Adequate gestational weight gain is required for optimal pregnancy outcome. Less than one-third (28 %) of the pregnant women in this study gained adequate gestational weight. The factors positively associated with the adequate gain of the weight were having high BMI at early pregnancy (≥25 kg/m2), engaging in regular physical exercise, visiting ANC frequently, and eating fruit, vegetables and meat.
In the study, the mean weight gain during pregnancy was 8.96 kg. This is consistent with the findings from a study in Pakistan (8.5 kg) [11], but less than the findings from research in Brazil, in which the mean GWG ranged from 11.7 to 13.9 kg depending on BMI at early pregnancy [12–14]. Although the proportion of the women who gained inadequate (69.3 %) and adequate (28 %) gestational weight in our study is similar to those found in studies conducted in other countries [15, 16], it is smaller than the findings of similar studies conducted in other areas [11, 14, 17, 18]. The inadequate gestational weight gain in our study is most likely related to the nutritional condition of the women, given that 84 % of the women had less than three meals per day. In addition, a significant proportion of women were underweight at the conception. Moreover, while IOM recommendations may be well suited to high-income countries, there may be a number of contextual factors that limit the applicability of these guidelines to low or middle income-countries such as Ethiopia. It is, therefore, important to consider GWG in the context of all the factors in a woman’s life and to develop a GWG guideline that could address the context of developing countries.
This study also indicated that the women with higher early pregnancy BMI were more likely to gain adequate gestational weight when compared to underweight women. This is consistent with previous research in Pakistan [11]. Women who are underweight at early pregnancy are required to gain more weight than their overweight or obese counterparts do in order to achieve a healthy GWG. It may be difficult for these women to gain a significant amount of weight during pregnancy, particularly if they tend to be underweight due to metabolic or food security factors. Overweight and obese women, on the other hand, are required to gain comparatively little weight to achieve adequate GWG as they are able to use a portion of their stored energy to support the growth of the fetus. As such, adequate GWG may be attained easily for these women.
At least a half-an- hour of physical exercise per day is believed to be vital during pregnancy for a healthy lifestyle and for weight management for both the mother and the fetus [19]. In the study, the mothers who undertook physical exercise at least once a week were 2.1 times more likely to gain adequate gestational weight compared to those that did not. This finding is in line with other studies conducted in the United states [20] and China [21].
The women who frequently visited ANC (≥4 times) were 2.9 times more likely to gain adequate gestational weight. This result supports the findings of the study in southern Brazil [15]. This may be explained by the fact that during ANC visits, women are likely to receive advice on weight management, the importance of maintaining a balanced diet, the need for proper nutrition during pregnancy. The women who gave birth at or after 37 weeks of gestation were 4.5 times more likely to have gained adequate gestational weight compared to than those who gave birth before 37 weeks. This is supported by research in Thailand [6], and may be attributed to an increased opportunity to gain weight by virtue of having an increase gestational period.
Women who eat fruit and vegetable for at least once per week were 2.7 times more likely to gain adequate gestational weight. This contrasts with finding of another study [20] in which fruit and vegetable consumption during pregnancy has no association with weight gain. The difference might be due to a small number of subjects (105) in the indicated study. However, in this study, 81.5 % of the women consumed fruit and vegetable most of the day during their current pregnancy.
The women from good family income (family income of > $100 per month) were 5 times more likely to gain adequate gestational weight than their counter parts, a finding supported by research in Southern Brazil [15]. It is likely that a good family income enhances household food security. In which case, pregnant women with a high family income are more likely to have consistent access to a varied diet and thus could gain appropriate weight during pregnancy.
This study has some limitations. Since the weight gain recommendation is the recommendation of developed countries, it may underestimate the proportion of gestational weight gain in developing countries such as Ethiopia, where this study was conducted. Moreover, early pregnancy BMI was taken before or at 16 weeks of gestation, at which time there may already have been an increase or decrease of gestational weight. Since variables like physical excersise and dietary habits were asked retrospectively, and they are qualitative in nature; it is difficult to measure objectively and does not indicate any specific trimester. Findings are also generalizable only for women who attended at least one ANC visit and gave birth at a health facility.