Uncovering the effects of obesity on IVF
The impacts of obesity and overweight are manifest in nearly every aspect of female reproductive life from puberty through to pregnancy. Dr. Kaberi Banerjee, MD Advance Fertility & IVF Centre shares how obesity has been associated with fertility.
In the new age of body positivity and self-acceptance, we often forget there is an invisible line between being fat and being healthy. People take their increasing weight as an opportunity to become social media influencers and normalize being fat by showcasing their achievements in life and telling everyone that size does not matter and you can still achieve a lot in life.
However, they fail to tell their audience about the problems that come along the way when we say the word ‘obesity.
Before going any further, let us understand obesity and how it impacts health and other things in life.
According to World Health Organization (WHO), obesity is an abnormal or excessive fat accumulation in the body that poses risks to one’s health.
Facts and data about obesity
- The data of obese people has been tripled since 1975.
- In 2016, research showed that about 650 million people were obese.
- Overweight and obesity is the bigger cause of death than underweight.
- In 2020 itself, about 39 million children below 5 were categorized as overweight.
What is BMI and its role in obesity?
Body mass index (BMI) is the calculation for weight-for-height that is used to categorize overweight and obesity in adults. You can calculate BMI by dividing kgs into the square of height in meters (kg/m2).
Adults: In adults, if the BMI is greater than or equal to 25, they are considered overweight. For obesity, the BMI is more than or equal to 30.
For children, age needs to be taken into account when defining overweight and obesity.
Obesity and issues in reproduction
A balance in hormones controls the period cycle in women. A hormone called leptin is higher in overweight and obese women. Excessive leptin can affect fertility. More the weight in excess, the more the problems in the fertility process.
A study revealed that obese women had more problems conceiving in a year of stopping contraception than normal-weight women.
Women with more weight conceive. However, the egg’s quality is reduced. Women with BMI above 29 have a low chance of getting pregnant by 4%. For women with a BMI of 35, the possibility of conceiving within a year is 26% less. For women with a BMI of 40, their possibility is 43% less.
Obesity and IVF
IVF makes the live birth of infants happen. Though, it depends on various factors. IVF is dependent on the response of the treatment by the ovaries in the female body. Some studies have quoted poor response in the ovaries in as much as 20% of the patients.
According to some studies, responses of ovaries to gonadotropins are unfavourable and obese women with IVF need a much higher dose of gonadototrophin to achieve the same response as a non-obese woman.
Role of obesity in IVF
Obesity is known to decrease natural fecundity, impact ovulation rate, and increase miscarriage rates. Also, pregnancy complications increase, like gestational diabetes, preeclampsia, gestational hypertension, fetal macrosomia, and postpartum haemorrhage. With the increase in the rates of obesity, more women are opting for assisted reproduction technology (ART). Let us understand what role does obesity has on in vitro fertilization (IVF) treatments.
There are different notions for more BMI/overweight when it comes to ART. In some studies, the impact of bigger BMI is worse on IVF. In others, the effect has been negative. Some studies suggest that when overweight women choose IVF to conceive, the live birth chances are lower. In most cases, the live birth rate with IVF lowers by 9% in overweight women and by 20% in obese women.
The findings of the research suggest that the sum of gonadotropin dose (p <0.001) and stimulation duration (p = 0.008) were high in the obese group in comparison to people with normal BMI. According to health experts, a higher dose of gonadotropins and longer stimulation durations, are needed in obese women as far as conceiving is concerned.
Another medical study observed that more obese women seek artificial reproductory processes than the ones with normal BMI. Even the duration to attain desired results can delay, and the success rate decreases with the higher BMI. Some findings suggest that the risk of infertility is three times in women with obesity than women with normal BMI.
Whether natural or assisted pregnancy, the weight might hamper the process. Around 5% pregnancy rate reduces with per BMI unit.
Paternal obesity and fertility
Some studies have also observed the impact of fathers’ obesity on reproductive outcomes. According to such studies, men with obesity are also likely to face infertility issues and have less possibility of live birth when using assisted reproduction technology (ART) like IVF.
Not only does obesity lower sperm quality, but the physical molecular structure of the sperm cells also may change.
Thus, obesity in women can hamper their reproduction process. Not only pregnancy but menstrual problems also begin with obesity. Other medical conditions l
ike ovarian follicular development, fertilization, qualitative and quantitative development of the oocyte, implantation, and embryo development also come with obesity. Obesity is associated with Polycystic Ovarian Syndrome. Pregnancy complications like miscarriage, high blood pressure, diabetes, preterm delivery, anaesthesia complications and increased caesarean section rates increase with Obesity.
The best way for obese or overweight females to conceive is to lose weight before planning a child. Therefore, one should always go by the rules and start working on their body. Eat healthily, follow an exercise routine, and maintain a healthy lifestyle. Though weight loss is the best way to attain desired results, you should not delay the artificial treatment as with increasing age, the egg quality worsens and complications increase.