We are presented these days with a great deal of information, some of it from scientific studies, that may be useful to us as parents. This has the potential to be a very good thing. However, we are only rarely provided with much information about these studies beyond the attention-grabbbing headlines. As a result, some of the recommendations that follow from these headlines cause undue worry that we parents are doing things incorrectly. Unfortunately, it falls to us to sort it all out. So, here is a quick guide to help you evaluate whether the next bit of scientific data you read or hear about is worth your consideration.

1. What does the study itself, not the press report actually say?
It is worth clicking through a news report to the study itself and looking at the abstract – a quick summary of the study written by the authors. At the end of the abstract you will find the author’s conclusions and recommendations for further evaluation. I don’t suggest that you read the entire study if that does not interest you, but it is wise to read beyond the version presented by the popular press. You may be surprised at how often and how dramatically the study itself differs from the article you just read. It will take just a few more minutes of your time and may go a long way to ease your concerns.

2. Who performed and funded the study?
Scientific studies are funded by four main sources: government agencies, pharmaceutical and biotechnology companies, consumer product companies, and industry lobbies. The source of funding for a particular study is an important bit of information to have because you would, of course, value a positive study on the benefits of say, apple juice, that was funded by a company that makes apple juice differently than you would if that study were funded by a less partial source. It is certainly not the case that every industry-sponsored study is biased. However, we must remember that these are businesses and some have regrettably come to use scientific-looking studies to promote their products. So, it would be wise to read a study produced by a source with potential conflict more closely. Finding and researching the source of a study may take an extra few moments of your time, but it will go a long way to put in perspective the topic you are interested in. If you can’t find a study’s funding course easily it is not a reputable study.

3. How many subjects were studied?
This question is important in understanding how generally the study results may apply. If a study includes, say, 10 mothers and their babies, its results may be able to raise an interesting question for further study. But it will be far from high-powered enough to warrant a recommendation to the general public. There is just too much chance that coincidence could be influencing the results. In contrast, a study that includes a large and varied population of mothers and babies and finds a particular result would be more likely to apply to you and your baby.

4. Were the subjects humans or animals?
Obviously, babies are not mice. But sometimes interesting animal results are reported as though they apply to humans without the human follow up to warrant such a conclusion. This is another example of prematurely reporting preliminary data. An important animal finding may certainly be newsworthy because of the scientific achievement that it represents. It is not typically cause to alter the recommendations we make to people.

5. Is this an exploratory study or has the research been replicated?
The second or third of fourth time that an association or outcome is found is typically less exciting to the popular press than a new discovery. But any doctor would argue that replicated results are actually the most exciting. Researchers work very hard to minimize the effects of random chance on their data. But we all feel most comfortable making recommendations based on data this has been duplicated over and over again by independent teams of researchers.

Pregnant women are bombarded these days with recommendations about what they can and cannot eat.

Unpasteurized dairy? No.

Deli meats and cheeses? Definitely not.

Seafood?…It’s a bit less clear.

We know that Omega 3 fatty acids from seafood are supportive to baby’s neurologic development. We also know that high levels of mercury can harm baby’s developing brain. Beyond this, the available data is less straightforward. There is a British study showing that infants born to mothers who consumed only small amounts of seafood during pregnancy were more likely to have suboptimal neurodevelopment as compared to infants born to mothers who ate larger amounts of fish. The women in the lower consumption group ate about 12 ounces of fish per week. But 12 ounces per week is the upper limit of the current recommendation from the FDA and the EPA. Confusing, right? Why isn’t it simply that more low-mercury fish is better?

The trouble is that the current EPA and FDA guidelines (2 6-ounce servings per week) have not been updated since 2004. Also, we have become more aware of how much of the fish we consume may contain harmful pesticides from agricultural runoff and other chemicals used in fish farms. So this has left pregnant women and their doctors in the position of having to come up with what they believe to be best and safest recommendations regarding seafood consumption. Many obstetricians are concerned that their patients are so frightened by the potential for harm that they are eating far less fish than we think is beneficial.

What I think is a reasonable recommendation is to strictly limit your fish consumption to low-mercury species and to have a goal of having about twelve ounces of wild fish per week. However, if you are having local fish or farmed fish, limit your consumption of that fish to six ounces in that week and try to make up the difference with wild fish. If you don’t know where the fish has come from, assume the worst. That system will limit both mercury and pesticide levels while still allowing for the dietary benefits of seafood. And of course, no raw or rare fish at all… I know, I know. More torture.

You and your healthcare provider should also discuss whether a DHA supplement made from wild, small fish is a suitable complement to your prenatal vitamin regimen. This may provide some of the benefits of eating whole fish without the worry about source, type or tolerability to nauseous tummies.

NYC has produced and handy guide to the mercury content of some common types of fish here.

An article was published in the Journal of the American Academy of Pediatrics in May of this year that addressed the potential for a relationship between swaddling and sudden infant death syndrome. The article caused a bit of a stir and, unfortunately, the data was presented in some scary ways in the press. So I thought it worthwhile to review what the study actually tells us and what it does not.

The design of this study, a meta-analysis, is meant to pool data from several smaller studies in order collect enough power to look at a given outcome. In this case, the authors found four collections of data looking at sudden infant death syndrome that included information about whether the infants were or were not swaddled, the ages of the infants, and their sleeping positions. The collective data spanned the years between 1988 and 2006 and included subjects in the US, the UK and Australia.

What the authors learned about their data during the analysis is very important. They found that there was significant heterogeneity among the studies. This means that the original study protocols were quite different from one another which complicates the idea of pooling together the data and treating the group of individual studies like one big study. To account for this complication, the researchers needed to apply a statistical calculation to make sure that they were not drawing conclusions that could be attributed to chance.

So, when the researchers compared the swaddled to the not swaddled group BEFORE accounting for potentially problematic differences among the studies, they found that swaddled babies were 1.53 more likely than babies who were not swaddled to die of SIDS. However, when they did account for the differences in the original studies, this increase in risk disappeared. Of note, the study authors call this set of data “of borderline significance” but it is actually statistically insignificant. They then drop one of the studies from the calculation and recalculate. The risk continues to be, statistically speaking, insignificant. However, they apply a substandard definition of statistical significance here again.

Where the data does seem to hold up is in the authors’ analysis of risks of swaddling older babies and risks associated with swaddled babies sleeping in any position but on their backs. The data revealed a trend toward an increased risk of SIDS as age increased with the highest and most statistically significant risk in infants older than six months. Babies who were found swaddled and on their bellies were rare in the study, but were 19 times more likely than unswaddled babies to die of SIDS. In a subset of the data that included the position in which the babies were last placed as well as found, it became evident that the practice of placing swaddled infants on their bellies to sleep was very rare and so it seemed that the babies who were found on their bellies had rolled over.

In their discussion, the authors offer the insight that in the Netherlands, a country with low rates of SIDS, swaddling is encouraged but parents are advised not to initiate swaddling after the fourth month and to discontinue swaddling any infant who is signaling that they are interested in rolling over and all infants at six months when they are very likely to be able to roll over even if it has not yet been witnessed. These seem to be very reasonable recommendations given the information that is available to us including how useful swaddling can be in soothing young babies. Perhaps the most useful takeaway from this study is the need for improvements in messaging to parents considering swaddling from the medical community here in the US.

The article can be found in its entirety on the AAP website here.