Effects of Purchase Restrictions on Smoking During Pregnancy: An Analysis of U.S. Birth Records.

INTRODUCTION: In December 2019, the minimum legal sales age (MLSA) for tobacco products in the United States was raised from 18 to 21 years as a measure of preventing smoking initiation. Smoking during pregnancy, which causes maternal, fetal, and infant morbidity and mortality, is a major public health concern. We first study the effects of purchase restrictions on smoking during different stages of pregnancy covering the entire United States and using the records of all live births during 2014-2018 by birthing people aged 18-21 years. AIMS AND METHODS: Our identification strategy utilizes the variation in the MLSA of tobacco products over time and across counties in the United States during 2014-2018 using a two-way fixed effects model, modified to accommodate a partially observable treatment indicator. RESULTS: The results show that 37.4% of potential smokers in our study population would have been prevented from smoking before pregnancy, 50.5% during the first trimester, 53.4% during the second trimester, and 14.8% during the third trimester if the law prevented selling tobacco products to them in the locality they live. A purchase restriction is estimated to cause the smoking intensity of those who smoke, the intensive margin, to drop by 5.4% before pregnancy, 10.4% during the first trimester, 14.8% during the second trimester, and 5.2% during the third trimester. CONCLUSIONS: Our results show that purchase restrictions are highly effective in preventing smoking among birthing people in the 18-21 years age group. The effect on smoking prevalence during the first and second trimesters is more pronounced. IMPLICATIONS: Many countries around the world have recently tightened age-based purchase restriction policies as a tobacco control measure. We first study the effects of purchase restrictions on smoking during different stages of pregnancy using the birth records of all pregnancies in the United States by birthing people aged 18-21 years during 2014-2018. The study utilizes the variation in the MLSA of tobacco products over time and across counties during that period. Our results show that purchase restrictions are highly effective in preventing smoking among birthing people in the 18-21 years age group.

Adversity in Infancy and Childhood Cognitive Development: Evidence From Four Developing Countries.

Objectives: We investigated whether adverse experiences at age 1 (AE-1) affect the level of and change in cognition during childhood using harmonized data from four developing countries. Methods: Data included children born in 2001/2002 and were followed longitudinally in 2006/2007 and in 2009/2010 by Young Lives study in Ethiopia, India, Peru, and Vietnam. Childhood cognition was measured using the Peabody Picture Vocabulary Test (PPVT) at ages 5 (PPVT-5) and 8 (PPVT-8). We also examined the effect on a change in cognition between age 5-8 (PPVT-Change). The AE-1 scores were constructed using survey responses at age 1. The ordinary least squares regression was used for estimation. Results: We found that children with higher adversities as infants had lower cognition scores at ages 5 and 8. The change in cognition between the two ages was also generally smaller for those with severe adversities at infancy. The negative association between adversities and childhood cognition was strongest for India. Conclusion: The results provide policy relevant information for mitigation of undesirable consequences of early life adversities through timely interventions.

The impact of IOM recommendations on gestational weight gain among US women: An analysis of birth records during 2011-2019.

The prevailing guidelines of the Institute of Medicine (IOM) of United States on gestational weight gain (GWG) are based on women's prepregnancy body mass index (BMI) categories. Previous research has shown that the guidelines issued in 1990 and revised in 2009 had no effect. We investigate the effectiveness of new guidelines issued in 2009 analyzing the records of all singleton births in the U.S. during 2011-2019 (34.0 million observations). We use the discontinuity in recommended guidelines at the threshold values of BMI categories in a regression discontinuity (RD) research design to investigate the effect of IOM guidelines on GWG. We also use an RD analysis in a difference in difference (DID) framework where we compare the effect on women who had any prenatal care to others who did not receive prenatal care. The naïve RD estimator predicts an effect in the expected direction at the threshold BMI values of 18.5 and 25.0 but not at 30.0. After the DID based correction, the RD analyses show that the GWG, measured in kg, drop at the BMI values of 18.5, 25.0 and 30.0 by 0.189 [CI: 0.341, 0.037], 0.085 [CI: 0.179, -0.009] and 0.200 [CI: 0.328, 0.072] respectively when the midpoint of the recommended range in kg drops by 1.5, 4.5 and 2.25. This implies a responsiveness of 12.6%, 1.9% and 8.9% respectively to changes in guidelines at these BMI values. The findings show that the national guidelines have induced some behavioral changes among US women during their pregnancy resulting in a change in GWG in the expected direction. However, the magnitude of the change has not been large compared to the expectations, implying that the existing mechanisms to implement these guidelines have not been sufficiently strong.