A birth defect called gastroschisis is on the rise in the US and elsewhere, and experts think it might have something to do with the opioid crisis. A study linking the health condition to the drug has been published in the Morbidity and Mortality Weekly Report. 

Gastroschisis is a defect affecting the abdominal wall. Affected infants develop a hole close to the belly button, which causes their intestines to literally spill out from their tummy. The larger the hole, the more problematic the condition and the more likely an organ (the stomach or the liver, for example) also exits the body.

The good news is that it doesn't have to be fatal. It does, however, require instant surgery post-birth and plenty of recovery time. According to the Centers for Disease Control and Prevention (CDC), who were involved in the new research, it is also associated with longer-term digestive and feeding complications during childhood.

The CDC estimates some 1,871 babies are born with gastroschisis in the US every year, but admits this number appears to be rising, particularly among infants born to teen moms. This observation is backed up by their study analyzing birth data from 20 states between 2006 and 2015, which when combined account for 47 percent of births in the entire country during that period.

Researchers split the births into two groups – those occurring between 2006 and 2010 and those between 2011 and 2015. They then compared the number of babies born with gastroschisis with data on maternal age group, ethnicity, and opioid prescription rates. 

First, they noticed an increase of 10 percent between the first cohort (2006 to 2010) and the second (2011 and 2015), which is consistent with the course of the opioid crisis. Rates also tended to be higher among babies born to women under 20 and to white and hispanic mothers. But perhaps the most startling find was the correlation with state-wide opioid prescription rates.

In areas where opioid prescription rates were low between 2006 and 2015, rates of gastroschisis averaged 3.2 infants in every 10,000 births. But in areas where opioid prescription rates were high or medium, the number of infants with gastroschisis jumped to 4.6 infants per 10,000 births, respectively. That's a 60 and 40 percent increase. 

While this is a significant gap, it is still just correlation and correlation does not equal causation. As the researchers point out themselves, they were not able to link opioid use to individual mothers but could only compare statewide data. Neither can they completely rule out other socioeconomic factors.

"Given that the majority of infants with gastroschisis are born to mothers aged <25 years, continued research is needed to focus on possible causal factors in the unique association between young maternal age and gastroschisis," the study authors write. "The findings from the ecologic analysis can be used to prioritize basic science, public health, and clinical research on opioid exposure during pregnancy and its potential impact on birth defects."