Breakfast Skipping, Extreme Commutes, and the Sex Composition at Birth

Abstract

A growing body of literature has shown that environmental exposures in the period around conception can affect the sex ratio at birth through selective attrition that favors the survival of female conceptuses. Glucose availability is considered a key indicator of the fetal environment, and its absence as a result of meal skipping may inhibit male survival. We hypothesize that breakfast skipping during pregnancy may lead to a reduction in the fraction of male births. Using time use data from the United States we show that women with commute times of 90 minutes or longer are 20 percentage points more likely to skip breakfast. Using U.S. census data we show that women with commute times of 90 minutes or longer are 1.2 percentage points less likely to have a male child under the age of 2. Under some assumptions, this implies that routinely skipping breakfast around the time of conception leads to a 6 percentage point reduction in the probability of a male child. Skipping breakfast during pregnancy may therefore constitute a poor environment for fetal health more generally. IntroductionBreakfast skipping is a common and growing phenomenon among American women. Approximately 40 percent of women of childbearing age are attempting to lose weight (Cohen and Kim 2009), and rates of breakfast skipping have grown steadily over time, especially for adolescent women (Haines, Guilkey, and Popkin 1996;Siega-Riz, Popkin, and Carson 1998). Holtzman (2010) finds that 75 percent of women aged 18 to 26 skip breakfast at least one day a week, 58 percent skip breakfast at least four days a week, and 29 percent skip breakfast every day. Using detailed time use data we find that on a given day, 51 percent of employed women between the ages of 15 and 45 report not eating between the hours of 5 a.m. and 10 a.m. 1 Even among pregnant women, 24 percent report skipping meals (Siega-Riz et al. 2001).Given the vast and growing literature documenting the profound and lasting effects of the prenatal environment on long-term health and socioeconomic success (e.g., Almond and Currie 2011), one might be concerned that the rising incidence of breakfast skipping among women of childbearing age might have important intergenerational ramifications. Pregnant women who extend the overnight fast by skipping breakfast experience a sharp drop in glucose levels and other associated biochemical changes referred to as "accelerated Address correspondence to Bhashkar Mazumder, Federal Reserve Bank of Chicago, 230 S. La Salle Street, Chicago, IL 60604, USA. E-mail: bhash.mazumder@gmail.com 1 This is based on the Eating and Health module subsample of the data, which includes all primary and secondary activities.Color versions of one or more of the figures in the article can be found online at www. tandfonline.com/hsbi. 188 B. Mazumder and Z. Seeskinstarvation" (Metzger et al. 1982). Declines in glucose levels as a result of overnight fasts of 10 to 12 hours in length have been observed in women as early as the sixth to tenth weeks of pregnancy (Mills et al. 1998)....

Son‐biased fertility stopping, birth spacing, and child nutritional status in Pakistan

“…In other words, the negative effect of short birth intervals seems to be primarily impacting sons. This result aligns with a large literature suggesting that male fetuses are more vulnerable to adverse prenatal environments than girls (DiPietro & Voegtline, 2017; Mazumder & Seeskin, 2015). Data from the nationally representative DHS suggest a strong preference for two sons among Pakistani women (Table 10).…”

“…In other words, the negative birth‐order gradient, at least for boys, has its incipience in the period before birth through short birth intervals. This result coincides with the burgeoning literature on the impacts of in utero fetal insults to child health, including variation in rainfall affecting food availability (Maccini & Yang, 2009; Rocha & Soares, 2015; Shah & Steinberg, 2017); exposure to air pollution (Currie et al., 2009); and milder nutritional deficiencies, including skipping breakfast (Mazumder & Seeskin, 2015) or exposure to Ramadan fasting (Almond & Mazumder, 2011; Almond et al., 2015; Greve et al., 2015; Karimi & Basu, 2018; Oosterbeek & van der Klaauw, 2013). Each of these studies emphasizes that not only do early investments matter but increasingly the earliest investments might matter the most for child health.…”

Twin Birth and Maternal Condition

“…The reason that our finding is potentially a major challenge is that maternal condition is multidimensional and almost impossible to fully measure and adjust for. To take a few examples, fetal health is potentially a function of whether pregnant women skip breakfast (Mazumder & Seeskin, 2015), they suffer bereavement in pregnancy (Black et al, 2016), or they are exposed to air pollution (Chay & Greenstone, 2003).…”

Twin Birth and Maternal Condition

“…The reason that our finding is potentially a major challenge is that maternal condition is multidimensional and almost impossible to fully measure and adjust for. To take a few examples, fetal health is potentially a function of whether pregnant women skip breakfast (Mazumder & Seeskin, 2015), they suffer bereavement in pregnancy (Black et al, 2016), or they are exposed to air pollution (Chay & Greenstone, 2003).…”