The Chelkas Yaakov (Even Ha’ezer 80) was asked about a girl who was supposedly 28 years old a the time of her engagement and when it was time to get married three years later, it was discovered that she was 36 and not 28. Does the chosson have halachic grounds to break the engagement?
The Chelkas Yaakov answers that we don’t find anywhere in the Gemara, in mesechtos Chulin or Kesubos, among the list of mumim, blemishes, that age is considered a mum. However, the Chasam Sofer says that the Gemara in Bava Basra says that a women who is over 40 years old and was never married cannot have children, and therefore, not only can you break a shidduch, but even if they were already married, one should divorce her because of the mitzvah of peru urevu. Other than that, he says, breaking an engagement because of age is not justified.