Participants. The aim is to recruit 250 pre-randomized (125 intervention vs. 125 control group) mothers at birth who quit smoking in the 2 months before pregnancy or no later than the end of 1st pregnancy trimester and remained abstinent until delivery, biochemically confirmed through expired carbon monoxide. The mothers are approached during the delivery hospital stay in two of the largest obstetrics-gynecology clinics in Cluj-Napoca, Romania. Enrollment criteria include willingness and ability to participate in the study, age 18 or older, married or living with a stable partner, with a mobile phone, and willing to provide mobile phone contact for their husband or partner. Their husband or life partner is also approached and invited into the study at recruitment, if present, or by phone in the first weeks after birth.