Weight related comorbidities in pregnancies, the role of the obesity epidemic

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2021-1-HU01-KA220-HED-000027613 - COHRICE
Erasmus++


Syllabus

Weight related comorbidities in pregnancies, the role of the obesity epidemic

(Basic level)

Obesity is worldwide growing epidemic, affecting, both children and adults. A double fold has been observed in the incidence in more than 70 countries since 1980s, and the number of obese people in the globe tripled since 1975. The American Medical Association (AMA) declared obesity an epidemic, and the World Health Organization (WHO) called it the greatest health challenge of the 21st century. Obesity negatively impacts both mental and physical abilities and associating with comorbidities it increases the morbidity and the mortality of other conditions, like dyslipidaemia, type 2-diabetes, coronary heart diseases, ischemic stroke, gallbladder disease, osteoarthritis, sleep apnoe, pulmonary diseases, and malignancies (breast, endometrium, colon). Evaluating the body shape of each patient can enable us to assess the risk of occurrence in several diseases. Mostly, the impaired organ function is the result of organ enlargement, but accumulating fat tissue, for instance in case of the heart, or around the trachea plays important role in the pathogenesis. The aim of the current presentation is to shed light the special challenges and need of obese pregnant patients.

How can we determine obesity?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. (BMI) is a person’s weight in kilograms divided by the square of height in meters. BMI is an inexpensive and easy screening method for weight category—underweight, normal (healthy) weight, overweight, and obesity. BMI does not measure body fat directly, but BMI is moderately correlated with more direct measures of body fat. Furthermore, BMI appears to be as strongly correlated with various metabolic and disease outcome as are these more direct measures of body fatness.

What is the pathomechanism of excess weight gain?

The abundance of stored fat is required for survival during nutritionally deprived states such as starvation. In times of prolonged abundance of food, however, very efficient fat storage results in the excessive storage of fat, eventually resulting in obesity.8-10 It has been hypothesized that the storage of fatty acid as triacylglycerol within adipocytes protects against fatty acid toxicity; otherwise, free fatty acids would circulate freely in the vasculature and produce oxidative stress by disseminating throughout the body. however, the excessive storage that creates obesity eventually leads to the release of excessive fatty acids from enhanced lipolysis, which is stimulated by the enhanced sympathetic state existing in obesity. The release of these excessive free fatty acids then incites lipotoxicity, as lipids and their metabolites create oxidant stress to the endoplasmic reticulum and mitochondria. This affects adipose as well as nonadipose tissue, accounting for its pathophysiology in many organs, such as the liver and pancreas, and in the metabolic syndrome. The free fatty acids released from excessively stored triacylglycerol deposits also inhibit lipogenesis, preventing adequate clearance of serum triacylglycerol levels that contribute to hypertriglyceridemia. Release of free fatty acids by endothelial lipoprotein lipase from increased serum triglycerides within elevated β lipoproteins causes lipotoxicity that results in insulin-receptor dysfunction. The consequent insulin-resistant state creates hyperglycemia with compensated hepatic gluconeogenesis. The latter increases hepatic glucose production, further accentuating the hyperglycemia caused by insulin resistance. Free fatty acids also decrease utilization of insulin-stimulated muscle glucose, contributing further to hyperglycemia. Lipotoxicity from excessive free fatty acids also decreases secretion of pancreatic β-cell insulin, which eventually results in β-cell exhaustion [Richard N. Redinger, MD: The Pathophysiology of Obesity and Its Clinical Manifestations].

Obesity interacts with inherited factors and leads to hyperinsulinaemia. Thismetabolic abnormality is responsible for altered glucose metabolism, and predispose to type 2 diabetes, cardiovascular disease, dyslipidaemia and hypertension. When clustered together with other insulin-resistance related subclinical abnormalities, these are referred to metabolic syndrome [William’s Obstetrics, 23rd Edition-McGrow Hill, Chapter 43]. Complications and their possible cause are demonstrated in the presentation.

What will be the consequences of maternal obesity?

Obviously, all pregnant women gain weight, since near term the fetus weights 3.5 kg, the amniotic fluid weight 1.5 kg and the placenta weights 1 kg in average, not to mention the increased plasma volume and the accumulating water in the body due to progesterone effect. What is mor important, whether the women were considered to be obese before conception or gained excess weight during the 9 months of pregnancy. The ideal weight gain during pregnancy is determined by the Institute of Medicine (IOM) recommendation, in which height and race related recommendations apply, although classification is based on BMI values. 

If the mother was prepragncy obese, she should not start weight loss during the pregnancy, since catabolic state can harm the fetus, and disrupt fetal development. Although weight gain recommendations still apply for them, with extra precautions. For example, obesity is associated with increased incidence of neural-tube defects. therefore, early folic acid supply is necessary. 

What kind of complications can arise during pregnancy in obese women?

Adverse pregnancy events include:

1, Early pregnancy:

-Miscarriage

-Congenital anomalies e.g. neural tube defects

2, Late pregnancy:

-Preterm labour

-Hypertension/ pre-eclampsia

-Gestational diabetes

-Thrombo-embolism

3, Labour & Delivery

-Difficulty in fetal surveillance

-Prolonged labour/ dysfunctional labour

-Increased rate of instrumental deliveries

-Increased perineal trauma

-Increased incidence of shoulder dystocia

-Increased incidence of genital and urinary tract infections

-Instrumental deliveries

-Caesarean sections

-Primary postpartum haemorrhage

-Higher risk of anaesthetic complications

4, Postpartum:

-Increased risk of perineal / caesarean wound breakdown and infection

-Postpartum endometritis

-Secondary PPH

-Postpartum thrombophlebitis / thromboembolism

-Reduced breastfeeding

5, Fetus and neonate:

-Macrosomia

-Intrauterine Growth Restriction

-Intrauterine death

-Early neonatal death

-Hypoglycaemia

-Childhood adiposity

-Meconium aspiration

-Birth trauma

-Neural tube defects

-Cardiovascular anomalies

-Ano-rectal atresia

-Hydrocephaly

-Limb reduction anomalies

-Septal anomalies

Conclusions

Excessive weight has become one of the major health problems in affluent societies. Obesity is a condition that is habitually present, and its prevalence continued to increase since the 1960s. There are many obesity-related medical conditions, together they significantly reduce the life span of an individual. Obese women who became pregnant, and their fetuses, are predisposed to variety a serious pregnancy-related complications. This also includes increased risk of maternal mortality and morbidity; moreover recent studies highlight the that the offspring of obese mother also suffer long-term morbidity.


Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the Foundation for the Development of the Education System. Neither the European Union nor entity providing the grant can be held responsible for them.