The Impact of Placental Pathology on Body and Brain Growth and Neurodevelopmental Outcome at 1 Year of Age in Infants Undergoing Neonatal Cardiac Surgery

Background: In infants with complex type of congenital heart disease (CHD) operated after birth the long-term neurodevolpmental (ND) outcome may be impaired. Multiple factors contribute to an impaired ND outcome either before birth including placental function and brain development or after birth due the need of cardiopulmonary bypass surgery and long-stay perioperative intensive care. The specific impact of pathologic placental findings on ND outcome is not well described, so far. We hypothesized an additional impact of pathologic placental findings on body and head growth until birth and on brain growth (determined by perioperative cerebral MRI findings) after birth and ND outcome at one year of age.

Methods: We analyzed the placental pathology reports of infants born with complex type of CHD being operated within the first six weeks of life (from two former prospective cohort studies) according to the Amsterdam classification including the available data of perioperative cerebral MRI (determining total and regional brain volumes), and ND outcome (Bayley III) at one year of age.

Results: We included 53 (14 female) infants. Placental findings were scored as normal (n = 27), or pathologic (n = 26). Cardiac diagnosis included infants with biventricular CHD (n = 38) (most frequently arterial switch for simple D-TGA, n = 17), or single ventricle palliation (n = 15) (Norwood I for HLHS, n = 8). The mean birth weight, placental weight, the ratio of both, as well as head circumference at birth were slightly reduced in children with pathologic placental findings versus normal, no difference between the groups was found for gestational age at birth. Total and regional perioperative brain volume were smaller in infants with additional pathological placenta findings (total brain volume: 341.9 ± 21.9 mL vs. 294.1 ± 73.5 mL, p < 0.05). No significant differences in the Bayley outcome composite scores at one year of age related to placental pathology.

Conclusion: The placenta may play an additional role due to its energy supply during fetal development, which at birth is reflected in smaller birth weight, placental weight, head circumference and reduced perioperative brain volumes. Nevertheless, the impact on ND outcome at one year of age is rather low. Further long-term research data on ND outcome in larger and more well-defined cohorts of CHD patients are needed to better understand placental impact on altered brain development and clinical outcome.

Publication History

Article published online:
13 February 2024