoking now and both you and your baby will get the benefits immediately. The carbon monoxide and other chemicals quickly leave your body. It means there's more oxygen in your blood, making you and your baby much healthier.
These facts came from here:
https://smokefree.nhs.uk/smoking-and-pregnancy/?&gclid=CJ6apNWfqasCFcMKfAod_0C50Q