1. Introduction

Metabolic syndrome (MS) is a complex metabolic disorder defined by a combination of factors, including central obesity, impaired glucose metabolism, dyslipidemia, and hypertension. MS has emerged as a significant public health concern globally due to its strong links to cardiovascular disease, type 2 diabetes mellitus, and an increased risk of overall mortality (1,2).

The incidence of MS has increased dramatically over recent decades, particularly among women of reproductive age. This rise can be attributed primarily to sedentary lifestyles, poor dietary choices, and rising obesity rates (3). MS, which is well-known for its effects on cardiometabolic health, is increasingly associated with reproductive dysfunction in women. Key components of MS, including insulin resistance, hyperglycemia, and excess body fat, can disrupt the hypothalamic-pituitary-ovarian axis. This disruption negatively affects follicle development, alters sex hormone metabolism, and adversely affects ovulation (4,5,6). These metabolic disturbances can compromise endometrial receptivity and embryo implantation, thereby decreasing the chances of a successful pregnancy (7).

Infertility is a common reproductive health issue that affects about 10 to 15% of couples around the world. IVF is one of the most effective assisted reproductive technologies for managing infertility. However, despite significant advancements in laboratory techniques and ovarian stimulation protocols, the success rates of IVF remain relatively limited. Identifying modifiable metabolic and clinical factors that affect IVF outcomes is of significant clinical importance (8). Growing evidence indicates that metabolic issues can negatively impact IVF results. Obesity and insulin resistance are linked to decreased oocyte quality, changes in embryo development, lower implantation rates, and increased miscarriage rates (9–11). Women with metabolic syndrome, especially those with impaired glucose metabolism, may experience poorer reproductive outcomes, even without overt diabetes mellitus (12). However, previous studies have reported inconsistent findings regarding the role of individual components of metabolic syndrome—such as fasting blood glucose, lipid profile, and waist circumference—in IVF outcomes. Additionally, data from Middle Eastern populations remains limited (15). Additionally, the duration of infertility has been identified as a significant prognostic factor in assisted reproductive treatments. Extended infertility may indicate accumulated endocrine, metabolic, and ovarian changes that adversely affect treatment outcomes (16). The impact of metabolic syndrome components and infertility duration on IVF success has not been thoroughly investigated (17).

2. Objectives

With the increasing prevalence of MS and its possible effects on reproductive health, this study aimed to compare the components of MS and the duration of infertility among women with successful and unsuccessful outcomes from IVF. Understanding these connections may help identify high-risk patients and emphasize the importance of metabolic evaluation and optimization before starting IVF.

3. Materials and Methods

3.1. Study Design 

This cross-sectional study was conducted in 2024 at a private infertility clinic in Mashhad, Iran. Women aged 18 to 50 undergoing IVF were enrolled. The study was approved by the Research Ethics Committee of Islamic Azad University, Mashhad Branch (IR.IAU.MSHD.REC.1402.180). Written informed consent was obtained from all participants.

3.2. Participants

Women aged 18 to 50 undergoing IVF were included in the research, and no specific exclusion criteria were set. Participants were divided into two groups based on the outcome of their IVF: those with a successful outcome and those with an unsuccessful outcome.

3.3. Data gathering

We recorded demographic information, including age, height, weight, body mass index (BMI), and duration of infertility. Blood pressure was measured using a standard sphygmomanometer after the participants rested for 10 minutes. Blood samples were collected following an overnight fasting period to assess fasting blood glucose (FBS), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) within a single laboratory setting. Additionally, waist circumference was measured at the level of the umbilicus using a standardized tape measure. Metabolic syndrome was defined according to the NCEP/ATP III criteria as the presence of three or more of the following components: Waist circumference ≥88 cm, Fasting blood glucose ≥100 mg/dL or treatment for hyperglycemia, Triglycerides ≥150 mg/dL or treatment for high triglycerides, HDL-C <50 mg/dL or treatment to increase HDL, Blood pressure ≥130/85 mmHg or treatment for hypertension (1).

3.4. Statistical analysis

Data were analyzed using IBM SPSS Statistics version 20. Normality was assessed using the Kolmogorov–Smirnov test. Independent t-tests or Mann–Whitney U tests were applied as appropriate. Categorical variables were analyzed using chi-square or Fisher’s exact tests. A P-value <0.05 was considered statistically significant.

4. Results

A total of 24 women undergoing IVF were included in the final analysis and were classified into successful and unsuccessful IVF outcome groups. The baseline characteristics of the study population are summarized in Table 1. The mean age of participants was 33.16 ± 6.45 years, and the mean body mass index (BMI) was 26.48 ± 4.13 kg/m². Overall, 33% of the participants reported a history of underlying medical conditions, while the majority (95%) were normotensive at the time of assessment. The baseline demographic and anthropometric characteristics were similar between the two groups. As shown in Table 2, there were no statistically significant differences in age, height, weight, or BMI between women with successful and unsuccessful IVF outcomes (all P > 0.05). This suggests that the study population was homogeneous with respect to these demographic factors.

The comparison of MS parameters between the two groups is presented in Table 3. A statistically significant difference in FBS levels was noted between the groups. Women with unsuccessful IVF outcomes had notably higher median FBS levels compared to those who achieved successful IVF outcomes (99 mg/dL vs. 90 mg/dL; P = 0.03). Furthermore, the median duration of infertility was significantly longer in the unsuccessful IVF group than in the successful group (3.85 years vs. 3 years; P = 0.02). In contrast, no significant differences were detected between the two groups regarding serum triglyceride levels, HDL-C, systolic or diastolic blood pressure, waist circumference, or the number of MS components (all P > 0.05), as detailed in Table 3.

The frequency of MS was low in both groups. As shown in Table 4, there was no statistically significant difference in the prevalence of metabolic syndrome between women with successful and unsuccessful IVF outcomes (P > 0.05). Additionally, an analysis of underlying medical conditions revealed no significant differences between the two groups (Table 5). The overall frequency and distribution of comorbid conditions were similar among women with both successful and unsuccessful IVF outcomes (P > 0.05).

Table 2. The comparison of participants' demographic variables across study groups.

Table 3. The comparison of metabolic syndrome variables across study groups

Table 4. The prevalence of metabolic syndrome across study groups

Table 5. The comparison of the frequency of underlying diseases among participants in each study group

5. Discussion