Very little is known about marijuana use and breastfeeding. One study suggests that moderate amounts of THC find their way into breast milk when a nursing mother uses marijuana. 112 Some evidence shows that exposure to THC through breast milk in the first month of life could result in decreased motor development at 1 year of age. 113 There have been no studies to determine if exposure to THC during nursing is linked to effects later in the child's life. With regular use, THC can accumulate in human breast milk to high concentrations. 98 Because a baby's brain is still forming, THC consumed in breast milk could affect brain development. Given all these uncertainties, nursing mothers are discouraged from using marijuana. 102,114 New mothers using medical marijuana should be vigilant about coordinating care between the doctor recommending their marijuana use and the pediatrician caring for their baby.
Fortunately many moms-to-be can now safely cope with chronic health problems by using medication. High blood pressure can be treated with methyldopa or a number of other medications. But it's best to avoid a group of drugs called ACE inhibitors, commonly used to treat high blood pressure. These drugs can damage fetal kidneys after the first trimester. While most asthma medications are considered safe, (including inhaled steroids and bronchodilator sprays containing terbutaline sulfate or albuterol), less is known about sprays containing salmeterol, so consult your doctor before use.