Infertile couples undergoing Assisted Reproductive techniques are really receptive to any intervention intended to enhancement their fertility. Successful implantation of an embryo requires a receptive endometrium, a good quality embryo, and embryo endometrial synchronization in all species. Pharmacological agents such as aspirin and sildenafil have been included in previous clinical trials to improve endometrial vascularity and perifollicular blood flow but the results were inconsistent. To evaluate the effect of oral low dose aspirin or vaginal sildenafil citrate on endometrial thickness, retrieved oocyte, degree of maturation, embryo quality and pregnancy test. This comparative prospective study was conducted on the 60 infertile women who participated in intracytoplasmic sperm injection (ICSI) cycles at the infertility clinic associated with the "High Institute of Infertility Diagnosis and Assisted Reproductive Technologies, Al-Nahrain University / Baghdad/ Iraq." December 2020 to June 2022. In the present study the count of total oocytes retrieved was significantly higher in aspirin treated group in comparison to sildenafil treated group 12.5 ±5.3 versus 9.37 ±5.5 respectively. No significant variation in mean endometrial thickness among study groups. Regarding biochemical pregnancy test, positive results were obtained in 12 (40.0 %), 10 (33.3 %) in aspirin treated group, sildenafil treated group respectively and the difference was not significant. Aspirin treatment resulted in higher number of total retrieved oocytes, aspirin and sildenafil did not improve endometrial thickness, but they resulted in improvement of sub endometrial vascularity; however, biochemical pregnancy test was not affected by either pharmacological agent.
E ndometrial thickness (ET) is one of the best predictors of implantation rate and pregnancy success rate because endometrial growth depends on hormones. Estrogen regulates the proliferative phase, endometrial proliferation induced by estrogen after menstruation is largely dependent on blood flow to the basal endometrium that produces progesterone receptors which are required for progesterone-regulated endometrial growth in the secretory process. To compare the effect of estradiol valerate vs. sildenafil citrate on endometrial receptivity and subsequent pregnancy outcome in unexplained infertility patients receiving letrozole for ovulation induction. Herein, 21 patients with unexplained infertility underwent ovulation induction by letrozole (2.5 mg). Patients were divided into 2 groups; group A (10 patients) were given sildenafil tablets vaginally (25 mg) four times daily and group B (11 patients) were treated with estradiol valerate tablet 2 mg/12 hours. Patients were evaluated by transvaginal ultrasonography (TVS) to determine endometrial thickness, pattern, size, and the number of the dominant follicles, serum assessment of Vascular Endothelial Growth Factor (VEGF) level at trigger day, and chemical pregnancy outcome 14 days later. Results showed that the endometrial thickness, patterns of the endometrium, VEGF, size of the dominant follicle at the trigger day, and pregnancy rates were not significantly different between the two groups. However, the difference in the number of the dominant follicles at trigger day was statistically significant which is more in the sildenafil treated group. The present study confirmed the findings of both Sildenafil and E 2 valerate to boost endometrial receptivity and pregnancy rate.
In a perfect world, the peak of receptivity of the endometrial lining would occur simultaneously with the entry into the uterine cavity of a healthy blastocyst, which would then be able to adhere, attach, invade, and develop protected until the time of delivery. This would be the ideal scenario. The study was carried out on 200 infertile women who have thin , poorly vascularized endometrium, those patients were divided into five groups ; 40 patients in each group, group A received esterofem oral, group B received vagifem vaginal tablets, group C received sildenafil citrate gel, group D received pentoxifylline oral and group E received 4 grams of pentoxifylline vaginal gel. The endometrial thickness, vascularity zones, sub endometrial flow, and both uterine arteries resistance and pulsatility indices were assessed at the middle of the menstrual cycle (day 11–14) on a monthly basis for six cycles or until a positive pregnancy test was obtained. Pentoxifylline vaginal gel, pentoxifylline+ vitamin E capsule, and sildenafil vaginal gel have improved the vascularity indeces of endometrium and uterine arteries, while the vagifem and esterofem were less effective in terms of improving the vascularity indeces of endometrium and uterine arteries. The study also showed that 57.5% of women succeed to get pregnant after six months of receiving pentoxifylline vaginal gel, 35% of women succeed to get pregnant after six months of Pentoxifylline+vit E, while 22.5% of women succeed to get pregnant after six months of sildenafil, about 10% of women got pregnant after six months of vagifem, and finally 2.5% of women got pregnant after six months of receiving estrofem tablets. It was discovered that pentoxifylline vaginal gel, pentoxifylline tablet plus vitamin E capsule, and sildenafil vaginal gel were able to improve the vascularity index of the endometrium, the uterine arteries and endometrial thickness, and enhance the pregnancy rates in patients with thin poorly vascularized endometrium.