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I didn't get "anything that the baby and the mother are not exposed to". Does it mean "anything that the baby and the mother are closed related/touched?"

Context:
"The wonderful thing about this metabolite is that it is always present in high levels" during pregnancy, he says. "It's not like we are giving anything that the baby and the mother are not exposed to."
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anything that the baby and the mother are not exposed to = anything that the baby and the mother do not touch/inhale/absorb/etc.
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not exposed to = not already in contact with.
The mother and the baby are already in contact with the metabolite in question. [in contact with it / exposed to it] in the sense that it is already in their bodies.
If they already have the metabolite in their bodies, giving them more of the same metabolite will not [expose them to / put them in contact with] something new.
CJ