Management of IUGR fetuses

Background: When decisions about the optimal timing of delivery have to be made in pregnancies complicated by intrauterine growth retardation, the risks of prematurity must be balanced against the risks of prolonged fetal exposure to a hostile intra-uterine environment. Investigation of the time sequence in which alterations of fetal monitoring parameters oecur, may assist in the management of these pregnancies.
Methods: 110 singleton fetuses with intrauterine growth retardation were studied longitudinally from 24 weeks of gestation onwards. Short-term variation (STV) of fetal heart rate, pulsatility indices (PI) of arterial and venous Doppler waveforms and amniotic fluid index were assessed at each monitoring session. The study population was divided into two groups: group 1 comprised pregnancies with severely prematüre fetuses, which were delivered < 32 weeks and group 2 ineluded pregnancies delivered after 32 completed weeks. Logistic regression was used for modeling the probability for abnormality of a variable in correlation to the time interval before delivery. Trends över time were analyzed for ali variables by multilevel analysis.
Results: 93 (6() in group 1 and 33 in group 2) fetuses had at least three data sets (median: 4; range: 3-27) and last measurements were taken within 24 hours of delivery or intrauterine death. The percentage and degree of abnormal findings were much higher in group 1 as compared to group 2. Amniotic fluid index and umbilical artery PI were the first parameters to become abnormal and they were followed by the middle cerebral artery, aorta, STV, eluetus venosus and inferior vena cava. in group 1, STV and duetus venosus PI showed mirror images of each other in their trend över time. Perinatal mortality was significantly higher if both parameters were abnormal as compared to only one or neither of them being abnormal [13/33 (39%) vs 4/60 (7%); P = 0.0002].
Conclusions: Duetus venosus PI and STV of fetal heart rate a re important indicators for the optimal timing of deliveıy before 32 weeks of gestation. Delivery should be considered if one of these parameters becomes persistently abnormal.
Key Words: intrauterine growth retardation, Fetal moniloring, Fetal heart rate, Fetal Doppler, Amniotic fluid index, Short-term variation, Duetus venosus.