Overweight and fertility are more closely related than one might initially think. Nevertheless, many patients who visit a reproductive clinic for the first time are unaware of its real impact on the present or future possibilities of creating descendants.
“In the first place one must realise that when we talk about weight as such, we are really referring to obesity. Which in itself should really be considered as a general illness, and as it affects all the organs and tissues of our body, it’s quite clear that the reproductive system is also hugely affected, and therefore the spermatozoids, ovules, embryos and the uterine receptiveness also suffer this deterioration”, as doctor Adolfo de Prados, doctor in UR IMED Valencia and university professor of Human Reproduction, explains to us. There are multiple studies published which show endocrinal and metabolic alterations generated by excess weight which negatively influence the reproductive functions: from hyperinsullinism, hyperandrogenism, to an absence of ovulation making way towards a proinflammatory state.” Obese women are going to have fewer possibilities of having a live healthy newborn. In the first place, because they will have less possibilities of actually becoming pregnant, whether it’s naturally or with assisted reproductive techniques, with which they will have poorer results, and in addition there is an elevated risk of abortion and ectopic pregnancy, as with the associated maternal and foetal complications, above all during the second and third terms of gestation”, de Prados points out.
Diet and fertility in women
Infertility affects approximately 15% of women in their reproductive age. Feminine obesity has been related to a heightened risk of not becoming a mother by three times and by four times of never actually becoming pregnant. This problem increases as the Body Mass Index (BMI) increases. With a BMI of over 29kg/m², for each unit of increase in the BMI this produces a decrease of 5% in the rate of cumulative pregnancy during the whole year, a similar effect to the passing of age.
Given that obese women have an increased risk of infertility, they are more inclined to opt for Assisted Reproductive Techniques ( ART ). The first problem they are likely to encounter is a limited ovarian response to the treatments, with a greater rate of cancellation and a greater follicular asynchronous. In addition the results are also worse because the number of oocytes obtained as well as their quality and maturity is lower, which gives rise to a poorer embryonic quality with less possibility of embryonic transfer.
Neither must we forget the illnesses which are directly related to being overweight and which affect reproductive health. Among which we find arterial hypertension, hyperlipidemia, cardiovascular disease, ovulatory alterations, diabetes type II, arthrosis, gout, thrombophlebitis, erectile dysfunction, and psychiatric pathologies as well as different types of cancer.
Pregnancy and weight loss
This heading rings true to such an extent that weight loss is the most important measure to improve or even to restore fertility in obese women, “Just a loss > 5% in body weight can significantly improve the reproductive situation of the patient”, explains Prados. And according to this member of the team located at our reproductive clinics in Spain, a low calorie diet should be implemented, based on a daily calorie restriction of between 500-1000kcal, with respect to the habitual intake. In addition it should be low in fats ( 30% of the total intake ), and as such a maximum of 10% of the energy should originate from saturated fats. “Obviously, the diet should be adapted to suit the patients preferences and feeding patterns, which means that the nutritionist is the most appropriate person to determine the optimum diet”, indicates the doctor.
Excess weight and male fertility
The relationship between weight and fertility not only affects women. It also affects men and in quite an important way. “Several studies carried out in nucleus of young fertile males have detected an important alteration in the masculine hormonal pattern of obese males. A significant reduction in some spermatozoid parameters have also been observed such as the spermatic concentration and the total sperm count, and a tendency to present a weaker morphology as well as a poorer motility. Recent studies have not shown a clear correlation between the male BMI and the classic parameters of the seminogram, but what has been confirmed is that the reproductive results are worse”.concludes De Prados.
Remember:
– With a BMI over 29kg/m², for every unit of increase in the BMI a reduction of 5% in the rate of cumulative pregnancy is produced throughout the year, an effect similar to that of aging.
– The relationship between weight and fertility not only affects women. It also affects men and in quite a considerable way.
– Neither must be forget the illnesses directly related to being overweight which also affect reproductive health.
