ACE and chronic kidney disease: ,45 Limited clinical data suggest to avoid angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers by breastfeeding mothers of preterm babies in the first few weeks postpartum to avoid profound neonatal hypotension.44, 45, 46, 47, 48, 49 In our cohort, which represents a sample of women already engaged in care by virtue of their attendance to a clinic visit before pregnancy as a cohort entry requirement, less than 50% of those with prepregnancy CKD had eGFR and proteinuria checked by a laboratory during pregnancy.