Middle cerebral artery Doppler in severe intrauterine growth restriction

Objective To examine longitudinal changes in middle cerebral artery blood f low assessed by Doppler in severely growth restricted fetuses. Methods Eighteen structurally normal singleton pregnancies complicated by s uspected intrauterine growth restriction were monitored by serial measureme nt of the pulsatility index of the middle cerebral artery over 7 to 72 days . Outcome measures included indication for delivery, umbilical venous pH an d admission to and length of stay in neonatal intensive care. Results Thirteen fetuses demonstrated severe intrauterine growth restrictio n based on subsequent birth weights being below the 2.5th centile, two had intrauterine growth restriction (birth weights between the 2.5th and 5th ce ntiles), and three had birth weights between the 5th and 50th centiles. The middle cerebral artery pulsatility, index showed rapid and sharp changes b etween examinations in those severely, growth restricted fetuses which requ ired delivery before 34 weeks. This pattern was not obvious in severely gro wth restricted fetuses delivered after 34 weeks, or in those less severely growth restricted, regardless of the gestation at delivery. Changes in midd le cerebral artery pulsatility index contributed to the decision to deliver in three cases. The middle cerebral artery pulsatility index demonstrated greater variation in those fetuses with cord pHs of less than 7.25. The len gth of stay in neonatal intensive care decreased with increasing gestationa l age and birth weight. Conclusions The difference in the pattern of change in middle cerebral arte ry pulsatility index in intrauterine growth restricted fetuses may be a ref lection of maturity in addition to the degree of fetal compromise. The deci sion to deliver was multifactorial. The middle cerebral artery pulsatility inner only influenced the decision to deliver when changes in other paramet ers were evident.