Tufts Medical Center in Boston delivered healthy twin boys 24 days apart.

In February 2014, Lindalva DaSilva was already in labor only 24 weeks into the pregnancy. She was rushed to Tufts where the doctors were left with no choice but to deliver the baby. Doctors injected potassium sulfate to stop DaSilva's labor but when their efforts failed, they decided to do a rare technique of keeping one baby in the womb even after its twin is already born.

Born weighing one pound and ten ounces following a fast delivery, Alexandre was DaSilva's first child. The 35-year-old mother immediately recovered after his birth and visited her son in the ICU where she often sang to him. The doctors told her that the remaining twin could be born in the next hour or day or week but he would have better chances of survival the longer he stays in the womb.

"When you have a situation where one baby is born and labor stops, you are given this window of opportunity," director of Maternal-Fetal Medicine at Beth Israel Deaconess Medical Center Dr. Steven Ralston said. "But it's a rare window. Most times, labor does not stop." DaSilva took antibiotics to fight infections which are common following the procedure. She was fortunate not to have her cervix stitched up to stop the delivery.

Alexandre developed in the intensive care unit incubator while his brother grew in their mother's womb until she started getting contractions 24 days after her first child was born. Second twin Ronaldo was born at a stronger three pounds and three ounces. Three weeks could make a huge difference as Ronaldo came like a normal baby who did not need a tube for breathing or anything else. The boys are growing stronger in the hospital and both now weigh more than six pounds each.

Delayed deliveries are very rare and have a risk of infection. It can only be done on fraternal twins who do not share only one placenta and if the mother's contractions slow down following the birth for the first child.

DaSilva hopes to take her children home from the ICU this month, which is the time of the twins' original due date. Three months after Alexandre and Ronaldo were born, both of them are doing well despite the older one being a little smaller than his twin and may need an eye surgery later on.