Study Needlessly Worries Pregnant Moms
If you’ve read about a study that makes a correlation between induced labor and autism, we want to calm your fears. This study, released last month, possesses several key flaws in design and analysis. We know you have enough on your minds as you prepare for what will hopefully be the successful delivery of a healthy baby. You shouldn’t have to worry about inconclusive research based on assumptions.
To give you a little background, the study, published in the journal JAMA Pediatrics, reviewed North Carolina birth records from 1990 to 1998 and child education records from 1997 to 2007 that identified children with a diagnosis of autism.
An interesting comparison perhaps, but consider these facts:
1. The diagnosis of autism was solely based on educational records. This is problematic as there is the potential to make mistakes in recording when you’re handling a large quantity of computer records. In addition, there is no indication of how or by whom the diagnosis of autism was made. In regards to autism and autism spectrum disorders, the methods used to diagnose have a large impact on the frequency of diagnosis.
2. Since the study only looked at birth records to identify numbers of inductions, it didn’t consider those medical diagnoses leading to inductions that are also associated with the development of autism. For example, the diagnosis of intrauterine growth restriction (IUGR, which is associated with decreased uterine blood flow, is associated with an increased risk of the development of autism. Many mothers who have fetuses with IUGR undergo induction of labor to decrease risk of stillbirth. Was the induction or the IUGR more likely to increase the risk of autism?
3. Birth weight, which is considered a possible factor in the development of autism, was not even included in the study as a variable.
4. The study failed to address the important distinction between association and cause. Association is the relationship between two factors. It doesn’t imply that one factor causes the other to act in a certain way. Cause is when one factor is the specific agent of change or when an event occurs as a direct result of another factor.
For example, within this study, it was noted that maternal college education was associated with a higher risk of autism than induction — a 33% increase versus a possible 13-27% increase due to induction (depending on how you compute their numbers). However, the authors did not claim that mothers-to-be should stop going to school, reading books or taking tests toward graduation. The reason college education is seen as a factor in the incidence of autism is because college-educated women often delay having children until they’re older; and increased maternal age is associated with an increased risk of autism.
Hence, the authors may have made the classic mistake of claiming association is cause. The authors acknowledge that other factors may have caused a higher risk of autism, but they chose to highlight the potential role of induction of labor.
5. The authors did not associate the length of time women in labor were exposed to induction agents, and that might affect the risk of autism. They might have looked at length of labor or total dosage of medication. This is important because if a medication were associated with a disease, the more exposure would tend to increase the risk of the disease. Using only large databases of general information, the authors had no way of evaluating this theory.
We applaud responsible research that helps us understand and plan for real risks during pregnancy and delivery. While the authors of this recent study did acknowledge that their research did not prove induction could cause or increase the risk of autism, it has caused unnecessary panic. It may encourage some patients to put off induction or augmentation of labor when it is warranted to decrease the risk of stillbirth.
Studies such as this one illustrate the possible danger of releasing inconclusive data to the public without explaining all the possible elements that could taint the results.
The doctors and nurses at the High Risk Pregnancy Center strive to be a resource for the latest proven research and information on the subjects of obstetrics and maternal-fetal medicine. We welcome any questions or concerns you might have. If you live in the Las Vegas area, you can make an appointment for a consultation anytime. If your questions are general, please consider posting them on our Facebook page and we can discuss them there.