The effect of peri-implantation administration of uterine relaxing agents in assisted reproduction treatment cycles: a systematic review and meta-analysis

Effects of Phloroglucinol on Embryo Transfer: A Systematic Review and Meta-Analysis

INTRODUCTION

Phloroglucinol may be able to improve embryo transfer outcomes. We aimed to systematically evaluate the effects of phloroglucinol on embryo transfer outcomes.

METHODS

The databases searched were PubMed, Ovid MEDLINE, Web of Science, Wanfang, CQVIP, China National Knowledge Infrastructure, and ClinicalTrials.gov. The last search was on February 7, 2023. The included studies were written in English or Chinese. Randomized controlled trials and cohort studies aiming to assess the effect of phloroglucinol on embryo transfer outcomes were included. The studies reported at least one of the primary outcomes (biochemical pregnancy rate, clinical pregnancy rate, and live birth rate). The odds ratio (OR) and 95% confidence interval (CI) were calculated. A random-effects or fixed model was used where applicable to estimate the results.

RESULTS

Seventeen articles reporting 5,953 cycles were included. Biochemical pregnancy rate (OR = 1.58, 95% CI = 1.20-2.08, I2 = 71%), clinical pregnancy rate (OR = 1.69, 95% CI = 1.35-2.10, I2 = 64%), and live birth rate (OR = 1.45, 95% CI = 1.23-1.71, I2 = 36%) were improved by phloroglucinol. Less miscarriage (OR = 0.46, 95% CI = 0.35-0.60, I2 = 0%), less ectopic pregnancy (OR = 0.45, 95% CI = 0.28-0.72, I2 = 0%), higher implantation rate (OR = 1.45, 95% CI = 1.24-1.71, I2 = 62%) but more multiple pregnancy rate (OR = 1.48, 95% CI = 1.13-1.94, I2 = 0%) were induced by phloroglucinol. Endometrial peristaltic waves were improved by phloroglucinol (OR = 22.87, 95% CI = 5.52-94.74, I2 = 72%).

CONCLUSION

Phloroglucinol may improve the outcomes of embryo transfer, including biochemical pregnancy, clinical pregnancy, and live birth rates. Further studies are warranted.

Evidence of Nitric Oxide Impairment During Hypertensive Pregnancies

Hypertensive disorders of pregnancy complicate up to 10% of pregnancies worldwide, and they can be classified into (1) gestational hypertension, (2) preeclampsia, (3) chronic hypertension and (4) chronic hypertension with preeclampsia. Nitric oxide (NO) plays an essential role in the haemodynamic adaptations observed during pregnancy. It has been shown that the nitric oxide pathway's dysfunction during pregnancy is associated with placental- and vascular-related diseases such as hypertensive disorders of pregnancy. This review aims to present a brief definition of hypertensive disorders of pregnancy and physiological maternal cardiovascular adaptations during pregnancy. We also detail how NO signalling is altered in the (a) systemic vasculature, (b) uterine artery/spiral arteries, (c) implantation and (d) placenta of hypertensive disorders during pregnancy. We conclude by summarizing the anti-hypertensive therapy of hypertensive disorders of pregnancy as a specific management strategy.

Evaluating interventions and adjuncts to optimize pregnancy outcomes in subfertile women: an overview review

BACKGROUND

There is a wealth of information regarding interventions for treating subfertility. The majority of studies exploring interventions for improving conception rates also report on pregnancy outcomes. However, there is no efficient way for clinicians, researchers, funding organizations, decision-making bodies or women themselves to easily access and review the evidence for the effect of adjuvant therapies on key pregnancy outcomes in subfertile women.

OBJECTIVE AND RATIONALE

The aim was to summarize all published systematic reviews (SRs) of randomized controlled trials (RCTs) of interventions in the subfertile population, specifically reporting on the pregnancy outcomes of miscarriage and live birth. Furthermore, we aimed to highlight promising interventions and areas that need high-quality evidence.

SEARCH METHODS

We searched the Cochrane Database of Systematic Reviews and PubMed clinical queries SR filter (inception until July 2021) with a list of key words to capture all SRs specifying or reporting any miscarriage outcome. Studies were included if they were SRs of RCTs. The population was subfertile women (pregnant or trying to conceive) and any intervention (versus placebo or no treatment) was included. We adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) for determining the quality of the evidence. Exclusion criteria were overview reviews, reviews that exclusively reported on women conceiving via natural conception, reviews including non-randomized study designs or reviews where miscarriage or live birth outcomes were not specified or reported.

OUTCOMES

The primary outcome was miscarriage, defined as pregnancy loss <24 weeks of gestation. Data were also extracted for live birth where available. We included 75 published SRs containing 121 251 participants. There were 14 classes of intervention identified: luteal phase, immunotherapy, anticoagulants, hCG, micronutrients, lifestyle, endocrine, surgical, pre-implantation genetic testing for aneuploidies (PGT-As), laboratory techniques, endometrial injury, ART protocols, other adjuncts/techniques in the ART process and complementary interventions. The interventions with at least moderate-quality evidence of benefit in reducing risk of miscarriage or improving the chance of a live birth are: intrauterine hCG at time of cleavage stage embryo transfer, but not blastocyst transfer, antioxidant therapy in males, dehydroepiandrosterone in women and embryo medium containing high hyaluronic acid. Interventions showing potential increased risk of miscarriage or reduced live birth rate are: embryo culture supernatant injection before embryo transfer in frozen cycles and PGT-A with the use of fluorescence in situ hybridization.

WIDER IMPLICATIONS

This review provides an overview of key pregnancy outcomes from published SRs of RCTs in subfertile women. It provides access to concisely summarized information and will help clinicians and policy makers identify knowledge gaps in the field, whilst covering a broad range of topics, to help improve pregnancy outcomes for subfertile couples. Further research is required into the following promising interventions: the dose of progesterone for luteal phase support, peripheral blood mononuclear cells for women with recurrent implantation failure, glucocorticoids in women undergoing IVF, low-molecular-weight heparin for unexplained subfertility, intrauterine hCG at the time of cleavage stage embryo or blastocyst transfer and low oxygen concentrations in embryo culture. In addition, there is a need for high-quality, well-designed RCTs in the field of reproductive surgery. Finally, further research is needed to demonstrate the integrated effects of non-pharmacological lifestyle interventions.

4D ultrasound as a method to assess uterine peristalsis

OBJECTIVE

To study uterine peristalsis using step-by-step 4-dimensional (4D) ultrasound assessment video, explore its relationship with progesterone levels in a select in vitro fertilization population, and assess the reproducibility of the technique.

DESIGN

Four-dimensional uterine ultrasound and a retrospective analysis of outcomes in relation with progesterone levels. The videos were also analyzed by a senior doctor, junior doctor, and a nurse for their reproducibility.

SETTING

Instituto Bernabeu of Alicante is a private clinic.

PATIENT(S)

The study included 197 consecutive patients undergoing in vitro fertilization (from 2018 to 2019) with a history of recurrent implantation failure (defined as unsuccessful implantation of a total number of ≥3 blastocysts originated from oocyte donation cycles). Because it is known that most failures are attributed to the quality of the embryo, we deemed it important to explore the potential uterine factors explaining the failures in oocyte donation cycles, the use of which decreases the probability of embryo-related factors influencing it.

INTERVENTION(S)

The participants were evaluated for uterine contractions and serum progesterone levels (10-30 minutes before the embryo transfer procedure). Uterine contractility (UC) was assessed by recording a 6-minute-long video using a 4D mode (Voluson E10; General Electric, Boston, MA), which was performed by a single operator (B.M.).

MAIN OUTCOMES MEASURE(S)

The contractions were seen like waves going through the endometrial cavity. They were counted on a ×15 accelerated recording video. To define high-frequency UC, we separated uterine peristalsis (contractions per minute [cpm]) into quartiles. The highest quartile defined the hypercontractility group (>1.51 cpm; n = 41), considering the remaining quartiles as the normal contractility group (≤1.51 cpm; n = 156). The Mann-Whitney U test was performed. The intraclass correlation coefficient was used to validate variability. P <.05 was considered significant. SPSS version 21.0 was used for the statistical analysis. The institutional review board's approval was obtained.

RESULT(S)

Overall, an average of 1.1 cpm was found in the study population. There were no differences between the groups (hypercontractility vs. normal contractility) in terms of patient age and the presence of any uterine factor (adenomyosis, myomas, adhesions, or polyps). An inverse association was observed between UC and progesterone levels. Low progesterone levels (15.9 vs. 19.5 ng/mL; P = .027) were observed in the HUP and NUP group, respectively. The intraclass correlation coefficient to evaluate the interobserver variability was 0.75 (0.63-0.85; P = .000).

CONCLUSION(S)

Four-dimensional ultrasound assessment provides a dynamic view of uterine contractions, including their directionality and frequency. Even though recurrent implantation failure is yet a title of obscure definition and probably associated with multiple factors, a subgroup of patients with elevated UC associated with "low" progesterone levels may have a potential effect on their outcomes. Four-dimensional scan evaluation of UC constitutes a promising diagnostic tool in clinical practice; however, larger studies confirming our initial results are still pending.

Effects of pre-pregnancy body mass index on pregnancy and perinatal outcomes in women with PCOS undergoing frozen embryo transfer

BACKGROUND

Previous studies have shown that among women with polycystic ovary syndrome who have difficulties conceiving, frozen-embryo transfer resulted in increased live birth rates and decreased ovarian hyperstimulation syndrome risk than did fresh-embryo transfer. In the present retrospective analysis, we sought to determine the effect of body mass index (BMI) on pregnancy and perinatal outcomes in women with PCOS undergoing FET.

METHODS

Women with PCOS (n = 1556) undergoing FET were divided into groups based on weight, with those with normal weight having a BMI of 18.5-24.9 kg/m2,those who were overweight having a BMI of 25-29.9 kg/m2, and those who were obese having a BMI ≥30 kg/m2. Both pregnancy and perinatal outcomes were compared among these groups.

RESULTS

The normal-weight, overweight, or obese groups exhibited similar pregnancy outcomes, including clinical pregnancy rate, miscarriage rate, ongoing pregnancy rate and live birth rate. In singletons, birth characteristics regarding newborn gender, gestational age, birthweight and length at birth were comparable between the three groups. For adverse neonatal outcomes, the three groups showed no significant differences on the rates of low birthweight, very low birthweight, preterm birth, and very preterm birth after adjustment. In addition, the obstetric complications and the frequencies of live-birth defects were also comparable between the three groups except that overweight and obese women were more likely than women of normal weight to have delivered via cesarean section.

CONCLUSION

BMI did not affect the pregnancy or perinatal outcomes in women with PCOS undergoing FET.

Obesity alters the uterine environment before pregnancy

Obesity is a metabolic disorder that predisposes to numerous diseases and has become a major global public health concern. Cafeteria diet (CAF) is the animal model used for the study of obesity that more closely reflects Western diet habits. Previously, we described that CAF administration for 60 days induces obesity in female rats and their fetuses develop macrosomia. Given that, in our model, rats are not genetically modified and that obese mothers were fed standard chow during pregnancy, the aim of the current study was to test the hypothesis that obesity alters the intrauterine environment prior to pregnancy, and this may explain the exacerbated fetal weight gain. We found that uteri from obese rats during the estrous phase developed insulin resistance through mechanisms that involve the induction of uterine hypoxia and the down-regulation of the insulin receptor gene. Moreover, uterine cell proliferation was induced by obesity concomitantly with the reduction in the uterine contractile response to a β2 AR agonist, salbutamol, and this may be consequence of the down-regulation in the uterine β2 AR expression. We conclude that CAF-induced obesity alters the uterine environment in rats during the estrous phase and may cause the fetal macrosomia previously described by us in obese animals. The lower sensitivity of the uterus to a relaxation stimulus (salbutamol) is not a minor fact given that for implantation to occur the uterus must be relaxed for embryo nidation. Thus, the alteration in the uterine quiescence may impair implantation and, consequently, the foregoing pregnancy.