Impact of Body Mass Index on Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection Among Polycystic Ovarian Syndrome Patients

Na Cui, Huixia Wang, Wei Wang, Jie Zhang, Yueming Xu, Lei Jiang, Aimin Yang, Guimin Hao
2016 Cellular Physiology and Biochemistry  
Key Words Body mass index (BMI) • Obesity • Polycystic ovarian syndrome (PCOS) • In vitro fertilization (IVF)/ Intracytoplasmic sperm injection (ICSI) • Infertility Abstract Background: The aim of this study is to assess the effect of body mass index (BMI) on outcomes of in vitro fertilization (IVF) / intracytoplasmic sperm injection (ICSI) among polycystic ovarian syndrome (PCOS) and non-PCOS patients. Methods: This was a retrospective cohort study that was performed in the Second Hospital of
more » ... Second Hospital of Hebei Medical University. Patients who were under 35 years old were included in the study and were divided into four groups based on their BMI. The number of retrieved oocytes, implantation rate, clinical pregnancy rate, miscarriage rate and live births among PCOS and non-PCOS patients were compared between different BMIs. Results: IVF/ICSI pregnancies in obese PCOS women had a considerably higher risk of miscarriage and low rate of clinical pregnancy than in non-obese PCOS pregnancies. However, in non-PCOS patient, obesity significantly elevated miscarriage rate but did not affect clinical pregnancy rate. Conclusion: Obesity in PCOS patients led to poor outcomes of IVF/ICSI. of studies had pointed overweight and obesity as major causes of chronic diseases such as hypertension, cardiovascular disease, abnormal lipid concentrations, and type 2 diabetes [2, 3] . In particular, evidence has elucidated that obesity has an adverse impact on reproduction. Despite the complications of pregnancy including miscarriage, gestational diabetes and hypertensive disorders induced by obesity, it appears that overweight and obesity are more likely to have anovulatory infertility than normal-weight women [4, 5] . With regard to the effects of a raised BMI on the outcome of assisted reproduction technology (ART), early studies documented that BMI had no influence on in vitro fertilization (IVF) outcomes, which was argued by more recent researches that suggested an opposite conclusion [6] [7] [8] . The influence of obesity on the outcomes of IVF/ intracytoplasmic sperm injection (ICSI) remains controversial. Studies have stated that elevated BMI was associated with lower clinical pregnancy rates, higher miscarriage rates, and reduced live birth rates [9, 10] . A retrospective data from 488 IVF cycles of 385 patients demonstrated that BMI had no effect IVF/ICSI outcomes [11] . Another study found that the rates of pregnancy and live birth were reduced progressively with each unit of BMI (kilograms per square meter) without affecting embryo quality [12] . In the setting of IVF, increased doses of gonadotropin for inducing ovulation or stimulating the ovaries to obtain mature oocytes were required in obese women [6, 13] . Impaired ovarian responsiveness to gonadotropin stimulation and reduced number of oocytes retrieved were reported to be associated with obesity [14, 15] . Polycystic ovary syndrome (PCOS) is influencing 4-6% of women [16, 17] . Of the patients with PCOS, about half of them are obese [18] . Reduction of weight could improve fertility in PCOS patients who attempted spontaneous conception [19, 20] . To date, the impact of BMI on ART outcomes in PCOS patients has not been fully demonstrated. A previous investigation showed that obesity and PCOS were independently associated with smaller oocyte diameter among patients undergoing ICSI [21] . PCOS patients with low BMI had more favorable ART cycle characteristics compared to patients with higher BMI but showed no significant difference [22] . Therefore, this study was aimed to investigate the effect of BMI on the outcomes of IVF/ICSI-ET by comparing the number of retrieved oocytes, implantation rate, clinical pregnancy rate, miscarriage rate and live births between PCOS and non-PCOS patients using prospectively collected clinical data. Materials and Methods Patients A retrospective cohort study of was performed in the patients who received assisted reproduction in the Second Hospital of Hebei Medical University from July 2012 to December 2013. A total of 2256 cycles were included in this study, of them 1848 cycles were non-PCOS patients and 408 cycles were PCOS patients. All patients were under 35 years old. All patients agreed with our data utilization, and signed informed, written consent forms before this investigation. This study was approved by the ethics committee of The Second Hospital of Hebei Medical University (#68-06-2009). Definition of overweight and obesity The height and weight of all subjects were measured by medical assistants using standardized protocols as per clinical practice. BMI was calculated according to the standard formula: BMI = weight/ height 2 (kg/m 2 ). BMI values between 24 and 28 kg/m 2 were defined as overweight and BMI ≥28 kg/m 2 was defined as obesity [23, 24] . Individual BMI was compared to the age-and sex-specific cutoff points, and the resulting status (normal, overweight, or obese) was recorded. Patients were divided into four groups, low weight group (BMI<18.5 kg/m 2 ), normal weight group (18.5 kg/m 2 ≤BMI<24 kg/m 2 ), overweight group (24 kg/m 2 ≤ BMI < 28 kg/m 2 ), obese group (BMI ≥28 kg/m 2 ).
doi:10.1159/000447873 pmid:27744442 fatcat:ongx22qn6fdqfaf565be3bxoum