Complex sentence: Notably, the P50 value for fetal hemoglobin (i.e., the partial pressure of oxygen at which the protein is 50% saturated; lower values indicate greater affinity) is roughly 19 mmHg, whereas adult hemoglobin has a value of approximately 26.8 mmHg.
Split into simpler sentences: Notably, the P50 value for fetal hemoglobin is lower than adult hemoglobin (i.e., the partial pressure of oxygen at which the protein is 50% saturated; lower values indicate greater affinity). The P50 of fetal hemoglobin is roughly 19 mmHg, whereas adult hemoglobin is approximately 26.8 mmHg.