Normal standards for fetal neurobehavioral developments--longitudinal quantification by four-dimensional sonography.

Aim: To construct normal standards for fetal neurobehavioral development using longitudinal observations through all trimesters by four-dimensional sonography.

Subject And Methods: A group of 100 healthy normal singleton pregnancies were recruited for longitudinal 4D US examinations to evaluate fetal neurodevelopmental parameters between 7 to 40 weeks' gestation. Variables of maternal and fetal characteristics including gestational age, eight fetal movements patterns in the first trimester and 14 parameters of fetal movement and fetal facial expression patterns recorded thereafter for the construction of fetal neurological charts.

Results: Measurement of 7 parameters in the first trimester and 11 parameters in the second and third trimesters correlated with gestational age (P<0.05). Those parameters have been followed longitudinally through all trimesters and showed increasing frequency of fetal movements during the first trimester. A tendency towards decreased frequency of facial expressions and movement patterns with increasing gestational age from second to third trimesters has been noticed.

Conclusion: With 4D sonography, it is possible to quantitatively assess normal neurobehavioral development. There is urgent need for further multicentric studies until a sufficient degree of normative data is available and the predictive validity of the specific relationship between fetal neurobehavior and child developmental outcome is better established.