Effects of Prenatal Opiates Exposure on Human Pregnancy and Breastfeeding

The effect of the endogenous opioid system as analgesics was not identified until the early 1970’s [1]. Since the 3rd century BC, however, it has been known that opium as the main compound of opiates, harvested from the juice of the opium poppy was of use in managing pain, as well being addictive [1,2]. The introduction in 1680 of Sydenham’s Laudanum, a mixture of opium with sherry wine and herbs, saw opium widely accepted in the UK as a medicinal compound and thus freely available [3]. Diacetylmorphine was first synthesized in 1874, but it would be almost 25 years before ‘heroin’ was first marketed by the Bayer Company in Germany. Initially used to treat the distressing cough associated with tuberculosis and as a cure for morphine addiction, heroin was quickly recognized to be itself highly addictive, and legislation to curtail its use ensued. Beginning in the 1970s, the endogenous opioid peptides and their various receptors were described and their functions characterized. The action of heroin, morphine and their semisynthetic and synthetic analogs act to relieve pain, as well as produce tolerance and physical dependence is produced by mimicking the various endogenous opioids and by binding to an opioid receptor (Table 1). The recent reviews provide more details on the appropriate use of opioids and opiates for pain management during pregnancy, parturition and post-partum [4,5].