Health authorities said the case was “unheard of” and “a very relevant scientific feat.”
The triplets, a girl and two boys, were tested four hours after being born at 7-1/2 months last week in the central state San Luis Potosi at the Ignacio Morones Prieto Central Hospital, health authorities said.
Initially, health authorities said the mother was believed to be an asymptomatic carrier of the virus. But her tests later showed that neither she nor the father were infected.
“The parents’ results are negative, which catches our attention,” said Monica Rangel, secretary of health for the state, during a news conference on June 23. “We specifically requested since yesterday … that a group of experts investigates the case.”
“What we need to look at is a situation where perhaps [the virus] is being transmitted through the placenta. That’s not something that we can be sure of. Those are theories that we have to look at. It’s a new virus. There still is not literature available internationally on this issue, but it will be worth reviewing,” Rangel said.
Two of the babies born on June 17 are in good health and show no symptoms of COVID-19, doctors treating the triplets said, while the third one has pneumonia but is in stable condition.
“The triplets we are monitoring are stable. They are evolving favorably. One of them continues using an antibiotic, but they are doing well. We hope this continues so they can be reunited with their parents soon,” Rangel said Wednesday.
Rangel added that the triplets will remain hospitalized and under observation.
Mexico is closing in on 200,000 COVID-19 cases. On Tuesday, the country recorded another daily record of confirmed cases with the health ministry reporting 6,288 new cases. That brings the country’s total to 191,410.
The ministry said there were 793 new deaths from the virus, bringing the country’s death toll to 23,377.
They said they were investigating several potential sources of contagion such as the mother’s breast milk, officials said.
By Rocio Lopez
CNN Wire and Reuters contributed to this report.