Effective of Sildenafil Citrate on Pregnancy Outcome in infertile women undergoing induction of ovulation by Letrzole and Clomiphene Citrate

INTRODUCTION

Endometrial thickness of less than 14 mm is generally considered normal at any stage of the menstrual cycle. ¹ During menstruation, the diameter of the endometrium in premenopausal women is between 2 and 4 mm. ²

Sildenafil Citrate improve uterine blood flow and leads to estrogen-induce proliferation of the endometrium. ^{2, 3} The powerful effects of sildenafil led researchers to evaluate sildenafil as a treatment in assisted reproduction where reduced uterine blood flow is thought to contribute to implantation failure. ³

Uterine heart rate indices decreased in women receiving sildenafil while undergoing simultaneous in vitro fertilization, indicating decreased vascular

resistance in the uterus and increased uterine blood flow.⁴

Letrozole was introduced as reproduction therapy after the occurrence of many side effects of CC, the limited therapeutic success of CC and the complexity of gonadotropin treatment^{. 5} Letrozole suppresses estrogen production in the hypothalamic-pituitary axis, resulting in increased GnRH and FSH. Letrozole has a selective effect by blocking the peripheral conversion of androgens into estrogen and reducing the amount of estrogen, which creates a positive feedback in the pituitary gland, increases FSH and improves ovulation. ⁶

Clomiphene competes and binds to estrogen receptors throughout the reproductive system, remaining bound for a long period of time, ultimately reducing receptor levels by interfering with receptor recycling. ⁷ Decreased estrogen negative feedback leads to natural compensatory mechanisms that alter the pattern of GnRH secretion and stimulate overexpression of pituitary gonadotropin, which in turn fuels follicle growth in the ovaries^{. 8}

At the hypothalamic level, estrogen receptor depletion prevents accurate interpretation of circulating estrogen level. ⁹ Reduced estrogen negative feedback triggers normal compensatory mechanisms that alter the pattern of Gonadotropin-Releasing Hormone (GnRH) secretion and stimulate increased pituitary gonadotropin release, which in turn drives ovarian follicular development. ¹⁰

This study purposes to assess the safety and efficacy of sildenafil on endometrium thickness, Number of mature follicle, Doppler indices of uterine artery and determine the effect on pregnancy outcome and rate of miscarriage.

PATIENTS AND METHODS

This study was conducted at the Department of Obstetrics & Gynecology in Assuit Al- Azhar University Hospital. Ethical committee approved the study protocol and an informed consent was obtained from every participant prior to commencing the study.

The study was conducted on 300 Patients were included in the study that performed in the department of obstetrics and gynecology of Al-Azhar University Hospital (Assuit) Egypt. Divided into 3 groups: Group I: included 100 patients (letrzole with sildenafil citrate). Group II: included 100 patients (letrzole with Placebo). Group Ⅲ: included 100 patients (Clomiphene Citrate with Sildenafil Citrate).

Included criteria were; age 20-35 years old, patient hypothalamic pituitary ovarian axis, patients having ovulatory infertility, no medical disorders as DM, chronic HTN, cardiac, renal or blood disorders, women with documented ovulation, having patent tubes and Normal uterine cavity, conceive with sexual intercourse, normal hormonal profile and not using hormonal contraception. Exclusion criteria were; age less than 20- or more than 35 years old, male factor of infertility, congenital uterine anomaly, tubal factor that relates to infertility, history of medical disorders, resistance to clomiphene, pelvic adhesion, any contraindication to sildenafil citrate, letrzole or clomiphene citrate.

Clinical examination were general, abdominal, and pelvic, vaginal and cervical, ultrasound (Abdominal and Vaginal) and Doppler Indices. Laboratory investigations were complete blood count, Hormonal profile (F.S.H, L.H, DHEA, serum testosterone, TSH and PRL), progesterone level at med luteal phase (>5 ng/ml), Liver function tests, Random blood sugar, kidney function profile, Semen analysis (satisfaction) and B HCG Subunit and titre.

In patients undergoing induction of ovulation, oral sildenafil citrate may improve endometrial thickness, number and diameter of follicles, uterine artery blood flow and pregnancy rate. Group (1); which will include of 100 infertile women will receive: Aromatase inhibitor (letrozole 2.5 mg) 1 tablet twice daily for induction of ovulation for five-days, beginning from the 2^nd day of cycle, and Sildenafil citrate: 1 tablet three times per day from with the start of Letrzole therapy until the day of HCG administration. Group (II); which will include of 100 infertile women will receive: Aromatase inhibitor (letrozole 2.5 mg) 1 tablet twice daily for induction of ovulation for five-days, starting from the 2^nd day of cycle and Placebo tablets: 1 tablet three times per day from with the start of Letrzole therapy until the day of HCG administration. Group (III); which will include of 100 infertile women will receive: Clomiphene citrate (clomide 50 mg) 2-tablet once daily for induction of ovulation for five-days, starting from the 2^nd day of cycle and Sildenafil citrate: 1 tablet three times per day from with the start of Clomiphene Citrate therapy until the day of HCG administration.

Each patient will receive one treatment regimen for 3 consecutive cycles unless ovulation or pregnancy occurs. The development of the ovarian follicles were monitored by Tran's vaginal ultrasound measurement of the mean follicular diameter every 3 days during the follicular phase starting from day 10   until ovulation occur (18-20 mm) also the endometrial thickness and pattern were monitored by the trans-vaginal ultrasound. Doppler flow parameters of uterine vessels were measured on the third day of the cycle and on the day of HCG administration using colored Doppler US for comparison. The study was discontinued with positive pregnancy test or after three successive treatment cycles. Serum B-HCG were done to detect pregnancy occurrence.

Statistical data analysis was performed using SPSS as follows: quantitative variables were described as the mean, standard deviation and range were described, qualitative variables and percentages were described, and the non-comparative t-test was used for the comparison used. Two groups as follows: Consider a qualitative variable in the parametric data (SD < 50% mean), Chi2 test was used for statistical analysis of categorical data, P value >0.05 insignificant, P value

RESULTS

Table 1: comparison between three groups in endometrial thickness at HCG injection

P. value: Comparison between all groups calculated by Chi-square test for categorical data. (Significant difference). P1: (High significant difference). P2: (Not significant difference). P3: (High significant difference).

Table 2: comparison between three groups in number of follicle18-22mm at HCG injection

P. value: Comparison between all groups calculated by Chi-square test. (High significant difference). P1: (High significant difference). P2: (High significant difference). P3: (High significant difference).

Table 3:  comparison between three groups in Doppler indices at HCG injection.

P. value: Comparison between all groups calculated by Chi-square test for categorycal data. (Significant difference). P1: (Significant difference). P2: (Not significant difference). P3: (Not significant difference).

Table 4: comparison between three groups in pregnancy rate.

P. value: Comparison between all groups calculated by Chi-square test for categorical data. (Not significant difference). P1: (High significant difference). P2: (Not significant difference). P3: (High significant difference).

Table 5: comparison between three groups in Abortion rate.

P. value: Comparison between all groups calculated by Chi-square test for categorical data. (Not significant difference). P1: (High significant difference).  P2: (Significant difference).  P3: (Not significant difference).

Table 6: comparison between three groups in ovarian hyper stimulation syndrome rate.

P. value: Comparison between all groups calculated by Kruskal Wallis test. (High significant difference).

Table 7: comparison between three groups in CFMF rate.

P. value: Comparison between all groups calculated by Chi-square test for categorical data. (Not significant difference).CFMF=congenital fetal malformation