Moderate-to-severe ovarian hyperstimulation syndrome: A retrospective multivariate logistic regression analysis in Chinese patients.

BACKGROUND: Ovarian hyperstimulation syndrome (OHSS), a life-threatening complication occurring in stimulated ovarian cycles, arises from treatment with gonadotropin for inducing follicular maturation. OBJECTIVES: The aim of this study was to compare the risk factors between patients with severe OHSS and those without OHSS after in vitro fertilization by intracytoplasmatic sperm injection/embryo transfer (IVF-ICSI/ET). Identifying the associated risk factors may provide guidance for clinicians on how to prevent OHSS. MATERIAL AND METHODS: The retrospective study involved patients who had completed IVF-ICSI/ET cycles. The difference in markers for predicting the occurrence of OHSS between groups was compared. The potential protective and risk factors, as well as the predictive markers, were identified. RESULTS: Patients with OHSS were younger (p = 0.015), had higher basal antral follicle counts (AFC) (p < 0.001) and lower total dosages of gonadotropin (Gn) (p = 0.011). On the day of human chorionic gonadotropin (hCG) administration, significantly higher total numbers of follicles (p < 0.001), serum estradiol (E2) (p < 0.001) and progestrone (Pg) (p = 0.001) levels, numbers of oocytes (p < 0.001) and metaphase II (MII) oocytes (p < 0.001) were also observed in the OHSS group when compared to the non-OHSS group. A univariate regression analysis revealed that age (OR = 0.898, 95% CI = 0.822-0.981) and total dosage of Gn (OR = 0.999, 95% CI = 0.999-1.000) were protective factors, whereas AFC (OR = 1.090, 95% CI = 1.051-1.131) and, on the day of hCG injection, the number of follicles (OR = 1.185, 95% CI = 1.027-1.230), serum E2 (OR = 1.000, 95% CI = 1.000-1.000) and Pg (OR = 2.773, 95% CI = 0.510-3.370) levels, the number of oocytes (OR = 1.254, 95% CI = 0.894-1.472) and MII oocytes (OR = 1.238, 95% CI = 0.747-1.217) were risk factors for OHSS. However, a multivariate regression analysis showed that the total number of follicles (OR = 1.124, 95% CI = 1.027-1.230) was the only predictive factor for the occurrence of OHSS. CONCLUSIONS: The study demonstrated that the follicle count measured on the day of hCG administration was the only predictive factor for the occurrence of OHSS. This provides basic guidance to clinicians on the prevention of the complication when using assisted reproductive technologies (ART).

Enhanced performance of CH3NH3PbI3-x Cl x perovskite solar cells by CH3NH3I modification of TiO2-perovskite layer interface.

In this work, perovskite solar cells (PSCs) with CH3NH3PbI3-x Cl x as active layer and spiro-OMeTAD as hole-transport media have been fabricated by one-step method. The methylammonium iodide (CH3NH3I) solution with different concentrations is used to modify the interface between mesoporous TiO2 (meso-TiO2) film and CH3NH3PbI3-x Cl x perovskite layer. Several techniques including X-ray diffraction, scanning electron microscopy, optical absorption, electrochemical impedance spectroscopy (EIS) and photoluminescence are used to investigate the effect of the interfacial modification. It is found that the interfacial modification by CH3NH3I enhance the crystallinity and increase the grain size of CH3NH3PbI3-x Cl x layer, and improve the surface wetting properties of perovskite precursor on meso-TiO2 film. The sunlight absorption and external quantum efficiency of PSCs in the visible region with wavelength less than 600 nm have been improved. The Nyquist plots obtained from the EIS suggest that the CH3NH3I modification can reduce the charge recombination rates. The photoluminescence measurement shows that the exciton dissociation in the modified devices is more effective than that in the control samples. The photovoltaic performance of the modified devices can be significantly improved with respect to the reference (control) devices. The CH3NH3I modified devices at the optimized concentration demonstrate the average power conversion efficiency of 12.27 % in comparison with the average efficiency of 9.68 % for the reference devices.