High body mass index and altered androgen hormones are the disruptors of fertility among women undergoing ART

Background: The body mass index (BMI) affects reproduction and pregnancy outcomes. Infertility is dened as the inability to conceive despite having frequent, unprotected sex for at least one year. The inability to have children affects men and women across the globe. Methods: It was a retrospective study on couples coming for treatment of subfertility in Lahore Institute of Fertility and Endocrinology (LIFE). The institutional ethical review committee approved. Patients are divided into three groups, normal weight (BMI ≤ 25kg/m²), overweight (26-30 kg/m²), and obese (>30 kg/m²). Data were collected from July 2017 to May 2018. The number of infertile women who underwent assisted fertilization at LIFE was 222. Results: Two hundred and twenty-two sub-fertile patients were selected. Their ages were between 25-36 years. The mean age was 31 ± 3.91 years. There was a signicant relationship between the number of follicles and BMI (p-value=0.03). Outcome parameters are signicantly correlated with all groups of BMI. Embryo transfer is insignicantly correlated with BMI. (p-value = 0.07) Conclusion: According to this study, obesity is associated with poor embryos in obese women with more than 30 BMI. Furthermore, women who were obese might need a higher dose of FSH, and the live birth rate is higher in women with normal BMI.


Introduction
Over the last decade, obesity has turned into one of the leading health challenges of the developed world.
Extremes of body mass have proven to have widespread adverse effects on the female reproductive cycle, especially among patients using assisted reproductive technology. 1 In clinical practice, excessive body mass is measured using the body mass index (BMI), determined by dividing the weight in kilograms by the square of the height in meters. The NICE guidelines divides BMI into the following categories: Healthy (18.5-24.9 kg/m 2 ), Overweight (25.0-29.9 kg/m 2 ) and Obese (30.0-39.9 kg/m 2 ). 2 According to WHO, approximately 26% of women in Pakistan were obese in past years, which gradually increased to 38%. This increase in obesity has led to many health problems that develop among these women and burden the healthcare system. Obesity has been correlated with diminished chances of both natural and assisted contraception and contributes to increased rates of miscarriages, congenital anomalies, and gestational congenital disabilities like spinal cord defects and congenital heart anomalies. 3 Maternal obesity is also directly related to increased maternal complications such as gestational diabetes, pregnancy-induced hypertension, and pre-eclampsia. Moreover, stillbirth, premature labor, assisted birth, caesarian delivery, and maternal mortality are often linked with obesity. 3 Extremes of BMI result in an adverse intrauterine environment for the developing fetus. Previous studies have directly linked low birth weight (an indicator of intrauterine growth) and maternal obesity, resulting in signi cantly higher prenatal and perinatal mortality rates.
Female fertility primarily depends on the ovarian reserve, which refers to the reproductive potential left within the woman's two ovaries based on the number and quality of eggs. While there is a clear link between body mass and adverse reproductive effects involving menstruation disturbance and anovulation, 4 there is no evidence that BMI affects the number or quality of embryos. The uterus may be altered acceptance due to decreased endometrial receptivity, resulting in reduced pregnancy rates. [5][6][7][8][9] However, recent studies had indicated that uterine receptivity might be unimpaired in women with increased BMI when hormonal support and embryo quality were standardized. 10 According to NICE guidelines published in 2004 regarding the assessment and treatment of infertility, it is recommended that women with a BMI of more than 29 kg/m² have a much higher risk to conceive, and if not ovulating, should be informed that losing weight is likely to increase their chances of conception. 2 Some studies revealed an adverse effect of obesity on ART, and others suggest similar outcomes in obese and non-obese women. 11 A comprehensive retrospective study of 5019 cycles of in-vitro fertilization revealed that obesity was associated with a longer duration and increased amounts of gonadotrophin stimulation, an increased frequency of cycle cancellation for an inadequate response, and lower oocyte yield. 12 Another study conducted in 2010 indicated that increases in BMI were associated with reduced rates of clinical intrauterine gestation. 12 The objective of this study was to determine the association between obesity and the quality of embryos.
Other studies with varying results show no signi cant adverse response of obesity on ovarian response during controlled ovarian stimulation in ART cycles. Still, they offer a substantial effect on the quality of oocytes.
This study aims to examine the effect of BMI on ovarian stimulation, oocyte quality, fertilization, and clinical pregnancy outcomes in IVF/ICSI.

Methods And Materials
Study design: It was a retrospective study on couples coming for treatment of subfertility in Lahore Institute of Fertility and Endocrinology (LIFE). An institutional ethical review committee approved this study of Hameed Latif Hospital.
Inclusion criteria: The women included in this study were aged between 25-36 years, with tubal factors and unexplained factors as a cause of subfertility.
Exclusion criteria: Women with severe PCO and endometriosis will be excluded from this study. Women with any pelvic pathology were also excluded. Couples with azoospermia and severe oligoasthenospermia were also excluded.
Preliminary assessment: Preliminary examination was done, including hormonal pro le, i.e., FSH (rFSH), prolactin, and E2 (Estradiol-E2) on cycle day 2. Moreover, thyroid pro le T3, T4, TSH, and screening tests including hepatitis pro le, CBC, and blood sugar were done. In addition, a transvaginal scan (EUB 5500 Hitachi) was done to exclude pelvic pathology. Moreover, antral follicle count and uterine status, endometrial thickness was also measured. Recombinant HCG (IVF-C Galaxy) was given at a speci c follicular size (18-20mm), and egg retrieval in dosage 5000 or 10000 IU was performed 36 hours later. In addition, embryo transfer was done 3-5 days later.
Data Analysis: SPSS 25.0 will be used for data analysis; descriptive analysis will be done, i.e., frequencies and percentages of categorical variables, mean standard deviation, and variance for numerical variables. The chi-square test will check the association between BMI and ovarian hyper-stimulation. The level of signi cance will be 0.05 or 5%.

Results
Two hundred and twenty-two subfertile patients were selected. Their ages were between 25-36 years. The mean age was 31 ± 3.91 years.
The detailed characteristics of subfertile patients are given in Table 1. Regarding antral follicle count (AFC), 60.3% of patients of group A had less than eight antral follicles as compared to group B and C (p-value=0.13). 75% of patients in group A had 9-12 antral follicle count as compared to group B (20.2%) and group C (4.8%). 62.2% of patients with more than 13 antral follicular count were in group A as compared to group B and C (26.7%, 11.1%) respectively.
As given in Table 2, the mean number of days of stimulation was 12 in group A, 13 in group B, and 15 in group C. Number of days of stimulation was not signi cantly different in various groups of BMI. (p-value = 0.31). As for the starting dose of stimulatory drugs, 150IU was the mean starting dose in group A, 200IU in group B, and 150IU in group C. Group C has a higher stimulatory drug dose than group A and B. The endometrial thickness on decision day in groups A, B, and C were not signi cantly different.
Regarding endometrial thickness, the mean thickness was 10.24 in group A, 10 in group B, and 10.5 in group C (p=0.63).
The mean number of follicles in group A was 14, in group B was 15, and in the group, C was 13. There was a signi cant relationship between the number of follicles and BMI (p-value=0.03).
In Table 3, the number of follicles, eggs retrieved, fertilized eggs, matured embryos, and cleavage rate decreases as BMI increases. Outcome parameters are signi cantly correlated with all groups of BMI.

Discussion
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][14][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 signi cant 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][17][18][19][20][21][22][23] Similarly, the duration of infertility was also insigni cant, with the mean duration for all three BMI groups to be ve 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. Similarly, there were no signi cant 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 signi cant.
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 signi cant 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 pro le, endometrial thickness, oocyte quality and number, and embryo transfer do not affect obesity. Another study described that endometrial thickness had a signi cant 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 insigni cant 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 signi cant 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 signi cant 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.

Declarations
Con ict of Interest: The authors declared no con ict of interest.
33. Host E, Lindenberg S, Ernst E, Christensen F 1999 Sperm morphology and IVF: embryo quality in relation to sperm morphology following the WHO and Kruger's strict criteria. Acta Obstetricia et Gynecologica Scandinavica 78, 526-529. Figure 1