Change in active transportation and weight gain in pregnancy

Skreden et al. International Journal of Behavioral Nutrition and Physical Activity (2016) 13:10 DOI 10.1186/s12966-016-0332-7 RESEARCH Open Access Change in active transportation and weight gain in pregnancy Marianne Skreden1*, Nina C. Øverby1, Linda R. Sagedal2, Ingvild Vistad2, Monica K. Torstveit1, Hilde Lohne-Seiler1 and Elling Bere1 Abstract Background: Pregnancy is characterised by large weight gain over a short period, and often a notable change in mode of transportation. This makes pregnancy suitable for examining the plausible, but in the scientific literature still unclear, association between active transportation and weight gain. We hypothesize that women continuing an active mode of transportation to work or school from pre- to early pregnancy will have a lower gestational weight gain (GWG) than those who change to a less active mode of transportation. Methods: We analysed prospective data from the Norwegian Fit for Delivery (NFFD) trial. Between September 2009 and February 2013 606 women were consecutively enrolled in median gestational week 16 (range; 8–20). Of 219 women who used an active mode of transportation (biking, walking, public transportation) pre-pregnancy, 66 (30 %) converted to a less active mode in early pregnancy (“active-less active” group), and 153 (70 %) continued with active transportation (“active-active” group). Pre-pregnancy weight was self-reported. Weight at gestational (GA) weeks 16, 30, 36, and at term delivery was objectively measured. Weight gain was compared between the two groups. Linear mixed effects analysis of the repeated weight measures was performed including the group*time interaction. Results: A significant overall group effect was observed for the four time points together (“active-active” group: 77.3 kg vs. “active-less active” group: 78.8 kg, p = 0.008). The interaction term group*time was significant indicating different weight gain throughout pregnancy for the two groups; the mean differences between the groups were 0.7 kg at week 16, 1.4 kg at week 30, 2.1 kg at week 36, and 2.2 kg at term delivery, respectively. Conclusion: The findings indicate that active transportation is one possible approach to prevent excessive weight gain in pregnancy. Keywords: Active transportation, Biking, BMI, Pregnancy, Public transportation, Walking, Weight gain Background In the last few decades overweight and obesity have become a major threat to public health worldwide [1]. Preventing weight gain is preferable to treating overweight and obesity because of the limited sustainability of weight loss [2]. Gestational weight gain (GWG) in line with the recommendations given by the Institute of Medicine [3], is known to optimize mother and child health outcome [3]. However, appropriate GWG is * Correspondence: 1 Department of Public Health, Sports and Nutrition, University of Agder, Kristiansand, Norway Full list of author information is available at the end of the article achieved by a minority of pregnant women in most parts of the world [4, 5]. In general physical activity is inversely associated with weight gain [6–8], and increasing physical activity is a priority [9, 10]. Although there are few contraindications to low to moderate intensive physical activity in pregnancy, reduction in physical activity level is the norm compared to pre-pregnancy [11–17]. Common barriers to physical activity during pregnancy are lack of time and pregnancy symptoms [12, 15, 18–20]. Active transportation is one way to promote physical activity in pregnancy, and has also environmental benefits [21]. Furthermore, active transportation is often built into people’s day-to day routines, facilitating adherence [22]. © 2016 Skreden et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Skreden et al. International Journal of Behavioral Nutrition and Physical Activity (2016) 13:10 The literature on active transportation to school or work in pregnancy is scarce. Private car seems to be the most frequent mode of transportation among pregnant women in developed countries [23–25]. We have earlier reported that 66 % used private transport, 10 % walked, 8 % biked and 16 % used public transportation to work or school before GA week 20 [24]. Haakstad et al. found that 53 % drove their own car, while 32 % used public transport and 15 % walked or biked to work in third trimester of pregnancy [25]. Pregnant women bike less in pregnancy, compared to pre-pregnancy [12, 25], and they often continue walking [12, 25]. Both longitudinal [26], and large population-based studies [27–29] in non-pregnant populations have reported that active transportation to work was associated with lower BMI [27, 28], and lower probability of being overweight [29]. A similar association has been demonstrated in longitudinal studies among children [30] and adolecents [31] and among adults in two recent systematic reviews [32, 33]. Most studies included in these two systematic reviews were, however, cross-sectional. Furthermore, heterogenous study design and lack of comparability of outcomes weakened the conclusions. A third systematic review concluded that there was little robust evidence that active transportation intervention prevents obesity [34]. Randomised controlled intervention trials in non-pregnant populations have reported mixed findings on the association between active transportation and reduction in body weight [35–37]. In order to detect significant associations between active transportation and weight gain, large-scale randomized trials manipulating mode of transportation over a long time period are needed. Such trials would, however, be hard to conduct and probably not feasible. Because of these shortcomings, there has been a call for longitudinal and more explorative studies in adults [27, 32–34]. Pregnancy is characterized by a series of specific metabolic changes such as the stimulation of accretion of adipose tissue in early pregnancy and increased insulin resistance later in pregnancy [38]. Furthermore, there is a notable change in the mode of transportation from pre-pregnancy to early pregnancy. Thus, we hypothesize that women continuing an active mode of transportation to work or school from pre-pregnancy to early pregnancy (≤20 GA weeks) will have lower GWG than those who change to a less active mode of transportation. Methods We analysed prospective data from the Norwegian Fit for Delivery (NFFD) trial, where half of the part (...truncated)