Body mass index is not a common term for everyone, but being underweight, overweight, or obese is common. Most people don’t even know how BMI affects male and female reproductive health. Infertility is already becoming a big concern, and BMI challenges in people are leading to its worst phase. Fertility and weight have a direct impact on everyone, and everyone should know this.
Through this article, Aveya Fertility Centre aims to raise awareness related to the impact of BMI on male and female reproductive health.
What BMI?
Body mass index is defined as the ratio of height to weight. It helps in measuring the level of fat deposition in different parts of the body. According to the CDC, a BMI (body mass index) between 18 and 25 is considered normal weight, more than 25 is overweight, and more than 30 is a sign of obesity. This is for both men and women. One thing both should keep in mind is that a BMI less than 18 is also a sign of a health issue, as underweight can also negatively impact fertility and lead to reproductive health complications like infertility.
Why does PI (Ponderal Index) matter in fertility?
PI (ponderal index) is used by doctors to analyze he impaired fetal growth, assess neonatal malnutrition, and study their physical growth. Elevated PI highly influences the endocrine system by disturbing its balance, altering ovarian function, hormonal imbalance, and reducing the chances of providing outcomes in natural conception and fertility treatments. It starts with disturbed ovulation, and by the time, the quality of eggs decreases. Most obese women face these challenges due to the altered inflammatory environment. While in men, high PI reduced libido, erectile dysfunction, higher rate of DNA fragmentation, increased reactive oxygen species (ROS) damages sperm DNA, develops abnormal morphology, and increases the risk of infertility.
Link between Fertility and Weight
Female
- Decreased Estrogen- Low BMI
Estrogen is produced by adipose tissue or body fat. Women with low BMI store less fat, which is not enough to produce an adequate amount of estrogen. Also, hypothalamic amenorrhea is a hormone that regulates the reproductive level, and this disrupted hormonal balance decreases estrogen. Ovaries prevent themselves from releasing eggs (ovulation).
Not only this, Follicle Stimulating Hormone (FSH) is hindered because of the low body weight, which creates issues in follicle growth. Although low estrogen does not always result in endometriosis, it does play a huge role in this health complication, which creates inflammation, scar tissue, and blocks the fallopian tubes, preventing ovulation and interfering with embryo implantation.
- Obesity- High BMI
Obesity significantly impairs female fertility through hormonal, metabolic, and inflammatory pathways. The abnormal fat in the body elevates the production of estrogen from the fat tissue, which is toxic to the endocrine system. Due to the hormonal imbalance, there are disturbed menstrual cycles, anovulation (lack of ovulation), and egg quality. Based on the analysis published in Current Obesity Reports, pregnancy chances can be lowered by 4% if the BMI of the woman is over 29.
Obesity also disrupts endometrial receptivity, and it increases the difficulty of embryo implantation. Pregnancy obesity increases the risk of gestational diabetes, preeclampsia, and cesarean section and leads to neonatal complications like macrosomia and NICU admission.
- PCOS- High fat deposition
Obesity is directly linked to Polycystic Ovary Syndrome (PCOS), the principal cause of infertility. It can worsen the insulin resistance and hyperandrogenism because of the high fat accumulation. About 60% of women with PCOS are overweight, and insulin resistance, common with obesity, aggravates ovulatory dysfunction. Overweight women require more shots of fertility medication but produce fewer, inferior eggs, doubling the likelihood of treatment failure and miscarriage.
Male
- High BMI- Alter hormones
Obesity disables the fertility of men by altering hormone levels, deteriorating the quality of sperm, and increasing oxidative stress. Excess fat leads to reduced levels of testosterone and increased estrogen (just opposite to what happens to women), interfering with the hypothalamic-pituitary-gonadal axis. This hormonal dysfunction reduces sexual desire, destroys spermatogenesis, and induces erectile dysfunction.
- High Fat- Increase scrotum temperature
Men with high fat deposition or obesity possess lower sperm count, poor motility, and abnormal morphology. All these changes are due to high scrotal temperature resulting from fat accumulation and systemic inflammation that results in damage to sperm DNA. It creates fatty tissue, inhibiting the scrotum’s ability, impairing heat dissipation, and leading to a chronic inflammatory state.
- High BMI- Issue with metabolic syndrome
Obesity is also associated with metabolic syndrome, including insulin resistance, hypertension, and dyslipidemia, all of which have negative impacts on reproductive health. Studies revealed that paternal obesity may have effects on offspring’s health through sperm DNA methylation changes, which may lead to intergenerational metabolic disease.
- Low BMI- Oxidative stress
Men with low body fat might have less antioxidant protection, which makes sperm cells vulnerable to oxidative damage. Due to this, leptin levels drop, which impairs the mitochondrial function in sperm, decreases the protective antioxidant enzymes in the testicles, and makes sperm DNA vulnerable to damage.
Passes on to the next generation
You might not know about this, but complication generation due to high or low body mass index in men and women can pass the challenges to their children through epigenetic modification. These changes affect gene expression without altering DNA sequences.
While in men, it affects sperm DNA methylation, small RNA profile, and histone modification, altering embryonic development and increasing the low birth rate, impaired glucose metabolism, and reduced fertility in male offspring.
Also, children born with abnormal BMI are likely to experience an altered reproductive hormone profile, a higher risk of obesity, and delayed puberty.
Slightest enhancements can bring improvement.
Even a 5–10% weight loss before fertility treatment can significantly improve prognosis, enhancing ovulation, egg quality, and implantation rates. Preconception counselling and individualized weight control recommendations are advised by gynecologists for minimizing these risks. Also, this can be done through diet management, exercise, and managing stress.
Gynecologists and andrologists point out that lifestyle interventions such as weight loss, exercise, and dietary changes restore endocrine balance and improve sperm parameters. In assisted reproduction technology (ART), obese men are often found to have lower rates of success, and hence, weight regulation prior to therapy is important.
Weight management is crucial: Aveya Fertility Centre can help.
In short, a healthy lifestyle and adding a proper regime in your daily activities can not just help you to have a healthy reproductive system, but also good overall health. If you are struggling with managing weight, it is best to get yourself checked and take guidance from a professional. Aveya Fertility Centre specializes in helping people overcome challenges that impact their fertility.
Book your appointment to get a healthy life.
