One hundred twenty-three women were eligible and interested in participating in the study; 30 (26%) were contactable and consented to an interview. Participants were recruited from: SSS (Glasgow (n = 4), Leicester (n = 7), London (n = 2)), Nottinghamshire antenatal clinic (n = 4) and health visitor clinics (n = 10), Tommy’s Facebook (n = 2), and informally (n = 1).

There were nine current-EC users, 11 ex-users and 10 never-users; 16 smoked and 14 were ex-smokers (see Table 1). Seven of the nine current EC users were dual users of cigarettes and ECs. Participants were aged 21 to 38 years, the majority were white British, lived with a partner, did not attend formal education beyond 18 years and were employed. Among the 15 pregnant women, three were in the first trimester (≤ 12 weeks gestation), seven in the second trimester (13 to 26 weeks), and five in the third (27–40 weeks). Fifteen women were postpartum: six were 0–3 months postpartum and nine were 4–6 months. Ten pregnant women gave consent to be re-interviewed postpartum and, of those, five were interviewed and five were uncontactable. Two of the participants changed their smoking/EC status by the second interview; one smoker/never EC user tried an EC since the interview and an ex-smoker/current EC user had returned to smoking. Interviews lasted for a mean (SD) 29 (8.7) minutes (range 18 to 53 min). We considered that data saturation and been reached following the initial 30 interviews.

Table 1 Characteristics of participants Full size table

The initial codes were very similar for each level of experience of using ECs as well as for pregnancy and postpartum women, except that aspects related to triggers for use and experiences of use were not relevant for never users. Therefore, it was decided that a common analytical framework would be developed, while noting any divergence for particular sub-groups of participants. The framework included six categories: social factors, general experience and usage, patterns of usage, comparison of ECs and NRT, perceived benefits of ECs and negative views on ECs; nested under these categories were a total of 32 codes (see Additional file 7). Review of the matrices, through discussion between the entire team, suggested that five main themes offered the best explanation of the data: motivations to use ECs, social stigma, using the EC, consumer aspects, and harm perceptions. The process of defining and labelling the themes was influenced by both the study objectives and by new concepts identified inductively from the data. Any differences in views according to level of experience of ECs or between pregnant and postpartum women are highlighted below. When pregnant women were interviewed for a second time at postpartum their views appeared unchanged except regarding the perceived stigma of ECs (see ‘Social Stigma’ theme).

Motivations for use

Most women were motivated to quit smoking; some felt that ECs could help them quit and dual users of ECs and cigarettes said they felt that ECs helped them to reduce their smoking.

‘I tried them but at the time [prior to pregnancy] I didn’t really have the motivation to stop properly but then, as I say, when I fell pregnant this time the first thing I did was buy an electronic cigarette’. (06 antenatal smoker and current EC user)

The majority indicated that they believed ECs were a less harmful alternative to smoking during pregnancy, reducing foetal exposure to toxins. Most women were aware that ECs usually contained nicotine but were unaware of other ingredients. Some said that ECs would reduce smoke odours on their clothes, in their home and on their children. A few felt ECs were safer than cigarettes for second-hand smoke exposure.

‘it [EC] doesn’t pass on second-hand smoke, because even if the baby was close-by, which I wouldn’t have a baby close-by, it wouldn’t be dangerous’. (19 antenatal ex-smoker and current EC user)

Most interviewees felt ECs were a cheaper alternative to smoking. A few women were motivated to use an EC based on cost alone. In terms of what first triggered women to use ECs, some women were introduced to ECs, and encouraged to quit using ECs, by family and friends. A few tried ECs after recommendations from a health professional. Others reported experimenting out of curiosity, often on the ‘Spur of the moment’ (09 antenatal ex-smoker and ex-EC user) and these women generally reported they were not ready to quit, so didn’t pursue the EC.

‘They [family] were a lot happier about me using that [EC] than obviously smoking. My Mum actually bought me the e-cigarette and she never ever bought me cigarettes in my life’. (08 antenatal smoker and current EC user)

A few women, having quit smoking, said they were more likely to use NRT than ECs if they relapsed, primarily due to the potential for ECs to steer them back to smoking, as a result of the similarity to smoking. Some ‘never’ and ex-users believed NRT would better support a quit attempt than ECs as regards ‘weaning off’ nicotine.

Social stigma

Most women expressed feeling uncomfortable (both actual and perceived experience) about using ECs in public during pregnancy and, for some, also in postpartum, especially when with children. The women said they felt that they would be judged and perceived as a bad mother. Two women who were interviewed again after pregnancy indicated they felt more comfortable about the idea of using ECs after the pregnancy, believing that there was less public judgement and less risk to the baby at this time. Some women also expressed a strong belief that it was socially unacceptable for a pregnant woman to smoke or vape in public.

‘If I was pregnant I would feel embarrassed because I think it looks disgusting. If I’m honest, pregnant women drinking or smoking any type of fags, cigar, electronic fags, I don’t think it looks very nice, so I wouldn’t do it pregnant in public. Afterwards I wouldn’t be bothered. I suppose it depends if I had the baby with me in a pushchair I wouldn’t be too keen on the idea.’ (04 antenatal ex-smoker and ex-EC user)

Compared with cigarette smoking, some felt it was more socially acceptable to use an EC and felt empathetic towards pregnant women using ECs as they could relate to the struggles of cessation. A few mentioned that a benefit of NRT is that it can be administered discreetly in public.

Using the EC (EC current users/ex-users only)

Regarding the context of where the EC was used, EC ‘triers’ reported vaping with friends and family, often in the home environment. Regular users generally reported vaping in similar environments as for smoking, often the home, workplace or car. A few said that, similarly to smoking, they avoided using ECs around their children.

Some said they were attracted by ECs as they replicated and substituted smoking, especially in terms of inhaling and blowing vapour and the hand-to-mouth action. One woman, who had struggled to quit using NRT, said she found that ECs helped her as they assisted with both the addiction and behavioural aspects of smoking. However, some ex-users indicated they felt ECs were too much of a reminder of smoking but, compared with a cigarette, didn’t provide the same satisfaction and often required use over longer periods in order to alleviate cravings.

‘One thing I missed when I have quit smoking is inhaling the smoke, so when I used an e-cigarette obviously you’ve got that kind of experience of inhaling the vapour. It was too much, it was too similar to having a cigarette, so it made me miss it even more.’ (01 antenatal ex-smoker and ex-EC user)

Some women reported negative first experiences of ECs; others felt side effects reduced as they adapted. One woman compared her initial experience to learning to smoke.

Consumer aspects

Among EC users/ex-users there was a general preference for smaller and lighter ECs; one woman reported she liked the convenience of it fitting in her handbag. Most participants were aware of the variety of flavours and some were aware of various nicotine strengths. To economise, a few women purchased the cheapest EC; however, they also felt the price of ECs reflected their value, with more expensive devices being more user-friendly. Women tended to either choose an EC impulsively, based on cost, or based on the advice of friends/family. Many had not received instructions about their device from the retailer or on the EC packaging, leaving some feeling uninformed.

‘When you are pregnant you want to know….how is the best way to use it [EC] to help you stop….you literally had to go and buy it like a loaf of bread’. (07 postpartum smoker and current EC user)

Rather than receiving information about ECs from retailers, women generally said they would prefer to receive information from a health professional or through National Health Service leaflets or websites.

Harm perceptions

Never-users, in particular, and some ex-users, said they felt there was a lack of information available about the safety of ECs, which led to fears. In order to make an informed decision about whether to use ECs, they said they needed further information and advice, preferably from health professionals.

‘Everyone just says ‘oh there’s only five chemicals in an e-cigarette, while there’s 4000 in a cigarette’ but my concern was those five chemicals that are in the e-cigarette’. (18 postpartum smoker and ex-EC user)

Women were asked whether they thought ECs should be made available on prescription and many felt it was important to first establish their safety. One smoker and never user said that she would require the government to provide assurance on their safety in pregnancy before she would consider using one.

‘Yeah and I think obviously if there was some sort of government stamp on it or you know you don’t buy toys without having something, you don’t buy anything without, even the bad stuff you know, you buy a packet of cigarettes and the government have put what it can do to you on it, with all the pictures. Whereas there’s nothing is there? There’s no nothing, no good, no bad, no nothing.’ (15 antenatal smoker and never user)

Some women indicated they felt more confident about NRT because the health service clearly advocated it, whereas they had received conflicting advice from health professionals about using ECs. Concerns about the safety of ECs were heightened by negative media reports, referring to malfunctioning devices, links to cancer or other health harms. A couple of women were concerned that ECs were becoming a fashion accessory, and one woman reported ECs had appealed to her young nephew.

Several women were worried that vaping might increase their consumption of nicotine compared with smoking:

‘Obviously with a cigarette you can only smoke it for so long till it’s finished, but with an e-cigarette you can smoke for as long as you want to. So sometimes, I guess, I was taking in more than the usual nicotine intake that I would have done with a cigarette.’ (01 antenatal ex-smoker and ex-EC user)