This study was conducted at the Lahore Institute of Fertility and Endocrinology, and we compared the incidence of infertility in different groups divided according to their BMI; each of these three groups further underwent investigations, including hormone level assay and transvaginal ultrasonography, to assess their antral follicle count (AFC) and thus their degree of infertility. Two hundred twenty-two women were selected based on their subfertility. Patients with PCOS and endometriosis were excluded from this study. Most women belong to our research's 26-30 kg/m2 category.
Age is one of the most critical factors that affect embryo quality, and in older patients is probably the main factor that determines the success rate in IVF. 13–15 In the present study, the mean age was 31 ± 3.91 years in obese women and 33 ± 4.29 years in overweight women.
This study revealed no significant association between the type of infertility and increases in body mass index. In contrast, theoretically, any extremes of BMI should have had adverse effects on the fertility of the women.16–23 Similarly, the duration of infertility was also insignificant, with the mean duration for all three BMI groups to be five years.
For further analysis, we then resorted to the hormone level assay of the patients to determine the basis of their infertility and to see if there was any relation to the BMI. The baseline levels of 5 hormones, namely FSH, TSH, AMH, Prolactin, and E2, were measured. Still, according to our results, there were no significant changes in these hormones with increasing body mass. FSH and TSH levels both had minor increases with increases in BMI. In contrast, AMH levels, often taken as an indicator for ovarian reserve in female patients, had no significant changes between patients with a healthy BMI of 21-25 kg/m² and patients with a BMI exceeding 30 kg/m². This indicates that extremes of body mass do not affect the number or quality of the eggs.
Similarly, there were no significant differences in E2 levels between different body mass groups, but prolactin levels were slightly decreased in patients with a BMI exceeding 30 kg/m². However, as these values still fall within the normal range of prolactin hormone during pregnancy, they are not considered significant.
In obese women, infertile women, anovulation has been the primary cause of infertility. 25 To assess the antral follicle count, transvaginal ultrasonography was also conducted on all patients. Antral follicle counts in all three groups of BMI have no significant difference between each group. In group A the number of AFC was higher than the other two groups. A study shows that BMI and AFC both are inversely related; by increasing the body mass index (BMI), Ovarian volume was decreased. 26
The requirements of total FSH dose for stimulation increased with increasing the BMI, long period of ovarian stimulation and the chance of follicles development was lower in those patients who were obese, which leads to fewer oocytes.27–28 Our study shows the same results. Another study suggested that an Inadequate FSH dose may prevent the patient from hyperstimulation. Later on, it concluded that increasing the FSH dose may lead to better oocytes yield and pregnancy rate. 29
Different studies showed that obesity correlates with severe reproductive outcomes, including anovulation, infertility, and poor response to ART procedures.30–31 Many factors like hormonal profile, endometrial thickness, oocyte quality and number, and embryo transfer do not affect obesity. Another study described that endometrial thickness had a significant role in implantation and pregnancy outcomes in obese women. The pregnancy rate may be increased if endometrium thickness was average and lower the miscarriage rates and pregnancy-related problems.32 Our results show insignificant association in endometrial thickness regarding BMI, and the number of follicles counted during decision day ranged from 13-15 in all three groups, which are within normal ranges.
According to a study, there was a significant association between obese women and their embryo quality. Compared to women with normal BMI, the embryo quality was poor in obese patients. Basically, in IVF cycles, the primary outcome was not the embryo quality. Only a single study showed the oocyte grading system to check the oocyte quality. 17 It was expected that an increase in body mass would have affected the quality of the embryo themselves and contributed to an adverse environment for pregnancy. However, our study indicates no significant association between a higher BMI and the number or quality of oocytes.
Sperm quality was also another factor that is responsible for embryo quality. Nevertheless, another study showed no association between different groups of BMI patients with any malefactor, and only 13% of patients present who had ICSI procedure; according to previous studies, the embryo structure was also dependent on oocyte quality and blastomere, cleavage rate was restricted to the effect of sperm. 33 However, obesity affects the pregnancy by creating an adverse environment for the fetus, leading to low birth weight and other pregnancy complications. Hence all obese patients are counseled to reduce their body weight and maintain a healthy lifestyle to minimize complications.