Identical quadruplet sisters meet their brothers for the 1st time

A family in Texas has welcomed home all four of their rare identical quadruplets after the infants spent over three months in the neonatal intensive care unit (NICU).

The sisters -- named Hannah Grace, Lucy Marie, Rebecca Claire and Petra Anne -- were born on May 1, after their mom, Mercedes Sandhu, delivered them at 29 weeks and three days.

Sandhu carried what is known as a monochorionic pregnancy, meaning all four babies shared the same placenta, according to Texas Children's Hospital, where Sandhu gave birth.

The babies were born just before Mother's Day, but Sandhu did not have all four daughters at home until Thursday, when Rebecca was discharged from the NICU.

Hannah and Petra were discharged on July 12, followed by Lucy nearly one week later.

"We're so happy they can be together too," the babies' father, Jonathan Sandhu, told "Good Morning America." "The past few weeks are the only moments they have ever been apart. Even in the NICU, they were always within a few feet of each other."

The quadruplets' reunion at home was also the first time all four sisters got to meet their older brothers, Luke, 4, and Aaron, nearly 2, who were not allowed in the NICU because of their ages, according to Jonathan Sandhu.

"The best part has been watching our boys welcome their baby sisters ... They are obsessed with the girls," he said. "Seeing our little family come together has been the most heartwarming moment of our lives."

The quadruplets' birth on May 1, meant the Sandhus had welcomed six kids in a span of four years. The quadruplets were conceived naturally, without the help of fertility treatments.

When it comes to being able to differentiate the quadruplets, Jonathan Sandhu said they are able to tell two of the babies apart because they were born with hemangiomas, a benign growth of extra blood cells in the skin that is one of the most common skin conditions among infants, according to Texas Children's Hospital.

The couple also keeps the babies in labeled bassinets and lines them up in birth order -- Hannah, Lucy, Rebecca, Petra, for feedings.

"Because they're identical, they literally have the exact same DNA so keeping them correctly identified is pretty important," Jonathan Sandhu told "GMA."

The Sandhus have been documenting the journey of their "miracle" babies on their Instagram account, @thesandhucrew.

They said the babies are proving to be healthy and happy at home, with no ongoing medical needs after their time in the NICU.

While the babies were born weighing around two pounds each, they each now weigh between six and seven pounds each.

"With high order multiples, all sharing one placenta, they were at elevated risks for nearly all the bad things that can accompany premature infants," Jonathan Sandhu said. "We've had a few little bumps, but nothing that ever became life-threatening or would need life-long care."

The quadruplets' birth was so complex that a team of over 20 specialized medical personnel were on hand in the delivery room, in addition to the usual nurses, obstetricians and more, according to Dr. Nathan Sundgren, the attending neonatologist at Texas Children's Hospital who oversaw the delivery.

"We gathered a full neonatal resuscitation team, which includes between four and five team members, for each baby," Sundgren told "GMA." "So we had about 18 people in the two rooms we used to stabilize the babies. That’s not including the team of obstetricians, anesthesiologists, and nurses caring for the mother. It looks crowded, but we have the facilities and space at Texas Children’s to handle it."

Now at home, Jonathan Sandhu said he and his wife are navigating the normal challenges that accompany a newborn -- like sleep deprivation -- but multiplied by four.

"If you've ever taken care of a newborn at night, imagine that, but with a few more crying mouths and dirty diapers," he explained. "My wife and I take shifts at night and one person feeding and changing multiple babies can take two hours. Then you have to repeat it all a few hours later."