What is the most important risk factor for spontaneous abortion in healthy women?

Advanced maternal age is recognized as the most significant risk factor for spontaneous abortion, particularly in healthy women. As women age, the quality and quantity of their oocytes (eggs) diminish, which increases the likelihood of chromosomal abnormalities occurring during conception. This increase in abnormalities is correlated with a higher risk of miscarriages in older women.

Research has established that women over the age of 35 are more susceptible to experiencing spontaneous abortions compared to younger women. The risk further escalates as women reach their late 30s and early 40s. In biological terms, the natural decline in reproductive function and the increased incidence of genetic issues such as aneuploidy contribute to this heightened risk.

While other factors such as smoking, obesity, and poor nutrition can certainly impact pregnancy outcomes and contribute to complications, advanced maternal age stands out as the most critical risk factor specifically linked to the increased rate of spontaneous abortions in healthy women.