Obesity is a multifactorial epidemic that Involves genetic, physiological, environmental and social
factors. The adipose tissue is an endocrine organ which regulates production of various hormones
involved on metabolism, homeostasis of individual and on same time, human reproduction.
Nutrition is on of the determinants for a good health status, physical and mental performance of
individual´s productivity. Obesity is the result of an imbalance of nutrition between intake and
energetic expenditure. This imbalance usually is a consequence of diets with high energy
(calories), high in carbohydrates and fats, and also low fiber. The prevalence of obesity increase
worldwide, including Mexico. It is characterized by an excess in the storage of lipids (fatS)
In reproductive matters, estrogene and progesterone, sex steroid produced during menstrual
cycle, plays a role as regulator in the reproductive process of women, also in the body´s energy
balance and are mediators in the dietary behavior. During the phases of menstrual cycle many
changes in the pattern of food consumption are recorded due the secretion of these hormones.
This pattern of consumption decrease during ovulating when estrogen levels are higher and
progesterone are lower, and increase after ovulation when levels of progesterone are
predominant.
Appetite control is a highly complex behaviour that is not exclusively regulated by turning on and
off signals originating from certain hormones. But by a much more complex system influenced by
the individual´s will. Among the appetite inhibiting signals we an mention the increase in
concentrations of leptin, insulin, glucose, peptid yy similar to glucagon peptid 1, oxintomoduline
and decrease of ghreline.
serotonin is known to be a neurotransmitter of a great importance in the biological system
related to eating. It is involved in the effects of the nutritional composition of the diet on brain
function and on the control of eating patterns as well as the urge to eat. Serotonin is involved in
both physical symptoms and changes of humor that occur during the menstrual cycle nd is
considered the mediating factor that relates appetite to humor. Premenstrual dysphoric disorder
is defined as a sever form of premenstrual syndrome . it has been suggested that craving for
certain food products such as carbohydrates are consumed to increase serotonin levels in the
brain and may even be an adaptive mechanism to compensate fo the relative lack of serotonin a
few days before the onset of menstrual flow. Eating carbohydrates is a form of self-medication to
improve mood.
Adverse effects of obesity
Obesity is known to carry various medical disorders throughout the life cycle of a person, it
damages health by increasing the risk of diabetes mellitus type 2. Dyslipidemia, high blood
pressure, insulin resistance, even cancer. It affects psychological development with various
personal and social repercussions, and it also has repercussions on female fertility.
There are several factors that determine weight gain in women: eating behavior, food
consumption patterns, genetic background, age, the side effects of medications such as hormonal
contraceptives and antidepressants, pregnancy, lactation, life style, etc
These factors alter the production of the hormones involved in reproductive cycle.. consequently
obesity increase risk of infertility, polycystic ovary, preeclampsia, eclampsia, diabetes and
obstetric difficulty at the delivery time. Obese women has three times more likely to infertility
decrease against no obese women.
The effects of obesity on fertility can be:
– At an endocrine level, where there is an effect on hormones production
– At ovary level, where there is an effect on the quality/quantity of ovules,embryos
produced.
– At uterus and endometrium level, where there is an effect on the implantation rates of the
embryo.
Effects of obesity on the ovary.
The function of the ovary must be evaluated, it is done through the production of ovules,
fertilization rates and embryonic quality.
Obese or overweight women have been observed to:
Require higher doses of medication, or lower respond to controlled ovarian stimulation
with gonadotropins.
Has a significant deterioration in embryonic quality, including a decreased of oocytes.
They have fewer mature oocytes
They present a lower quality of oocytes reflected in a lower fertilization rate.
They present fewer embryos transferred
They have lower pregnancy rates, as well as births from life products.
The endocrine functions of adipose tissue involve a few of hormonal signs which have control on
metabolism. To alter this signs is a consequence of obesity, has metabolism alter and organs
develop, affecting it self to reproduction organs.
Obesity affects the ovulation, mature of oocyte, grow of endometrium, uterine receptivity,
implantation, embryonic quality, and high probability of misscarriage.
Considering that obesity is increasing by the years in our country, it is of vital important a new
design of prevention and treatment to decrease the incidence of obese patients to fertility clinics.
The weigh lose in consequence of a healthy diet and life style must be a starting treatment for
overweight and obese women who goes to assisted reproduction clinics.