Patients in their forties are often grouped together in both treatment and analyses of ART outcomes. This study was undertaken to assess differences in rates of pregnancy, pregnancy loss and high order multiples among patients aged 40 and older. Retrospective analysis of 4004 consecutive fresh, non-donor in vitro fertilization (IVF) cycles resulting in embryo transfer in patients >40 years between 1995 and 2003. A retrospective review was preformed of 4004 patients who underwent standard ovulation induction, oocyte retrieval, fertilization, culture and embryo transfer. Patients were divided into incremental groups: 40, 41, 42, 43 and >44 years. Pregnancy documented by beta-human chorionic gonadotropin (b-hcg PR), pregnancy documented by transvaginal ultrasound with fetal heart activity (clinical PR), live birth (LB) and higher order multiple (HOM) rates were tabulated and analyzed using chi-square analysis with a statistically significant value of p3 fetal heartbeats (FHB) within 4 weeks of embryo transfer. The loss rate was defined as the difference between the clinical pregnancy rate and the live birth rate. There were 4,004 cycles performed in patients aged >40 years. There was a statistically significant difference in b-hcg PR, clinical PR and LB rates between all 5 age groups (Table 1, a:p<0.0001, b:p<0.0001, c:p<0.0001). The loss rate was significantly different between the age groups (p<0.05) increasing from 28.8% in patients aged 40 to 56.3% in patients 44 and older (Figure 1). The HOM rate decreased from 5.2% in 40 year olds to 0% in patients older than 42 which was also a statistically significant difference (Figure 1, p<0.0001).Tabled 1View Large Image Figure ViewerDownload (PPT) Grouping women 40 years of age and over as a single entity eliminates the ability to observe significant differences that exist within this age group. The findings of this study show statistically significant differences between older women in each age increment with respect to b-hcg pregnancy rate, clinical pregnancy rate and live birth rate. Regardless of the number of embryos transferred, the HOM rate was very low in all patients 40 years and over with no HOM pregnancy occurring in any woman over 42 years in 978 cycles. This finding, along with the high pregnancy loss rate, rising to over 50% in patients 44 and over, supports the replacement of higher numbers of embryos in this age group. These findings have important implications for the counseling and management for ART cycles for women 40 and over.