Re: What (natural) choices/options do I have with a hospital birth?
The March of Dimes does in fact recommend that the PKU be repeated if done as <24 hours because there is a slight chance (mostly depending on which test is used) that a baby might be missed who does in fact have an error of metabolism.
However, they absolutely do not recommend waiting to be screened until 1-2 weeks of age. It is imperative that as many children as possible are screened and the missing enzyme be recognized as early as possible. Babies with PKU can live healthy lives, but the longer PKU goes unrecognized, the longer permanent brain damage continues. The March of Dimes also stongly recommends that a diet low in phenylalanine start by 7-10 days after birth.
PKU has nothing to do with breastmilk. PKU is caused by a missing enzyme that prevents the body from breaking down the specific protein phenylalanine.
In most states the newborn heel prick tests for a wide variety of errors in metabolism. Perhaps there is another screening that is part of these tests that is changed by consumption of breastmilk. However, this does not make logical sense to me. If your body is missing the genetic material to produce an enzyme, no amount of breastmilk will change that. And, all babies are tested - regardless of whether they are breast of formula fed. I would be very interested in seeing the research.
I honestly, cannot think of any reason to avoid the newborn screenings in a healthy newborn. So much permanent damage can be done to baby if these errors are not discovered early.