The terms subfertility and infertility are often used interchangeably, but they aren’t the same. Subfertility is a delay in conceiving. Infertility is the inability to conceive naturally after one year of trying.
In subfertility, the possibility of conceiving naturally exists, but takes longer than average. In infertility, the likelihood of conceiving without medical intervention is unlikely.
According to research, most couples are able to conceive spontaneously within 12 months of having regular unprotected intercourse.