Obesity has been recognized as disease since 1998 by the World Health Organization [1] because it is a condition that significantly increases morbidity and mortality from many different health issues like type 2 diabetes, hypertension, dyslipidemia, heart disease, obstructive sleep apnea, certain types of cancers, COVID-19, and many more. But there is little awareness when it comes to obesity and its effects on infertility among women and men.
It turns out, obesity increases the risk of developing infertility both in men and women, mostly because obesity produces a kind of chain reaction that affects many different factors that makes getting pregnant harder. In the case of women, pregnancy itself comes at a higher risk, for both mother and baby, when the expectant mother is obese or was before pregnancy.
In the United States, approximately 36% of adult males and 38% of adult females are obese according to data of 2016 [2]. And most women struggling with obesity are of child-bearing age. Just to put this into perspective: Nearly 20% of women have obesity at the time of conception and over 80% of the patients undergoing bariatric surgery are of child-bearing age [3].
Obesity has been strongly associated with a high difficulty to conceive, and to deliver full-term and normal weight babies. This is true for both women and men and is due to a diversity of reasons. Keep on reading to know more about how obesity can affect fertility, which are the main causes and which are the most effective treatments to overcome it.
Infertility
Infertility is defined by the failure to achieve a clinical pregnancy after 12 months or more of appropriate, timed unprotected intercourse [4]. The probability of any couple getting pregnant in a menstrual cycle, without using any contraception, is of 20 to 25%. But approximately 10 to 15% of couples usually experience delays in fertility. Obesity in itself has been associated with a longer time to pregnancy, almost double, in comparison with couples of normal weight [4].
Effects of obesity in male infertility
Obesity also affects male fertility. Among men, Body Mass Index (BMI) is associated with infertility with odds of 12%. The worst BMI range in terms of fertility for men is between 32 and 43 [5]. The reasons behind these trends can be any of the following:
- Evidence shows that obesity affects the quality of semen in men. More specifically, it affects sperm count. A study of 1,1558 Danish army men from showed that the prevalence of oligospermia (meaning, a sperm concentration that is lower than 20 million of sperms per milliliter) was higher in overweight and obese men than in normal weight controls (24.4% in comparison to 21.7%) [6].
- The sperm’s DNA fragmentation in men’s semen is also affected by obesity. Obesity leads to a higher sperm’s DNA fragmentation than in men with normal weight [5]. If the sperm’s DNA in a men’s semen is highly fragmented, this in turn reduces fertility and, at the same time, it increases the risk of pregnancy loss and conceiving babies with congenital health issues [7].
- Men with obesity also tend to have erectile dysfunction which is explained by decreased testosterone levels and elevated pro-inflammatory cytokines [5].
- Obesity usually leads to diminished general mobility and activity, which could translate to also having less sex.
- Men with obesity tend to have fat deposition in the abdomen and scrotum. This may increase local testicular temperature, which affects sperm generation and sperm count.
- Obesity also affects general testosterone and estrogen levels in men. It decreases testosterone levels and, at the same time, it increases estrogen levels; both these mechanisms affect sperm generation and, consequently, sperm count.
- Sleep apnea also may worsen the low serum testosterone levels in obese men [5].
Weight loss can improve men’s hormonal levels and their general mobility; it can also reduce the risk of erectile dysfunction. Weight loss is the best alternative for treating obesity-related infertility.
Effects of obesity in female infertility
Obesity affects female fertility in many ways. It impacts the whole process of trying to get pregnant, and it affects pregnancy itself and its outcomes.
- Women with obesity have a significantly higher risk of developing Polycystic Ovary Syndrome (POCS). PCOS is a endocrinopathy that affects between 5% and 10% of women of reproductive age [4]. This condition affects all kinds of women, but its prevalence is much higher in women struggling with obesity. Almost 50% of women dealing with obesity also have PCOS [3]. According to the American Society for Reproductive Medicine Criteria, a patient has PCOS when she has at least 2 of the following symptoms:
- Oligomenorrhea and/or anovulation. Oligomenorrhea is a condition in which menstrual periods are highly irregular, but mostly infrequent. Anovulation, on the other hand, happens when the ovaries don’t release an oocyte during the menstruation cycle. In other words, ovulation fails to take place. For some women, this might happen during a single and random cycle, and that’s no reason to worry. However, when this happens more frequently, it leads to chronic anovulation and infertility.
- Hyperandrogenism. This is a condition in which females experience high levels of androgens, such as testosterone. Hyperandrogenism manifests in symptoms like hair loss, excess growth of body or facial hair, or acne. It also leads to absence or lower frequency of menstrual cycles.
- Polycystic ovaries. This condition consists in the presence of more than 12 follicles in each ovary, or increased ovarian volume. Follicles are small collections of fluids, gathered together in the ovary. Not all PCOS patients have cysts in their ovaries, and many healthy women without PCOS do have small cysts in their ovaries.
PCOS is highly associated with infertility, both because of the anovulation and polycystic ovaries. Polycystic ovaries also increase the risk of miscarriage. However, the symptoms of PCOS are very responsive to weight changes; weight loss of as little as 5% can improve ovulatory dysfunction and restore fertility [4]
- Both obesity and PCOS are also associated with insulin resistance, which leads to increased production of insulin levels or hyperinsulinemia, and elevated levels of luteinizing hormone, due to excess of leptin. All these mechanisms affect general ovulation and fertility.
- Women with obesity have a harder time achieving in vitro fertilization and higher odds of losing their pregnancy [4]
- Pregnant women that struggle with obesity have double odds of having a cesarean delivery, in comparison with normal weight women [3].
- Obesity is also a significant risk factor for difficult intubation, aspiration, and maternal death during anesthesia [3].
- Women with obesity are at a higher risk of developing gestational diabetes, gestational hypertension and preeclampsia during pregnancy.
- Women with obesity also have a higher risk of having preterm labor.
- Pregnant women with obesity have a higher tendency of delivering newborns that weight more than 8 pounds.
- Babies born to mothers with obesity are also prone to risks, most of them related to obesity comorbidities, like hypertension and type 2 diabetes, once they grow up.
Treatments
Weight loss is the most effective way of treating obesity-related infertility, both in men in women. In the case of women, there is evidence for improved gestational age at delivery and reduced maternal morbidity when weight loss is achieved prior to pregnancy [4].
According to the American Society for Metabolic & Bariatric Surgery, and endorsed by the American College of Obstetricians and Gynecologists and the Obesity Society:
Bariatric surgery is effective in achieving significant and sustained weight loss in morbidly obese women and has been shown in case control studies to improve fertility [4]
Bariatric surgery can accomplish as much as 30% of total body weight loss in as soon as 6 months or one year, depending on the type of procedure. Examples of bariatric surgery are the gastric sleeve, gastric bypass, duodenal switch, intragastric balloon and gastric clip.
Surgical treatments for obesity significantly diminish the risks of developing gestational diabetes, hypertension, and pre-eclampsia. It also boots fertility, as it reduces PCOS rates and the need for fertility treatments. Bariatric surgeries also influence on better outcomes in artificial reproductive techniques, and a decrease in miscarriage rates. They even help with the regularization of the menstrual pattern.
However, it is very important to consider that pregnancy after bariatric surgery should be delayed to at least 1 year of post-operation, preferably 18 months or more. Currently, the Centers for Disease Control recommends the usage of contraception during the first 2 years of post-operation. This is where the safest period to seek pregnancy starts because, during the first year of post-operation, patients can expect to lose a big amount of weight at a rapid pace. Depending on the surgical procedure, a patient could lose as much as half his weight in sooner than a year. Both pregnancy and bariatric surgery have a tremendously strong effect on the body, its weight, its posture, the skin, and so much more. It’s best to wait for the body to stabilize from one major intervention, before heading on to a major event like pregnancy.
Bariatric surgery and motherhood are two events that can profoundly change your life. It is important that patients are educated in order to protect their health and the health of their baby. At LIMARP International Center of Excellence for Obesity, we can help you consider all your choices.
Contact us
If you are interested in knowing more about treatments for obesity and fertility, contact our clinic today. At LIMARP we offer integral bariatric programs that treat obesity from a multidisciplinary approach, involving medical, psychological, nutritional and behavioral interventions. Call today to schedule a free consultation. Our team of experts will be glad to help.
References
[1] F. Arrieta and J. Pedro-Botet, “Recognizing obesity as a disease: A true challenge,” Rev. Clin. Esp., May 2021, doi: 10.1016/j.rceng.2020.08.005.
[2] World Health Organization, Noncommunicable diseases country profiles 2018. World Health Organization, 2018. [Online]. Available: https://apps.who.int/iris/handle/10665/274512
[3] T. Mishra and S. N. Kothari, “Pregnancy Issues and Bariatric Surgery,” in The ASMBS Textook of Bariatric Surgery, 2nd ed., N. T. Nguyen, S. A. Brethauer, J. M. Morton, J. Ponce, and R. J. Rosenthal, Eds. Springer, 2020, pp. 545–552.
[4] M. A. Kominiarek, E. S. Jungheim, K. M. Hoeger, A. M. Rogers, S. Kahan, and J. J. Kim, “American Society for Metabolic and Bariatric Surgery position statement on the impact of obesity and obesity treatment on fertility and fertility therapy Endorsed by the American College of Obstetricians and Gynecologists and the Obesity Society,” Surg. Obes. Relat. Dis., vol. 13, no. 5, pp. 750–757, May 2017, doi: 10.1016/j.soard.2017.02.006.
[5] J. R. Loret de Mola, “Obesity and Its Relationship to Infertility in Men and Women,” Obstet. Gynecol. Clin. North Am., vol. 36, no. 2, pp. 333–346, Jun. 2009, doi: 10.1016/j.ogc.2009.03.002.
[6] T. K. Jensen et al., “Body mass index in relation to semen quality and reproductive hormones among 1,558 Danish men,” Fertil. Steril., vol. 82, no. 4, pp. 863–870, Oct. 2004, doi: 10.1016/j.fertnstert.2004.03.056.
[7] L. Simon, B. Emery, and D. T. Carrell, “Sperm DNA Fragmentation: Consequences for Reproduction,” in Genetic Damage in Human Spermatozoa, vol. 1166, E. Baldi and M. Muratori, Eds. Cham: Springer International Publishing, 2019, pp. 87–105. doi: 10.1007/978-3-030-21664-1_6.
