Prenatal Dangers

Prenatal Dangers

There are a lot of things that can go wrong during pregnancy, but doctors help reduce the risk by doing a lot of things right

By Nancy Maes

When a woman learns that she is pregnant, happy visions of decorating the nursery and choosing pint-sized clothes can soon be overshadowed by fears of complications for the fetus and the mother-to-be. But medical advances in the field have been made in many areas to ensure safer pregnancies and births.

For starters, there are preventative measures that can be taken.

Previously, fetal testing for abnormalities was done with two invasive procedures: chorionic villus sampling, which requires removing cells from the placenta, and amnio-centesis, which removes amniotic fluid with a needle. Both methods carry risks of miscarriage.

Kelly Moyer, a genetic counselor with the Maternal-Fetal Medical Services at Loyola University Medical Center says that a practice has recently begun using a safe, new, noninvasive prenatal procedure called cell-free DNA screening that uses next-generation sequencing technology. The method works by testing the mother’s blood (which carries a small amount of DNA from the fetus) for the pr­­esence of Down syndrome and other chromosomal abnormalities. “This test is over 98 percent accurate,” says Moyer, “but if the results come back positive, it is recommended that it be followed up with amniocentesis.”

In addition, improvements have been made with regard to ultrasound technology used in labor and delivery, which produces pictures of the fetus to gather information about its size and position and also check for problems.

“There is less risk of injuring the baby because you know exactly where to apply the forceps on the side of the head or to put the vacuum in the right position to deliver the baby,” says Dr. Xavier Pombar, a physician with Women’s Health Consultants and an associate professor in the Department of Obstetrics and Gynecology at Rush University Medical Center. He notes that images are now clearer and more detailed and can now analyze images in 3-D and 4-D. This allows practitioners to analyze fetuses for specific anomalies. “While the average patient doesn’t require a 3-D or 4-D ultrasound, [these] play a role in diagnosing soft tissue, vascular and cardiac anomalies,” he says.

Physicians are also making strides in minimizing some of the discomforts that pregnancy can trigger. While many survive morning sickness by following helpful tried-and-true tips, nausea and vomiting can become serious if not treated properly.

“Some women do get significantly dehydrated and lose weight, so they need to be hospitalized for rehydration,” says Dr. Paula Melone, a maternal-fetal medicine specialist at Loyola Health System in Maywood. “We also have a myriad of drugs we’ve been using successfully for many years.”

When it comes to the actual birth, there are a number of varying factors to take into account.

Premature births may pose special risks that need to be dealt with. “In spite of years of investigation, no one is quite sure how to prevent preterm delivery in the average patient,” Pombar says. “…We have recently started administering progesterone to reduce the risk in certain high-risk populations.”

While some doctors prescribe bed rest to reduce the risk of pre-term delivery, Pombar has a different perspective. “There is very little evidence that bed rest in itself prolongs pregnancy,” he says. “I try to persuade women to lounge around the house as opposed to being on strict bed rest because being immobilized puts them at risk for developing a clot in the lower extremities.”

Ultimately, Pombar says, “One wants to avoid delivery before 39 weeks if possible because we have very good data that demonstrates that the brain of a 37-week-old infant is different [from] the brain of a 39-week-old infant… During the last two weeks, there are significant changes that improve long-term neurological abilities and functions of a baby.”

As a result of the increase in the rates in Caesarean births (C-section) over the past 10 years, Melone says that a growing number of women who are having more than one birth by C-section are experiencing complications because the placenta grows into the wall of the uterus and does not detach easily. She points out that the death rate for women with this disorder, called adherent placenta, can be as high 10 percent; 50 percent of patients have significant blood loss and require a blood transfusion. Loyola has a team of specialists who offer prenatal diagnosis of adherent placenta and management of its complications.

Women also face the heartbreak of miscarriage. As Dr. Mary Stephenson, director of the Recurrent Pregnancy Loss Program at the University of Illinois College of Medicine at Chicago points out, “The risk of pregnancy loss prior to 6 weeks approaches 50 percent, mostly due to random chromosome errors. At six weeks of pregnancy, the risk of pregnancy loss markedly decreases to 15 percent, and at 10 weeks, the risk is 3 percent for the remainder of the pregnancy.

Stephenson underscores the importance of finding the causes of miscarriage. The American Society for Reproductive Medicine recently stated that evaluation for recurrent pregnancy loss is appropriate after the second miscarriage; previously guidelines had suggested waiting for the third.

“If the chromosomes of the second miscarriage are abnormal, further [chromosomal] testing of the woman and her partner is not necessary. This miscarriage occurred because of a chromosome error, and fortunately, such an event is random, meaning the risk of subsequent miscarriage is not increased,” Stephenson explains, “but if the chromosomes are normal, the miscarriage is unexplained, and further evaluation is required.”

Recurrent pregnancy loss may be caused by a number of factors, such as maternal thyroid disease, which can be treated with medications, and problems with the endometrium (lining of the uterus), which responds to hormones such as progesterone or antibiotics. Abnormalities of the uterus can be corrected with surgery. Autoimmune factors, which can result in clotting and/ or inflammation of the placenta, can be treated with heparin [or] low-dose aspirin.

“When an evaluation for recurrent pregnancy loss is undertaken, one or more factors are identified,” Stephenson says, “but conversely, in 40 percent of couples, no factor is identified.” Still Stephenson and her team forge on. “My research is focused on answering why recurrent pregnancy loss occurs, especially in those difficult cases where a cause is not found.”

Published in Chicago Health Winter/Spring 2013