599: Isolated neonatal acidemia: What is the long-term outcome?

Abstract

Fetal acidemia has been associated with Hypoxic Ischemic Encephalopathy (HIE) and delayed development (DD). Criteria for pathologic acidemia have been primarily derived through consensus with little evidence to support routine measurement of cord gases at birth. Further, the appropriate management for full or near-term newborns who are clinically stable with normal APGAR scores but cord gas evidence of acidemia (pH< 7.10, base deficit (BD)< -11.0) is not known. We sought to determine whether isolated fetal acidemia is associated with DD milestones. We hypothesize that these neonates have a similar incidence of DD when compared to non-acidemic neonates. Retrospective case control study of newborns with acidemia (pH< 7.10, BD< -11.0), born 2015-2019, at ≥36 weeks gestational age (GA) at a tertiary referral center with universal cord gas collection. Cases were paired with controls matched by date of birth, birth weight, GA, and NICU or nursery admission. The primary outcome was DD milestones as defined by diagnosed speech/motor delay by a specialist up to 24 months after birth. 148 neonates were matched with controls of whom 46% were female, 38% non-Hispanic Caucasian, full or near term (39 ± 1.4w), and of normal weight (3270±560g). 80 were admitted to the newborn nursery. Eleven cases had DD. There was no significant difference in incidence of DD milestones between the acidemic and control groups (p=0.58 for nursery admission, p=0.69 for NICU admission). Neonates with DD did not have any significant difference in arterial or venous pH or BD (p≥0.16), however the 5 min Apgar scores were significantly lower for DD babies in both acidemic (7.3 vs 8.3) and control (7.7 vs 8.7) groups (p≤0.01). Category II/III Fetal Heart Tracings were significantly associated with incidence of acidemia (p≤0.01) but not DD (p≥0.33). Isolated fetal acidemia with a 5 min Apgar ≥7 is not associated with short term delayed developmental milestones. Future studies should include a prospective analysis of acidemic babies with later assessment of developmental data.