Adjuvant L-arginine treatment in controlled ovarian hyperstimulation: a double-blind, randomized study

L-Arginine supplementation in pregnancy: a systematic review of maternal and fetal outcomes

BACKGROUND/AIM OF THE STUDY

L-Arginine (L-Arg)/Nitric Oxide (NO) system is involved in the pathophysiology of relevant Obstetric conditions. This review aims at summarizing the effects of L-Arg supplementation in pregnancy looking at safety and efficacy.

METHODS

We conducted a systematic review of the literature utilizing PubMed for studies published from inception to September 2022. The search included human and animal studies where L-Arg was supplemented pre-conceptionally or during pregnancy, by either oral or intravenous route. The main perinatal outcomes were focused.

RESULTS

Among 1028 publications, 51 studies were eligible for inclusion, 25 were performed in women, and the remnant in animals. Compared to controls/placebo, the supplementation with L-Arg reduced the development of pre-eclampsia (four studies), decreased blood pressure, and reduced the need for antihypertensive drugs in women with Hypertensive Disorders of Pregnancy (HDP, eight studies). In women carrying growth retarded fetuses, L-Arg improved fetoplacental circulation, birth weight and neonatal outcomes (five studies), while in the case of threatened preterm birth, L-Arg reduced uterine contractions (two studies). In several animal species, L-Arg supplementation in pregnancy improved reproductive performance by increasing the litter number and size. Moreover, in pre-eclamptic and metabolic syndrome experimental models, maternal hypertension and fetal growth were improved.

CONCLUSION

L-Arg displays biological activities in pregnancies complicated by HDP and growth restriction, both in women and animal models. L-Arg administration is safe and could be a candidate as an intervention beneficial to maternal and fetal outcomes, at least in moderate clinical disorders.

Plasma and amniotic fluid concentrations of nitric oxide: Effects on uterine artery and placental vasculature in women who underwent voluntary pregnancy termination and in women with missed and threatened abortion. A pilot study

OBJECTIVES

First trimester miscarriage is a multifactorial event. Various angiogenic factors have been proposed as possible early markers of non-viable pregnancies. The aim of the present study was to evaluate the systemic nitric oxide (NO) production in healthy early pregnancy and its possible role in first trimester miscarriage.

STUDY DESIGN

We prospectively enrolled women referred to our Unit for elective termination of pregnancy, threatened abortion or missed abortion. Blood samples were taken for testing circulating NO plasma levels. Subsequently, all patients underwent 2-D ultrasonographic analysis and Color Doppler imaging to assess the pulsatility index of the uterine arteries. 3-D ultrasonographic and power Doppler analysis allowed a volumetric and vascular reconstruction of the placenta. During dilatation and vacuum aspiration, amniotic fluid was collected.

RESULTS

Seventy-two patients were enrolled: 25 with elective termination of pregnancy (Group I); 17 with threatened abortion (Group II); 30 with missed abortion (Group III). Group II showed greater placental volume and lower uterine arteries PI than others. The plasma NO concentration resulted statistically higher in women with threatened abortion, while amniotic fluid NO concentration were higher in the viable pregnancies (Group I) than in the aborted fetuses (Group III). Plasma NO was inversely correlated with both mean arterial pressure and uterine artery PI and was positively correlated with amniotic fluid NO and CRL; amniotic fluid NO was positively correlated with placental Vascularization Index and Vascularization-Flow Index.

CONCLUSION

Amniotic NO concentration was higher in viable pregnancies and positively related to Doppler 3D indices of vascularization and blood flow within the placenta. Further studies are needed to elucidate its role in first trimester miscarriage.

Characteristics of the vaginal microbiome in women with premature ovarian insufficiency

PURPOSE

To investigate the relationship between vaginal microbial community structure and premature ovarian insufficiency (POI).

METHODS

Twenty-eight women with POI and 12 healthy women were recruited at Shenzhen Maternity and Child Healthcare Hospital between August and September 2020. Blood samples were collected for glucose tests and detection of sex hormone levels and vaginal secretions were collected for microbial group determination. Vaginal microbial community profiles were analysed by 16S rRNA gene sequencing using the Illumina MiSeq system (Illumina Inc., San Diego, CA, USA).

RESULTS

Compared to the controls, the serum levels of follicle-stimulating hormone, luteinizing hormone, testosterone, and the follicle-stimulating hormone/luteinizing hormone ratio, significantly increased, and oestradiol and anti-Müllerian hormone levels significantly decreased in women with POI. Higher weighted UniFrac values were observed in women with POI than in healthy women. Bacteria in the genera Lactobacillus, Brevundimonas, and Odoribacter were more abundant in the microbiomes of healthy women, while the quantity of bacteria in the genus Streptococcus was significantly increased in the microbiomes of women with POI. Moreover, these differences in microbes in women with POI were closely related to follicle-stimulating hormone, luteinizing hormone, oestradiol, and anti-Müllerian hormone levels and to the follicle-stimulating hormone/luteinizing hormone ratio.

CONCLUSIONS

Women with POI had altered vaginal microbial profiles compared to healthy controls. The alterations in their microbiomes were associated with serum hormone levels. These results will improve our understanding of the vaginal microbial community structure in women with POI.

TRIAL REGISTRATION

CHICTR, ChiCTR2000029576 . Registered 3 August 2020 - Retrospectively registered, https://www.chictr.org.cn/showproj.aspx?proj=48844 .

Antioxidants for female subfertility

BACKGROUND

A couple may be considered to have fertility problems if they have been trying to conceive for over a year with no success. This may affect up to a quarter of all couples planning a child. It is estimated that for 40% to 50% of couples, subfertility may result from factors affecting women. Antioxidants are thought to reduce the oxidative stress brought on by these conditions. Currently, limited evidence suggests that antioxidants improve fertility, and trials have explored this area with varied results. This review assesses the evidence for the effectiveness of different antioxidants in female subfertility.

OBJECTIVES

To determine whether supplementary oral antioxidants compared with placebo, no treatment/standard treatment or another antioxidant improve fertility outcomes for subfertile women.

SEARCH METHODS

We searched the following databases (from their inception to September 2019), with no language or date restriction: Cochrane Gynaecology and Fertility Group (CGFG) specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and AMED. We checked reference lists of relevant studies and searched the trial registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among women attending a reproductive clinic. We excluded trials comparing antioxidants with fertility drugs alone and trials that only included fertile women attending a fertility clinic because of male partner infertility.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary review outcome was live birth; secondary outcomes included clinical pregnancy rates and adverse events.

MAIN RESULTS

We included 63 trials involving 7760 women. Investigators compared oral antioxidants, including: combinations of antioxidants, N-acetylcysteine, melatonin, L-arginine, myo-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D+calcium, CoQ10, and omega-3-polyunsaturated fatty acids versus placebo, no treatment/standard treatment or another antioxidant. Only 27 of the 63 included trials reported funding sources. Due to the very low-quality of the evidence we are uncertain whether antioxidants improve live birth rate compared with placebo or no treatment/standard treatment (odds ratio (OR) 1.81, 95% confidence interval (CI) 1.36 to 2.43; P < 0.001, I2 = 29%; 13 RCTs, 1227 women). This suggests that among subfertile women with an expected live birth rate of 19%, the rate among women using antioxidants would be between 24% and 36%. Low-quality evidence suggests that antioxidants may improve clinical pregnancy rate compared with placebo or no treatment/standard treatment (OR 1.65, 95% CI 1.43 to 1.89; P < 0.001, I2 = 63%; 35 RCTs, 5165 women). This suggests that among subfertile women with an expected clinical pregnancy rate of 19%, the rate among women using antioxidants would be between 25% and 30%. Heterogeneity was moderately high. Overall 28 trials reported on various adverse events in the meta-analysis. The evidence suggests that the use of antioxidants makes no difference between the groups in rates of miscarriage (OR 1.13, 95% CI 0.82 to 1.55; P = 0.46, I2 = 0%; 24 RCTs, 3229 women; low-quality evidence). There was also no evidence of a difference between the groups in rates of multiple pregnancy (OR 1.00, 95% CI 0.63 to 1.56; P = 0.99, I2 = 0%; 9 RCTs, 1886 women; low-quality evidence). There was also no evidence of a difference between the groups in rates of gastrointestinal disturbances (OR 1.55, 95% CI 0.47 to 5.10; P = 0.47, I2 = 0%; 3 RCTs, 343 women; low-quality evidence). Low-quality evidence showed that there was also no difference between the groups in rates of ectopic pregnancy (OR 1.40, 95% CI 0.27 to 7.20; P = 0.69, I2 = 0%; 4 RCTs, 404 women). In the antioxidant versus antioxidant comparison, low-quality evidence shows no difference in a lower dose of melatonin being associated with an increased live-birth rate compared with higher-dose melatonin (OR 0.94, 95% CI 0.41 to 2.15; P = 0.89, I2 = 0%; 2 RCTs, 140 women). This suggests that among subfertile women with an expected live-birth rate of 24%, the rate among women using a lower dose of melatonin compared to a higher dose would be between 12% and 40%. Similarly with clinical pregnancy, there was no evidence of a difference between the groups in rates between a lower and a higher dose of melatonin (OR 0.94, 95% CI 0.41 to 2.15; P = 0.89, I2 = 0%; 2 RCTs, 140 women). Three trials reported on miscarriage in the antioxidant versus antioxidant comparison (two used doses of melatonin and one compared N-acetylcysteine versus L-carnitine). There were no miscarriages in either melatonin trial. Multiple pregnancy and gastrointestinal disturbances were not reported, and ectopic pregnancy was reported by only one trial, with no events. The study comparing N-acetylcysteine with L-carnitine did not report live birth rate. Very low-quality evidence shows no evidence of a difference in clinical pregnancy (OR 0.81, 95% CI 0.33 to 2.00; 1 RCT, 164 women; low-quality evidence). Low quality evidence shows no difference in miscarriage (OR 1.54, 95% CI 0.42 to 5.67; 1 RCT, 164 women; low-quality evidence). The study did not report multiple pregnancy, gastrointestinal disturbances or ectopic pregnancy. The overall quality of evidence was limited by serious risk of bias associated with poor reporting of methods, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

In this review, there was low- to very low-quality evidence to show that taking an antioxidant may benefit subfertile women. Overall, there is no evidence of increased risk of miscarriage, multiple births, gastrointestinal effects or ectopic pregnancies, but evidence was of very low quality. At this time, there is limited evidence in support of supplemental oral antioxidants for subfertile women.

Do antioxidants improve serum sex hormones and total motile sperm count in idiopathic infertile men?

OBJECTIVE

Reactive oxygen species reduce the male sex hormone levels and disrupt the hormonal balance that regulates male reproductive functions. They disrupt spermatozoa and other testicular cells. This study aimed at evaluating the effect of antioxidant treatment on serum gonadal hormones and sperm parameters in men with idiopathic infertility.

MATERIAL AND METHODS

A total of 100 idiopathic infertile men aged 23-46 years were included in the study. Control group and antioxidant treatment group consisted of 50 men each. Patients in the treatment group received oral antioxidant supplement once a day. The antioxidant supplement content included L-carnitine, L-arginine, vitamin E, vitamin C, coenzyme Q, glutathione, beta-carotene, magnesium, vitamin B12, zinc, vitamin A, vitamin B6, vitamin D3, folic acid, and selenium. Reproductive hormones and sperm parameters were compared between the groups at 6 months after starting the antioxidant therapy.

RESULTS

No significant differences were observed in the patient age (p=0.861), partner age (p=0.081), total motile sperm count (TMSC) (p=0.324), and follicle-stimulating hormone (FSH) (p=0.557), luteinizing hormone (LH) (p=0.235), and total testosterone levels (p=0.851) at baseline between the treatment and control groups. Although the mean TMSC did not increase significantly, the mean FSH (p=0.008), LH (p=0.008), and total testosterone (p=0.006) levels significantly increased from baseline to post-treatment in the treatment group. However, no significant differences from baseline to post-treatment were observed in TMSC (p=0.486), FSH (p=0.712), LH (p=0.696), and total testosterone levels (p=0.546) in the control group.

CONCLUSION

The research draws attention to the alternate treatment approaches in infertile men. Antioxidant treatment can increase the serum sex hormone levels.

Effects of N-carbamylglutamate and arginine on steroidogenesis and proliferation of pig granulosa cells in vitro

Results of in vivo studies indicate dietary N-carbamylglutamate (NCG) and arginine (ARG) can enhance reproductive performance in gilts. It was hypothesized that both NCG and ARG will alter hormone-induced estradiol (E2) production by granulosa cells (GC), explaining why these compounds could improve reproductive performance in pigs. The objective of these studies, therefore, was to evaluate the direct effects of NCG and ARG on porcine GC proliferation and steroidogenesis, using an in vitro cell culture system. The GC from small (SM; 1-5 mm) and large (LG; >5 mm) pig follicles were cultured for 2 days in 5% fetal bovine serum and 5% porcine serum-containing medium followed by 2 days in serum-free medium containing 500 ng/mL of testosterone (as an E2 precursor), and NCG or ARG at various doses in the presence of either follicle-stimulating hormone (FSH; 30 ng/mL), insulin-like growth factor-1 (IGF1; 30 ng/mL), or both. Numbers of GC were determined at the end of the experiment and concentrations of progesterone (P4) and E2 in culture medium were determined. Results indicated that LG-follicle GC were more responsive to NCG and ARG than SM-follicle GC. Specifically, in LG-follicle GC, NCG inhibited (P <  0.05) basal and FSH-induced P4 and E2 production but stimulated cell numbers; whereas ARG inhibited FSH-induced E2 production and cell numbers. In SM-follicle GC, treatment with NCG and ARG decreased IGF1 plus FSH induced P4 production, but E2 production and cell proliferation were not affected. These studies indicate that NCG and ARG may directly affect follicular function in pigs.

Antioxidants for female subfertility

BACKGROUND

A couple may be considered to have fertility problems if they have been trying to conceive for over a year with no success. This may affect up to a quarter of all couples planning a child. It is estimated that for 40% to 50% of couples, subfertility may result from factors affecting women. Antioxidants are thought to reduce the oxidative stress brought on by these conditions. Currently, limited evidence suggests that antioxidants improve fertility, and trials have explored this area with varied results. This review assesses the evidence for the effectiveness of different antioxidants in female subfertility.

OBJECTIVES

To determine whether supplementary oral antioxidants compared with placebo, no treatment/standard treatment or another antioxidant improve fertility outcomes for subfertile women.

SEARCH METHODS

We searched the following databases (from their inception to September 2016) with no language or date restriction: Cochrane Gynaecology and Fertility Group (CGFG) specialised register, the Cochrane Central Register of Studies (CENTRAL CRSO), MEDLINE, Embase, PsycINFO, CINAHL and AMED. We checked reference lists of appropriate studies and searched for ongoing trials in the clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among women attending a reproductive clinic. We excluded trials comparing antioxidants with fertility drugs alone and trials that only included fertile women attending a fertility clinic because of male partner infertility.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible studies, extracted the data and assessed the risk of bias of the included studies. The primary review outcome was live birth; secondary outcomes included clinical pregnancy rates and adverse events. We pooled studies using a fixed-effect model, and calculated odds ratios (ORs) with 95% confidence intervals (CIs) for the dichotomous outcomes of live birth, clinical pregnancy and adverse events. We assessed the overall quality of the evidence by applying GRADE criteria.

MAIN RESULTS

We included 50 trials involving 6510 women. Investigators compared oral antioxidants, including combinations of antioxidants, N-acetyl-cysteine, melatonin, L-arginine, myo-inositol, D-chiro-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D+calcium, CoQ10, pentoxifylline and omega-3-polyunsaturated fatty acids versus placebo, no treatment/standard treatment or another antioxidant.Very low-quality evidence suggests that antioxidants may be associated with an increased live birth rate compared with placebo or no treatment/standard treatment (OR 2.13, 95% CI 1.45 to 3.12, P > 0.001, 8 RCTs, 651 women, I2 = 47%). This suggests that among subfertile women with an expected live birth rate of 20%, the rate among women using antioxidants would be between 26% and 43%.Very low-quality evidence suggests that antioxidants may be associated with an increased clinical pregnancy rate compared with placebo or no treatment/standard treatment (OR 1.52, 95% CI 1.31 to 1.76, P < 0.001, 26 RCTs, 4271 women, I2 = 66%). This suggests that among subfertile women with an expected clinical pregnancy rate of 22%, the rate among women using antioxidants would be between 27% and 33%. Heterogeneity was moderately high.There was insufficient evidence to determine whether there was a difference between the groups in rates of miscarriage (OR 0.79, 95% CI 0.58 to 1.08, P = 0.14, 18 RCTs, 2834 women, I2 = 23%, very low quality evidence). This suggests that, among subfertile women with an expected miscarriage rate of 7%, use of antioxidants would be expected to result in a miscarriage rate of between 4% and 7%. There was also insufficient evidence to determine whether there was a difference between the groups in rates of multiple pregnancy (OR 1.00, 95% CI 0.73 to 1.38, P = 0.98, 8 RCTs, 2163 women, I2 = 4%, very low quality evidence). This suggests that among subfertile women with an expected multiple pregnancy rate of 8%, use of antioxidants would be expected to result in a multiple pregnancy rate between 6% and 11%. Likewise, there was insufficient evidence to determine whether there was a difference between the groups in rates of gastrointestinal disturbances (OR 1.55, 95% CI 0.47 to 5.10, P = 0.47, 3 RCTs, 343 women, I2 = 0%, very low quality evidence). This suggests that among subfertile women with an expected gastrointestinal disturbance rate of 2%, use of antioxidants would be expected to result in a rate between 1% and 11%. Overall adverse events were reported by 35 trials in the meta-analysis, but there was insufficient evidence to draw any conclusions.Only one trial reported on live birth, clinical pregnancy or adverse effects in the antioxidant versus antioxidant comparison, and no conclusions could be drawn.Very low-quality evidence suggests that pentoxifylline may be associated with an increased clinical pregnancy rate compared with placebo or no treatment (OR 2.07, 95% CI 1.20 to 3.56, P = 0.009, 3 RCTs, 276 women, I2 = 0%). This suggests that among subfertile women with an expected clinical pregnancy rate of 25%, the rate among women using pentoxifylline would be between 28% and 53%.There was insufficient evidence to determine whether there was a difference between the groups in rates of miscarriage (OR 1.34, 95% CI 0.46 to 3.90, P = 0.58, 3 RCTs, 276 women, I2 = 0%) or multiple pregnancy (OR 0.78, 95% CI 0.20 to 3.09, one RCT, 112 women, very low quality evidence). This suggests that among subfertile women with an expected miscarriage rate of 4%, the rate among women using pentoxifylline would be between 2% and 15%. For multiple pregnancy, the data suggest that among subfertile women with an expected multiple pregnancy rate of 9%, the rate among women using pentoxifylline would be between 2% and 23%.The overall quality of evidence was limited by serious risk of bias associated with poor reporting of methods, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

In this review, there was very low-quality evidence to show that taking an antioxidant may provide benefit for subfertile women, but insufficient evidence to draw any conclusions about adverse events. At this time, there is limited evidence in support of supplemental oral antioxidants for subfertile women.

Nitric oxide donors increase the pregnancy rate in patients with unexplained infertility undergoing clomiphene citrate stimulation and intrauterine insemination: a randomized controlled pilot study

This study evaluated the effects of nitric oxide donor's treatment on the pregnancy rate and uterine blood flow in patients with unexplained infertility undergoing clomiphene citrate stimulation and intrauterine insemination. A total of 120 patients were randomly allocated to a control group who received 100 mg clomiphene citrate daily from day 5 to 9 of cycle plus placebo vaginal tablets, and a study group received clomiphene citrate plus isosorbide mononitrate 10 mg vaginal tablets. Vaginal ultrasound was done before treatment and every other day starting from day 12 of cycle to count mature follicles and ovulation was triggered by IM injection of 10 000 IU hCG when one follicle measured 18 ≥ mm followed by intrauterine insemination after 36 h. The endometrial thickness, uterine arteries resistance and pulsation indices, and endometrial vascular flow and vascular flow indices were measured before treatment and at day of hCG injection. Results were analyzed after one cycle treatment using the Mean ± SD, the Student t test and the Fisher Exact test. Significant result was considered at p values <0.05. The study group had significant higher pregnancy rate/cycle, higher endometrial and lower uterine artery blood flow indices (p < 0.05).

Physiopathology of human embryonic implantation: clinical incidences

Embryo implantation consists of a series of events promoting the invasion of the endometrium and then the uterine arterial system by the extra-embryonic trophoblast. In order for this semi-heterologous implantation to succeed, the endometrium has to first undergo a number of structural and biochemical changes (decidualization). The decidua's various constituents subsequently play a role in the embryonic implantation. The third step is the transformation of the uterine vascular system and the growth of the placenta, which will provide the foetoplacental unit with nutrients. Several physiopathological aspects will be discussed: 1) the implantation window, regulated by maternal and embryonic hormonal secretions and thus influenced by any defects in the latter: dysharmonic luteal phase, 21-hydroxylase block, abnormal integrin expression, 2) the successive trophoblast invasions of uterine vessels which, when defective, lead to early embryo loss or late-onset vascular pathologies, as preeclampsia, 3) the pregnancy's immunological equilibrium, with a spontaneously tolerated semi-allogeneic implant, 4) the impact of pro-coagulant factors (thrombophilia) on the pregnancy's progression, 5) the environment of the uterus, ranging from hydrosalpinx to uterine contractions. In summary, the least anatomical or physiological perturbation can interfere with human embryonic implantation - a very particular phenomenon and a true biological paradox.

Antioxidants for female subfertility

BACKGROUND

A couple may be considered to have fertility problems if they have been trying to conceive for over a year with no success. This difficulty with conception may affect up to a quarter of all couples planning a child. The reported prevalence of subfertility has increased significantly over the past twenty years. It is estimated that for 40% to 50% of couples, subfertility may be a result of female problems, including ovulatory disorders, poor egg quality, fallopian tube damage and endometriosis. Antioxidants are thought to reduce the oxidative stress brought on by these conditions. Currently, limited evidence suggests that antioxidants improve fertility, and trials have explored this area with varied results. This review assessed the evidence for the effectiveness of different antioxidants in female subfertility.

OBJECTIVES

To determine whether supplementary oral antioxidants compared with placebo, no treatment/standard treatment or another antioxidant improve fertility outcomes for subfertile women.

SEARCH METHODS

We searched the following databases (from inception to April 2013) with no language restrictions applied: Cochrane Menstrual Disorders and Subfertility Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS and OpenSIGLE. We also searched conference abstracts and citation lists in the ISI Web of Knowledge. Ongoing trials were searched in the Trials Registers. Reference lists were checked, and a search on Google was performed.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among women attending a reproductive clinic. Trials comparing antioxidants with fertility drugs alone and trials that exclusively included fertile women attending a fertility clinic because of male partner infertility were excluded.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened 2127 titles and abstracts, and 67 of these potentially eligible trials were appraised for inclusion and quality through review of full texts and contact with authors. Three review authors were involved in data extraction and assessment of risk of bias. Review authors also collected data on adverse events as reported from the trials. Studies were pooled using fixed-effect models; however, if high heterogeneity was found, a random-effects model was used. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for the dichotomous outcomes of live birth, clinical pregnancy and adverse events. Analyses were stratified by type of antioxidant, by indications for subfertility and by those women also undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection techniques (ICSIs). The overall quality of the evidence was assessed by applying GRADE criteria.

MAIN RESULTS

A total of 28 trials involving 3548 women were included in this review. Investigators compared oral antioxidants, including combinations of antioxidants, pentoxifylline, N-acetyl-cysteine, melatonin, L-arginine, vitamin E, myo-inositol, vitamin C, vitamin D+calcium and omega-3-polyunsaturated fatty acids with placebo, with no treatment/standard treatment or another antioxidant.Antioxidants were not associated with an increased live birth rate compared with placebo or no treatment/standard treatment (OR 1.25, 95% CI 0.19 to 8.26, P = 0.82, 2 RCTs, 97 women, I(2) = 75%, very low-quality evidence). This suggests that among subfertile women with an expected live birth rate of 37%, the rate among women taking antioxidants would be between 10% and 83%.Antioxidants were not associated with an increased clinical pregnancy rate compared with placebo or no treatment/standard treatment (OR 1.30, 95% CI 0.92 to 1.85, P = 0.14, 13 RCTs, 2441 women, I(2)= 55%, very low-quality evidence). This suggests that among subfertile women with an expected clinical pregnancy rate of 23%, the rate among women taking antioxidants would be between 22% and 36%.Only one trial reported on live birth in the antioxidant versus antioxidant comparison, and two trials reported on clinical pregnancy in this comparison. Only subtotals were used in this analysis, and meta-analysis was not possible as each trial used a different antioxidant.Pentoxifylline was associated with an increased clinical pregnancy rate compared with placebo or no treatment (OR 2.03, 95% CI 1.19 to 3.44, P = 0.009, 3 RCTs, 276 women, I(2) = 0%).Adverse events were reported by 14 trials in the meta-analysis and included miscarriage, multiple pregnancy, ectopic pregnancy and gastrointestinal effects. No evidence revealed a difference in adverse effects between antioxidant groups and control groups, but these data were limited.The overall quality of evidence was 'very low' to 'low' because of poor reporting of outcomes, the number of small studies included, high risk of bias within studies and heterogeneity in the primary analysis.

AUTHORS' CONCLUSIONS

The quality of the evidence in the 'antioxidant versus placebo/no treatment' and in the 'antioxidant versus antioxidant' comparisons was assessed to be 'very low'. Antioxidants were not associated with an increased live birth rate or clinical pregnancy rate. There was some evidence of an association of pentoxifylline with an increased clinical pregnancy rate; however, there were only three trials included in this comparison. Future trials may change this result. Variation in the types of antioxidants given meant that we could not assess whether one antioxidant was better than another. There did not appear to be any association of antioxidants with adverse effects for women, but data for these outcomes were limited.

L-arginine plus drospirenone-ethinyl estradiol in the treatment of patients with PCOS: a prospective, placebo controlled, randomised, pilot study

OBJECTIVE

To verify the effects of a pill containing drospirenone on the surrogate markers of arterial function and to evaluate the possible improvements induced by the addition of L-arginine.

DESIGN

A prospective, placebo controlled, randomised, pilot study.

SETTING

University of Bologna.

POPULATION

Twenty-eight young women with PCOS.

METHODS

Random submission to: drospirenone + ethinylestradiol+ a placebo (Group I; n = 15) or drospirenone + ethinylestradiol + oral L-arginine (4 g × 2/daily) (Group II, n = 13).

MAIN OUTCOME MEASURES

Medical examination; blood measurement of nitrites/nitrates, biochemical and hormonal parameters; ultrasonographic analysis and colour Doppler evaluation of uterine, stromal ovarian and ophthalmic arteries; analysis of brachial artery flow-mediated vasodilatation; and 24-h ambulatory blood pressure monitoring. The above parameters were evaluated before and after 6 months.

RESULTS

The low dose oral contraceptive containing drospirenone favoured a pre-hypertensive state. The L-arginine supplementation increased the circulating levels of nitrites/nitrates and improved the endothelium-dependent vasodilatation counteracting the negative effect of the contraceptive pill.

CONCLUSIONS

Although, the present pilot study was conducted in a limited number of patients, it seems that the L-arginine co-treatment may improve the long-term side effects of the pill reducing the risk of cardiovascular diseases.

Negative association of L-arginine methylation products with oocyte numbers

BACKGROUND

The aim of this study was to determine the concentrations of L-arginine and methylarginines in follicular fluid obtained from women participating in our IVF program and to find clinical correlates of these biochemical parameters.

METHODS

Follicular fluid was obtained from 108 women by ultrasonography guided transvaginal puncture following controlled ovarian hyperstimulation. Follicular fluid L-arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and monomethylarginine (MMA) concentrations were determined with liquid chromatography-tandem mass spectrometry. The integrated index of arginine methylation (arg-MI) was calculated according to the formula: arg-MI = (ADMA + SDMA)/MMA.

RESULTS

There were significant inverse relationships between IVF embryo number and follicular fluid L-arginine (r = -0.507, P < 0.001), ADMA (r = -0.356, P < 0.024), SDMA (r = -0.347, P < 0.028), MMA (r = -0.449, P < 0.004) and to L-arginine/ADMA ratio (r = -0.328, P < 0.031). By contrast, arg-MI was directly related to IVF embryo number (r = 0.426, P < 0.006). Moreover, the number of IVF oocytes was also inversely related to ADMA (r = -0.202, P < 0.037) and MMA (r = -0.384, P < 0.012) and positively to arg-MI (r = 0.450, P < 0.03).

CONCLUSIONS

The elevated levels of follicular fluid l-arginine and methylarginines appear to have an adverse influence on the reproductive processes as reflected by a reduction in the number of oocytes and embryos conceived. In contrast, the integrated methylation index proved to be positively correlated to the above parameters of fertilization.

Cardiovascular risk in normal weight, eumenorrheic, nonhirsute daughters of patients with polycystic ovary syndrome: a pilot study

OBJECTIVE

To verify whether healthy daughters with polycystic ovaries (PCO) of patients with polycystic ovary syndrome (PCOS) have an increased risk of cardiovascular disease in comparison with healthy controls.

DESIGN

Prospective observational study.

SETTING

University hospital.

PATIENT(S)

Seventeen eumenorrheic daughters with PCO of patients with PCOS (group 1) and 20 healthy volunteers (group 2) with regular ovulatory cycles.

INTERVENTION(S)

Fasting blood sampling, ultrasonographic and Doppler analyses, 24-hour ambulatory blood pressure monitoring.

MAIN OUTCOME MEASURE(S)

Medical examination; blood measurement of nitrites and nitrates, biochemical and hormonal parameters; utero-ovarian ultrasonographic analysis and color Doppler evaluation of uterine and stromal ovarian arteries; brachial artery flow-mediated vasodilatation; 24-hour ambulatory blood pressure monitoring. An oral glucose tolerance test was performed to analyze glucose, insulin, and C-peptide levels.

RESULT(S)

At Doppler analysis a significantly higher uterine and a lower ovarian artery pulsatility index was found in group 1 compared with group 2. The brachial artery diameter, after the reactive hyperemia, showed a greater vasodilatation in controls in comparison with women with PCO. The 24-hour blood pressure monitoring demonstrated that patients with PCO have significant higher 24-hour, daytime, and nighttime diastolic and mean arterial pressure values than controls. The nitrites and nitrates plasma levels were lower in group 1 compared with group 2. The glucose and insulin plasma values were higher in patients with PCO than in controls.

CONCLUSION(S)

Eumenorrheic nonhirsute daughters of patients with PCOS who have PCO appearance on ultrasound have an increased cardiovascular risk.

Risk assessment for the amino acids taurine, L-glutamine and L-arginine

Taurine, glutamine and arginine are examples of amino acids which have become increasingly popular as ingredients in dietary supplements and functional foods and beverages. Animal and human clinical research suggests that oral supplementation of these amino acids provides additional health and/or performance benefits beyond those observed from normal intake of dietary protein. The increased consumer awareness and use of these amino acids as ingredients in dietary supplements and functional foods warrant a comprehensive review of their safety through quantitative risk assessment, and identification of a potential safe upper level of intake. The absence of a systematic pattern of adverse effects in humans in response to orally administered taurine (Tau), l-glutamine (Gln) and l-arginine (Arg) precluded the selection of a no observed adverse effect level (NOAEL) or lowest observed adverse effect level (LOAEL). Therefore, by definition, the usual approach to risk assessment for identification of a tolerable upper level of intake (UL) could not be used. Instead, the newer method described as the Observed Safe Level (OSL) or Highest Observed Intake (HOI) was utilized. The OSL risk assessments indicate that based on the available published human clinical trial data, the evidence for the absence of adverse effects is strong for Tau at supplemental intakes up to 3 g/d, Gln at intakes up to 14 g/d and Arg at intakes up to 20 g/d, and these levels are identified as the respective OSLs for normal healthy adults. Although much higher levels of each of these amino acids have been tested without adverse effects and may be safe, the data for intakes above these levels are not sufficient for a confident conclusion of long-term safety, and therefore these values are not selected as the OSLs.

Evidence of improving quality of reporting of randomized controlled trials in subfertility

BACKGROUND

The quality of randomized controlled trials (RCTs) in subfertility and their suitability for inclusion in meta-analyses have been assessed in the past and found to be insufficient. Our aim was to assess whether this quality has improved over time, particularly since the publication of the Consolidated Standards of Reporting Trials (CONSORT) statement, and to assess what proportion of trials could be included in the meta-analyses of pregnancy outcomes such as those included in Cochrane Reviews.

METHODS

A selection of subfertility trials published in 1990, 1996 and 2002 was collected from the Cochrane Menstrual Disorder and Subfertility Group (MDSG) database. Only trials published in English as full journal articles, claiming to be randomized and reporting on pregnancy outcomes, were included.

RESULTS

One hundred and sixty-four trials met our inclusion criteria. Twenty-four (15%) were found not to be randomized, despite claims, and only 10 trials (6%) provided adequate details on the methods of randomization and allocation concealment. Of these, only three had sufficient details extractable to allow for an intention-to-treat analysis of the outcome 'live birth'.

CONCLUSIONS

Although an improvement in some subfertility-specific issues was observed, the quality of reporting of RCTs still needs to improve to make them suitable for inclusion in meta-analyses such as those in the Cochrane Library.

Uterine vascularization and pregnancy outcome in patients undergoing intracytoplasmatic sperm injection: the role of nitric oxide

PURPOSE

To evaluate whether, after pituitary desensitisation, the impedance to flow in the uterine vessels may be an indicator of an ICSI programme outcome, and to test the relationship between intrafollicular nitric oxide and oocyte/embryo quality.

METHODS

Thirty-eight women, on the basis of impedance to flow at the level of uterine artery, evaluated on the first day of COH, were divided in patients with normal (Pulsatility Index--PI, 2.5; Group II, n=27) PI values. The patients were submitted to hormonal, ultrasonographic and Doppler evaluations. Plasma and follicular fluid concentrations of nitrites/nitrate (NO(2) (-)/NO(3) (-)) were assayed.

RESULTS

In the Group I, the impedance to flow remained lower than in Group II and was associated to good quality embryos and to a higher pregnancy rate. Follicular fluid NO(2) (-)/NO(3) (-) levels were inversely correlated with the embryo quality. The uterine artery PI and the pregnancy rate were inversely correlated. The PIs analysed on the day 1 of stimulation, were positively correlated with those registered on day 8 and on the day of ovum pick-up.

CONCLUSIONS

A Doppler analysis done on day 1 of controlled ovarian hyperstimulation may be an useful indicator of ART outcome.

What can the clinician do to improve implantation?

Implantation is a complicated process that requires the orchestration of a series of events involving both the embryo and the endometrium. Even with the transfer of high quality embryos, implantation rates remain relatively low. The growing tendency towards transferring fewer embryos provides further incentives to improve implantation rates. In this article, the various clinical strategies employed to increase the chance of implantation are reviewed. Embryo transfer technique is a critical step in assisted reproductive technology cycles. Recent studies have shown significant improvements in clinical pregnancy rates resulting from careful embryo transfer technique, appropriate catheter type and placing for embryo transfer. Increasingly, adjuvant pharmaceutical therapies are also being applied with the aim of improving embryo implantation. However, the evidence for their efficacy and safety is limited. Recent evidence suggests that adoption of milder ovarian stimulation regimens may provide a more effective clinical approach to improving implantation, since beneficial effects have been shown for both endometrial receptivity and embryo quality.

Role of oxidative stress in female reproduction

In a healthy body, ROS (reactive oxygen species) and antioxidants remain in balance. When the balance is disrupted towards an overabundance of ROS, oxidative stress (OS) occurs. OS influences the entire reproductive lifespan of a woman and even thereafter (i.e. menopause). OS results from an imbalance between prooxidants (free radical species) and the body's scavenging ability (antioxidants). ROS are a double-edged sword - they serve as key signal molecules in physiological processes but also have a role in pathological processes involving the female reproductive tract. ROS affect multiple physiological processes from oocyte maturation to fertilization, embryo development and pregnancy. It has been suggested that OS modulates the age-related decline in fertility. It plays a role during pregnancy and normal parturition and in initiation of preterm labor. Most ovarian cancers appear in the surface epithelium, and repetitive ovulation has been thought to be a causative factor. Ovulation-induced oxidative base damage and damage to DNA of the ovarian epithelium can be prevented by antioxidants. There is growing literature on the effects of OS in female reproduction with involvement in the pathophysiology of preeclampsia, hydatidiform mole, free radical-induced birth defects and other situations such as abortions. Numerous studies have shown that OS plays a role in the pathophysiology of infertility and assisted fertility. There is some evidence of its role in endometriosis, tubal and peritoneal factor infertility and unexplained infertility. This article reviews the role OS plays in normal cycling ovaries, follicular development and cyclical endometrial changes. It also discusses OS-related female infertility and how it influences the outcomes of assisted reproductive techniques. The review comprehensively explores the literature for evidence of the role of oxidative stress in conditions such as abortions, preeclampsia, hydatidiform mole, fetal embryopathies, preterm labour and preeclampsia and gestational diabetes. The review also addresses the growing literature on the role of nitric oxide species in female reproduction. The involvement of nitric oxide species in regulation of endometrial and ovarian function, etiopathogenesis of endometriosis, and maintenance of uterine quiescence, initiation of labour and ripening of cervix at parturition is discussed. Complex interplay between cytokines and oxidative stress in the etiology of female reproductive disorders is discussed. Oxidant status of the cell modulates angiogenesis, which is critical for follicular growth, corpus luteum formation endometrial differentiation and embryonic growth is also highlighted in the review. Strategies to overcome oxidative stress and enhance fertility, both natural and assisted are delineated. Early interventions being investigated for prevention of preeclampsia are enumerated. Trials investigating combination intervention strategy of vitamin E and vitamin C supplementation in preventing preeclampsia are highlighted. Antioxidants are powerful and there are few trials investigating antioxidant supplementation in female reproduction. However, before clinicians recommend antioxidants, randomized controlled trials with sufficient power are necessary to prove the efficacy of antioxidant supplementation in disorders of female reproduction. Serial measurement of oxidative stress biomarkers in longitudinal studies may help delineate the etiology of some of the diosorders in female reproduction such as preeclampsia.

Nitric oxide is associated with poor embryo quality and pregnancy outcome in in vitro fertilization cycles

OBJECTIVE

To evaluate the association between follicular and serum nitric oxide (NO) levels and embryo development and outcome in IVF.

DESIGN

Prospective, case-control study.

SETTING

University hospital, tertiary medical center.

PATIENT(S)

Eighteen patients with tubal or peritoneal factor infertility and 18 female partners from couples with male factor infertility underwent controlled ovarian stimulation and IVF/intracytoplasmic sperm injection (ICSI).

INTERVENTION(S)

Controlled ovarian stimulation and oocyte retrieval followed by IVF/ICSI and embryo culture.

MAIN OUTCOME MEASURE(S)

Degree of fragmentation of embryos and pregnancy rate.

RESULT(S)

Higher follicular NO levels were associated with advanced fragmentation of embryos. Follicular soluble Fas could not prevent embryo fragmentation. Higher serum NO levels were found among nonpregnant patients with tubal or peritoneal factor infertility. No elevated serum NO levels were found in the female partners from couples with male factor infertility.

CONCLUSION(S)

Up-regulation of serum NO is associated with implantation failure in patients with tubal or peritoneal factor infertility.

Embryonic production of nitric oxide and its role in implantation: a pilot study

PURPOSE

To investigate the ability of human embryos to produce nitric oxide (NO) and correlate its production with embryo quality and pregnancy rate.

METHODS

Twenty-three women participated in the study and were submitted to controlled ovarian stimulation and intracytoplasmic sperm injection. Embryos were singularly cultured in medium microdrops of 50 microL and were replaced, by transcervical transfer, at the 2- to 6-cell stage. In the culture media of each embryo the NO production was assessed by monitoring the levels of its stable oxidation products (nitrites/nitrates).

RESULTS

All the 23 patients underwent embryo transfer. After microinjection 64 embryos were obtained. The mean number of transferred embryos was 2.61 +/- 0.46 and the pregnancy rate was 26%. The mean nitrite/nitrate concentrations of culture medium of each embryo was significantly higher (5.88 +/- 2.34 micromol/L) than in pure P-1 medium (0.81 +/- 0.21 micromol/L; p < 0.001) demonstrating an embryonic secretion of NO. Comparing pregnant (7.34 +/- 2.72 micromol/L) versus nonpregnant patients (5.53 +/- 1.49 micromol/L; p = 0.022), the mean nitrite/nitrate concentrations were significantly higher. Furthermore, the best quality embryos of pregnant women produced significantly higher nitrite/nitrate concentrations than those of not pregnant patients.

CONCLUSIONS

It seems that NO production in nidating embryos is increased and that it may be primarily associated with a better morphology and a better growth potential of developing embryos.

Effects of L-arginine and sodium nitroprusside on the spontaneous contractility of human non-pregnant uterus

BACKGROUND

The aim of this study was to investigate, in isolated human non-gravid myometrium, the involvement of the cyclic guanosine monophosphate (cGMP) pathway in nitric oxide (NO) induced relaxation.

METHODS

Strips of human myometrium from hysterectomized women were suspended in organ baths for recording of isometric tension. Cumulative concentration-response curves for L-arginine and sodium nitroprusside were performed in the presence of methylene blue (10 micromol/l) or vehicle (control). The effect of increasing concentrations of 8-bromo-cGMP on uterine spontaneous contraction was also studied.

RESULTS

L-arginine and sodium nitroprusside induced a concentration-dependent decrease in the amplitude of the myometrial spontaneous contractions. Pre-treatment with methylene blue enhanced the inhibitory effect of L-arginine and sodium nitroprusside on myometrial spontaneous contractions. In addition, 8-bromo-cGMP had no effect on spontaneous contractions in human myometrium.

CONCLUSIONS

These data provide evidence that L-arginine and sodium nitroprusside inhibit the spontaneous contractions of the non-pregnant human uterus through a cGMP independent pathway.