Alexandra Houston-Ludlam

Program: Human and Statistical Genetics

Current advisor: Andrew C. Heath, DPhil

Undergraduate university: University of Maryland – College Park

Research summary
Population-level trends on sociodemographic risk factors for cigarette smoking during pregnancy (SDP) and outcomes for offspring exposed to maternal SDP are well established. However, the more complex task of understanding individual risk-prediction, including differences by maternal race/ethnicity, and its clinical application, remains incomplete. Characterizing the relative influence of environmental and individual characteristics as risk or protective factors for continued SDP is a necessary next step for informing individual- and public health-level interventions to produce successful smoking cessation prior to pregnancy, substantially reducing smoking-related mortality in child-bearing people. In this dissertation, I wanted to explore how multiple levels of influence, from individual, to family, to neighborhood, interact to confer risk or protection for SDP. First, I used a population-level birth cohort from state birth records of first births including geocoded maternal address at time of childbirth to compare individual and neighborhood level sociodemographics as risk and protective influences for SDP. I found important social influences on cigarette smoking during first pregnancy—marital status,
reproductive partner acknowledgement of paternity, and census tract-level SDP rate. Moreover, there were differences in risk factors by maternal race/ethnicity, in particular, among Black/African Americans, where SDP was higher in tracts with a greater proportion of white non-Hispanic residents. To examine how clinical factors, namely nicotine dependence, modulate risk for SDP, I used research data from a well-characterized like-sex female twin pair sample, connected to birth records for children born to the twin participants. I found that lifetime heaviness of nicotine dependence contributed as much risk to SDP as maternal sociodemographics at time of childbirth; however, the contribution of nicotine dependence to SDP risk was diminished at high levels of sociodemographic risk. These findings were limited to white non-Hispanic participants, as there was insufficient sample size from Black/African American participants. Finally, I wanted to use findings from administrative data to inform research design and address the needs of historically excluded populations, considering protective as well as risk factors. I wanted to identify protective factors for SDP among women who identify as American Indian or Alaska Native, as most existing research either excludes Native women, or only identifies higher rates of smoking, including SDP, without considering risk and protective factors. I conducted a pilot data collection from ten women recruited from birth records to examine the roles of positive racial identity, engagement with traditional tobacco use, and social influence by reproductive partner and cohabitants during pregnancy that might be associated with SDP. While I did not achieve a sufficient sample size for statistical analysis, I identified ways future work could explore these questions, including by working with a specific Tribe or Nation to address their questions about pregnancy and perinatal health and/or partnering with Tribal Epidemiology Centers to improve recruitment opportunities.

Graduate publications
Wang Y, Liu Y, Waldron M, Houston-Ludlam AN, McCutcheon VV, Lynskey MT, Madden PAF, Bucholz KK, Heath AC, Lian M. 2021 Temporal trends in smoking and nicotine dependence in relation to co-occurring substance use in the United States, 2005-2016. Drug Alcohol Depend, 226():108903.

McCutcheon VV, Bucholz KK, Houston-Ludlam AN, Waldron M, Heath AC. 2021 Timing of mortality in mothers with recurrent convictions for driving under the influence of alcohol and their children, from childbirth to child age 17. Drug Alcohol Depend, 221():108620.

Houston-Ludlam AN, Waldron M, Lian M, Cahill AG, McCutcheon VV, Madden PAF, Bucholz KK, Heath AC. 2020 Marital status, partner acknowledgment of paternity, and neighborhood influences on smoking during first pregnancy: findings across race/ethnicity in linked administrative and census data. Drug Alcohol Depend, 217():108273.

Houston-Ludlam AN, Bucholz KK, Grant JD, Waldron M, Madden PAF, Heath AC. 2019 The interaction of sociodemographic risk factors and measures of nicotine dependence in predicting maternal smoking during pregnancy. Drug Alcohol Depend, 198():168-175.

Wolf AR, Wesener DA, Cheng J, Houston-Ludlam AN, Beller ZW, Hibberd MC, Giannone RJ, Peters SL, Hettich RL, Leyn SA, Rodionov DA, Osterman AL, Gordon JI. 2019 Bioremediation of a Common Product of Food Processing by a Human Gut Bacterium. Cell Host Microbe, 26(4):463-477.e8.

McCutcheon VV, Bucholz KK, Houston-Ludlam AN, Heath AC. 2019 Elevated maternal and child mortality among women with multiple DUI convictions compared with socio-demographically matched controls. Addiction, 114(11):1981-1991.

Houston-Ludlam AN, Grant JD, Bucholz KK, Madden PAF, Heath AC. (2018) Big data approaches in translational science: The influence of psychiatric and trauma history in predicting future smoking during pregnancy in a cohort of female like-sex twin pairs. Annual Translational Science Meeting, Washington, DC, Abstract.

Houston-Ludlam AN, Grant J, Bucholz KK, Madden PAF, Heath AC. (2018) Fagerström Heavy Smoking Index outperforms DSM-IV Nicotine Dependence diagnosis in predicting future smoking during pregnancy in a sample of female like-sex twin pairs. Society for Research on Nicotine and Tobacco Annual Meeting, Baltimore, MD, Abstract.