The Combined Impact of Female and Male Body Mass Index on Cumulative Pregnancy Outcomes After the First Ovarian Stimulation

Effect of BMI on cumulative live birth rates in patients that completed IVF treatment: a retrospective cohort study of 16,126 patients

Although several studies have reported that high maternal BMI could influence the cumulative live birth rate (CLBR) in fresh embryo transfer cycles, the association of BMI with CLBR remains unclear in patients that completed IVF treatment. In this study, we examined the association of maternal BMI with CLBR, including repetitive one oocyte pick-up (OPU) and all fresh and frozen embryo transfer until live birth or embryos were run out. A total of 16,126 patients' data were included in the analysis and were divided into four groups based on BMI. We found that patients' characteristics, embryo parameters, and pregnancy outcomes differed among different BMI groups. Multivariate logistic regression showed that being underweight was associated with a higher possibility of having live birth than the reference group (OR (95% CI) 1.40 (1.22-1.59), P < 0.001), whereas being overweight and obese were associated with a lower possibility of having live birth than the reference group ((OR (95% CI) 0.81 (0.74-0.90), P < 0.001) and (OR (95% CI) 0.68 (0.55-0.85), P < 0.001)). After adjustment for confounding factors, the reference group was associated with a higher possibility of having live birth, with a significant difference found between the obese and reference groups (OR (95% CI) 0.55 (0.43-0.70), P < 0.001). An association was found between CLBR and BMI, indicating that an increase in BMI results in a decline in CLBR. Moreover, the CLBR of patients with different characteristics differed in the various BMI groups. Taken together, our data show that maternal BMI has a significant impact on CLBR.

Sperm DNA damage: The possible link between obesity and male infertility, an update of the current literature

Obesity prevalence worldwide is increasing significantly. Whilst maternal obesity has clear detrimental impacts on fertility, pregnancy and foetal outcomes, more recently there has been an increasing focus on the role of paternal obesity in human fertility. Recent meta-analyses have indicated that obesity in men negatively affects basic sperm parameters such as sperm count, concentration and motility, increases the incidence of infertility and reduces the chances of conception. Sperm DNA damage, typically characterised by DNA strand breaks and oxidation of DNA nucleotides, is a specialised marker of sperm quality that has been independently associated with recurrent miscarriage, reduced assisted reproduction success and increased mutational loads in subsequent offspring. Whilst, there are still conflicting data in humans as to the association of obesity in men with sperm DNA damage, evidence from rodent models is clear, indicating that male obesity increases sperm DNA damage. Human data are often conflicting because of the large heterogeneity amongst studies, the use of body mass index as the indicator of obesity and the methods used for detection of sperm DNA damage. Furthermore, comorbidities of obesity (i.e., heat stress, adipokines, insulin resistance, changes in lipids, hypogonadism and obstructive sleep apnoea) are also independently associated with increased sperm DNA damage that is not always modified in men with obesity, and as such may provide a causative link to the discrepancies amongst human studies. In this review, we provide an update on the literature regarding the associations between obesity in men and fertility, basic sperm parameters and sperm DNA damage. We further discuss potential reasons for the discrepancies in the literature and outline possible direct and indirect mechanisms of increased sperm DNA damage resulting from obesity. Finally, we summarise intergenerational obesity through the paternal linage and how sperm DNA damage may contribute to the transmission.

Obesity: A Doorway to a Molecular Path Leading to Infertility

The dramatic rise in obesity has recently made it a global health issue. About 1.9 billion were overweight, and 650 million global populations were obese in 2016. Obese women suffer longer conception time, lowered fertility rates, and greater rates of miscarriage. Obesity alters hormones such as adiponectin and leptin, affecting all levels within the hypothalamic-pituitary-gonadal axis. Advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are inflammatory cytokines that may play an important role in the pathophysiology of ovarian dysfunction in obesity. In obese males, there are altered sperm parameters, reduced testosterone, increased estradiol, hypogonadism, and epigenetic modifications transmitted to offspring. The focus of this article is on the possible adverse effects on reproductive health resulting from obesity and sheds light on different molecular pathways linking obesity with infertility in both female and male subjects. Electronic databases such as Google Scholar, Embase, Science Direct, PubMed, and Google Search Engine were utilized to find obesity and infertility-related papers. The search strategy is detailed in the method section. Even though multiple research work has shown that obesity impacts fertility in both male and female negatively, it is significant to perform extensive research on the molecular mechanisms that link obesity to infertility. This is to find therapeutics that may be developed aiming at these mechanisms to manage and prevent the negative effects of obesity on the reproductive system.

Impact of paternal body mass index on assisted reproduction treatment outcomes: An updated systematic review and meta-analysis

AIM

The aim was to provide updated evidence on the association of male body mass index (BMI) with outcomes of assisted reproduction technology (ART).

METHODS

PubMed, Embase, and Scopus databases were systematically searched. The review included observational studies in patients undergoing ART, that is, either in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and compared rate of clinical pregnancy and live birth based on different categories of male BMI. Quality of the pooled findings was assessed using the GRADE criteria.

RESULTS

A total of 19 studies were included in the review. Among subjects undergoing IVF, there were no significant differences in the rates of clinical pregnancy among overweight (odds ratio [OR] 1.38, 95% confidence interval [CI]: 0.65, 2.96) and obese (OR 1.86, 95% CI: 0.75, 4.58) BMI, compared to normal male BMI. Similarly, there were no significant differences in the rates of live birth among overweight (OR 1.04, 95% CI: 0.97, 1.13) and obese BMI (OR 0.90, 95% CI: 0.69, 1.18) when compared to males with normal BMI. Further, among those undergoing ICSI, there were no significant differences in the odds of clinical pregnancy among overweight (OR 0.98, 95% CI: 0.73, 1.33) and obese (OR 0.89, 95% CI: 0.62, 1.29). The odds of live births among overweight (OR 0.97, 95% CI: 0.89, 1.05) and obese (OR 0.95, 95% CI: 0.84, 1.07) male BMI were statistically similar to males with normal BMI undergoing ICSI.

CONCLUSIONS

The low to very low-quality findings suggest no significant association of overweight and obese BMI with clinical pregnancy and live birth rates among couples undergoing either IVF or ICSI.

Abnormal BMI in Male and/or Female Partners Are Deleterious for Embryonic Development and Pregnancy Outcome During ART Process: A Retrospective Study

OBJECTIVE

To investigate the effect of BMI in male and/or female partners on embryo development and clinical pregnancy outcome during ART.

METHODS

Data of 11,130 cycles between January 2018 and December 2020 were retrospectively analyzed. They were divided into Group A, B, C, and D based on couples' BMI values, also were divided into Group I, II, III and IV in IVF cycles and Group i, ii, iii, and iv in ICSI cycles. After grouping, inter-group indicators comparisons and logistic regression analysis were performed.

RESULTS

In IVF cycles, CPR in Group I and Group III were higher than Group IV. In Group III, it was higher than Group II. The AR in Group IV was higher, but the LBR was lower than Group I, Group II, and Group III. Logistic regression analysis results suggested that AR in Group IV was higher than that in Group I in IVF cycles, whereas LBR was lower.In ICSI cycles, high-quality embryo rate in Group i and Group ii were both higher than that in Group iii and Group iv. The CPR in Group i was higher than Group ii and Group iv, and in Group iii was higher than Group ii and Group iv. The AR in Group i was lower than Group iii and Group iv, and AR in Group ii was lower than Group iv. LBR, in Group I it was higher than Group ii, Group iii, and Group iv. Logistic regression analysis results suggested CPR in Group ii was significantly lower than that in Group i. AR in Group iii was considerably higher than that in Group i. LBR in Group ii and Group iv were significantly lower than that in Group i.

CONCLUSION

Female higher BMI was not conducive to the formation of high-quality embryos in ICSI cycle. Female and/or male BMI affected AR and LBR more than CPR not only in IVF cycles, but also in ICSI cycles.

Impact of dyslipidemia on the cumulative pregnancy outcomes after first ovarian stimulation

OBJECTIVES

To investigate the cumulative live birth rate (CLBR) according to lipid metabolism in patients with or without polycystic ovarian syndrome (PCOS) undergoing their first complete in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles.

PATIENTS

A total of 1,470 patients with PCOS and 3,232 patients without PCOS who underwent their first complete IVF/ICSI cycles from January 2016 to June 2018 were included. During a minimum of 2 years of follow-up, they had achieved at least one live birth or used all available embryos. The cumulative pregnancy outcomes were compared based on the patients' blood lipid parameters, including triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), in the two populations. Patients with an abnormal level of one or more of these four indicators were considered the dyslipidemia group. Patients whose four indicators were normal were considered the control group.

RESULTS

Among 1,470 patients with PCOS, the cumulative pregnancy outcomes were similar in the dyslipidemia group and control group. Logistic regression analysis showed that the TC levels were significantly negatively associated with the cumulative live birth rate (CLBR) after adjustment for confounding factors such as age and BMI (aOR 0.81, 95% CI 0.66-0.98, P<0.05). Among the 3,232 patients without PCOS, there was no significant difference in the cumulative pregnancy outcomes between the dyslipidemia group and the control group. No significant correlations were found in other logistic regression analyses.

CONCLUSIONS

TC negatively impacts the CLBR after first ovarian stimulation in PCOS patients. PCOS patients with dyslipidemia caused by elevated TC may have a poor CLBR.