The Unintended Toll of Extended Parental Leave: A 50-Year European Study

The policy seemed straightforward: give new mothers more time off work to bond with their babies and recover from childbirth. What could go wrong?

According to a major European study tracking 8,500 mothers across five decades, quite a lot—including a significantly higher likelihood of smoking later in life.

Researchers from the University of Vienna have uncovered an uncomfortable truth about extended parental leave policies. While shorter breaks from work appear protective, mothers who take very long periods away from their jobs—particularly without adequate financial support—face increased risks of developing smoking habits that persist for decades.

“We actually expected that longer career breaks would lead to mothers smoking less,” admits Sonja Spitzer, the study’s lead author and a demographer at the University of Vienna. “However, our results clearly show that the likelihood of smoking later in life increases with longer periods of parental leave.”

The Numbers Tell a Troubling Story

The study, published in the Journal of Health Economics, analyzed data from 14 European countries between 1960 and 2010. Using policy changes as natural experiments, researchers found that each additional month of parental leave increases a mother’s chance of smoking later in life by 1.2 percentage points.

That might sound small, but the cumulative effects are substantial:

• Total smoking duration increases by 7 months per additional month of leave
• Daily cigarette consumption rises by 0.2 cigarettes per day
• Overall “pack years” (a measure of lifetime smoking exposure) increase by 0.6 years
• Effects are strongest for mothers who lacked financial support during leave

The Stress Connection

Why would time with a newborn lead to smoking? The answer appears to lie in unintended consequences of prolonged work absence. Extended leave can trigger a cascade of problems: financial strain, social isolation, and career setbacks that persist long after returning to work.

The research reveals smoking as a coping mechanism for stress that becomes entrenched through habit formation. Mothers already facing the pressures of new parenthood find themselves dealing with additional burdens that policies intended to alleviate.

“Financial worries during an already sensitive phase of life such as around the time of birth can increase the pressure even more,” Spitzer explains. “This stress seems to have a particularly significant impact on health behavior in the long term.”

The Sweet Spot

The findings don’t condemn parental leave entirely. Instead, they suggest a U-shaped relationship where shorter periods may actually protect against smoking, while very long absences become counterproductive.

The research team found that mothers lacking partner financial support were hit hardest by extended leave policies. This pattern held even after controlling for official government benefits, suggesting that financial security requires more than statutory payments.

Global Implications

These results arrive as countries worldwide debate optimal parental leave policies. The United States remains an outlier with no federally mandated paid leave, while some European nations offer up to 40 months of job-protected time off.

The Vienna study suggests that more isn’t always better. “Our findings shed new light on parental leave policies: parental leave is intended to relieve parents, but it can also have unintended side effects on health—especially when there is financial uncertainty surrounding the birth,” notes Spitzer.

The research calls for policies that balance protection around childbirth with financial security and timely workforce reintegration. It also highlights the importance of encouraging fathers to take leave, potentially reducing the burden on mothers alone.

Perhaps most importantly, the study serves as a reminder that good intentions in policymaking require careful measurement of all consequences—including those that emerge years or decades later in the privacy of individual choices and habits.