Author:

Abstract:

Obesity is considered to be one of the greatest health care challenges of the current era, with an ever growing incidence worldwide. As it affects the function of various organs, it has widespread consequences for overall health. Obesity is also known to affect pregnancy as it increases the risk of a multitude of adverse outcomes. As such treating obesity prior to conception is advised. Treating obesity is difficult, as the body aims to achieve a set point of weight defined by genetical, biological and environmental factors. In most patients, this set point aims for a weight that is higher than medically recommended, as a thrifty metabolism was advantageous throughout human evolution. As such, lifestyle interventions alone are ill suited to counteract the natural drive of the human body towards weight gain. One treatment option that has been proven effective and long term is bariatric surgery. These types of surgery improve the metabolic hormonal profile, thus lowering the bodies set point of fat mass and achieving a healthier weight through the use of the bodies own protective measurements against overweight. These effects do not only lower weight, but also improve the prevalence and incidence of obesity related comorbidities. As 80% of patients who undergo bariatric surgery are women, many of whom are of reproductive age, pregnancies after bariatric surgery are also becoming increasingly common. Due to the reduced incidence of obesity related adverse outcomes, pregnancies are generally healthier. However, some adverse effects caused by the surgery itself have been noted, such as micronutrient deficiencies and fetal growth restriction. Therefore, evidence based guidelines are required to optimize the care for this growing population of patients. The aim of this doctoral thesis was to provide these guidelines, and to improve overall evidence on common complications. We reported risk factors related to fetal growth restriction after bariatric surgery. We noted that inadequate gestational weight gain was more common in pregnancies affected by fetal growth restriction. Furthermore, mothers of babies with fetal growth restriction lost more weight themselves after surgery. Nutritional advice following surgery seemed to be protective against fetal growth restriction. Fetal growth velocity is impaired from 30w of gestation onwards in pregnancies affected by fetal growth restriction. As fetal adipose subcutaneous tissue thickness was lower in small babies, we suspect fetal malnutrition or frequent maternal hypoglaecemia to be a causal factor, rather than placental disfunction. Furthermore we provided more background on micronutrients during pregnancies after bariatric surgery and how they can affect fetal and maternal outcomes. We performed a review that comprehensively summarizes the most described vitamins and minerals during pregnancy. This work culminated in the development of a multivitamin, tailored to the specific needs of this population. We delved deeper into gestational weight gain. We found that compliance to international guidelines was low in our population of patients. Insufficient gestational weight gain was associated with fetal growth restriction, whilst excessive weight gain increased the risk for weight retention in the postpartum and could precipitate weight regain after surgery. Finally, our word culminated in a guideline by an international group of experts who provided evidence-based recommendations on the nutritional management and perinatal care of pregnant women after bariatric surgery. We concluded that women of reproductive age with a history of bariatric surgery should receive specialized care regarding their reproductive health.