Newsletter

Table of Contents

19.11.2007

Newsletter No. 6/2007

Aspirin in IVF: Review and metaanalysis
Endometrial thickness and embryo implantation
Laser assisted hatching
Bed rest after embryo transfer

1. Aspirin in IVF: Review and metaanalysis

Many trials have evaluated the effects of aspirin in women undergoing IVF or intracytoplasmic sperm injection (ICSI) treatment. These trials have generally shown inconclusive or inconsistent findings. Therefore a systematic review of trials of aspirin during IVF or ICSI treatment was conducted to generate more precise estimates of effects and attempt to explore the reasons for the inconsistencies. Seven trials of low-dose aspirin supplementation versus placebo or no supplementation including 1,241 women undergoing controlled ovarian hyperstimulation (COH), IVF, or ICSI and day 3 embryo transfer were examined. Clinical pregnancy and live birth were the main outcome measures. Searches were conducted in MEDLINE, EMBASE, Cochrane Library, ISI Proceedings, and SCISEARCH, and all randomized controlled trials that evaluated the effectiveness of aspirin compared to placebo or no treatment in women undergoing IVF-ICSI treatment were included. Study selection, quality appraisal, and data extractions were performed independently and in duplicate. Seven relevant trials were identified. Meta-analysis of these studies did not show a significant benefit of aspirin therapy in improving clinical pregnancy rate (relative risk [RR] 1.11, 95% confidence interval [CI] 0.95, 1.31) or live birth rate (RR 0.94, 95% CI 0.64, 1.39). There was no significant difference in miscarriage rate (RR 1.06, 95% CI 0.53, 2.11) or ectopic pregnancy rate (RR 2.24, 95% CI 0.70, 7.24). An improvement was noted in uterine artery pulsatility index (weighted mean difference: -0.78, 95% CI -0.87, -0.69) in women taking low-dose aspirin. The evidence regarding other outcomes was either not significant or contradictory. It is concluded that currently available evidence does not support the use of aspirin in IVF or ICSI treatment. However, the noted trend of improvement in clinical pregnancy, and the lack of power even when the studies were pooled highlight the need for a definitive trial.

Khairy M, Banerjee K, El-Toukhy T, Coomarasamy A, Khalaf Y. Aspirin in women undergoing in vitro fertilization treatment: a systematic review and meta-analysis. Fertil Steril. 2007 Oct;88(4):822-831

2. Relationship between endometrial thickness and embryo implantation

This retrospective study was conducted to evaluate the relationship between endometrial thickness and clinical outcome of IVF and ET. One thousand two hundred and ninety-four infertility patients were included with IVF and fresh autologous ET of two blastocyst-stage embryos with at least one good-quality blastocyst. Clinical pregnancy rate (PR) and spontaneous abortion rate were the main outcome measures. Endometrial thickness was greater in cycles resulting in pregnancy than in cycles not resulting in pregnancy (11.9 vs. 11.3 mm, respectively). Clinical pregnancy rates increased gradually from 53% among patients with a lining of <9 mm, to 77% among patients with a lining of > or =16 mm. Multiple logistic regression analysis indicated significant effects of age, embryo quality, and endometrial thickness on both clinical pregnancy rates and live-birth or ongoing pregnancy rates. There was also a marginally significant trend toward decreasing rates of spontaneous pregnancy loss with increasing endometrial thickness. It is concluded that clinical pregnancy and live-birth or ongoing pregnancy rates increase significantly with increasing endometrial thickness, independent of the effects of patient age and embryo quality.

Richter KS, Bugge KR, Bromer JG, Levy MJ Relationship between endometrial thickness and embryo implantation, based on 1,294 cycles of in vitro fertilization with transfer of two blastocyst-stage embryos. Fertil Steril. 2007 Jan;87(1):53-9. Epub 2006 Nov 1

3. Laser assisted hatching in good prognosis patients undergoing in vitro fertilization-embryo transfer

This prospective randomized controlled trial was conducted to evaluate whether assisted hatching improves clinical outcomes of embryo transfers to good prognosis patients, defined as patients < or =39 years with normal follicle-stimulating hormone (FSH) and E(2) levels, no more than one previous unsuccessful cycle of in vitro fertilization (IVF)-embryo transfer, and good embryo quality The study comprised one hundred ninety-nine good prognosis patients undergoing IVF-embryo transfer on day 3 after oocyte retrieval with or without assisted hatching using a 1,480-nm wavelength infrared laser. Clinical intrauterine pregnancy, spontaneous pregnancy loss, and live birth were the main outcome measures.. Rates of clinical intrauterine pregnancy with fetal cardiac activity (53% vs. 54% per cycle), spontaneous pregnancy loss (13% vs. 16% per pregnancy), and live birth (47% vs. 46% per cycle) were very similar between treatment cycles with laser-assisted hatching and control cycles in which embryos were transferred without assisted hatching. There were no significant differences between treatment and control groups in any measured clinical outcome parameters. Assisted hatching does not improve clinical outcomes among good prognosis patients.

Sagoskin AW, Levy MJ, Tucker MJ, Richter KS, Widra EA Laser assisted hatching in good prognosis patients undergoing in vitro fertilization-embryo transfer: a randomized controlled trial. Fertil Steril. 2007 Feb;87(2):283-7. Epub 2006 Nov 13.

4. Bed rest after embryo transfer: a randomized controlled trial.

This randomized controlled study was conducted to determine whether bed rest after embryo transfer leads to improved pregnancy rates The study included patients undergoing 164 cycles of IVF and were randomized to 30 minutes of bed rest after embryo transfer or immediate discharge from the clinic. Clinical PR defined by visualized fetal heart beat and ongoing PR defined by viable intrauterine gestation beyond 11 weeks were the main outcome measures. The clinical and ongoing PR for both groups were 50% and 46.3%, respectively, with no statistically significant difference between the two groups. It is concluded that thirty minutes of bed rest after embryo transfer does not improve PR.

Purcell KJ, Schembri M, Telles TL, Fujimoto VY, Cedars MI. Bed rest after embryo transfer: a randomized controlled trial. Fertil Steril. 2007 Jun;87(6):1322-6. Epub 2007 Mar 23.

Gerhard Leyendecker