This study, conducted by Anne-Marie Nybo Andersen, Jan Wohlfahrt, Peter Christens, Jørn Olsen, and Mads Melbye, aimed to estimate the association between maternal age and fetal loss (spontaneous abortion, ectopic pregnancy, and stillbirth) while considering a woman's reproductive history. The research was a prospective register linkage study using data from Danish health registries covering the period from 1978 to 1992. A total of 634,272 women and 1,221,546 pregnancy outcomes were analyzed. The study found that 13.5% of pregnancies intended to be carried to term ended in fetal loss. The risk of spontaneous abortion increased significantly with maternal age, from 8.9% in women aged 20-24 to 74.7% in those aged 45 or older. High maternal age was a significant risk factor for spontaneous abortion, regardless of parity, previous miscarriages, or calendar period. The risk of ectopic pregnancy and stillbirth also increased with maternal age. The results suggest that fetal loss is particularly high in women in their late 30s and older, and this should be considered in pregnancy planning and counseling. The study highlights the importance of taking into account a woman's reproductive history when assessing the risks associated with maternal age.This study, conducted by Anne-Marie Nybo Andersen, Jan Wohlfahrt, Peter Christens, Jørn Olsen, and Mads Melbye, aimed to estimate the association between maternal age and fetal loss (spontaneous abortion, ectopic pregnancy, and stillbirth) while considering a woman's reproductive history. The research was a prospective register linkage study using data from Danish health registries covering the period from 1978 to 1992. A total of 634,272 women and 1,221,546 pregnancy outcomes were analyzed. The study found that 13.5% of pregnancies intended to be carried to term ended in fetal loss. The risk of spontaneous abortion increased significantly with maternal age, from 8.9% in women aged 20-24 to 74.7% in those aged 45 or older. High maternal age was a significant risk factor for spontaneous abortion, regardless of parity, previous miscarriages, or calendar period. The risk of ectopic pregnancy and stillbirth also increased with maternal age. The results suggest that fetal loss is particularly high in women in their late 30s and older, and this should be considered in pregnancy planning and counseling. The study highlights the importance of taking into account a woman's reproductive history when assessing the risks associated with maternal age.