Possible relation between maternal consumption of added sugar and sugar-sweetened beverages and birth weight – time trends in a population

Abstract

BackgroundHigh birth weight (BW) is a risk factor for later obesity. In Norway, mean BW and proportion of large newborns increased from 1989 to 2000 and subsequently decreased to the 1989 level by 2010. The purpose of the study was to explore causes of this temporary increase.MethodsFrom a regional prospective database pregnancy and newborn data were extracted for all 33088 singleton pregnancies resulting in live infants born at term without malformations during 1989–2010. Trends in BW, ponderal index and proportion of large newborns were related to individual prenatal exposures, including pre-pregnancy body mass index (PP-BMI) and gestational weight gain (GWG) for the years 2001–2010, and thereafter related ecologically to national population data on consumption of nutrients and physical activity.ResultsFor the regional cohort mean (standard deviation) BW increased from 3580 (453) grams in 1989/90 to 3633 (493) grams in 2001/02 (p<0.001), and decreased to 3583 (481) grams in 2009/10 (p<0.001). The proportion with BW>4500 grams increased from 2.6% to 4.8% (p<0.001) and subsequently decreased to 3.3% (p=0.002). The trends remained after adjustment for relevant exposures. For the years 2001/02 to 2009/10 (n= 15240) mean (SD) PP-BMI increased from 24.36 (4.44) to 24.85 (5.02) kg/m2 (p<0.001) while GWG decreased from 14.79 (5.85) to 13.86 (5.79) kg (p<0.001). The estimated net effect of changes in PP-BMI, GWG and other known exposures was a 6 grams reduction in BW from 2001/02 to 2009/10, leaving 44 grams reduction unexplained. National consumption of major nutrients did not change, but consumption of sucrose, in large part as sugar-sweetened beverages (SSB) changed in parallel to the BW trends.ConclusionThe temporary increase in BW and large babies in the regional cohort was identical to that reported for Norway. Individual level data on known pregnancy related predictors for BW could not explain these changes, but the parallel time trend in national consumption of sucrose, in particular as SSB, may lend support to a hypothesis that intake of sugar may have a direct effect on BW and infant body proportions independent of effects through PP-BMI and GWG.

Is consumption of sugar‐sweetened soft drinks during pregnancy associated with birth weight?

“…We have previously shown that temporary increases in mean BW and HBW babies in Norway occurred in parallel to a marked increase and subsequent decrease in national consumption of SSC, and we suggested a causal relationship (Grundt et al, 2012). This study may seem to contradict that hypothesis, but it may still be true.…”

“…In this study, fewer participants had pre‐pregnancy diabetes or were diagnosed with GDM than both nonparticipants and the participants in our previous cohort study where data were available for all pregnant women within a region (Grundt et al, 2012, Nilsen et al, 2009). As SSC consumption decreased and leisure time exercise increased in Norway during the recruitment period to the MoBa study (Grundt et al, 2012), glucose tolerance among pregnant women was probably generally better. Furthermore, women with increased cardio‐metabolic risk factors, such as obesity, reduced glucose tolerance, or GDM, may have been early adopters of the trend to reduce intakes of SSC.…”

“…Due to the parallel trends of BW and SSC consumption in Norway since 1990 (Grundt et al, 2012), we considered SSC intake to be of special interest and grouped the women into low (<100 ml/day), medium (≥100 and <500 ml/day) and high (≥500 ml/day) SSC consumers.…”

“…A temporary 50% increase in the national consumption of SSC was associated timewise with a 50% increase in the proportion of babies with BW above 4,500 g (Grundt, Nakling, Eide, & Markestad, 2012). Similar national trends in BW and consumption of sugar‐sweetened soft drinks have been reported for USA, Denmark, Australia, and Sweden ( Supplementary Appendix; Supplementary Information 1), but the causes of possible relationships have not been addressed.…”

“…A previous study compared data from a large regional pregnancy register, where the time trends for BW were equal to the national Norwegian trends, and simultaneous national statistics on nutrition and exercise, and suggested that the relationship between SSC and BW was positive and causal (Grundt et al, 2012). The aim of this study was to examine if the same relationship was also present in a large pregnancy cohort where detailed information on maternal diet, including consumption of SSC and other sources of sugar, and relevant confounders were collected prospectively.…”