This is the first time news of a newborn baby contracting the virus has emerged.
Medical experts are still not certain how the triplets contracted the deadly virus, so they have started an investigation to ascertain whether the disease could have been passed on through the mother’s placenta during pregnancy.
Two of the babies are boys, with one being a girl. One of the boys and the girl are in stable condition, but the other boy is in a critical condition, hence undergoing treatment for respiratory disease in a hospital in San Luis Potosí state.
A very small number of newborn babies have been known to pick up the virus after birth, but health officials say they do not believe this is what happened in this case.
State Health Secretary Mónica Liliana Rangel Martínez said: "It would be impossible for them to have been infected at the moment of birth."
Mexico’s COVID-19 positive case count is 185,000, with 22, 584 deaths, since recording their first case on February, 2020.