Influence of Women's Residence Region on Assisted Reproduction Treatments - Experience of a Tertiary Center in Northern Portugal

Objective: Data on the possible influence of women's region of residence, within the same country, on the outcomes of medically assisted reproduction cycles are scarce. This study aims to assess the impact of the women's region of residence on the results of in-vitro fertilization cycles. Methods: We evaluated in-vitro fertilization cycles between 2010 and 2017, performed in a northern Portugal assisted reproduction center. We defined two groups: Douro Litoral (group 1; n=783), and Tras-os-Montes and Alto Douro (group 2; n=178). We analyzed demographics and cycle-related variables, and we calculated the rates for embryo transfer cycles. We used the Mann-Whitney and Chi-square tests and p<0.05 was considered statistically significant. Results: We included 961 cycles. The region of residence had no effect on the following variables: women's age; body mass index; or duration of infertility (p>0.05). Group 2 had a statistical significant lower number of previous cycles than group 1 (1.310.5 and 1.510.7; p=0.005). In the sub-analysis of cycles with embryo transfer (n=781), group 1 obtained had rates of normal fertilization (62.5% vs. 57.5%; p=0.04), miscarriage rate (30.0 vs. 10.9%; p=0.007), and lower implantation rates compared to group 2 (33.3% vs. 50.0%; p<0.001). Conclusions: Women from the region of Tras-os-Montes e Alto Douro had a lower number of previous cycles, compared to those from the Douro Litoral, despite the absence of statistical significant differences in terms of age or infertility duration. These findings reinforce the need to contemplate the sociodemographic and socioeconomic variables in this context.