Changes

We get a resulting caffeine concentration in the milk of 4ug/ml to 8ug/ml<ref name="Stavchansky-"/>, which is a total caffeine intake of between 2mg to 13mg, or 0.6 to 4 mg/Kg body weight. The upper end of that level is quite high. However, the baby's half-life for caffeine is 6031-100 132 hours(average 82 hours)<ref name="Parsons-1981"/>, compared with an adult's 2-10 hour half-life, so the caffeine will build up over time. A 24 hour half live (which is easier to calculate) would result in about a 3mg to 26mg, which is 1 to 8 mg/Kg. I'm guessing that would result in the baby not sleeping well! Conversely, a baby whose mother takes caffeine during pregnancy and is then given formula milk may undergo caffeine withdrawal after birth<ref name="McGowan-1988"/>. Even if the mother breast feeds, the varying levels of caffeine may cause withdrawal symptoms<ref name="Martín-2007"/>. Also, caffeine has been shown to increase fetal heart rate<ref name="Buscicchio-2012"/>.