Unlike what has been in practice and long considered, a new clinical study says weight loss may not translate into better odds of getting pregnant. Published in the PLOS Medicine, the randomised study of 379 women with obesity and unexplained infertility found that intensive lifestyle changes did not result in better chances of pregnancy.
“We have known for decades that obese women often have difficulty getting pregnant,” noted researcher Daniel J Haisenleder, PhD, of the University of Virginia School of Medicine’s Center for Research in Reproduction. “For this reason, many physicians advise weight loss prior to conception. However, there are few studies that have addressed the issue comparing a healthy lifestyle — i.e., exercise — vs. exercise plus weight loss.”
The study divided participants in two groups. While half the women were on a diet using meal replacements, increased physical activity, and medications, other half simply increased their physical activity without trying for weight loss. Both the groups after completing the respective programs received three rounds of standard infertility treatments.
Notably, women in the weight loss program ended up losing seven per cent of their body weight, while participants in the exercise-only group maintained their weights.
The FIT-PLESE study then noted that eventually there was no significant difference between the two groups in terms of healthy birth frequency. In total, 23 of the 188 women who completed the 16-week intensive weight loss program ended up giving birth; among the 191 who completed the exercise-only program, 29 gave birth.
However, the intensive dieting program did offer various benefits like reduced metabolic syndrome that increases the chances of diabetes, stroke, and heart disease.
“Weight loss improved metabolic health in these subjects. Unfortunately, the changes seen did not improve fertility,” Haisenleder said in the study. “Infertility within this population remains an important health issue, and will require further studies to address the problem in the future.”
However, experts say that obesity and pregnancy chances are inversely related which means that more the weight, lesser the chances of conception and having a healthy baby.
If a person is overweight with a BMI (body mass index) of more than 25, weight loss will improve their chances of conception, even if they have (or do not have) Polycystic Ovary Syndrome (PCOS), said Dr Manjiri Mehta, consultant gynecologist, Hiranandani Hospital, Vashi – A Fortis network Hospital.
Dr Mehta is of the opinion that obesity affects fertility in both men and women. “Excessive weight affects fertility by changing the way the body stores female sex hormones. Fat cells convert a male hormone (androstenedione) to female hormone (estrone). This further has effect on brain centre that regulates ovarian and testicular hormones. While being healthy is super important, excessive weight loss with high-impact exercise and crash dieting may be counterproductive. Start by eating healthy and maintaining a healthy body weight so that you do not put undue stress on your body. Making these lifestyle changes will make a difference to your overall health, even if they don’t lead to weight loss,” she told indianexpress.com.
Dr Kinjal Shah, obstetrician and gynecologist, Bhatia Hospital Mumbai also stated, “definitely chances of fertility increases with weight loss.
It has been seen that 20 per cent of the PCOS women conceive with five per cent weight loss”. “This is because weight loss has significantly been associated with ovulation and has a benefit in women planning to conceive. Stress and sedentary lifestyle are the leading causes of uncertain fertility. Regular 45 minutes of exercise and healthy diet needs to be emphasised to women with fertility issues,” Dr Shah said.
According to Mehta, a study was done in 2014 that showed that even 10 per cent weight loss increased the chances of conception from 50 to 80 per cent. This means that a person has a greater chance of getting pregnant and having a healthy baby if they are close to a healthy weight. “If a person is overweight with a BMI of more than 25, weight loss will improve their chances of conception, even if they have (or do not have) PCOS,” said Mehta.
Obesity in women can also increase the risk of miscarriages and impair the outcomes of assisted reproductive procedures and pregnancy, asserted Dr Bhavini Shah Balakrishnan, consultant obstetrician and gynecologist, Masina Hospital, Mumbai. “Infants of diabetic mothers are also prone to various neonatal adverse outcomes, including metabolic and hematologic disorders, respiratory distress, cardiac disorders and neurologic impairment due to perinatal asphyxia and birth traumas,” said Dr Balakrishnan.
Stating that there has been a lot of controversy regarding the effect of weight on fertility and whether weight loss really helps conception, Dr Balakrishnan said that “despite all the argument, a healthy lifestyle which includes age and height appropriate weight” has been beneficial for a woman not just during the reproductive age group but also helps makes the peri-menopausal to menopause transition smooth.