Obesity continues to be a major health risk in the US, caused by lifestyle, diet, metabolic dysfunction, and genetic and socioeconomic factors. The Centers for Disease Control has documented the dramatic rise in its prevalence for decades and reports that more than two in five adults have obesity. Its distribution is not equitable and, as of 2019, the cost of treatment of associated chronic health conditions is $179 billion annually.
Along with other known causative factors, weight gain associated with pregnancy has a unique impact on risk of obesity in the mother and on the next generation. Nearly half of US women begin the pregnancy overweight or obese, and a similar percentage exceed recommended weight gain in pregnancy.
These trends influence long-term risk of obesity. Further, maternal obesity may result in epigenetic changes in the fetus, resulting in predisposition to childhood obesity. Childhood obesity or overweight at 3 years of age leads to obesity or overweight in 90% of individuals in adolescence.
Long-term consequences of obesity are not yet fully defined, as was the case with the time lapse needed to identify all diseases related to smoking. Higher prevalence of comorbidities of pre-diabetes, Type 2 diabetes mellitus, hypertension, and cardiovascular disease with higher BMI have been documented. Increased incidence of at least 13 cancers has been linked to obesity, making the condition one of the leading preventable causes of malignancy.
The molecular pathways and interactions present in obesity are elegantly described by De Pergola and Silvestris. These interactions not only promote development of cancer and its growth, but also facilitate metastasis of the cells.
Early onset of some cancers in patients with obesity has been described. In the case of colorectal cancer, this has led to a change in recommendations for an earlier age for cancer screening. It is possible that similar findings for other malignancies more common in obesity may be exposed in the future, further enforcing the need to address the epidemic.
Obstetrical Conditions
Most pregnancies in women with obesity achieve successful outcome. However, there is an increased incidence of adverse clinical outcomes, affecting both mother and fetus (see Table 1).
Of note, transitioning from normal weight to overweight or obesity between pregnancies was associated with an increased risk of stillbirth and neonatal mortality, particularly with inter-pregnancy interval of less than 18 months. Mothers with obesity are less likely to initiate or maintain breastfeeding, potentially not availing their infants the protection of breast milk in development of obesity.
Gynecologic Conditions
Hormonal imbalance, leading to a relative estrogen excess, and inflammation associated with presence of excess adipose tissue, are the causative effect of majority of gynecologic conditions except for pelvic organ prolapse (POP) (see Table 2). POP results from herniation of the intraabdominal organs due to sustained increase in intraabdominal pressure.
Ovarian and uterine corpus malignancies have been linked to obesity. Screening tests that are cost-effective or applicable to the general population are not yet available, underscoring the need for primary prevention strategies.
Women with obesity are at risk for poor obstetrical outcomes and infer an increased risk of overweight or obesity on the next generation by epigenetic changes and lifestyle. These patients are also at risk of several gynecologic conditions, which may result in a more challenging surgical procedure, such as presence of large myomas or fibrosis related to endometriosis or an unexpected diagnosis of uterine or ovarian malignancy.
OB/GYNs and other healthcare providers can encourage weight loss through a personalized approach, which may include behavioral modification and psychological intervention, surgical intervention, or medical therapy guided by precision medicine to achieve optimal outcomes. Bariatric surgery has been shown to improve obstetrical outcomes and reduce the incidence of cancer and risk of cancer recurrence in cancer survivors.
Primary prevention must be the focus for the medical community. Adherence to national guidelines on healthy lifestyle and maintaining normal weight are associated with lower risk of many chronic conditions, including some obesity-related cancers, and mortality in cancer survivors.
