A baby on the way is oftentimes a compelling enough reason for an expectant mother to quit smoking. But the added stress and life changes that come with a newborn’s arrival may push them right back into the habit, according to new research published in the journal Addiction.

"More women quit smoking during pregnancy than at any other time — but as many as 90 per cent start again within a year of their baby being born. This is particularly true among women in lower socioeconomic groups,” said lead study author Dr. Caitlin Notley, of the University of East Anglia’s Norwich Medical School, in a press statement . "We wanted to understand why this happens, and identify ways of preventing it. This is important both for the health of the mother, as well as to stop children being exposed to secondhand smoke, and because young people are more likely to start smoking if they grow up with smoking in the family.”

Analyzing more than 1,000 interviews taken with new mothers, the researchers keyed in on several factors that influenced the mothers’ decisions to relapse into smoking.

"We found that many women see smoking as a way of coping with stress. They also believe that physiological changes influence cigarette cravings, and that they no longer need to protect the baby from smoking's harmful effects,” Notley said. As one example, Notley and her colleagues found that their urge for nicotine, which had either disappeared or been dulled during pregnancy, often came back with a vengeance post-birth. "We also found that women who saw smoking as a way of coping with stress were more likely to relapse. And that feeling low, lonely, tired, and coping with things like persistent crying were also triggers.”

A self-defeating or selfless attitude towards their original decision to quit was also predictive of taking the habit back up. "In many women, the motivation to stop smoking was linked to their pregnancy — but they didn't see it as stopping for good and adopting a life without smoking. Relapse seemed almost inevitable where women admitted that they didn't quit for themselves,” explained Notley.

One of the largest impacts on mothers’ smoking habits came from the newly-minted father. ”We particularly noted that it was extremely difficult for women to remain smoke free when their partners smoked,” said Notley. "The majority of women who had successfully remained smoke free said that the support of their partner was a strong factor. Partners who gave up smoking, or altered their own smoking behaviours, were a particularly good influence. And those who helped ease the stress of childcare were also praised by women who had resisted the urge to light up."

Ultimately, Notley and her team believe that the best way to maintain smoking cessation in new mothers is to ease their transition into a new phase of their life, without making them feel as though quitting smoking will strip them of their old selves.

"In order for women to continue their lives smoke free after pregnancy, we need to see a cultural shift — where women feel more motivated to remain abstinent, and where they feel more comfortable with the change of identity that motherhood brings. Support from partners is vital, but support from health professionals can be very important as well."

Source: Notley C, et al. Postpartum Smoking Relapse - a thematic synthesis of qualitative studies. Addiction. 2015.