Having friends who smoke increases women’s prenatal smoking risk
MedWire: Relationships with fellow smokers may increase a woman's risk for continuing her smoking habit during pregnancy, say researchers.
"Although many women stop smoking upon pregnancy recognition, a large number continue to smoke," write Gregory Homish (University at Buffalo, New York, USA) and colleagues. "The likelihood of continued smoking during pregnancy is not equally spread across the population with younger, lower income, and less educated women more likely to smoke during pregnancy."
This study published in the journal Addictive Behaviors, looked into the socio-environmental factors that may affect the likelihood of smoking, in addition to these known individual-level factors.
Women in their first trimester of pregnancy with a partner (n=316) were recruited for the investigation and completed a series of four interviews: one at the end of each trimester and one 2 months after the birth.
The Timeline Follow-Back Interview was used to assess daily tobacco, alcohol, and cannabis use at each appointment. Saliva samples were also taken and the amount of cotinine analyzed to determine smoking status.
After controlling for smoking levels pre-conception, the researchers found that the women with a greater proportion of friends, but not relatives, who smoked were at a greater risk for prenatal smoking than women with more non-smoker friends.
Also, women were more likely to smoke during their first trimester if their partner was a smoker than if their partner did not smoke; there was a 37% increase in the risk for smoking in the first trimester among the women whose partners also smoked.
However, there was no association between increased risk for prenatal smoking and the presence of other household members that smoke.
The researchers note that the reason for the differential influences of friends and relatives remains uncertain, but suggest that it could be due to the amount of time women spend with each, or due to the nature of the relationship. Similar studies into the influence of social networks on drinking levels in newly married couples showed that the nature of the relationship with "drinking buddies" is an important factor.
"Future work will need to examine if there are changes in smoking throughout the pregnancy on the basis of social network factors," conclude Homish and team. "Additionally, future work should attempt to describe the mechanisms of how the social network impact changes in substance use can help inform intervention efforts."
By Chloe McIvor