Does Suboxone Cause SIDS?

Originally posted 1/13/2013
In a recent Google search about Suboxone and pregnancy, one of the top links included the frightening statement that Suboxone and buprenorphine have been linked to SIDS or sudden infant death syndrome, commonly called ‘crib death.’
The statement was from a health forum where a woman wrote about taking Suboxone during pregnancy.  She wrote that her child went through opioid withdrawal after delivery, recovered, and then died two months later from SIDS.  She then claims that her doctors told her that Suboxone was a possible reason for her child’s death.
Suboxone and SIDS?
I don’t know if the woman’s story is true. If it is, I hope my comments do not cause her pain, and I’m sorry for her loss.  But someone should comment on the information, given the number of young women on Suboxone who become pregnant and frantically search the internet for reassurance that their baby will be OK.  I know that pregnant women in my practice lose a great deal of sleep because of guilt over taking buprenorphine.  I am not a SIDS specialist, obstetrician, or pediatrician, and I do not actively follow the SIDS literature.  But I have done some reading to prepare for this post, and I’ll do my best to address the issue.
While the causes of SIDS are not completely understood, a number of factors have been associated with sudden infant death, including maternal age and socioeconomic status (higher rates in infants of poorer, younger mothers), maternal smoking, air pollution, low birth weight, season of birth (higher in infants born in the winter), too high or too low room temperature, male sex, history of premature birth, and bottle feeding (instead of breastfeeding).
One of the biggest risk factors is the easiest to correct: sleeping position. The incidence of SIDS is thought to be about twice as high for babies who are placed prone (face-down).  Since 1992, when 4895 deaths were attributed to SIDS in the US, a public relations campaign to encourage parents to place infants on their backs may have reduced the incidence of SIDS by 50%.  I write ‘may have’ because some experts attribute the decrease to changes in how infant deaths are coded and reported, rather than to a true decrease in cases.
SIDS is a leading cause of death among healthy US infants.  But the actual risk is very low, estimated at about one death from SIDS per 2000 infants.  Deaths from prematurity or from congenital disorders are far more common than SIDS.
When I started this post, I planned to write that the link about buprenorphine causing SIDS was nonsense.  And it may be nonsense.  Realize that it is very difficult to determine the risk factors for things that rarely occur. Only relatively common factors like smoking or prematurity are identified as risks for SIDS in controlled studies.  Unless the connection is very strong (and it isn’t), there are not enough pregnant women on buprenorphine to cause a detectable rise in deaths from SIDS, even in the largest studies.
So what about the link in search engines about SiDS and Suboxone?  From what I can tell, the connection between buprenorphine, Suboxone and SIDS comes from a 2007 study in Finland that prospectively followed 67 women who had babies while prescribed buprenorphine.  In that study, 2 of the 67 infants were reported to have died from SIDS, an incidence of 3%.  A number that high is certainly frightening. But at the same time, an effect that strong would be evident in the larger SIDS studies—- especially those including thousands of women.
A closer look at the Finnish study reveals that the two infants who were thought to have died from SIDS were born to women who were not compliant with the buprenorphine program, i.e. who were using other opioids including heroin.  The associations between SIDS and other risk factors—risk factors that are common among active drug users, such as smoking, low socioeconomic status, low birth weight, and prematurity— confound the results of the study.  Are women struggling with active opioid dependence as likely to know that infants should be placed on their backs? Some SIDS researchers have questioned the numbers from the Finnish study, The forensic uncertainties often associated with SIDS, the significant risk of death associated with co-sleeping, and the challenge of monitoring women who are actively using opioids further confound the Finnish study.
One possible cause of death in SIDS is the accumulation of carbon dioxide in soft blankets or clothing, close to the mouth and nose of a baby sleeping prone (face down).  That cause of death suggests danger for an infant who is for some reason administered opioids, since opioids reduce respiratory response to carbon dioxide.  Opioids are secreted in breast milk, including buprenorphine.  The infants of mothers on Suboxone/Subutex would be tolerant to any buprenorphine in breast milk, since the exposure would be less, if anything, than the exposure during pregnancy.  But mothers who are noncompliant, i.e. intermittently dosing with high-potency opioid agonists, could in theory expose their infants to levels of opioids higher than the infants’ opioid tolerance.  I did not find any reported associations between opioid use, SIDS, and breast feeding.
My take on the data is that the safest situation for any infant is to develop in the womb of a woman who is not drinking alcohol, smoking cigarettes, taking prescription medications, or using illicit opioids.  Out of all of these things, being compliant with a stable dose of buprenorphine or Suboxone likely carries the least amount of risk.  If there was certainty that pregnant women could remain free from opioids after stopping buprenorphine maintenance, then stopping buprenorphine during pregnancy would be a good idea.
But unfortunately, far more women PLAN to remain opioid-free after Suboxone, than actually remain opioid-free.  The intermittent use of illicit opioids, and the malnutrition, cigarette smoking, poor sleep, poverty, needle-sharing, and other risky behaviors that come with opioid dependence create the worst-case-scenario, making the stable use of Suboxone or buprenorphine far safer in comparison to ‘planned abstinence.’
As with everything, there is the world we want, and the world we live in.  I encourage women addicted to opioids to do all in their power to maintain compliance in a Suboxone/buprenorphine program.  I also encourage these women to look forward to a life of doing the ‘next right thing’ for their children— and cutting themselves some slack over taking buprenorphine.  Efforts to stop Suboxone would be better used to avoid alcohol, tobacco, and illicit substances, and to maintain appropriate prenatal care.