December 29th, 2009 
Women working as scientists and pharmacists run a greater risk of having babies with birth defects as compared to women in other professions, suggests a new study by the New York State Department of Health.
The study, published in the journal Occupational and Environmental Medicine, involved 8,977 cases of birth defects and 3,833 healthy controls from the National Birth Defects Prevention Study.
On analyzing mothers of around 9,000 children with birth defects, the researchers observed that certain abnormal birth conditions were more likely to be found in children of janitors, pharmacists or biological and chemical scientists.
“Given those job titles, one would expect those women to work with different chemicals or something that could possibly be an exposure,” said lead author Michele Herdt-Losavio from the New York State Department of Health.
Depending on the profession of the mother, the baby could be born with any of the physical defects, which are not related to the DNA, found Dr. Herdt-Losavio and her colleagues after studying 45 specific birth defects among mothers with 24 different occupations.
Women working as janitors were found to be more likely to give birth to a child with one or more of the defects including ear and eye defects, musculoskeletal problems, gastrointestinal problems, oral clefts and various other defects.
However, not all women working as janitors face similar risks, as Dr. Herdt-Losavio said, “There’s lots of questions that can be asked…. What do you do as a janitor? What products do you use? What hours do you work? How many hours do you work?”
The researchers, however, did not probe the probable reasons for this association between the birth defect of a child and his mother’s profession but they did offer a possible reasoning.
“What we can guess by looking at these job titles is that … it’s possible that they work with chemicals,” said Dr. Herdt-Losavio. “It’s not possible to say what those chemicals might be, or how much they might work with. But what we can do is point other [researchers] in the direction and give them some idea of where they might want to dig further and collect more data.”
Related
- Low Choline Levels in Pregnant Women Raise Babies’ Risk for Brain and Spinal-Cord Defects
A newborn’s risk for brain and spinal-cord defects rises if the mother has low blood levels of the nutrient choline during pregnancy, researchers at the Stanford University School of Medicine have discovered.
The scientists used a collection of 180,000 blood samples from pregnant California women to look for risk factors for two neural tube birth defects: anencephaly, a lethal condition in which the brain and skull do not develop, and spina bifida, a spinal-cord malformation that causes paralysis and lifelong disability. Neural tube defects have become less common since the 1996 decision to fortify the U.S. food supply with folic acid, a B-vitamin shown to prevent the defects, but they have not disappeared.
“Families whose infants die or suffer permanent disability from NTDs still feel the burden of these defects,” said Gary Shaw, DrPH, professor of neonatology and primary author of the new research, which will appear Aug. 14 in Epidemiology.
About 500 pregnancies per year are affected by neural tube defects in California alone, noted Shaw. “We’re keen on understanding what risk factors explain the continued disease.”
Shaw’s study targeted a group of nutrients suspected to promote brain and spinal-cord development. In early pregnancy, a sealed tube forms along the embryo’s back that later grows into the brain and spinal cord. Neural tube defects occur if the tube does not seal correctly. Based on prior research on folic acid, scientists believe that development of the neural tube may depend on a specific biochemical pathway that requires several vitamins and essential nutrients to operate properly. Shaw’s team measured blood levels of 13 of these nutrients in two groups of women who participated in California’s prenatal birth-defect screening program.
From 180,000 pregnant women screened between 2003 and 2005, the researchers identified 80 whose pregnancies were affected by neural tube defects. Their blood samples were compared to 409 samples randomly selected from among the women whose infants had no structural birth defects.
Choline, an essential nutrient found in egg yolks, soy, wheat germ and meats, was the only nutrient measured whose blood levels were linked to risk of neural tube defects.
“As choline levels went up, risk went down,” Shaw said. Risk for neural tube defects was 2.4 times higher in women with the lowest blood choline levels compared to women with average blood choline levels. The highest blood choline levels were associated with the lowest risk. A previous study by Shaw’s group showed that consumption of choline-rich foods was associated with lower risk for neural tube defects, but this is the first study to evaluate blood levels of choline and NTD risk.
Shaw cautioned that the blood samples tested were obtained between the 15th and 18th week of pregnancy, well after formation of the neural tube, which seals around the sixth week of pregnancy. Future research will be needed to examine blood choline levels in early pregnancy, he said. Researchers also need to test whether choline supplements given in early pregnancy reduce the rates of neural tube defects. Right now, prenatal multivitamins contain little or no choline.
- High Levels of Weed Killer in Drinking Water Linked to Birth Defects: Not Disclosed to Public
According to an investigative report published in the Huffington Post, a weed killer linked to birth defects and used extensively throughout the country on farms and golf courses is seeping into our nation’s drinking water supply at alarming levels, which exceed federal safety limits in four states. But the public is kept in the dark about the hidden dangers in the drinking water.
The weed killer is an herbicide named, atrazine and is manufactured by the Swiss company, Syngenta. When the EPA renewed approval for atrazine to be used in the U.S., the agency imposed new testing requirements on the company, requiring the company to test the levels of atrazine in the water of about 150 watersheds on a weekly basis. The results are sent to the EPA, state regulators and local water companies, but they are not made available to the public. Neither the EPA nor the water companies are legally required to do so.
Under the Federal Safe Drinking Water Act, the EPA is only required to make public, the testing results conducted by state regulators and state regulators only test the drinking water, up to a maximum of four times per year. In practice, the state testing is infrequent and doesn’t provide complete information about temporary, but harmful spikes in the levels of atrazine in the drinking water.
The Huffington Post Investigative Fund obtained the records of the test results conducted by Syngenta from 2003 through 2008, through the Freedom of Information Act, and found alarming average yearly levels of atrazine in the states of Illinois, Indiana, Ohio, and Kansas, as well as temporary spikes that exceeded safety levels. The levels detected would have triggered an automatic notification to water customers, but since the results did not come from state tests, customers weren’t notified of the danger.
The EPA says it does not consider atrazine a health hazard and that it complied with all applicable laws regarding reporting test results to the public. Although it’s true the EPA found that the herbicide is “not likely” to be a carcinogen; the agency does officially consider atrazine to be a potential hormone disruptor.
Additionally, several peer-reviewed scientific studies found that atrazine was potentially harmful to developing fetuses. One study found that birth defect rates in the United States were highest for women who conceived during periods of atrazine spikes in the water supply.
- Study ties common antibiotics with birth defects
Researchers studying antibiotics in pregnancy have found a surprising link between common drugs used to treat urinary infections and birth defects. Reassuringly, the most-used antibiotics in early pregnancy — penicillins — appear to be the safest.
Bacterial infections themselves can cause problems for the fetus if left unchecked, experts said, so pregnant women shouldn’t avoid antibiotics entirely. Instead, women should discuss antibiotics choices with their doctors.
The new study is the first large analysis of antibiotic use in pregnancy. It found that mothers of babies with birth defects were more likely than mothers with healthy babies to report taking two types of antibiotics during pregnancy: sulfa drugs (brand names include Thiosulfil Forte and Bactrim) and urinary germicides called nitrofurantoins (brand names include Furadantin and Macrobid).
It was the first time an association had been seen between urinary tract treatments and birth defects, said lead author Krista Crider, a geneticist with the Centers for Disease Control and Prevention, which funded the research.
Used for many decades, the antibiotics in question predate the Food and Drug Administration and its requirements for rigorous safety testing. The FDA now grades all drugs for safety to the fetus based on available research, but rigorous studies are so lacking in many cases, that no antibiotics get the highest grade of “A.”
Sulfa drugs are the oldest antibiotics and some animal studies have found harm during pregnancy. Nitrofurantoins previously have been viewed by doctors as safe to treat urinary tract infections during pregnancy.
The study, appearing in November’s Archives of Pediatrics and Adolescent Medicine, may cause doctors to change the drugs they choose to treat pregnant women with infections. The findings were released Monday.
The researchers analyzed data from more than 13,000 mothers whose infants had birth defects and nearly 5,000 women who lived in the same regions with healthy babies.
The women were interviewed by phone from six weeks to two years after their pregnancies. Those who remembered taking antibiotics during the month before conception through the first three months of pregnancy were identified as exposed to antibiotics.
The women’s memories could have been faulty, a substantial weakness of the study, which the authors acknowledged. About one-third of the women who took antibiotics couldn’t remember the specific type of drug they took.
It’s also unclear whether the birth defects were caused by the drugs or by the underlying infections being treated, Crider said.
Birth defects linked to sulfa drugs included rare brain and heart problems, and shortened limbs. Those linked to nitrofurantoins (ny-troh-fyoor-AN’-toyns) included heart problems and cleft palate. The drugs seemed to double or triple the risk, depending on the defect.
The FDA recommends that pregnant women discuss medications with their doctors, said FDA spokeswoman Sandy Walsh. The agency has proposed changes to prescription drug labeling that would require more complete information for women of childbearing age, pregnant women and those who breastfeed.
- Birth Defect Risk from Insect Bites Received by Mother During Pregnancy
A North Carolina State University researcher has discovered that bacteria transmitted by fleas-and potentially ticks-can be passed to human babies by the mother, causing chronic infections and raising the possibility of bacterially induced birth defects.
Dr. Ed Breitschwerdt, professor of internal medicine in the Department of Clinical Sciences, is among the world’s leading experts on Bartonella, a bacteria that is maintained in nature by fleas, ticks and other biting insects, but which can be transmitted by infected cats and dogs as well. The most commonly known Bartonella-related illness is cat scratch disease, caused by B. henselae, a strain of Bartonella that can be carried in a cat’s blood for months to years. Cat scratch disease was thought to be a self-limiting, or “one-time” infection; however, Breitschwerdt’s previous work discovered cases of children and adults with chronic, blood-borne Bartonella infections-from strains of the bacteria that are most often transmitted to cats (B. henselae) and dogs (B. vinsonii subsp. berkhoffii) by fleas and other insects.
In his most recent case study, Breitschwerdt’s research group tested blood and tissue samples taken over a period of years from a mother, father and son who had suffered chronic illnesses for over a decade. Autopsy samples from their daughter-the son’s twin who died shortly after birth-contained DNA evidence of B. henselae and B. vinsonii subsp. berkhoffi infection, which was also found in the other members of the family.
Both parents had suffered recurring neurological symptoms including headaches and memory loss, as well as shortness of breath, muscle weakness and fatigue before the children were born. In addition, their 10-year-old son was chronically ill from birth and their daughter died due to a heart defect at nine days of age.
Results of the parents’ medical histories and the microbiological tests indicated that the parents had been exposed to Bartonella prior to the birth of the twins, and finding the same bacteria in both children, one shortly after birth and the other 10 years later, indicates that they may have become infected while in utero.
“This is yet more evidence that Bartonella bacteria cause chronic intravascular infections in people with otherwise normal immune systems, infections that can span a decade or more,” Breitschwerdt says. “Also this new evidence supports the potential of trans-placental infection and raises the possibility that maternal infection with these bacteria might also cause birth defects.”
- Agricultural Chemical Spray Linked to Birth Defect Risk
There’s a link between a birth defect called gastroschisis and the agricultural chemical atrazine, a new study has found.
Gastroschisis is an abdominal wall defect in which the intestines, and sometimes other organs, develop outside the abdomen through an opening in the abdominal wall. The incidence of this birth defect, also called infant abdominal hernia, has doubled to quadrupled over the past 30 years.
In the new study, researchers at the University of Washington in Seattle investigated whether environmental exposures were a factor in a higher than normal number of cases in the eastern part of the state.
“Our state has about two times the national average number of cases of gastroschisis,” study co-author Dr. Sarah Waller said in a news release. “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.”
Waller and colleagues analyzed 805 cases of live-born infants with gastroschisis between 1987 and 2006, along with 3,616 normal infants who acted as controls. The researchers matched birth certificates with U.S. Geological Survey databases of agricultural spraying of atrazine, nitrates, and 2,4-dichlorophenoxyacetic acid.
Gastroschisis occurred more often among infants born to mothers who lived less than 25 kilometers (or about 15.5 miles) from the site of high surface water contamination with atrazine. There was no increased risk associated with the other chemicals. The study authors also found that the risk of gastroschisis was higher for women who conceived in the spring (March through May), when agricultural chemical use is more prevalent.
