255 - Longitudinal neonatal cardiovascular function after fetal growth restriction and preterm birth: a prospective cohort study (NeoLifeS-Heart II)

Publication Number: 4251.255

Celina L. Brunsch, University Medical Center Groningen, Groningen, Groningen, Netherlands; Bineta Lahr, University Medical Center Groningen, Groningen, Groningen, Netherlands; Fatima Almusabbeh, Boston Children's Hospital, Groningen, Groningen, Netherlands; Michelle Evelyn. van der laan, University Medical Center Groningen, Groningen, Groningen, Netherlands; Elisabeth M.W.. Kooi, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, Groningen, Netherlands

Background: Fetal growth restriction (FGR) and preterm birth are associated with perinatal morbidity and mortality. Both can induce cardiovascular remodelling, altered cardiac function and cerebral perfusion with metabolic and cardiovascular disease later on. FGR often results in preterm delivery, hence distinguishing the risks of FGR from those of preterm birth is challenging. Few studies investigated cardiovascular function in FGR neonates longitudinally, and differences between FGR and non-FGR preterm birth remain unclear.

Objective: The NeoLifeS-Heart II study aimed to discern longitudinal effects of preterm birth and FGR on cardiovascular function, and its associations with short-term neurologic and cardiopulmonary outcomes.

Design/Methods: We included preterm neonates born < 30 weeks and/or < 1000 grams, stratified by FGR status based on Gordijn criteria. From speckle-tracking echocardiography in the first postnatal week and 6 months post-term age, we derived the left ventricular longitudinal strain (LVLS). Cerebral autoregulation, representing vascular adaptability, was assessed as correlation between cerebral tissue oxygenation and heart rate (TOHRx) on the day of the first echocardiography, with impairment defined as TOHRx <-0.3. We explored associations between first week's LVLS and TOHRx with intraventricular hemorrhage (IVH) and bronchopulmonary dysplasia (BPD).

Results: Of 109 neonates with median gestational age 28.1 (26.9-29.1) weeks and birth weight 1056±248 grams, 25 (22.9%) were FGR, 51 (46.8%) were appropriate for gestational age (AGA, birth weight >p30) and 33 (30.3%) were unclassified. The LVLS did not differ between FGR and AGA neonates 1 week after birth (-17.6±2.6% vs. -17.8±2.5%, p=0.81) and 6 months post-term (-20.0±1.6% vs. -20.5±1.3%, p=0.51). The LVLS changed significantly between both timepoints in AGA (-18.2±2.3% vs. -20.4±1.4%, p=0.01), but not in FGR neonates (Figure 1). FGR neonates spent more time with impaired TOHRx (35.2± 12.9% vs. 29.2±10.0%, p=0.02, Figure 2). The LVLS and impaired TOHRx were not associated with severe IVH or moderate/severe BPD.

Conclusion(s): The lack of change in LVLS in FGR neonates between 1 week after birth and 6 months post-term age may reflect suboptimal myocardial function compared to AGA preterm neonates. The increased time with impaired TOHRx in FGR neonates could be a sign of vascular remodelling with decreased cerebral vascular reactivity, albeit not related to notable injury. Future studies with larger cohorts may confirm diminished/disturbed early cardiovascular development in FGR neonates.

Figure 1. The left ventricular longitudinal strain rate (LVLS, %)
LVLS in appropriate for gestational age (left panel) and fetal growth restricted (right panel) neonates at 1 week after birth (blue) and 6 months post-term age (green). More negative LVLS values represent higher myocardial contractility, which is observed over time in healthy term-born neonates.

Figure 2. The time spent with impaired cerebral autoregulation
Cerebral autoregulation was measured as tissue oxygenation heart rate reactivity index (TOHRx <-0.03, %) in appropriate for gestational age (left boxplot) and fetal growth restricted (right boxplot) neonates.