The impact of body mass index on laboratory, clinical outcomes and treatment costs in assisted reproduction: a retrospective cohort study.

BACKGROUND: The aim of this study was to evaluate the influence of the body mass index (BMI) on laboratory, clinical outcomes and treatment costs of assisted reproduction, as there are still controversial and inconclusive studies on this subject. METHODS: This research was retrospective cohort study, including women undergoing assisted reproduction in a Reproductive Medicine Center between 2013 and 2020. The participants were divided into groups according to BMI (kg/m2): Group 1 < 25; Group 2, 25-29.9 and Group 3, ≥ 30. A total of 1753 in vitro fertilization (IVF) fresh embryo transfer (ET) cycles were included for assisted reproduction outcomes analysis and 1869 IVF-ET plus frozen embryo transfer (FET) for cumulative pregnancy analysis. RESULTS: As higher the BMI, higher was the proportion of canceled IVF cycles (G1 (6.9%) vs. G2 (7.8%) vs. G3 (10.4%), p = 0.002) and gonadotropin's total dose (IU) and treatment costs (G1 (1685 ± 595, U$ 683,02) vs. G2 (1779 ± 610, U$ 721,13) vs. G3 (1805 ± 563, U$ 764,09), p = 0.001). A greater number of mature oocytes was observed in G1 and G2 (6 [6.4-7.0] vs. 6 [5.6-6.6] vs. 4 [4.6-6.7], p = 0.011), which was not found in oocyte maturity rate (p = 0.877). A significant linear tendency (p = 0.042) was found in cumulative pregnancy rates, pointing to worse clinical outcomes in overweight and obese patients. CONCLUSION: These findings highlight the importance of considering the higher treatment costs for these patients, beyond all the well-known risks regarding weight excess, fertility, and pregnancy, before starting IVF treatments.

Influence of overweight and obesity on perinatal outcomes in assisted reproduction: a retrospective cohort study.

BACKGROUND: In spontaneous pregnancies, maternal weight and gestational diabetes are independent risk factors for macrosomia and large-for-gestational-age newborns. Furthermore, maternal body mass index (BMI) of ≥25 kg/m2 is associated with worse neonatal vitality, classified as an Apgar score of < 7 at the fifth minute of life. However, few studies have evaluated the influence of BMI on perinatal outcomes in pregnancies resulting from assisted reproduction. Therefore, this study aimed to analyze whether the perinatal outcomes of assisted reproduction are influenced by BMI. METHODS: This was a retrospective cohort study performed at a reproductive medicine center. Patients undergoing assisted reproduction (2013-2020) were divided into three groups according to their BMI (kg/m2): group 1, < 25; group 2, 25-29.9, and group 3, ≥30. In total, 1753 in vitro fertilization embryo transfer cycles were analyzed. Data were expressed as mean ± standard deviation or frequency (%). The analysis of variance and chi-square test were performed for comparison. To determine the participants and number of cycles for these analyses, generalized estimating equations were used, considering p < 0.05. RESULTS: In groups 1, 2, and 3, the rates of live birth were 33.5, 32.3, and 29.9% (p = 0.668); preeclampsia were 2.9, 6.1, and 6.3% (p = 0.268); small-for-gestational-age newborns were 23, 23.2, and 21.7% (p = 0.965); macrosomia were 1.9, 0.9, and 2.7% (p = 0.708); Apgar score > 7 at the fifth minute were 97.6, 98.2, and 100% (p = 0.616); and preterm birth were 29.6, 30.1, and 35.1% (p = 0.970), respectively. CONCLUSIONS: In conclusion, although the three groups had similar perinatal outcomes in this study, the study population was too small for conclusive results. The higher the BMI, the lower the chances of clinically relevant LBR and the higher the chances of premature labor and preeclampsia.