Asociación entre el número de óvulos obtenidos en un tratamiento de FIV y los recien nacidos.

Me premito poner el artículo en Ingles, pero si alguien está interesado y no puede leerlo en este idioma, se lo podemos enviar traducido.

Association between the number of eggs and live birth in IVF treatment: an analysis of 400 135 treatment cycles
Sesh Kamal Sunkara1, Vivian Rittenberg1, Nick Raine-Fenning2, Siladitya Bhattacharya3, Javier Zamora4 and Arri Coomarasamy5,*
+ Author Affiliations
1Assisted Conception Unit, Guy's and St Thomas' Foundation Trust, King's College London, London, UK
2Nottingham University Research and Treatment Unit in Reproduction (NURTURE), Division of Human Development, School of Clinical Sciences, University of Nottingham, Nottingham, UK
3Division of Applied Health Sciences, School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
4Clinical Biostatistics Unit, Hospital Ramon y Cajal. IRYCIS. CIBERESP, University Complutense of Madrid, Spain
5School of Clinical and Experimental Medicine, College of Medical & Dental Sciences, University of Birmingham, Academic Unit, 3rd Floor, Birmingham Women's Hospital, Birmingham B15 2TG, UK
*↵Correspondence address. Tel: +44-121-623-6835; Fax: +44-121-626-6619; E-mail: a.coomarasamy@bham.ac.uk
Received December 10, 2010.
Revision received March 2, 2011.
Accepted March 10, 2011.
Abstract
BACKGROUND While live birth is the principal clinical outcome following in vitro fertilization (IVF) treatment, the number of eggs retrieved following ovarian stimulation is often used as a surrogate outcome in clinical practice and research. The aim of this study was to explore the association between egg number and live birth following IVF treatment and identify the number of eggs that would optimize the IVF outcome.
METHODS Anonymized data on all IVF cycles performed in the UK from April 1991 to June 2008 were obtained from the Human Fertilization and Embryology Authority (HFEA). We analysed data from 400 135 IVF cycles. A logistic model was fitted to predict live birth using fractional polynomials to handle the number of eggs as a continuous independent variable. The prediction model, which was validated on a separate HFEA data set, allowed the estimation of the probability of live birth for a given number of eggs, stratified by age group. We produced a nomogram to predict the live birth rate (LBR) following IVF based on the number of eggs and the age of the female.
RESULTS The median number of eggs retrieved per cycle was 9 [inter-quartile range (IQR) 6–13]. The overall LBR was 21.3% per fresh IVF cycle. There was a strong association between the number of eggs and LBR; LBR rose with an increasing number of eggs up to ∼15, plateaued between 15 and 20 eggs and steadily declined beyond 20 eggs. During 2006–2007, the predicted LBR for women with 15 eggs retrieved in age groups 18–34, 35–37, 38–39 and 40 years and over was 40, 36, 27 and 16%, respectively. There was a steady increase in the LBR per egg retrieved over time since 1991.
CONCLUSION The relationship between the number of eggs and live birth, across all female age groups, suggests that the number of eggs in IVF is a robust surrogate outcome for clinical success. The results showed a non-linear relationship between the number of eggs and LBR following IVF treatment. The number of eggs to maximize the LBR is ∼15.