Factors that affect outcome of in-vitro fertilisation treatment

BACKGROUND The effectiveness of in-vitro fertilisation (IVF) treatment depends both on the overall success rate in the treating clinic and on the characteristics of the couple seeking treatment. Since 1991, the Human Fertilisation and Embryology Authority (HFEA) has been collecting information on all IVF cycles carried out in the UK. This database has been analysed to identify the factors that affect the outcome of treatment. METHODS All IVF treatment cycles and outcomes registered between August, 1991, and April, 1994, were identified (52507). Cycles that involved gamete or embryo donation, frozen embryo transfer, or micromanipulation and unstimulated cycles were excluded. Thus, 36961 cycles (70% of those registered) were included in the analysis. The main outcome measure was liverbirth rate per cycle started. The relation between age and outcome was investigated by fitting of different fractional polynomials of age with logistic regression models. All other factors were analysed by logistic regression with age included in the model. FINDINGS The overall livebirth rate per cycle of treatment was 13.9%. The highest livebirth rates were in the age-group 25-30 years; younger women had lower rates and there was a sharp decline in older women. At all ages over 30, use of donor eggs was associated with a significantly higher livebirth rate than use of the woman's own eggs, but there was also a downward trend in success rate with age (p = 0.04). After adjustment for age, there was a significant decrease in livebirth rate with increasing duration of infertility from 1 to 12 years (p < 0.001). The medical indication for treatment had no significant effect on the outcome. Previous pregnancy and livebirth significantly increased treatment success. The possibility of success decreased with each IVF treatment cycle. INTERPRETATION We were able to identify by logistic regression the factors that significantly affect the outcome of IVF treatment, and to measure the magnitude of that effect. These factors should be taken into account in assessment of IVF results. After allowance for background clinic success rates, these factors can be used to predict outcome in individual cases.

[1]  M. Derde,et al.  Higher success rate by intracytoplasmic sperm injection than by subzonal insemination. Report of a second series of 300 consecutive treatment cycles. , 1993, Human reproduction.

[2]  J. Lessing,et al.  Endometrial receptivity: the age-related decline in pregnancy rates and the effect of ovarian function. , 1993, Fertility and sterility.

[3]  Fivnat.  Pregnancies and births resulting from in vitro fertilization: French national registry, analysis of data 1986 to 1990. FIVNAT (French In Vitro National). , 1995, Fertility and sterility.

[4]  M. Weinstein,et al.  The Cost of Successful Delivery With In Vitro Fertilization , 1995 .

[5]  U. Waldenström,et al.  Hydrosalpinx reduces in-vitro fertilization/embryo transfer pregnancy rates. , 1994, Human reproduction.

[6]  G. Adamson,et al.  Stability of in vitro fertilization-embryo transfer success rates from the 1989, 1990, and 1991 Clinic-Specific Outcome Assessments. , 1995, Fertility and sterility.

[7]  T. Roseboom,et al.  The probability of pregnancy after embryo transfer is affected by the age of the patient, cause of infertility, number of embryos transferred and the average morphology score, as revealed by multiple logistic regression analysis. , 1995, Human reproduction.

[8]  J. Collins,et al.  An estimate of the cost of in vitro fertilization services in the United States in 1995. , 1995, Fertility and sterility.

[9]  M C Weinstein,et al.  The cost of a successful delivery with in vitro fertilization. , 1994, The New England journal of medicine.

[10]  L. Chambless,et al.  A comparison of direct adjustment and regression adjustment of epidemiologic measures. , 1985, Journal of chronic diseases.

[11]  C. Simón,et al.  Outcome of patients with endometriosis in assisted reproduction: results from in-vitro fertilization and oocyte donation. , 1994, Human reproduction.

[12]  R. Jansen,et al.  Elusive fertility: fecundability and assisted conception in perspective. , 1995, Fertility and sterility.

[13]  D. Cahill,et al.  Expectations of assisted conception for infertility. , 1992 .

[14]  P. Royston,et al.  Cumulative conception and livebirth rates after in-vitro fertilisation , 1992, The Lancet.

[15]  D. Lurie,et al.  Comparison of the cumulative probability of pregnancy after in vitro fertilization-embryo transfer by infertility factor and age. , 1994, Fertility and sterility.

[16]  J. Jenkins.  In vitro fertilisation and gamete intrafallopian transfer: an integrative analysis of research, 1987–1992 , 1995, British journal of obstetrics and gynaecology.

[17]  C. Christiansen,et al.  The economic impact of multiple-gestation pregnancies and the contribution of assisted-reproduction techniques to their incidence. , 1994, The New England journal of medicine.

[18]  P. Royston,et al.  Regression using fractional polynomials of continuous covariates: parsimonious parametric modelling. , 1994 .

[19]  J. Collins,et al.  The effect of treatment on pregnancy among couples with unexplained infertility. , 1991, International journal of fertility.

[20]  S. Buitendijk.  Evidence-based in-vitro fertilisation , 1995, The Lancet.

[21]  C. Christiansen,et al.  The economic impact of multiple-gestation pregnancies and the contribution of assisted-reproduction techniques to their incidence. , 1994, The New England journal of medicine.

[22]  S. Campbell,et al.  Pregnancy and birth rates of live infants after in vitro fertilization in women with an without previous in vitro fertilization pregnancies: a study of eight thousand cycles at one center. , 1994, American journal of obstetrics and gynecology.

[23]  Assisted reproductive technology in the United States and Canada: 1993 results generated from the American Society for Reproductive Medicine/Society for Assisted Reproductive Technology Registry. , 1995, Fertility and sterility.

[24]  A. Trounson,et al.  Female infertility: causes and treatment , 1994, The Lancet.

[25]  D. Baird.  Assisted conception on the NHS? , 1992, BMJ.

[26]  J. Studd,et al.  Pregnancy: Age, pregnancy and miscarriage: uterine versus ovarian factors , 1993 .

[27]  E. Altieri,et al.  Fertilization rate in couples with unexplained infertility. , 1992, Human reproduction.

[28]  M. Bustillo.  Assisted reproductive technology in the United States and Canada : 1993 results generated from the American Society for Reproductive Medicine/Society for assisted reproductive technology registry. Comment , 1995 .

[29]  H. Yavetz,et al.  Outcome of donor versus husband insemination in couples with unexplained infertility treated by in vitro fertilization and embryo transfer. , 1994, Fertility and sterility.

[30]  C. Johannes.  Correction to “Medical Research International, Society for Assisted Reproductive Technology (SART), The American Fertility Society. In vitro fertilization-embryo transfer (lVF -ET) in the United States: 1990 results from the IVF-ET registry. Fertil Steril 1992;57:15–24.” , 1993 .

[31]  R. Edwards.  Why are agonadal and post-amenorrhoeic women so fertile after oocyte donation? , 1992, Human reproduction.

[32]  A. Willan,et al.  The prognosis for live birth among untreated infertile couples. , 1995, Fertility and sterility.