Steven and Alison Pariani with their twins. Prenatal testing assured them that their twins were both growing at a healthy rate in the womb.
“I always knew having twins was a possibility since my dad has twin sisters. But it was still a shock,” says Alison Pariani. From that discovery on, her pregnancy would be treated as “high risk.”
Claire Serrato, M.D.
“A high-risk pregnancy is one in which we have reason to suspect that the mother or fetus might need more than the routine prenatal care,” says Pariani’s Mills-Peninsula obstetrician, Claire Serrato, M.D. “Twins are considered high risk because they have a greater chance of preterm delivery, growth problems or preeclampsia, a form of toxemia.”
Pariani’s twins shared a placenta, which can cause complications with Twin-to-Twin Transfusion Syndrome (TTTS). This means that one of the twins can receive more blood through the umbilical cord than the other, resulting in uneven growth and, if undetected and untreated, death.
“Dr. Serrato ordered ultrasounds every two weeks so that we could keep an eye on the twins’ growth and the amount of fluid in each sac,” says Pariani.
Early warnings
“Your life really does begin in the womb,” says Elliott Main, M.D., a specialist at Mills-Peninsula in high-risk pregnancies. “One of the things we’ve learned about fetal or maternal complications during pregnancy is that they can have a lifelong effect.”
For example, fetuses exposed to their mother’s undiagnosed high blood sugar (diabetes, a common complication) are often born born overgrown, weighing up to 10 pounds. This can not only cause delivery complications, but also puts babies at risk later in life for obesity and diabetes.
Fortunately, dramatic advances in prenatal screening and diagnostic testing in the last few years have made it possible for doctors to closely monitor the woman’s health, and even peek inside the womb to detect abnormalities, be better prepared to meet a baby’s health challenges at birth or, in some cases, address problems in utero.
Having twins or triplets is one reason that a pregnancy can be determined as high risk. Other factors include if the mother has diabetes, hypertension, or a family history of genetic problems (such as cystic fibrosis or sickle-cell disease).
“Prenatal screening can also detect these problems, as well as abnormalities such as Down syndrome and neural tube defects (openings in the baby’s spinal cord, such as spina bifida), and diagnose pregnancy complications,” says Denise Main, M.D., a specialist in prenatal testing for Mills-Peninsula.
Elliot Main, M.D. and Denise Main, M.D. The doctors Main are married and have been partnering together to help families improve their babies’ outcomes for over 30 years.
No baby left behind
“These tests are offered to every pregnant woman in California, not just high risk,” she says, which is a big change over the last six years.
California’s screening program consists of a blood test between 10 and 13 weeks of pregnancy and an ultrasound between 11 and 14 weeks. If a fetus tests positive for Down syndrome, the mother is offered further diagnostic tests.
“We used to think that women were at high risk for Down syndrome babies when they were over 35 years old,” the doctor says. “But most Down syndrome babies are born to younger women.”
While the risk for this chromosomal abnormality increases as a woman ages, more women under 35 have babies. So, even though their individual risk is lower, statistically more Down syndrome babies are born each year to younger women. “This new screening approach hopes to change that,” says Dr. Elliott Main.
“Identifying people as high risk based solely on age was simply not an efficient use of resources,” says Dr. Denise Main. “We’ve found that it’s better to do less invasive screening on everyone than more invasive screening on just a few people.”
If detected early, some problems can be corrected in utero, such as anemia or an abnormally fast heartbeat. Actual fetal surgery to correct conditions such as spina bifida, however, is still controversial.
Location, location, location
Another benefit of identifying high-risk conditions before birth is to make sure the mother delivers in a hospital that is equipped to handle them.
“For example, 1 percent of all babies are born with serious congenital heart defects,” says Dr. Denise Main. “The baby will have a better chance if we can detect that prenatally and arrange for the birth at a specialty hospital capable of pediatric cardiology surgery.”
It’s up to you
While prenatal screenings are encouraged, they are entirely voluntary. “Many people want information and reassurance as early as possible,” says Dr. Denise Main. “Other people prefer not to know.”
Women can meet a genetic counselor who works closely with the doctors. The counselors work to individualize family care and help people make decisions that are appropriate for their own value system.
We’ve come a long way, baby
Dramatic advancements in the quality of ultrasound and 3D imaging, and breakthroughs in laboratory science to detect genetic diseases, have catapulted the science of prenatal testing forward.
“And our partners in the intensive care nurseries are doing wonders, too,” says Dr. Elliott Main. “The fact that we’re delivering healthier babies, together with the huge advances that have been made in neonatal care, has greatly increased much better outcomes for our moms and newborns.”
Prenatal testing revealed that Alison Pariani’s twins did not have TTTS and were born healthy at 36 weeks. “But the testing made me feel so much more at ease because we were constantly aware of how the girls were doing,” says Pariani. “If it had turned out that they did have a birth defect, I wanted to know as early as possible so that my husband and I would have time to prepare ourselves to care for them.”