What a New Autism Study Means for Pregnant Women

When I was pregnant with my son nine years ago, I shunned alcohol, caffeine, cigarettes, the works. I exercised, lightly, every day. I let myself rest when the nausea came and slept hard when I needed to. And, thinking I was getting a great amount of protein in a light, tasty snack, I ate a can of tuna fish every day or so.

It wasn’t until years later that I read this from the American Pregnancy Association:

Fish that contain high levels of mercury should be avoided. Mercury consumed during pregnancy has been linked to developmental delays and brain damage. A sample of these types of fish include: shark, swordfish, king mackerel, and tilefish. Canned, chunk light tuna generally has a lower amount of mercury than other tuna, but still should only be eaten in moderation.

Dear reader, I wasn’t eating the canned, chunk light tuna, and I wasn’t eating it in moderation. I was chowing down on solid white albacore, sometimes straight from the can, and I did it throughout my pregnancy. Thankfully, our son is just fine, but there were moments during his toddlerhood — dark, neurotic moments, I admit — when something would seem amiss, and I’d wonder if I had inadvertently harmed his precious brain with my ignorance.

In my defense, my doctor never mentioned avoiding tuna fish, though during my subsequent pregnancies after the research on mercury in fish had come out, I did receive the medical advice to limit my intake. But, even now I wonder, what is today’s version of my tuna fish — the food, medication, or pollutant that pregnant women are ingesting without knowing the potential harm?

The problem is the dearth of gold-standard research on prenatal care. Researchers are rightly hesitant to do randomized studies on pregnant women for fear of harming a fetus. And so, during those nine months of pregnancy, we live in an information-light vacuum, seeking answers from lines that begin: “Studies suggest …” and “Research indicates …” as well as from old wives’ tales and nosy ladies in the grocery store.

So I perked up last week when I heard of a new study of twins by researchers at UCSF, which points to environmental factors as contributing to autism. Before this study, researchers believed autism stemmed mostly from genetics. But as autism rates skyrocketed in recent decades — now affecting 1 percent of U.S. children — researchers started looking at environmental factors, too. Deemed a “game changer” by Dr. Joseph Coyle, editor-in-chief of the journal that published it, the new study shows that autism can also be traced to environmental factors — everything a woman eats, breathes, and sleeps while pregnant. A related study shows that the use of antidepressants raises the chance of having an autistic child from 1-2 percent, though researchers urge caution for women taking such drugs as the risk is low.

Maybe now researchers will figure out ways to probe prenatal conditions for more definitive evidence not just on what causes autism, but on other conditions as well.

For me, the confusion didn’t end with the birth of my son. A few weeks later, I was in the throes of first-time-breastfeeding hell when I called my husband, a data-loving economist, in desperation and said, “Find me the study that proves this is all worth it!” (I’m pretty sure he swooned.) Within an hour, he was quoting various statistics, none of them iron-clad but some suggesting that claims of long-term benefits of breastfeeding were true.

I continued nursing, and once it got easier, I didn’t care much about what the studies proved or didn’t prove. But, during those excruciating first weeks, when I was in horrible pain and our baby was crying hysterically, I remember eyeing the closet where I’d stored the formula the nurses had given me at the hospital, and wondering if it would really be so bad to switch. I had no solid framework from which to base my decision.

Here’s hoping a new generation of parents won’t have to guess.