P0731 - Effects of Perinatal Acidemia in Very Low Birth Weight Infants on Short- and Long-Term Outcomes

Purpose of Study
Presence of metabolic acidemia at birth has been associated with abnormal outcomes in full term infants. However, few studies have reviewed this association in very low birth weight (VLBW) infants. This study aimed to describe potential association between perinatal acidemia in VLBW infants with short- and long-term outcomes.

Methods
Cord blood gases and blood gases on admission of all VLBW infants born at LAC+USC Medical Center between 2009-2019 were collected. Acidemia was defined as pH < 7.1 or a base deficit above 10 mmol/L. The most common neonatal morbidities [bronchopulmonary dysplasia, necrotizing enterocolitis, severe intraventricular hemorrhage (IVH) and severe retinopathy of prematurity] and mortality were analyzed. Bayley III scale at 6-12 months, 18-25 months, and 26-36 months was used to assess neurodevelopment measured by motor, cognitive, and language scales.

Results
Out of 314 VLBW infants, 15% (n = 47) had acidemia at birth. Infants presenting with acidemia had significantly higher rates for intubation (65.9% vs 42.4%, p = 0.005) and chest compression (32% vs 14%, p = 0.008) in the delivery room as well as requiring mechanical ventilation at 24 hours of life (70% vs 38.6%, p < 0.001), when compared to non-acidotic patients. Severe IVH rates were also significantly higher in acidotic babies (19% vs 3.2%, p < 0.001). Survival rates for infants born with acidemia were significantly lower (75% vs 93%, p < 0.001). Bayley scores at 6-12 months indicated decreased mean raw cognitive scores (89 vs 95, p = 0.031) as well as lower cognitive percentiles (16 vs 34 %, p = 0.019) in acidotic infants at birth. The effect persisted at 18-25 months with mean cognitive raw scores (80 vs 88 p = 0.027) as well as language percentiles (8 vs 16 %, p = 0.038) still diminished. Interestingly, at 18-25 months mean raw motor scores were also decreased (83 vs 92, p = 0.048) in acidotic infants.

Conclusions
VLBW infants with acidemia at birth require more extensive resuscitation at the time of delivery. These infants are at higher risk to develop severe IVH and have increased mortality. Importantly, acidotic VLBW infants show a decreased cognitive, language, and motor performance up to 25 months, as compared to their non-acidotic counterparts. These implications can help guide physicians in the risk assessment of VLBW infants and develop strategies to reduce perinatal acidemia.