Optimal endometrial thickness to maximize live births and minimize pregnancy losses: Analysis of 25,767 fresh embryo transfers.

RESEARCH QUESTION: What is the association of endometrial thickness with pregnancy losses and live births in IVF treatment and the optimal threshold that optimizes the IVF outcome? DESIGN: Data were analysed from 25,767 IVF cycles from centres of the CARE Fertility Group in the UK between 2007 and 2016. Transvaginal ultrasound was conducted to measure the maximum endometrial thickness during gonadotrophin stimulation. Live birth rates were per embryo transfer. Pregnancy loss rates included the combination of biochemical and clinical pregnancy losses. RESULTS: The live birth rate was 15.6% with 5 mm or less endometrial thickness and gradually increased to 33.1% with an endometrial thickness of 10 mm. On the other hand, the pregnancy loss rate was 41.7% with 5 mm or less endometrial thickness and gradually decreased to 26.5% with an endometrial thickness of 10 mm. Statistical modelling for optimal endometrial thickness threshold found 10 mm or more maximized live births and minimized pregnancy losses. This association was independent after adjusting for confounders such as age, oocyte number, number of transferred embryos, ovarian stimulation protocol and embryo quality for live births (crude RR 1.27; 95% CI 1.21 to 1.33; Adjusted RR 1.18; 95% CI 1.12 to 1.23) and pregnancy losses (crude RR 0.83; 95% CI 0.77 to 0.89; adjusted RR 0.86; 95% CI 0.8 to 0.92). CONCLUSIONS: Endometrial thickness is strongly associated with pregnancy losses and live births in IVF, and the optimal endometrial thickness threshold of 10 mm or more maximized live births and minimized pregnancy losses.

Investigating the effect of ethnicity on IVF outcome.

Success rates for IVF among women from different ethnic groups have been inconclusive. In this study, the relationship between ethnicity and IVF outcome was investigated. Results of a cohort study analysing 13,473 first cycles were compared with the results of meta-analysed data from 16 published studies. Adjustment was made for age, body-mass index, cause of infertility, duration of infertility, previous live birth, previous spontaneous abortion and number of embryos transferred. Black and South Asian women were found to have lower live birth rates compared with White women: Black versus White (OR 0.42 [0.25 to 0.70]; P = 0.001); South Asian versus White (OR 0.80 [0.65t o 0.99]; P = 0.04). Black women had significantly lower clinical pregnancy rates compared with White women (OR 0.41 [0.25 to 9 0.67]; P < 0.001). The meta-analysed results also showed that Black and South Asian women had statistically significant reduced odds of live birth (OR 0.62 [0.55 to 0.71); P < 0.001 and OR 0.66 [0.52 to 0.85); P = 0.001, respectively). Black and South Asian women seem to have the poorest outcome, which is not explained by the commonly known confounders. Future research needs to investigate the possible explanations for this difference and improve IVF outcome for all women.

Multicentre study of the clinical relevance of screening IVF patients for carrier status of the annexin A5 M2 haplotype.

Thrombophilia and impaired placental vasculature are a major cause of adverse pregnancy outcome. In 2007, a new hereditary factor for obstetric complications and recurrent pregnancy loss (RPL) was identified as a sequence variation in the core promoter of the annexin A5 gene, ANXA5, called the M2 haplotype. M2 carriership has been demonstrated in couples with recurrent miscarriage and its origin is embryonic rather than specifically maternal, confirmed by subsequent papers. The M2 haplotype is the first report of a hereditary factor related to pregnancy pathology caused by embryonic-induced anticoagulation. It has been demonstrated that couples with RPL had equal and significantly increased M2 carriership and that maternal and paternal carriership confers equal risk. Given its importance for patients with RPL, and potentially implantation failure, this study assessed the incidence of carrier status for the M2 ANXA5 haplotype in both the male and female of couples attending five CARE IVF centres. In 314 patients (157 couples), 44% of couples (one or both partners), 24% of females, 26% of males and 37% of couples with unexplained infertility were M2 carriers. This high incidence has provoked further urgent studies on specific patient populations and on the value of post embryo-transfer therapy.

Live birth after polar body array comparative genomic hybridization prediction of embryo ploidy-the future of IVF?

OBJECTIVE: To ascertain meiotic aneuploidy of the human egg using array comparative genomic hybridization to evaluate the 23-paired chromosome copy number of first polar body as an objective prognosticator of embryo viability for embryo transfer in the same cycle. DESIGN: Case report. SETTING: Independent-sector IVF program. PATIENT(S): A 41-year-old woman with a history of 13 failed cycles of IVF. INTERVENTION(S): Polar body biopsy of metaphase II eggs. MAIN OUTCOME MEASURE(S): Birth. RESULT(S): Two of the nine eggs were euploid, and the resulting embryos, although morphologically inferior to sibling embryos, were selected for transfer to the uterus, resulting in the birth of a normal healthy baby. CONCLUSION(S): Selection of euploid eggs, as an objective parameter of subsequent embryo viability and with the opportunity to transfer embryos in the same cycle could maximise the opportunity for live birth after IVF even in cases with poor prognosis.