Society for Maternal-Fetal Medicine, Feb. 1-6, 2010
The Society for Maternal-Fetal Medicine's 30th annual meeting took place Feb. 1 to 6 in Chicago and attracted about 1,800 attendees. Highlights included research aimed at reducing preterm and near-term births, managing difficult pregnancies, and identifying possible environmental causes of birth defects.
"One important study showed how maternal genes might interact with stressors to lead to preterm birth," said meeting chair, George Macones, M.D., of Washington University in St. Louis.
Samuel Parry, M.D., of the University of Pennsylvania in Philadelphia, and colleagues analyzed DNA samples from 744 women, including 306 who had asymptomatic bacterial vaginosis, and 68 who experienced spontaneous preterm birth at less than 37 weeks' gestation. In vaginosis-positive women, they found that spontaneous preterm birth was significantly associated with 20 haplotype-tagging (hap-tag) single-nucleotide polymorphisms, including nine polymorphisms in the FLT1, PRKCA, and IL6 genes (odds ratio, 2.0 to 7.0).
"The result is that chip assays for hap-tag single-nucleotide polymorphisms provide a powerful tool for studying genes related to preterm birth and increase our potential to find groups of single-nucleotide polymorphisms in biologically relevant pathways that might cause preterm birth," Parry said in a statement. "It is unlikely that any single single-nucleotide polymorphism is related with a large percentage of preterm births."
"One fantastic abstract focused on ultrasound measurements of the fetal adrenal gland to predict early delivery," Macones said. "Although the technique needs more study, it could provide us with a promising tool down the road."
Ozhan Turan, M.D., and colleagues from the University of Maryland in College Park and Yale University in New Haven, Conn., conducted prenatal ultrasound assessments of 62 singletons who were born at 23 to 37 weeks' gestation. They found that the ratio of the two-dimensional fetal zone of the adrenal gland to the depth of the whole gland was a more accurate predictor of preterm birth than measuring cervical length.
"We previously discovered that three-dimensional adrenal gland volume is a very accurate predictor of preterm birth," Turan said in a statement. "However, most people around the world don't have access to that technology; therefore, we have created measurements that can be done with two-dimensional ultrasound that are very effective to predict preterm birth."
A study presented by Jay Iams, M.D., of the Ohio State University Medical Center in Columbus, showed that a statewide educational initiative -- the Ohio Perinatal Quality Collaborative, conducted at 20 of the state's largest maternity centers -- reduced the rate of scheduled births between 36.1 and 38.6 weeks without a medical indication from 25 percent to less than 5 percent over a 14-month period.
"I think that over time, we doctors have allowed ourselves to become relaxed about allowing early scheduled deliveries, assuming that the babies would be okay at 37 and 38 weeks," Iams said in a statement. "However, the numbers tell us that babies delivered before 39 weeks are more likely to end up with complications, so it is important to reduce that number."
"This is a great model all of us can take back to help reduce the number of deliveries being scheduled before they should be," Macones added.
Several studies addressed potential advances in the management of difficult pregnancies. A study of 150 depressed pregnant women by Rosa N. Schnyer, of the University of Arizona in Tucson, and colleagues showed that depression-specific acupuncture was significantly more effective at reducing symptoms than either control acupuncture or massage.
"A lot of patients are reluctant to take medication during pregnancy," Macones said. "This was one of the first studies showing that an alternative low-risk therapy seems to work, and has some immediate applicability."
Other research, presented by researchers from the Leiden University Medical Center in the Netherlands, suggested that waiting for natural birth is an effective alternative to induced labor in cases of intrauterine growth restriction. The researchers randomly assigned 650 women with suspected intrauterine growth restriction after 36 weeks' gestation to either expectant monitoring or induced labor and found that expectant monitoring was associated with a significantly higher median birth weight (2,560 g versus 2,420 g) and a similar rate of adverse events.
Researchers from the Lehigh Valley Health Network in Allentown, Pa., presented results of a study in which 425 women undergoing cesarean section were randomly assigned to receive sutures or staples. They found that sutures were associated with a lower rate of wound separations (4.6 versus 16.8 percent), a lower composite rate of wound complications (9.1 versus 21.8 percent), and a lower rate of post-surgery physician visits (10.6 versus 36 percent).
A study presented by Sarah Waller, M.D., of the University of Washington in Seattle, suggested a possible link between exposure to the agriculture chemical atrazine and an increased risk of gastroschisis. Their analysis of 805 cases and 3,616 controls showed an increased risk of gastroschisis in infants whose mothers lived within 25 km of surface water contaminated with atrazine, especially those who were conceived from March through May, when use of the chemical is at its peak."Our state has about two times the national average number of cases of gastroschisis," Waller stated. "The life expectancy for fetuses with this diagnosis is better than 90 percent; however, it requires delivery at a tertiary care center with immediate neonatal intervention, which often separates families and can cause serious financial and emotional stress."