OP14.16: Cardiovascular changes and neonatal outcome in IUGR fetuses born to normotensive and preeclamptic mothers

Abstract

Objectives: To compare the effects of maternal hyperoxygenation on the Doppler waveforms in twin pregnancies where one fetus has IUGR and absent or reversed end diastolic flow (ARED) in room air. Methods: Women with monochorionic diamniotic twin pregnancies with one IUGR fetus with ARED in room air between 2006 and 2008 who were hospitalized after 24 weeks gestation for close surveillance and bed rest were included in the study. All fetuses had structurally normal hearts. None had evidence of twin-twin transfusion syndrome. Measurements of Doppler flow pattern in middle cerebral artery (MCA), free loop of umbilical artery (FLUA) and ductus venosus (DV) were made in room air and then after breathing 60% oxygen by face mask for twenty minutes. Results: Seven twin pregnancies were included. The normal cotwin in each case had normal Doppler waveforms in room air and oxygen. All seven IUGR fetuses had ARED in room air and dilated DV size. In five patients, the FLUA normalized (PI < 1.75) after breathing 60% oxygen (mean PI = 3.21 in room air versus mean PI = 1.65 in oxygen). These five patients who had positive change with oxygen delivered an average of 5 weeks (range 3–14 weeks) after hospitalization. The other two patients who had no change in FLUA with oxygen and had abnormal MCA and DV in room air were delivered for obstetric indications within one day of the test. Conclusions: Maternal hyperoxygenation may be associated with normalization of the FLUA in fetuses with ARED after 24 weeks of gestation. A positive maternal hyperoxygenation test can select IUGR fetuses who have an abnormal FLUA in room air with a better prognosis and may be useful in postponing delivery in these fetuses with ARED.