Maternal Obesity and Fetal Macrosomia: An Integrative Review of the Literature Regarding Interventions

Research suggests pre-pregnancy obesity is associated with an increased risk of macrosomia in the newborn. Since women are expected to gain weight during pregnancy, the standard recommendation of weight loss for obesity is not ideal for this population. In this systematic review of the literature regarding interventions for maternal obesity to reduce fetal macrosomia, 149 articles were screened using three different databases to identify recent randomized controlled trials related to this topic. A total of 11 full text articles were analyzed and included in the review. The articles addressed nutritional, lifestyle, and pharmacological interventions. The results indicated there is currently insufficient evidence to support specific treatment options for women with obesity during pregnancy to reduce the risk of fetal macrosomia. MATERNAL OBESITY AND MACROSOMIA 4 Maternal Obesity and Fetal Macrosomia: An Integrative Review of the Literature Regarding Interventions Among the Healthy People 2020 objectives, in the section “Maternal, Infant and Child Health,” objective number 16.5 is to “Increase the proportion of women delivering a live birth who had a healthy weight prior to pregnancy” (HealthyPeople.gov Staff, 2017, MICH-16.5). Recently, obesity is becoming a crucial topic among healthcare providers, due to its increasing prevalence and an increasing awareness of the negative health conditions with which it can be associated. Obesity in the pregnant mother requires specialized care based on the most current evidence, to best understand the many possible effects it could have on this unique state of health for the mother, as well as on the developing child. One important topic of researcher interest is the association between maternal pre-pregnancy obesity and macrosomia of the newborn. The World Health Organization [WHO] (2016) defined obesity as a body mass index of greater than or equal to 30 kg/m. Bray (2018), in a literature review, identified numerous risk factors associated with obesity. He noted the development of weight gain tends to occur in relation to certain life circumstances, such as pregnancy and menopause in women and, in men, the transition from an active lifestyle in younger men to the more sedentary lifestyle typically seen in the 30s and older. He also indicated the mother’s nutritional status during pregnancy can affect the later metabolic profile of her offspring. He posited activity as a protective factor against obesity, and, in contrast, he maintained sitting and watching television for a long time is associated with an increased risk of obesity. Other behaviors which may lead to weight gain include not getting enough sleep, MATERNAL OBESITY AND MACROSOMIA 5 quitting smoking, eating a lot of fat and sugar, binge-eating, and overeating, according to Bray. Weight gain can also be associated with taking certain medications, such as antidepressants and certain drugs for diabetes, Bray affirmed. He indicated obesity can also occur with certain diseases, such as Cushing’s syndrome or polycystic ovary syndrome, and other factors, such as genetics, environment, and psychological conditions. Obesity places a person at risk for many negative health conditions. Perreault (2018), in a literature review, indicated many studies have shown an increased risk of mortality in the obese population. Those with obesity are more likely to develop a chronic disease, such as diabetes, cancer, coronary heart disease, or depression, Perreault expressed. She noted there is evidence at least 11 different types of cancers may have links with obesity. She also mentioned obese men and women may face discrimination and stigma in society, and the financial cost of obesity is high, related to such factors as increased medical expenses and less productivity. Commonly used criteria for defining macrosomia include a fetal mass no less than 4000 g or, alternatively, 4500 g (Gaudet, Ferraro, Wen, & Walker, 2014). Abramowicz and Anh (2018), in a literature review, identified risks macrosomia carries for both the mother and the fetus. Adverse maternal outcomes can include such things as postpartum hemorrhage, surgical delivery, or rupture of the uterus, they reported. They indicated the offspring may experience shoulder dystocia, low blood glucose levels at birth, obesity later in life, and more. If the infant’s birthweight is 5000 g or more, he is at increased risk of death, they warned. The issue is of special concern in certain impoverished nations, MATERNAL OBESITY AND MACROSOMIA 6 since, according to Abramowicz and Ahn, mothers in these places may be at risk of pregnancy prior to full development of the pelvis or of having a small pelvis due to undernutrition. They may or may not have access to operative delivery if needed (Abramowicz & Ahn, 2018). Current literature provides evidence for the association between maternal obesity and macrosomia of the newborn. Abramowicz and Ahn (2018) declared obesity to be a significant risk factor for macrosomia, probably contributing to its development more often than diabetes. Similarly, in their systematic review and meta-analysis, Gaudet et al. (2014) identified strong support for the link between obesity and macrosomia in the research up to that time. Along the same lines, in a large study which included 276, 436 births in 23 countries, Koyanagi et al. (2013) noted a significant connection between a high body mass index and macrosomia. Finally, Lutsiv, Mah, Beyene, and McDonald (2015) in a systematic review and meta-analysis found data to support the idea the risk of a large-for-gestational-age infant may be able to be stratified by increasing body mass index. If the evidence leans in support of an association between maternal body mass index and macrosomia, the next question is: What options do obese mothers have available to reduce their risk? While it is best for women to lose weight prior to becoming pregnant, due to safety concerns if weight is lost during gestation (Abramowicz & Ahn, 2018), for some women, this weight loss is not accomplished. They enter pregnancy obese, and it is too late for prevention. A systematic review of literature regarding interventions to reduce the risk of fetal macrosomia in the offspring of obese pregnant MATERNAL OBESITY AND MACROSOMIA 7 women may help to shed light on options available to these women for whom prevention is no longer a possibility.