Myo-inositol effect on pregnancy outcomes in infertile women undergoing in vitro fertilization/intracytoplasmic sperm injection: A double-blind RCT

Abstract Background Myo-inositol is an intracellular mediator which is involved in various aspects of reproduction in women. Objective This study aimed to evaluate the impact of Myo-inositol on the outcomes of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles in infertile women. Materials and Methods This double-blind randomized controlled trial was conducted on 70 infertile women referred to the Infertility Treatment Center, Besat hospital, Sanandaj, Iran from May 2019 to September 2019 for IVF/ICSI cycles. The participants were randomly divided into 2 intervention (n = 36) and control (n = 34) groups. The intervention group received 2000 mg of Myo-inositol and 200 mcg folic acid twice a day for 2 months and the control group received 200 mcg of folic acid twice a day for 2 months in the IVF/ICSI cycles (from the third day of cycle until the end of the second month). Finally, the number of oocytes, the quality of embryos, and the IVF/ICSI outcomes were compared between the 2 groups. Results The mean numbers of oocytes, MII oocytes, and 2 pronuclear embryos were significantly higher in the intervention group than the control group. Also, the clinical pregnancy and live birth rates in the intervention group were significantly higher than in the controls (p = 0.04). Conclusion The administration of Myo-inositol may increase clinical pregnancy and live birth rates by increasing the number of total and meiosis II oocytes in infertile women undergoing IVF/ICSI.


Introduction
Nowadays assisted reproductive techniques (ARTs) are used to achieve fertility in infertile people. In vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) are effective ARTs (1). IVF and ICSI are the most appropriate treatments in infertility clinics. However, one of the most important problems of these methods is the low rate of pregnancy success (2). Despite significant advances in ARTs, there are still problems in achieving desirable results through IVF and ICSI techniques. Using supplements in ARTs can be very helpful in increasing pregnancy rates (3).
The balance between the production and clearance of reactive oxygen species is critical to the health of the female reproductive system.
Antioxidants are compounds that can decrease oxidative damage in infertile women (4).
Myo-inositol is a C6 sugar alcohol belonging to the B-group vitamins (5). Myo-inositol plays a key role in all aspects of cell physiology including lipid synthesis, cell morphogenesis, cell membrane structures, and cell membrane functions (6,7).
Studies on inositol and its isoforms (particularly Myo-inositol) in IVF have demonstrated that this molecule reduces insulin resistance and improves ovarian function, oocyte quality, and embryo pregnancy rates (8). The inositol 1,4,5-triphosphate receptor channel is found in mammalian cells which are intracellular mediators for the release of calcium (9,10). Evidence suggests that this receptor channel has a key role in regulating calcium signaling in the oocytes of mammals (11). The mechanisms of calcium release during oogenesis play an important role in the success of fertilization. Several reports point to the possible role of inositol phospholipids-calcium in oocyte development (12,13).

Outcomes and data collection
The number of clinical pregnancy, miscarriage, preterm delivery, and live birth in both study groups were recorded and compared. Furthermore, the total number of oocytes, meiosis II (MII) oocytes, germinal vesicle oocytes, degenerated oocytes, and the quality of the embryos were evaluated in the 2 groups.
Clinical pregnancy was defined as a fetal cardiac activity in the 6 th -7 th wk of pregnancy. Pregnancy loss earlier than the 20 th wk of gestation was defined as miscarriage. Preterm delivery was defined as the birth of a baby earlier than 37 wk gestation. Live birth was defined as a birth of a live infant ≥ 24 wk of gestation that showed signs of life.
The study was initially designed as a doubleblind trial. Participants and physicians who evaluated the outcomes were unaware of the random assignment of individuals to control and intervention groups. Study participants were assured that their data would remain confidential to researchers.

Results
Initially, the 121 women were evaluated based on our inclusion criteria. Out of them, 50 women did not meet the inclusion criteria. 1 women was also excluded due to dissatisfaction to continue participating in the study.  (Table I). Table II indicates that the mean numbers of oocytes, MII oocytes, and 2 pronuclear embryos were significantly higher in the intervention group than in the control group. In addition, the numbers of degenerated oocytes and grade A and B embryos were higher in the intervention group than in the controls. However, these differences were not statistically significant. Table III shows the results of the pregnancy outcomes in the 2 study groups. The number of clinical pregnancies in the intervention group was significantly higher than in the control group (p = 0.04). The number of women who had live births in the intervention group was also higher than in the control group (p = 0.04). The pregnancy rate in the control group was lower than that of the intervention group. However, this difference was not significant. The miscarriage and preterm delivery rates did not differ between the 2 groups (Table III).

Discussion
In the present study, administration of myoinositol in women candidates for IVF/ICSI was associated with a higher total number of oocytes and a higher number of M II oocytes. In addition, the clinical pregnancy and live birth rates were also higher in these women.
Infertility imposes a great deal of psychological and financial burden on the cases and their family.
A failure of specialized and expensive treatments may result in negative psychological effects on couples. Despite the expansion of experience in ARTs and significant advancements in infertility treatment, the failure of fertility therapy is a major challenge (14). Oocyte quality is the main predictor of the success rate in IVF (15). Various studies have investigated ways for increasing the quality of oocytes and embryos (16,17).
The normal function of the ovaries is of great importance for the health of the reproductive tract.
Antioxidant compounds are defensive barriers that maintain the active oxygen species balance.
Disruption of the antioxidant balance can interfere with oocyte maturation, ovulation, fertilization, implantation, and embryo development (17). A study reported that compounds such as Myo-inositol could reduce oxidative stress by enhancing the cellular antioxidant defense (16). The effectiveness of inositol in modifying the process of ovulation has been extensively studied (18,19).

Conclusion
We can conclude that Myo-inositol, an antioxidant compound, can increase the pregnancy success rate in IVF/ICSI cycles, likely by improving the quality of the oocytes and embryos.