A recent study investigates whether overweight and obese women and those of low socioeconomic status were at higher risk of gaining excessive weight in pregnancy. They also determined the role of prenatal education about diet and exercise in pregnancy weight gain.
There is widespread acceptance that a woman is meant to gain weight throughout her pregnancy in order to accommodate the growing fetus. However, each trimester is defined by different rates of change which are not typically known by the mother at the start of her pregnancy. The disparity in beliefs and overall lack of knowledge relating to pregnancy weight gain results in a tendency of mothers to put on more weight than necessary, which has both short and long-term effects to both mother and child.
Excessive weight gain in early pregnancy has been found to be associated with but not limited to gestational diabetes, insulin and glucose intolerances, and hypertensive disorders in the mother during and after pregnancy. Not only is the mother at risk but it also places her child at increased risk of obesity in their first four years of life and may contribute to an intergenerational cycle of obesity. Issues arise when mothers are not aware of the consequences of excessive weight gain because they are unknowingly putting both themselves and their child at risk.
A study conducted in Australia and published in BMC Pregnancy and Childbirth investigated the prevalence of excessive weight gain in early pregnancy from various demographics and collected data about their understanding of how much weight gain is expected of them during pregnancy, and whether they understand the risks of going over these weight recommendations.
Data was taken from 2,021 women who completed a questionnaire at their second prenatal visit. The women reported their own pre-pregnancy weight and height, and researchers asked questions relating to weight gain and health risks. The weight of the woman was then recorded at her current stage of pregnancy in order to estimate her rate of weight gain over the course of her pregnancy. Information relating to race and socioeconomic status were also reported in order to determine if either factor had bearings on the results.
The results indicated that a third of women gained too much weight in early pregnancy, which was defined as less than 22 weeks. Specifically, women with a BMI that indicated they were overweight or obese prior to becoming pregnant were much more likely to put on excess weight. Interestingly, the women in these BMI categories are required to put on no more than 7 kg or 11 lbs to 11.5 kg or 25 lbs of weight throughout the entire pregnancy, as compared to normal and underweight women who are meant to put on a minimum of about 11.5kg or 25 lbs.
Additionally, significant differences were seen in weight gain among women coming from a lower socioeconomic background, as they were two times more likely to gain excessive weight than women from more prosperous neighbourhoods. This may be attributed to the prevalence of stress, depression, lack of support, and unplanned pregnancies which can all influence poor lifestyle choices. Inconclusive results were found relating to cultural background and ethnicity but some differences indicate that it may be a factor that should be investigated in the future.
Furthermore, when asked to estimate recommended weight gain throughout pregnancy, 73.5% of overweight and 85.8% obese mothers overestimated the total. In addition, 51% of all the women were not aware of whether excessive weight gain would have an effect on them or their baby. This gives insight as to why even normal-weight women had gained excessive amounts of weight during early pregnancy. The study suggests that they are misinformed or uninformed entirely.
This study highlights the need for intervention and education for expectant mothers and women looking to become pregnant in the future. Weight is typically a sensitive subject for many women especially those already struggling with being overweight or obese, but it is important that this group of women understand what is considered healthy at each trimester. Women coming from lower-income households could benefit from having public health resources in place to help educate and support them in making healthy food and lifestyle choices for the sake of themselves and the child they are carrying.
It’s important to note that these results may not reflect all mothers around the world as the questionnaire was only conducted in Australia. Another discrepancy may lie in that data such as pre-pregnancy weight and height were all self-reported and may have been reported falsely, thus affecting BMI measurements. However, the total participant number was high and was not limited to any one cultural background or age group in an attempt to capture an image of Australian mothers in general. Future studies may want to focus on the differences between cultural backgrounds and beliefs in addition to tracking weekly weight gain rather than assuming an average based on total pregnancy weight gain before 22 weeks.
Written by Elena Popadic
Cheney, K., Berkemeier, S., Sim, K., Gordon, A., & Black, K. (2017). Prevalence and predictors of early gestational weight gain associated with obesity risk in a diverse Australian antenatal population: a cross-sectional study. BMC Pregnancy And Childbirth, 17(1). http://dx.doi.org/10.1186/s12884-017-1482-6