Study shows melatonin almost doubles IVF success rate in women with poor egg quality

Influence of oxidative stress on oocyte quality and protective role of melatonin as an antioxida Poor oocyte quality is an important cause of female infertility. Reactive oxygen species (ROS) are produced within ovarian follicles, especially during ovulation process, and it is thought that increased ROS activity may be a cause of impaired oocyte maturation. Pineal hormone, melatonin, is detected in the human follicular fluid and melatonin is known as a potent free radical scavenger. This study was undertaken to evaluate the relationship between oxidative stress and poor oocyte quality and whether melatonin administration improves oocyte quality by protecting them from radical cytotoxicity. Follicular fluid was sampled at oocyte retrieval [85 folliclar fluids from 85 patients were enrolled] during in vitro fertilization and embryo transfer (IVF-ET) program. Intrafollicular concentrations of 8-OHdG (8-hydroxy-2'-deoxyguanosine) were determined as an oxidative stress marker, and Cu,Zn-superoxide dismutase (SOD), glutathione (GSH) and melatonin were determined as antioxidants. There was no correlation between SOD, GSH and follicular growth. However, melatonin concentrations increased depending on follicular growth. Although SOD and GSH did not show any correlation with 8-OHdG, melatonin showed a negative correlation with 8-OHdG. It seems that melatonin is the most important antioxidant in the follicle. Oocytes recovered from immature ICR mice were incubated in medium with hydrogen peroxide (H2O2) and melatonin. After 12 hrs incubation, oocytes with first polar body were defined as mature oocytes, and ROS formation in oocytes were detected using a ROS dye (dichlorofluorescein). Reduced percentages of the oocyte with first polar body caused by H2O2 were recovered by melatonin addition. Fluorescence intensity caused by H2O2 was significantly decreased by melatonin treatment. H2O2 inhibits oocytes maturation but melatonin counteracted oxidative stress caused by H2O2. Women who failed to become pregnant in the previous IVF-ET (fertilization rate< 50%) took 3 mg tablets of melatonin in the next IVF-ET [115 patients were divided into two groups. In the next IVF-ET cycle, 56 patients were given melatonin treatment, 59 patients without melatonin treatment (control)], and fertilization rate and pregnancy rate were compared to the previous IVF-ET. The fertilization rate and pregnancy rate were improved by melatonin treatment [Fertilization rate was improved in melatonin treatment cycle (50.0%) compared with the previous cycle (20.2%). On the other hand, in 59 patients who were not given melatonin, the fertilization rate was not changed (22.8%) compared with previous cycle (20.9%). Pregnancy rate was higher in melatonin treatment cycle (19.6%; 11/56) compared with without melatonin treatment cycle (10.2%; 6/59)]. Intrafollicular melatonin concentrations were significantly increased and 8-OHdG levels were significantly decreased by melatonin treatment. In conclusion, ROS have a toxic effect on oocyte maturation and melatonin may protect oocyte from ROS.Melatonin administration is likely to improve oocyte quality. Note Some clarifying details have been added to this abstract, so it is slightly different from that in the programme book.