Benefits of fish may outweigh risks for pregnant women

Excerpts from the Globe's blog on the Boston-area medical community.

Pregnant women often worry about eating fish, which is rich in an omega-3 fatty acid essential to brain growth but may contain mercury, which can damage a fetus or child's developing nervous system. The federal government advises pregnant women and nursing mothers to avoid the kinds of fish known to have high mercury levels, and to eat no more than two servings a week of other fish.

Results from a Harvard-led study conducted in Denmark tip the scales in favor of eating more fish.

The benefits of eating fish low on the mercury list outweigh the risks, they said in a paper published in the American Journal of Clinical Nutrition.

Working with Danish researchers, the Harvard team tracked more than 25,000 women, asking them what they ate and how long they breast-fed their babies. When the babies were 6 months old and again at 18 months old, the mothers answered questions about developmental milestones.

Mothers who ate more fish while they were pregnant and breast-fed their babies longer than other mothers had children who showed better physical and cognitive development when they were 6 months old and again at 18 months old, the study shows. Both practices proved helpful.

Women who ate at least three servings of fish per week had children who were 25 percent more likely to score high on development at 6 months and 30 percent more likely to score high at 18 months than children of mothers who ate less than one serving of fish per week.

The authors note that the kind of fish most of the Danish women ate - cod, plaice, salmon, herring, and mackerel - are likely to have low mercury content.

"These results, together with findings from other studies of women in the United States and the United Kingdom, provide additional evidence that moderate maternal fish intake during pregnancy does not harm child development and may on balance be beneficial," lead author Dr. Emily Oken said in a statement.

People who go to retail clinics for treatment of simple medical problems often don't have primary care providers to turn to, according to a national study appearing days after Massachusetts approved licenses for its first two drugstore clinics.

The Health Affairs study, conducted by the RAND Corporation, a research organization, is one of the first to compare people who seek medical help at retail clinics with patients of primary care physicians. Retail clinics, including the CVS-owned MinuteClinics that will open next month in Medway and Tewksbury, are staffed by nurse practitioners.

Doctors in Massachusetts and across the country have opposed the retail clinics, saying they jeopardize the doctor-patient relationship and further splinter the healthcare system. Public health specialists contend that the clinics expand access for people who otherwise might not get appropriate care for their sore throats or ear infections, winding up in emergency rooms when no other option is available.

The RAND researchers, who analyzed 1.35 million retail clinic visits from 2000 to 2007, report that these clinic patients were less likely to have a regular physician than the US population as a whole. They were also more likely to be 18 to 43 years old than patients at primary care offices, according to national data on outpatient care. Most patients were using insurance to pay for their retail clinic visits, the study found.

In 90 percent of the retail clinic visits, patients were seeking treatment for the same cluster of problems: upper respiratory infections, sinusitis, bronchitis, sore throats, ear infections, conjunctivitis, or urinary tract infections. Flu shots, other immunizations, and blood-pressure checks were also common.

"There are patients who are not well served by the current healthcare system, and really value convenience for simple acute care over the relationship they might have with a primary care provider. Many don't have a primary care provider," Dr. Ateev Mehrotra, the lead author and a health policy analyst at RAND, said in an interview.

A program devoted to understanding a form of muscular dystrophy and its treatment will open next month, bringing together researchers, patient advocates, and biotech companies.

The Senator Paul Wellstone Research Center for Muscular Dystrophy, funded by a $9 million grant from the National Institutes of Health, will be housed at the Boston Biomedical Research Institute in Watertown. Its collaborators include basic and clinical researchers, patient advocates led by Daniel Paul Perez of Bedford, and biotech companies Acceleron Pharma and Genzyme Corp.

Researchers will focus on facioscapulohumeral muscular dystrophy, the second most common form of the muscle-weakening disease in adults, affecting 1 in 20,000 people worldwide. Myotonic is the most common type of muscular dystrophy in adults. There is no cure or treatment for either disabling disease.

The center's projects include finding ways to measure how well experimental therapies work during clinical trials, building a bank of muscle stem cells with and without the disease, and training scientists.

Five other Wellstone centers have been established.

ELIZABETH COONEY