A trial published yesterday in The BMJ found that offering up to £400 in shopping vouchers to pregnant smokers is highly beneficial.
Rewarding pregnant women this manner more almost doubled the proportion who were remained smoke-free by late pregnancy compared to those who received merely normal support, saving the NHS money in the long run.
However, most women who quit smoking during pregnancy reverted within six months.
Smoking during pregnancy increases the risk of stillbirth, SIDS, asthma, and childhood obesity.
Over the past 20 years, half as many women have smoked during pregnancy, but they are harder to contact.
Financial incentives can help pregnant women quit smoking, but substantial UK trials are lacking.
To address this, researchers analysed data from a successful phase 2 feasibility experiment in Glasgow, Scotland to see if financial incentives combined with UK stop-smoking programmes boost smoking cessation during pregnant.
Between January 2018 and April 2020, 7 stop-smoking services in Scotland, Northern Ireland, and England enrolled 941 pregnant women (average age 28).
At their first maternity appointment, on average 11 weeks into pregnancy, participants reported smoking at least once in the prior week. Then, 471 participants were randomly allocated to the intervention or control group (470).
The control group received psychotherapy and nicotine replacement therapy.
The intervention group received regular care and up to £400 ($440; €455) of high street shopping vouchers to encourage quitting and abstaining during pregnancy.
A carbon monoxide breath test confirmed four- and 12-week abstinence. Those who reported being smoke-free in late pregnancy (34–38 weeks) and had a saliva test received a final voucher.
Mother’s age, smoking history, income, usage of nicotine replacement therapy and e-cigarettes, birth time, and baby’s birth weight were considered.
More women in the incentives group (71% vs. 64%) used stop-smoking programmes and set a quit date. Saliva tests showed that 126 (27%) intervention group women had quit smoking by late pregnancy compared to 58 (12%) controls.
However, abstinence rates six months after delivering birth were low in both groups (6% in the intervention group vs. 4% in controls), suggesting that most women who quit smoking reverted.
443 intervention participants and 450 controls had comparable birth weights (average 3.18 kg vs 3.13 kg).
The researchers found a clinically important but not substantial (10%) increase in birth weight among those who quit when offered incentives and would not have quit without them, but they say more research is needed to understand this conclusion.
The intervention had no effect on miscarriages, stillbirths, or preterm birth severity.
The trial was well-designed, but the researchers note that only 23% of women screened by stop-smoking services were enrolled, which may have exaggerated quit rates in both groups. The results may not apply to other populations because most participants were white.
However, our results corroborate NICE guidelines by indicating that adding financial incentives to current stop smoking support for pregnant women is successful, does not disrupt UK stop-smoking programmes, and can save the NHS money in the long run.
They suggest studying which format, incentive amount, and frequency yield the best and most cost-effective results. An ongoing experiment is also investigating relapse prevention incentives 12 months following birth.
In a connected editorial, experts believe financial incentives for sustained smoking abstinence in pregnancy are among the most cost-effective healthcare interventions and a critical chance to minimise early life health inequities.
They note that most pregnant women’s partners smoke and suggest measures “To keep mother and kid smoke-free, should also target family smokers.
Effect of financial voucher incentives provided with UK stop smoking services on the cessation of smoking in pregnant women (CPIT III): pragmatic, multicentre, single blinded, phase 3, randomised controlled trial, The BMJ (2022). DOI: 10.1136/bmj-2022-071522