Growth patterns and cardiovascular abnormalities in SGA fetuses: 3. Late, adaptive and recovering growth restriction.

OBJECTIVE

To characterize abnormal growth processes and their associated cardiovascular abnormalities in SGA fetuses using Individualized Growth Assessment (IGA).

METHODS

This longitudinal investigation utilized a SGA cohort [EFW and BW <10th percentile] derived from the PORTO study. Fetuses categorized by their Fetal Growth Pathology Score [FGPS1] patterns [Pattern 2 { = 12}, Pattern 3 { = 11}, Pattern 5 { = 13}] were evaluated. Growth pathology was measured using the -FGPS1 and the individual composite Prenatal Growth Assessment Score {-icPGAS]. Paired cardiovascular assessments utilized measurements of the Pulsatility Index [umbilical artery {UA}, middle cerebral artery {MCA}, ductus venosus {DV}] and the myocardial performance index [MPI; heart]. Outcome variables were birth age [preterm or, term] and birth weight [small or normal (IGA criteria)].

RESULTS

Pattern 2 was usually characterized by a single, growth abnormality (67% of cases) of variable magnitude that occurred within two weeks of delivery {median onset age: 37.6 weeks}. The incidence of UA abnormalities was low (25%) while those of MCA and DV/MPI were high {60%, 42%}. Most neonates were of normal size (67%) and delivered at term (67%).Pattern 3 had an initial progressive growth restriction phase, followed by constant but abnormally low growth. Growth pathology had an early onset (median age: 31.6 weeks), was moderate but persistently abnormal. The incidences of cardiovascular abnormalities were moderate [30-50%]. Most neonates were abnormally small (80%) but delivered at term (90%).Pattern 5 had an initial progressive phase with an early onset [onset age {median}: 31.6 weeks]. However, this process was arrested and returned toward normal. Growth pathology magnitudes were minor as were the incidences of cardiovascular abnormalities. Neonatal size was usually normal and all fetuses delivered at term.

CONCLUSIONS

Characteristics of SGA Growth Restricted, Patterns 2, 3 and 5 are clearly different from those found in SGA Normal or SGA Growth Restricted Pattern 1 groups. They also differed from one another, indicating that growth restriction can manifest itself in several different ways. Pattern 2 is similar to "late" growth restriction reported previously. Patterns 3 and 5 are novel and have been designated as "adaptive" and "recovering" types of growth restriction.