Devenir des enfants issus des techniques d’assistance médicale à la procréation

Vasodilators for women undergoing fertility treatment

BACKGROUND

The rate of successful pregnancies brought to term has barely increased since the first assisted reproductive technology (ART) technique became available. Vasodilators have been proposed to increase endometrial receptivity, thicken the endometrium, and favour uterine relaxation, all of which could improve uterine receptivity and enhance the chances for successful assisted pregnancy.

OBJECTIVES

To evaluate the effectiveness and safety of vasodilators in women undergoing fertility treatment.

SEARCH METHODS

We searched the following electronic databases, trial registers, and websites: the Cochrane Gynaecology and Fertility Group (CGF) Specialised Register of controlled trials, the Cochrane Central Register of of Controlled Trials, via the Cochrane Register of Studies Online (CRSO), MEDLINE, Embase, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Knowledge, the Open System for Information on Grey Literature in Europe (OpenSIGLE), the Latin American and Caribbean Health Science Information Database (LILACS), clinical trial registries, and the reference lists of relevant articles. We conducted the search in October 2017 and applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing vasodilators alone or in combination with other treatments versus placebo or no treatment or versus other agents in women undergoing fertility treatment.

DATA COLLECTION AND ANALYSIS

Four review authors independently selected studies, assessed risk of bias, extracted data, and calculated risk ratios (RRs). We combined study data using a fixed-effect model and assessed evidence quality using Grades of Recommendation, Assessment, Development and Evaluation Working Group (GRADE) methods. Our primary outcomes were live birth or ongoing pregnancy and vasodilator side effects. Secondary outcomes included clinical pregnancy, endometrial thickness, multiple pregnancy, miscarriage, and ectopic pregnancy.

MAIN RESULTS

We included 15 studies with a total of 1326 women. All included studies compared a vasodilator versus placebo or no treatment. We judged most of these studies as having unclear risk of bias. Overall, the quality of evidence was low to moderate for most outcomes. The main limitations were imprecision due to low numbers of events and participants and risk of bias due to unclear methods of randomisation.Vasodilators probably make little or no difference in rates of live birth compared with placebo or no treatment (RR 1.18, 95% confidence interval (CI) 0.83 to 1.69; three RCTs; N = 350; I² = 0%; moderate-quality evidence) but probably increase overall rates of side effects including headache and tachycardia (RR 2.35, 95% CI 1.51 to 3.66; four RCTs; N = 418; I² = 0%; moderate-quality evidence). Evidence suggests that if 236 per 1000 women achieve live birth with placebo or no treatment, then between 196 and 398 per 1000 will do so with the use of vasodilators.Compared with placebo or no treatment, vasodilators may slightly improve clinical pregnancy rates (RR 1.45, 95% CI 1.19 to 1.77; 11 RCTs; N = 1054; I² = 6%; low-quality evidence). Vasodilators probably make little or no difference in rates of multiple gestation (RR 1.15, 95% CI 0.55 to 2.42; three RCTs; N = 370; I² = 0%; low-quality evidence), miscarriage (RR 0.83, 95% CI 0.37 to 1.86; three RCTs; N = 350; I² = 0%; low-quality evidence), or ectopic pregnancy (RR 1.48, 95% CI 0.25 to 8.69; two RCTs; N = 250; I² = 5%; low-quality evidence). All studies found benefit for endometrial thickening, but reported effects varied (I² = 92%) and ranged from a mean difference of 0.80 higher (95% CI 0.18 to 1.42) to 3.57 higher (95% CI 3.01 to 4.13) with very low-quality evidence, so we are uncertain how to interpret these results.

AUTHORS' CONCLUSIONS

Evidence was insufficient to show whether vasodilators increase the live birth rate in women undergoing fertility treatment. However, low-quality evidence suggests that vasodilators may slightly increase clinical pregnancy rates. Moderate-quality evidence shows that vasodilators increase overall side effects in comparison with placebo or no treatment. Adequately powered studies are needed so that each treatment can be evaluated more accurately.

Mild versus conventional antagonist ovarian stimulation protocols in expected normal responders undergoing IVF/ICSI: a case-control study

Mild controlled ovarian hyperstimulation (COH) protocols combining clomiphene citrate (CC) or letrozole with gonadotropins were introduced as an effective alternative of conventional COH in normal responders undergoing IVF/ICSI. In this case-control study, we compared 41 participants treated with a mild stimulation protocol receiving gonadotropins combined with either CC (n = 24) or letrozole (n = 17) with 71 subfertile participants with matching baseline characteristics, conforming with the same inclusion criteria and treated with a conventional antagonist protocol. Live birth was determined in reduced rates in the study group compared to the control group, reaching marginal statistical significance [4/41 versus 19/71, p = 0.050], as also in the respective number of clinical pregnancies [6/41 versus 22/71, p = 0.054], although the incidence of miscarriage was similar for both groups [2/41 versus 5/71, p = 0.714]. Most of the secondary parameters examined, favored the conventional antagonist protocol. There was no difference in any of the outcomes reported between the three different stimulation groups in post-hoc analysis. Mild stimulation regimens with the aid of either CC or letrozole employing GnRH antagonists do not seem to constitute an equally effective method as compared to the conventional antagonist protocol to be offered in good prognosis subfertile women seeking an induced cycle toward IVF/ICSI.

Sperm quality and paternal age: effect on blastocyst formation and pregnancy rates

BACKGROUND

Several studies suggest a decrease in sperm quality in men in the last decades. Therefore, the aim of this work was to assess the influence of male factors (sperm quality and paternal age) on the outcomes of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

METHODS

This retrospective study included all couples who underwent IVF or ICSI at Montpellier University Hospital, France, between 1 January 2010 and 31 December 2015. Exclusion criteria were cycles using surgically retrieved sperm or frozen sperm, with pre-implantation genetic diagnosis or using frozen oocytes. The primary outcomes were the blastulation rate (number of blastocysts obtained at day 5 or day 6/number of embryos in prolonged culture at day 3) and the clinical pregnancy rate. The secondary outcomes were the fertilization and early miscarriage rates.

RESULTS

In total, 859 IVF and 1632 ICSI cycles were included in this study. The fertilization rate after ICSI was affected by oligospermia. Moreover, in ICSI, severe oligospermia (lower than 0.2 million/ml) led to a reduction of the blastulation rate. Reduced rapid progressive motility affected particularly IVF, with a decrease of the fertilization rate and number of embryos at day 2 when progressive motility was lower than 32%. Paternal age also had a negative effect. Although it was difficult to eliminate the bias linked to the woman's age, pregnancy rate was reduced in IVF and ICSI when the father was older than 51 and the mother older than 37 years.

CONCLUSIONS

These results allow adjusting our strategies of fertilization technique and embryo transfer. In the case of severe oligospermia, transfer should be carried out at the cleaved embryo stage (day 2-3) due to the very low blastulation rate. When the man is older than 51 years, couples should be aware of the reduced success rate, especially if the woman is older than 37 years. Finally, promising research avenues should be explored, such as the quantification of free sperm DNA, to optimize the selection of male gametes.

Angiogenic markers in pregnancies conceived through in vitro fertilization

OBJECTIVE

Pregnancies that have been conceived through in vitro fertilization (IVF) have been associated with higher rates of preeclampsia and other complications that are associated with placental dysfunction. We evaluated whether IVF pregnancies, when compared with those conceived spontaneously, would be associated with alterations in serum angiogenic markers.

STUDY DESIGN

This was a retrospective cohort study from 3 US academic institutions (2006-2008). Women with singleton pregnancies who conceived via IVF or spontaneously were included. Placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were measured at 4 time points throughout gestation. Pregnancy outcomes that included diagnosis of preeclampsia or other obstetric complications were ascertained from the medical record. The relationship among IVF status, PlGF, and sFlt-1 were modeled over gestation and stratified by clinical pregnancy outcome.

RESULTS

Of the included 2392 singleton pregnancies, 4.5% (108 pregnancies) were conceived though IVF. IVF pregnancies were significantly more likely to be complicated by preeclampsia (15.7% vs 7.7%). IVF pregnancies had significantly higher levels of sFlt-1 at 18, 26, and 35 weeks of gestation (P = .04, P = .004, P < .0001, respectively) and lower levels of PlGF at 18 and 35 weeks of gestation (P = .007 and .0006, respectively). These differences persisted even after being controlled for maternal comorbidities or obstetric outcomes such as preeclampsia.

CONCLUSION

Pregnancies conceived via IVF were found to have an increased antiangiogenic profile (elevated sFlt-1 and decreased PlGF) at multiple time points throughout gestation when compared with spontaneously conceived pregnancies. Alterations in the angiogenic profile persisted even after we controlled for maternal comorbidities of clinically evident disorders of abnormal placentation such as preeclampsia. The increased antiangiogenic profile suggests fundamentally aberrant placentation related to in vitro fertilization, which may warrant closer fetal surveillance in these pregnancies.