Fetal brain imaging in pregnancies at risk for preterm birth

Background. In preterm born infants abnormal general movements (GMs) generally normalize before three months post term, but may persist when perinatal brain injury is present. Aims. To assess the continuity of GM quality from fetal to early neonatal period and its relation to brain echogenicity changes. Study design. Prospective study examining GMs and three vulnerable brain areas before and 7 days after birth. The quality of GMs was classified as normal or abnormal by Gestalt-perception. The brain was examined for moderate echogenicity changes (periv- entricular: brighter than choroid plexus, intraventricular: filling equal or more than 50% of the ventricle, and locally increased basal ganglia/thalami). Subjects. 94 fetuses from pregnancies complicated by preterm hypertensive disorders or labour at a gestational age between 26 and 34 weeks. Outcomes measures. Correlations of fetal GMs, echogenicity changes, and clinical param- eters (e.g. gestational age, parity, hypertensive disorders or preterm labour, oligohy- dramnios and fetal growth restriction) with neonatal GMs. Results. Fetal GMs were abnormal in 64%, normalizing in 68% within 7 days after birth. Fetal GMs were significantly related to postnatal GMs (p = 0.045). Moderate fetal brain echogenicity changes and clinical parameters were not significantly related to neonatal GM. Conclusions. In this population of pregnancies compromised by hypertensive disorders or preterm labour fetal GMs correlated with neonatal GMs. Presence of moderate echogenicity changes in the fetal brain was not related to neonatal GMs. INTRODUCTION In the third trimester of pregnancy the quality of general movements (GMs) is often altered in fetuses with growth restriction1;2 or fetuses exposed to oligohydramnios.3 Both speed and amplitude of fetal GMs can be affected, and in cases with fetal growth restriction (FGR) the complexity of GMs can become reduced as well. It has been postulated that these alterations may be the result of impaired central nervous system development caused by chronic nutritional deprivation,1 merely spatial restriction,3 or possibly prenatal brain injury.4 Previous research in growth restricted fetuses has shown a continuity in movement quality between prenatal and postnatal GMs.2 In cases with neonatal periand intraventricular haemorrhages (PIVH) deterioration of GM quality was noticed after birth. In preterm neonates a relationship between white matter injury, PIVH and abnormal early motor behaviour has been clearly demonstrated.5-9 In the present study we examine the continuity of the quality of GMs from before until one week after birth. The study is performed in a high risk population of pregnancies complicated by hypertensive disorders (HD) or preterm labour (PTL) between 26 and 34 weeks gestational age. The study is part of an ongoing longitudinal study assessing the relationship between fetal brain echogenicity changes, various perinatal parameters (e.g. amniotic fluid index and fetal growth) and neurological outcome. We hypothesize that GMs of most of these compromised fetuses will normalize after birth because of improved nutrition, restored oxygen status and suspension of movement restriction. In fetuses with solely spatial restriction in utero normalization of GMs may be realized soon after birth. However, in small-for-gestational-age (SGA) fetuses, and fetuses with moderate echogenicity changes in the brain, probably repre- senting mild or early stage brain injury, GMs might normalize at a later stage. Specific questions addressed are: 1. Are fetal GMs related to neonatal GMs in complicated pregnancies at risk for preterm birth? 2. Is presence of moderate echogenicity changes in the fetal and neonatal brain related to quality of early neonatal GMs and/or perinatal continuity of GMs in cases with abnormal GM quality? 3. Are clinical parameters like parity, gestational age, hypertensive disorders of pregnancy, preterm labour, SGA, and oligohydramnios related to quality of early neonatal GMs and/or perinatal continuity of GMs in cases with abnormal GM quality? MATERIALS AND METHODS Subjects All women admitted with a singleton pregnancy and at risk for preterm delivery between 26 and 34 weeks gestation were eligible for the study. Pregnancies were compli-