A randomized clinical trial of sildenafil plus clomiphene citrate to improve the success rate of ovulation induction in patients with unexplained infertility

Comparison of Adding Sildenafil Versus Estradiol to Clomiphene Citrate on the Applebaum Score and Pregnancy Rate in Patients With Unexplained Infertility: A Double-Blind Randomized Controlled Trial

BACKGROUND

Both sildenafil and estradiol are seen to improve endometrial thickness in patients with infertility who are undergoing clomiphene induction cycles. However, the correlation between endometrial thickness and pregnancy rate is debatable. This study investigated the effect of adding oral sildenafil to clomiphene citrate (CC), compared to adding estradiol valerate, on the uterine biophysical profile (Applebaum score) and pregnancy rate.

METHODS

This was a double-blinded, randomized controlled trial conducted in Kisangani in the Democratic Republic of the Congo from October 1, 2021, to October 31, 2023. Patients with unexplained infertility were randomly assigned to one of two groups: the interventional, which was given CC (2 x 50 mg/day from day 3 to day 7 of the menstrual cycle) + sildenafil (2 x 25 mg/day orally from day 8 to day 12) or (ii) the control group, which was given CC (similar dosage as the intervention group) + EV (2 x 2 mg/day orally from day 8 to day 12), for a maximum of three cycles. Applebaum scores and clinical pregnancy rates were measured.

RESULTS

Patients in the sildenafil and EV groups were similar in mean age (29.04 versus 28.89 years). Of the 74 patients enrolled in each group, 71 in the sildenafil group and 72 in the EV group received treatment and were followed to completion. The Applebaum scores were significantly higher in the sildenafil group than in the EV group (17.05 versus 15.14, respectively, P=0.000). In the sildenafil group, the clinical pregnancy rate was also significantly higher, at 28.92% versus 20.83% in the EV group (P = 0.04).

CONCLUSION

As compared to EV, the oral addition of sildenafil to CC is associated with a good Applebaum score and a high rate of clinical pregnancy in patients with unexplained infertility.

The definition of unexplained infertility: A systematic review

BACKGROUND

There is no consensus on tests required to either diagnose unexplained infertility or use for research inclusion criteria. This leads to heterogeneity and bias affecting meta-analysis and best practice advice.

OBJECTIVES

This systematic review analyses the variability of inclusion criteria applied to couples with unexplained infertility. We propose standardised criteria for use both in future research studies and clinical diagnosis.

SEARCH STRATEGY

CINAHL and MEDLINE online databases were searched up to November 2022 for all published studies recruiting couples with unexplained infertility, available in full text in the English language.

DATA COLLECTION AND ANALYSIS

Data were collected in an Excel spreadsheet. Results were analysed per category and methodology or reference range.

MAIN RESULTS

Of 375 relevant studies, only 258 defined their inclusion criteria. The most commonly applied inclusion criteria were semen analysis, tubal patency and assessment of ovulation in 220 (85%), 232 (90%), 205 (79.5%) respectively. Only 87/220 (39.5%) studies reporting semen analysis used the World Health Organization (WHO) limits. Tubal patency was accepted if bilateral in 145/232 (62.5%) and if unilateral in 24/232 (10.3%). Ovulation was assessed using mid-luteal serum progesterone in 115/205 (56.1%) and by a history of regular cycles in 87/205 (42.4%). Other criteria, including uterine cavity assessment and hormone profile, were applied in less than 50% of included studies.

CONCLUSIONS

This review highlights the heterogeneity among studied populations with unexplained infertility. Development and application of internationally accepted criteria will improve the quality of research and future clinical care.

Migraine and infertility, merging concepts in women's reproductive health: A narrative review

OBJECTIVE

The objective is to examine issues around treating infertility in patients with migraine.

BACKGROUND

Women outnumber men in migraine diagnosis with a 3:1 ratio; the disease is commonly expressed in women of child-bearing age and is influenced by changes in circulating hormones. Infertility is also common, and the use of treatment options, such as assisted reproductive technology, have expanded exponentially in recent years.

METHODS

We summarized the literature around the effect of infertility treatments on headache in the general population and migraine population. We also discuss sociobehavioral, economic, and biological factors affecting fertility in patients with migraine, describe infertility protocols, and propose areas of focus for future research. We searched PubMed for the combined key terms in vitro fertilization or assisted reproductive technology AND migraine, or headache. The search included all dates and specified English-language results only.

RESULTS

Migraine may negatively influence family planning and fertility. Patients face obstacles stemming from the impact of migraine on social relationships and the interference of preventive medications on pregnancy. Migraine may also be associated with an increased prevalence of endocrine disorders which in turn affect fertility. Moreover, infertility treatments are associated with mild headache as a side effect. In addition, we found only one retrospective study demonstrating an increase in headache frequency during in vitro fertilization in the migraine population.

CONCLUSIONS

We determined that there is little research focused specifically on migraine headache exacerbation and other migraine-associated health outcomes with infertility treatment. This topic merits further interdisciplinary exploration.

Sildenafil during the 2nd and 3rd Trimester of Pregnancy: Trials and Tribulations

Sildenafil, a phosphodiesterase 5 inhibitor with a vasodilatory and anti-remodeling effect, has been investigated concerning various conditions during pregnancy. Per indication, we herein review the rationale and the most relevant experimental and clinical studies, including systematic reviews and meta-analyses, when available. Indications for using sildenafil during the second and third trimester of pregnancy include maternal pulmonary hypertension, preeclampsia, preterm labor, fetal growth restriction, oligohydramnios, fetal distress, and congenital diaphragmatic hernia. For most indications, the rationale for administering prenatal sildenafil is based on limited, equivocal data from in vitro studies and rodent disease models. Clinical studies report mild maternal side effects and suggest good fetal tolerance and safety depending on the underlying pathology.

Effectiveness of phosphodiesterase type 5 inhibitors on the treatment of thin endometrium and pregnancy outcomes: An systematic review

Phosphodiesterase type 5 (PDE5) inhibitors are thought to play a role in increasing endometrial thickness and increasing the success rate of pregnancy outcomes. This study was done to investigate the effects of PDE5 inhibitors on infertile women with thin endometrium and pregnancy outcomes. In this systematic review, all randomized controlled trials (RCTs) and observational studies were retrieved from databases including Institute for Scientific Information (ISI), PubMed, and Scopus by interesting keywords. A checklist was designed to collect necessary data and pregnancy outcomes, and the required items were recorded. PDE5 inhibitors through various mechanisms such as induction of vasodilatory effect through the effect on NO/cGMP signaling on vascular smooth muscle, through regulating cells proliferation and induction angiogenesis by increasing the expression of tumor suppressor factor (p53), and vascular endothelial growth factor A (VEGF-A) and downregulating inflammation by downregulating proinflammatory cytokines, affect endometrial thickness that eventually increases and pregnancy outcomes. Although PDE5s inhibitors increase endometrial thickness by different mechanisms, especially in women with thin endometrial, this does not necessarily mean that they induce a positive effect in all situations. However, their positive effects on pregnancy outcome may be affected by the time of administration, type of infertility treatment, underlying diseases such as pelvic disorders and inflammation. So in this regard, there are still ambiguous aspects that required further RCTs study in this area.

Effect of Prepregnancy Lymphocyte Active Immunotherapy on Unexplained Recurrent Miscarriage, Pregnancy Success Rate, and Maternal-Infant Outcome

Objective

To evaluate the effect of prepregnancy lymphocyte active immunotherapy on unexplained recurrent miscarriage, pregnancy success rate, and maternal-infant outcome.

Methods

A total of 124 patients with recurrent miscarriage admitted to our hospital from January 2018 to December 2020 were selected as the research objects and divided into the experimental group and the control group according to the random number table method, with 62 patients in each group. The experimental group was treated with lymphocyte active immunotherapy, and the control group was given conventional treatment. The pregnancy success rate, estrogen indexes, hemorheology indexes, and psychological state of the two groups were compared.

Results

The experimental group garnered a notably higher pregnancy success rate and a prominently lower miscarriage rate than the control group (P < 0.05). Better results of self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were observed in the experimental group, as compared to the control group (P < 0.05). The experimental group yielded more desirable results in terms of treatment satisfaction, estrogen indexes, and hemorheology indexes in comparison with the control group (P < 0.05).

Conclusion

The use of lymphocyte active immunotherapy for patients with unexplained recurrent miscarriage can significantly increase the pregnancy success rate, optimize the maternal-infant outcome, drive down the miscarriage rate, and ameliorate the patient's estrogen levels and hemorheology indicators, which is worthy of promotion and application in clinical practice.

Sildenafil Supplementation for Women Undergoing Infertility Treatments: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The aim of this systematic review and meta-analysis is to summarize data on the effectiveness of Sildenafil supplementation for women undergoing assisted reproduction techniques. This meta-analysis of randomized controlled trials (RCTs) evaluates the effects of Sildenafil administration during infertility treatments compared with a control group in infertile women. Outcomes evaluated were endometrial thickness (ETh) and the clinical pregnancy rate (CPR). The chemical pregnancy rate (ChPR) was also evaluated. Pooled results were expressed as the risk ratio (RR) or mean differences (MD) with a 95% confidence interval (95% CI). Women undergoing ovulation induction who received Sildenafil showed higher ETh and a higher CPR in comparison to controls. In this group, both the ETh and ChPR resulted in significantly higher values only with delayed start administration. Women undergoing fresh or frozen embryo transfer who received Sildenafil showed no significant advantages regarding ETh and CPR in comparison to controls. In this group, we found a significantly higher ChPR in women receiving Sildenafil. A subgroup analysis revealed significant advantages regarding ETh with oral administration for women undergoing fresh or frozen embryo transfer. Sildenafil therapy appears to improve endometrial thickness and pregnancy rate in women undergoing timed intercourses but it resulted not effective in IUI and IVF treatments. Further RCTs with rigorous methodology are still mandatory.

Use of sildenafil and other phosphodiesterase type 5 inhibitors among pregnant women in Scandinavia

INTRODUCTION

For phosphodiesterase type 5 (PDE5) inhibitors, such as sildenafil, the only approved indication in women is for pulmonary arterial hypertension. These drugs are increasingly being proposed and tested for treatment of female infertility and complications in pregnancy. However, the extent of use of PDE5 inhibitors in the general pregnant population over the last decades is unknown. Therefore, we conducted a descriptive cohort study using data from the population health registers in the Scandinavian countries.

MATERIAL AND METHODS

By linking the Medical Birth Registers and the Prescribed Drug Registers in Denmark (1997-2017), Norway (2004-2017), and Sweden (2006-2016), women with filled prescriptions of PDE5 inhibitors in outpatient settings in the 90 days before the date of last menstrual period and/or during pregnancies were identified. With additional linkage to the National Patient Registers, information on maternal, pregnancy, and infant characteristics, co-morbidities, and co-medication was collected and described.

RESULTS

Among over 3 million singleton pregnancies, only 77 were pregnancies in women who had at least one filled prescription of a PDE5 inhibitor within the 90 days before the start of pregnancy to delivery. Prescription fills most often occurred before the last menstrual period and in the first trimester, with very few occurring later in pregnancy. Sildenafil was the most used PDE5 inhibitor. Among pregnant women using PDE5 inhibitors, 44% were 35 years of age or older, eight had a cardiovascular diagnosis, and three specifically had a diagnosis of pulmonary arterial hypertension. Among the infants born to mothers using PDE5 inhibitors, nine were born preterm, six were small-for-gestational age, five had an Apgar score at 5 minutes below 8, 18 were admitted to the Neonatal Intensive Care Unit, and eight had respiratory and cardiovascular conditions.

CONCLUSIONS

Few women used PDE5 inhibitors in outpatient settings before or during pregnancy in the Scandinavian countries in the last decades. Only a small proportion had a diagnosis for pulmonary arterial hypertension, suggesting off-label use in the remaining users. Use was predominantly in mothers over age 35 years. The safety of fetal exposure to sildenafil and other PDE5 inhibitors in pregnancy has not been established. As maternal age continues to increase and additional uses of PDE5 inhibitors are investigated, the safety of these drugs in pregnancy should be thoroughly evaluated.

Repurposing of the PDE5 Inhibitor Sildenafil for the Treatment of Persistent Pulmonary Hypertension in Neonates

Nitric oxide (NO), an important endogenous signaling molecule released from vascular endothelial cells and nerves, activates the enzyme soluble guanylate cyclase to catalyze the production of cyclic guanosine monophosphate (cGMP) from guanosine triphosphate. cGMP, in turn, activates protein kinase G to phosphorylate a range of effector proteins in smooth muscle cells that reduce intracellular Ca²⁺ levels to inhibit both contractility and proliferation. The enzyme phosphodiesterase type 5 (PDE5) curtails the actions of cGMP by hydrolyzing it into inactive 5'-GMP. Small molecule PDE5 inhibitors (PDE5is), such as sildenafil, prolong the availability of cGMP and therefore, enhance NO-mediated signaling. PDE5is are the first-line treatment for erectile dysfunction but are also now approved for the treatment of pulmonary arterial hypertension (PAH) in adults. Persistent pulmonary hypertension in neonates (PPHN) is currently treated with inhaled NO, but this is an expensive option and around 1/3 of newborns are unresponsive, resulting in the need for alternative approaches. Here the development, chemistry and pharmacology of PDE5is, the use of sildenafil for erectile dysfunction and PAH, are summarized and then current evidence for the utility of further repurposing of sildenafil, as a treatment for PPHN, is critically reviewed.

Beneficial effect of l-arginine in women using assisted reproductive technologies: a small-scale randomized controlled trial

This small-scale randomized controlled study aimed to examine the effect of l-arginine supplementation on the human chorionic gonadotropin (hCG)-positive rate and clinical pregnancy rate (CPR) in women undergoing assisted reproductive technology (ART) treatment for 3 months. From November 2017 to March 2018, 120 patients aged less than 40 years and planning for egg retrieval for embryo transfer were enrolled. The patients were divided into the AS2000 group (n = 36; l-arginine, 2 g; folate, 400 μg; and vitamin E, 10 mg), AS1000 group (n = 37; l-arginine, 1 g; and folate, 200 μg), and control group (n = 36). The main outcome was the hCG-positive rate or CPR in 3 months. The cumulative hCG-positive rates during the administration period were 44.2%, 54.2%, and 52.1%, and the CPRs were 39.5%, 41.7%, and 47.9% in the control, AS1000, and AS2000 groups, respectively. Odds ratios of the hCG-positive rate and CPR in the global l-arginine group (AS1000 and AS2000) versus those in the control group were 1.33 (95% confidence interval [CI], 0.62-2.90) and 1.11 (95% CI, 0.51-2.46), respectively. In the subgroup of women receiving ART because of male infertility, the hCG-positive rate and CPR were significantly increased in the l-arginine groups compared to those in the control group (13.42 [95% CI, 1.42-366.9] and 13.62 (95% CI, 1.42-367.6), respectively). Thus, arginine supplementation may be an option for women who desire pregnancy, especially those undergoing an ART program because of male infertility.