Are obese women more prone to infertility? An expert tells you about it

As per the World Health Organisation (WHO) and other national and international bodies, obesity is considered a chronic disorder. If your body mass index (BMI) is 25 kg/m2 or greater, you fall under the overweight category, and greater than 30 is termed obesity.

The incidence of obesity in India is 40 per cent; it is the highest in the southern part of the country and lowest in the east. It is higher among women than men, and more commonly seen in urban settings, as compared to rural. Furthermore, it is observed more among those who are educated, ageing, and in those who lead a sedentary lifestyle. It can also be caused due to a lack of physical activity, as well as disturbed eating patterns and habits. Stress also contributes to obesity.

Excess weight leads to multiple adverse health consequences and has a great impact on fertility. The process is complex and multifactorial.

Obesity and fertility

Obesity can lead to:

• Irregular menses
• Impaired ovarian follicular development
• Reduced qualitative and quantitative egg development
• Fertilization errors
• Compromised embryo growth and impaired implantation
• Increased risk of miscarriages
• Maternal and fetal complications during pregnancy

The greater the excess weight and abdominal fat, the greater the difficulty in conceiving. The leptin hormone produced by fat cells is higher in obese women, and raised leptin levels are associated with reduced fertility. Women with a BMI of more than 27 face three times more difficulty in conceiving than other women.

The more abdominal fat, the higher will be the insulin resistance. This means the body will produce more insulin to keep the blood sugar levels normal. High insulin resistance and obesity may cause an increase in the androgen hormone.

Here are some of the problems that can arise:

1. Disturbing the rhythm of the menstrual cycle
In such cases, cycles can be short. Plus, there can be scanty flow, delayed cycles, heavy flow, and irregular periods. Obesity can also result in amenorrhea, which is the absence of menstrual bleeding.

2. Aggravates the problem of PCOD
Polycystic ovary disorder (PCOD) is a multiple hormonal disorder, in which the cycles are irregular, egg formation becomes erratic, and conception becomes difficult. Obesity increases insulin resistance and further aggravates hormonal disturbance.

3. Increases the occurrence of ovulation disorder
Folliculogenesis or egg formation also gets disturbed due to hormonal disturbance, thus reducing the chances of implantation and maintenance of pregnancy. It also affects the quality of eggs released, thereby reducing the chances of fertilization.

4. Increases the risk of miscarriages
There is a high risk of miscarriage associated with obesity, due to high insulin resistance, hyperandrogenic state, and lack of progesterone hormone.

5. Reduces ART outcome
It also reduces the outcome of Assisted Reproductive Technologies (ART) and increases maternal and fetal complications. It has a detrimental effect on the stimulation of ovaries to produce multiple eggs. Obese women require higher doses of hormones and more days for stimulation, as compared to other women; the quality of eggs also is compromised. It also affects the development of the endometrium and its receptivity. The chances of having a live birth are lower for overweight women, as compared to women with normal BMI.

How can the issue be tackled?

Lifestyle modification is extremely important. Weight loss of 7% of body weight, regular exercise of moderate intensity for 60 minutes at least 5 days per week (on average), and a healthy, well-balanced diet are recommended to improve fertility.