"It's all behind them, these guys are doing just fine," Dr. Joseph A. Garcia said after he finished immunizing Nolan and Brooks Bauer, identical boys who developed in the same fetal sac, exposing them to dangers not encountered during most pregnancies.
Thursday's trip to the pediatrician was one of the family's first trips out of the house since coming home from the hospital in March. And their next medical appointment is not for two months, a welcome stretch for their parents, who spent several weeks of Katie's pregnancy hoping for the best but knowing that the worst could happen at any moment.
The pregnancy started out normally for Katie, 27, but at six weeks she began to have severe cramps and feared she might be having a miscarriage. The Bauers consulted a doctor and were shown two "jelly beans," said Katie's husband, Shane Bauer, 28. That's when they found out they were having twins.
At the end of Katie's first trimester, their doctor told them they were having typical identical twins, meaning there was a membrane separating the babies. But they were also told one that of the fetuses had significant chromosomal abnormalities.
"The doctor was like, 'Well, that's it,'" recalled Shane Thursday, before he and Katie packed Nolan and Brooks into their matching car seats for the doctor visit. Their first obstetrician, the Bauers said, seemed resigned to the fact that one of their children would die or be severely disabled.
That's when they went to Greater Baltimore Medical Center and the search for the amniotic membrane separating the boys began. Katie went to at least five appointments, she said, where different medical professionals at the Towson hospital tried to find the tissue that would keep the boys safe from each other's umbilical cords.
"No one could find the membrane," said Katie. "We kind of expected, deep down, that they were going to be momo twins. We understood that there wasn't going to be one [a membrane] there."
Only about 1 in 10,000 pregnancies is momo. Momo twins are "monochorionic" and "monoamniotic," meaning they share a chorion — which contributes to the formation of the placenta — and an amniotic sac. "Momo" pregnancies are so rare that Garcia, who has twins himself and has been practicing pediatrics for more than two decades, wasn't familiar with the term.
Momo babies' greatest threat is umbilical cord entanglement. Without the protection of a membrane between the fetuses, the babies' cords can become knotted, cutting off oxygen and nutrients to one or both babies.
The Bauers didn't learn until the fifth month of Katie's pregnancy, after Thanksgiving, that there was in fact no membrane separating their twins. Like other momo mothers, Katie chose to be hospitalized months before their due date in order to have regular monitoring of the fetuses.
Each day at the hospital she was tested several times, starting out in the morning with an ultrasound, to check the babies' health.
"We would, in particular, look at the blood flow through the umbilical cords," said Dr. Natalie Blagowidow, medical director of the genetics program at GBMC.
Seeing the multicolored sound-wave images, which often showed slight compression of the cords, didn't alarm Katie. They actually came as a relief, she said.
"The weird thing is, it made me feel better seeing them, because I knew what was going on," she said. After months of confusion about whether there was a membrane separating the boys, Katie said, she was glad to know she was able to get emergency care immediately if she needed it.
The Bauers, on their doctor's recommendation, decided to plan a Caesarean section at 32 weeks, eight weeks before a full term. The Bauers joined monoamniotic.org and a Facebook page for momo families, where parents can share their experiences with this unusual type of pregnancy.
"A lot of people [online] say, 'I let the babies decide when they come out,'" said Katie, who determined that she was not willing to leave her children's health to fate. "They were safer out of me than in me," she said.
Since the Bauers chose to have Brooks and Nolan delivered prematurely, the babies needed nutritional supplementation and respiratory support, which they received in GBMC's neonatal intensive care unit for several weeks.
"This was exactly the type of place these babies needed to be," said Dr. Howard Birenbaum, the unit's medical director. "You don't know what you're going to get until you get those babies out."
Birenbaum's team is likely going to get more experience with momo twins this year. Since Nolan and Brooks were born, two more sets of in-utero momo twins have come to GBMC, according to Dr. Victor A. Khouzami, the hospital's obstetrics head.
"Think positively," was Shane's advice to the parents of those two sets of twins. "Think of every appointment as a milestone, another goal."