FRIDAY, Feb. 10 -- A new childbirth study says 39 weeks' gestation is the best time for elective Cesarean delivery for women who have previously delivered via C-section.
The research was slated for presentation Friday at a meeting of the Society for Maternal-Fetal Medicine in Dallas.
"Prior studies have compared the perinatal risks of elective delivery at 37 to 41 weeks' gestation, but didn't evaluate the hazard of delivery versus not delivering at a specific time point," Dr. Giuseppe Chiossi, who conducted the study for the U.S. National Institute of Child Health and Human Development, said in a society news release.
"We wanted to compare the risks of elective repeat Cesarean at each gestational age starting at 37 weeks with the cumulative maternal and neonatal risks of not delivering at that particular gestational age," Chiossi said.
The researchers found that elective repeat Cesarean deliveries at a later gestational age were associated with much lower rates of poor health results for infants compared to deliveries at 37 and 38 weeks.
They also found that poor infant results were much more frequent in pregnancies that continued beyond 39 weeks compared to those in which the baby was delivered through elective surgery at 39 weeks.
Mothers' health results tended to be better with continued pregnancy rather than elective Cesarean at 37 or 38 weeks, but the difference was significant only at 37 weeks. Mothers' results were much worse for later deliveries compared to elective Cesarean at 39 weeks.
Research presented at medical meetings should be considered preliminary until published in a peer-reviewed medical journal.
-- Robert Preidt
SOURCE: Society for Maternal-Fetal Medicine, news release, Feb. 7, 2012
Study: Children Exposed to Chemotherapy in Second and Third Trimesters Develop Normally
By Salynn Boyles
WebMD Health News
Reviewed by Laura J. Martin, MD
Feb. 9, 2012 -- There is reassuring news for women who are pregnant and facing treatment for cancer.
A new study shows little evidence that exposure to chemotherapy in the womb in the second and third trimesters leads to health problems or developmental delays in childhood.
Children in the study whose mothers had an average of three to four cycles of chemotherapy during pregnancy were subjected to a battery of tests to assess their general health, intelligence, and behavioral development.
The tests suggested that fetal exposure to chemotherapy after the first trimester is not associated with developmental and health issues.
Intelligence scores were significantly lower among children who were born prematurely, but early delivery, and not exposure to chemotherapy, was thought to be the cause.
Researcher Frederic Amant, MD, PhD, of Belgium's Leuven Cancer Institute says the findings make it clear that planned early delivery to avoid such exposure should be avoided in most cases.
"This is a common practice, but it is not a practice that can be supported," Amant says. "After the first few months (of pregnancy), exposure to chemotherapy appears to be safer than premature delivery."
As many as 1 in 1,000 pregnancies occur in women who have malignancies requiring treatment, according to one study.
Although there is general agreement that chemotherapy should be avoided during the first trimester of pregnancy -- when the birth defect risk is greatest -- there is less agreement about the safety of exposure to cancer drugs later in pregnancy.
Until now, there has also been little follow-up of children born to women treated for malignancies during pregnancy, Amant says.
The new study, published in the journal The Lancet, included 70 exposed children whose average age was just over 2 1/2. The youngest child in the study was 1 1/2 and the oldest was 18.
Two-thirds of the children were born early and were less than 37 weeks' gestation at delivery.
The children underwent standard IQ tests, along with tests to assess their heart function, hearing, and physical and behavioral development.
Measures of behavior, general health, hearing, and growth were all within the normal range, but IQ scores were lower for the children born prematurely.
The researchers concluded that IQ scores increased by an average of 11 points for each additional month of gestation.
Although Amant and colleagues say larger studies with longer follow-up are needed to confirm their findings, they conclude that exposure to chemotherapy during the second and third trimester is generally safe with few long-term harms for babies.
"The clinical message is threefold," Amant says. "First, fear of chemotherapy is generally no reason to terminate a pregnancy. Second, fear of chemotherapy is generally no reason to delay treatment when pregnant. And third, delivery should not be rushed to avoid exposing the fetus to chemotherapy."
Women's cancer specialist Diana Contreras, MD, says the study confirms what most oncologists now believe.
Contreras directs the division of gynecology oncology at Long Island Jewish Medical Center in New Hyde Park, New York.
"These findings are not earth-shattering, but they are very reassuring," she says. "And it is very helpful to be able to show patients a study that confirms what we are telling them."
American Cancer Society Chief Medical Officer Otis Brawley, MD, agrees.
"This is not a big surprise," he says. "We have been giving chemotherapy to women who are pregnant for a long time."
He adds that some chemotherapies are avoided -- such as the drug methotrexate -- because they are known to increase the risk of birth defects.
"But many of the most commonly used cancer drugs do not cross the placental barrier and we have had good outcomes with these drugs," Brawley says.
SOURCES: Amant, F. The Lancet, Feb. 10, 2012.Frederic Amant, MD, PhD, Multidisciplinary Breast Cancer Center, Leuven Cancer Institute, Katholieke Universiteit Leuven, Belgium.Diana Contreras, MD, division director of gynecology oncology, Long Island Jewish Medical Center, New Hyde Park, N.Y.Otis Brawley, MD, chief medical officer and executive vice president, American Cancer Society, Atlanta.News release, The Lancet.
Study Shows Greater Risk for Breathing Problems Among Small Babies Delivered Early by C-Section
By Denise Mann
WebMD Health News
Reviewed by Louise Chang, MD
Feb. 9, 2012 -- Babies in the womb who are smaller than they should be have higher rates of breathing problems when delivered early by C-section vs. similar babies who are born vaginally, a new study shows.
In the past, obstetricians have often chosen to deliver a baby by C-section if a baby is not growing at the rate it should be. This was believed to be better for these infants. But this study casts that notion into doubt.
The new study was presented today at the 32nd Annual Society for Maternal-Fetal Medicine Meeting in Dallas.
It is not always clear why a fetus may be small, but common reasons for this include maternal high blood pressure during pregnancy, placenta problems, poor nutrition during pregnancy, and maternal smoking or alcohol use while pregnant.
Researchers reviewed birth certificate and hospital discharge data for 2,560 small-for-gestational-age babies who were delivered early. Those babies who were delivered by a C-section before 34 weeks of pregnancy had a 30% higher risk of developing respiratory distress syndrome than babies born vaginally at a similar gestational age, the study shows.
"C-section delivery doesn't offer any protection for these babies," says Diane Ashton, MD, MPH. She is the medical director of the March of Dimes. "It actually increases the risk of respiratory distress." The March of Dimes will be honoring the new study at the meeting.
There are some valid reasons to deliver a baby via C-section, she says. For example, if the baby is in distress or the heart rate is dropping, a C-section may be appropriate.
This study did not include babies with complications such as birth defects, delivery requiring use of forceps or vacuum assistance, or in women with a past history of C-sections . Ashton says she hopes the new study will change practice. C-section is a major surgery. There are risks to the mother as well as the baby.
James Ducey, MD, agrees. He is the director of maternal-fetal medicine at Staten Island University Hospital in New York. "You shouldn't have a C-section unless there is a good reason," he says. Some reasons pertain to moms and others to the baby.
"Being small, in and of itself, is not a reason to do a C-section," Ducey tells WebMD. "It is more risky for mom and there is no benefit for baby, so why should we do it?"
SOURCES: 32nd Annual Society for Maternal-Fetal Medicine Meeting, Dallas, Feb. 6-11, 2012.Diane Ashton, MD, MPH, medical director, March of Dimes, White Plains, N.Y.James Ducey, MD, director, maternal-fetal medicine, Staten Island University Hospital, New York.
WEDNESDAY, Feb. 8 -- Screening and treating expectant moms for thyroid problems at the end of the first trimester doesn't improve children's IQs at age 3, a new study finds.
Thyroid hormones are crucial for the development of a baby's brain and nervous system, and until the middle of the second trimester, those hormones come from the mother. Since a malfunctioning thyroid in the mother has been associated with mental impairments in her child, researchers reasoned that if they screened for maternal thyroid disease in pregnancy and treated any problems found, they might be able to improve function in the offspring. Treatment includes supplementary thyroid hormone medications such as levothyroxine.
However, this large study found that the intervention did not seem to help.
"This trial failed to show any beneficial effect on cognitive [mental] function in 3-year-old children whose mothers were receiving levothyroxine for impaired thyroid function -- mostly mild -- diagnosed at about 3 months of pregnancy," said study author Dr. John Lazarus, a professor of clinical endocrinology at the Centre for Endocrine and Diabetes Sciences at the Cardiff School of Medicine in Wales.
Results of the study are published in the Feb. 9 issue of the New England Journal of Medicine.
The thyroid is a small gland located in the front of the neck. It makes two hormones that are responsible for many functions in the body, including metabolism, brain development, breathing, heart functions, nervous system functions, blood cell creation, temperature regulation, muscle strength, bone health, skin dryness, menstrual cycles, weight, and cholesterol levels, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
Hypothyroidism (underactive thyroid) affects about three out of every 1,000 pregnancies, according to the NIDDK.
The study included almost 22,000 women from 10 centers in the United Kingdom and one center in Italy. The average length of pregnancy when the women were screening for thyroid disease was 12 weeks.
At the time of testing, half of the women were randomly assigned to the screening group and the other half served as a control group. A total of 390 women in the screening group tested positive for underactive thyroid, while 404 women in the control group did. Only the women in the screening group were given levothyroxine.
Children of women in both groups were given IQ tests at age 3 by psychologists who were unaware which group their mothers had been in.
Average IQ scores were 99.2 in the screening group and 100 in the control group. IQs of less than 85 were found in about 12 percent of the screening group and about 14 percent of the control group, according to the study.
Lazarus said there are several possible explanations for the findings. The thyroid screening and treatment initiation may have occurred too late in the pregnancy. Or, it may be that IQ is not a sensitive enough test to pick up subtle differences in children's mental function.
"Timing is a significant issue. This study was done at a time when the fetus doesn't supply its own thyroid hormone," noted Dr. Gregory Brent, a professor of medicine and physiology at the University of California at Los Angeles. So, it may be that by the time these women were screened and treated, it was too late to make a difference.
Lazarus added, "We don't know the effect on cognitive function if screening was done earlier. Another trial would be required."
Brent, who wrote an accompanying editorial in the same issue of the journal, also pointed out that most of the women in this study had a mild form of hypothyroidism. The researchers might have seen a statistically significant difference if the moms had more serious hypothyroidism.
Brent said the current guidelines from the major endocrine societies don't recommend universal screening for all pregnant women, but do encourage the screening of women who have a high risk of hypothyroidism. Those with a higher risk include women who have other autoimmune diseases -- such as type 1 diabetes, rheumatoid arthritis and lupus -- and those with a family history of thyroid disease.
And, although treating thyroid disease may not have an effect on early childhood cognition, Lazarus noted that treating thyroid problems may be important for a healthy pregnancy.
SOURCES: John Lazarus, M.D., professor, clinical endocrinology, Centre for Endocrine and Diabetes Sciences, Cardiff School of Medicine, Wales, U.K.; Gregory Brent, M.D., professor, medicine and physiology, University of California, Los Angeles; Feb. 9, 2012, New England Journal of Medicine
THURSDAY, Feb. 9 -- The longer Hispanic women live in the United States, the more likely they are to have a preterm birth, a new study says.
Researchers analyzed data from 2,141 Hispanic women with a prior live birth who took part in the U.S. National Health and Nutrition Examination Survey 1999-2006.
The study found that the frequency of preterm birth was 3.4 percent for women who had lived in the United States for less than 10 years, 7.4 percent for those who'd lived in the United States for more than 10 years, and 10 percent for those who were born in the United States.
The risk of preterm birth among the women in the study did not appear to be related to a number of preterm birth risk factors that were investigated in the study, the researchers noted.
They said their findings support the theory that preterm birth is, at least in part, related to environmental factors that are potentially preventable. However, it's still not clear which specific environmental factors increase or decrease the chances of preterm birth, the researchers said.
The study was slated to be presented Thursday at a meeting of the Society for Maternal-Fetal Medicine's annual meeting in Dallas.
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
-- Robert Preidt
SOURCE: Society for Maternal-Fetal Medicine, news release, Feb. 9, 2012
-- Migraines may pose a dilemma for pregnant women, since these painful headaches may strike more often during pregnancy.
At the same time, some migraine medicines can cause birth defects, so medical experts advise pregnant women not to use them.
The womenshealth.gov website offers these suggestions for pregnant women who are prone to migraines: