Marie Duncan of Dover described her triplet pregnancy as "a phenomenal pregnancy." Her blood pressure stayed low, she stayed comfortable, and her babies developed normally. Most important, many doctors say, she managed to hang onto them for 36 weeks, a full month longer than the average delivery age of triplets.

But despite even those good signs, Duncan's triplets were immediately transferred from the delivery room to intensive care after they were born. Her two girls, Liette and Hope, were healthy enough to come home a week later. But her son, Colby, was still being fed from a tube the day she packed the girls in car seats.

Duncan had been warned by her obstetrician and her fertility doctors about possible complications with her babies - the lung disorders and developmental problems that often affect multiples. But what happened next was totally unexpected. A few hours

after she brought the girls home, she started having trouble breathing. When she returned to the hospital, she was told she had a form of congestive heart failure that is a rare side effect of a multiples pregnancy. Her triplets are now 3 and healthy, but Duncan takes eight medications a day to manage her heart condition.

For parents with fertility problems, triplets can often sound like a blessing. But for doctors, a triplets pregnancy is a serious and potentially dangerous medical condition. Although many mothers deliver healthy babies and remain healthy themselves, nearly every risk associated with pregnancy and prematurity is amplified in a triplet pregnancy. Mothers more often get sick with disorders such as preeclampsia and gestational diabetes. Babies are often born with lung disorders, brain hemorrhages and birth defects.

For Amanda Tucker, 24, of Concord, now 28 weeks pregnant with her own triplets, the medical difficulties of her pregnancy are beginning to hit home. She now drives to Brigham and Women's Hospital in Boston every week so that a specialist in high-risk pregnancy can monitor her uterus and fetuses for any signs of trouble. She's been instructed to significantly reduce her movement. She's allowed a daily 10-minute shower, bathroom breaks, and a few minutes of sitting up to eat meals. Otherwise, she's been asked to lie on her side all day long, to reduce her risk of contractions and improve blood flow to the fetuses.

About a month ago, doctors found something that concerned them. Tucker's cervix, the area of muscle at the bottom of her uterus, had started to thin, a sign she might go into labor soon. She was hospitalized for five days, given special medications to speed up the development of her babies' lungs, and asked to consider an experimental medical procedure to sew her uterus shut. (She declined.)

Back home now, she feels healthy and is hoping to stay pregnant as long as she can. A test of the tissue in her cervix last week indicated that she was unlikely to go into labor for at least two more weeks.

"I make goals for myself," she said. Right now, the goal is 32 weeks, the average age for triplets birth. If she reaches 32 weeks, she'll aim higher.

The last month was a crucial one, said several obstetricians and pediatricians who treat premature infants, because the risks for serious complications goes down sharply between 24 and 28 weeks. If Amanda gave birth today, there's still a chance that one or more of her triplets could die, suffer brain damage or permanent injury to its lungs or eyes. But the risk of all those complications is much lower than it was when her doctor ordered her to stay in the hospital a month ago.

"Twenty-eight weeks is a huge milestone for any pregnancy, because that's the time when the survival of fetuses, if they have to be delivered, really increases dramatically," said Dr. E. Rebecca Pschirrer, a doctor of maternal-fetal medicine at Dartmouth-Hitchcock Medical Center, who is not treating Tucker. Studies of serious medical complications also show that the risk drops most sharply between 23 and 28 weeks. "That's kind of the first sigh of relief at 28 weeks, but that doesn't by any stretch mean that we wish for a 28-week baby."

Jennifer Larson of Dover made it past 28 weeks with her triplet pregnancy, but just barely. She started showing signs of preeclampsia at about 22 weeks. Preeclampsia, which causes high blood pressure and metabolic problems, is one of the most common medical problems that affect pregnant women - it happens in more than 5 percent of pregnancies - but Larson's was serious enough that her doctors initially thought she'd have to deliver the babies right away, at an age when doctors would not be able to save them.

Larson checked into the hospital and hung on, insisting on treatments such as acupuncture, which helped lower her blood pressure. She made it to 29 weeks. When her babies were born, they were so immature that they could not breathe, eat or warm themselves unaided. Their nervous systems were so undeveloped that they did not like to be touched. The last triplet didn't make it home for 12 weeks. Now, approaching two years old, Larson said her children have some minor developmental delays, but no worrisome health problems.

"We pretty much have escaped unscathed," she said. "It's really amazing."

But if 28 weeks is a milestone, every week afterward still counts. In an ordinary pregnancy, fetuses do the bulk of their growing in the last trimester, gaining as much as 250 grams a week, Pschirrer said. A brain structure that connects the left and right hemispheres starts forming. Skin and fat thicken to enable babies to keep themselves warm. Surfactant, a soapy chemical that helps lungs absorb oxygen, starts covering lung tissue. The instinct to suck and swallow develops, allowing babies to nurse.

But because triplets rarely make it to a full nine-month pregnancy, they are often born, like Larson's triplets, before their development is complete. Their prematurity alone is responsible for most of their health risks.

Single page