Poster #32 - Maternal Smoking During Pregnancy Effects on Respiratory Conditions in Childhood: A sibling-comparison study

• In Event: Poster Session 20

Abstract

In the U.S., 6% of women report smoking during pregnancy (CDC WONDER., 2019). This is important since maternal smoking during pregnancy (MSDP) has been associated with adverse respiratory health outcomes for children. Previous epidemiological research suggests, for example, that children exposed to MSDP exhibit compromised respiratory development measured through lung functioning and capacity (Balte et al., 2016). The current study uses a sibling comparison design, examining the role of MSDP on incidences of respiratory conditions in families who participated in the Missouri Mothers and Their Children study (N = 173 families). Through birth record data, families were identified where mothers indicated a change in smoking behavior (i.e., either an increase or decrease) between two pregnancies. Thus, siblings are discordant for exposure, but share other familial variables which, in part, control for genetic variance within families (Child/sibling 1: Mage = 12.99; Child/sibling 2 Mage 10.19).
MSDP was measured using maternal reports of timing, quantity, and duration of smoking which was quantified into an MSDP Smoking Gradient of Severity ranging from 1 to 7 (1 = did not smoke during pregnancy – 7 = smoked beyond first trimester, 20+ cigarettes per day) for each sibling. These sibling MSDP scores were averaged, indicating the familial risk/confound related to MSDP and representing the between-family effect. The within-family effect was indicated by each child’s individual MSDP score relative to the sibling average. A categorical variable was created to assess respiratory risk from mother’s report of doctor’s visits due to respiratory conditions in the child’s life, reflecting a count of asthma, asthma attack, bronchitis, and allergies recoded to reflect 0 (n=178), 1 (n=81), 2 (n=51), or 3+ (n=33) respiratory conditions. Data were analyzed using multilevel models treating respiratory problems as continuous (sensitivity analyses were run using a zero-inflated Poisson distribution) to examine associations between MSDP severity and respiratory conditions at the within-family (comparing co-siblings) and between-family level (comparing families to each other). The within-family association would imply that the sibling with higher MSDP also had more respiratory conditions than their co-sibling. The between-family association would imply that families with generally higher MSDP across both pregnancies also had children with higher respiratory conditions compared to families with lower smoking during pregnancy.
Results indicated no association between MSDP severity and respiratory condition count in childhood. It is important to note that all mothers were smokers in this study. Thus, while there was variability in smoking behavior from one pregnancy to the next, MSDP might not influence child respiratory health directly. Sociodemographic characteristics of families that put them at higher risk for smoke exposure may also limit their access to consistent child healthcare where respiratory screenings for conditions such as asthma would occur, limiting our ability to detect those children in our sample (Merianos et al., 2017). Future studies may aim to investigate other familial factors that are correlated with both MSDP and respiratory health that might also negatively impact child respiratory health, such as maternal respiratory health, postnatal second-hand smoke, and air pollution exposure.

Group Authors

Purdue University Human Development and Family Studies

Authors

• Nikolina Nonkovic, Purdue University, West Lafayette
  Presenting Author

• Kristine Marceau, Purdue University, West Lafayette

• Valerie Knopik, Purdue University, West Lafayette