Perinatal Outcome in Preterm Infants with Abnormal Umbilical Artery Doppler Results : Emphasizing on Early Onset Thrombocytopenia and its Risk Factors

ABSTRACT

PURPOSE:Umbilical artery Doppler study is a commonly used non-invasive tool in high risk pregnancies because of its good correlation with the degree of placental insufficiency. We analyzed hematologic profiles and perinatal outcome of preterm infants with abnormal umbilical artery Doppler results and the risk factors of early onset thrombocytopenia. METHODS:We retrospectively reviewed the medical records of preterm infants under 35 weeks of gestational age at birth who were admitted to the neonatal intensive care unit of Seoul National University Children's Hospital from January 1, 2002 through December 31, 2004, and whose mothers had undergone umbilical artery Doppler studies within 5 days before delivery. Sixty two neonates were divided into three groups; the 1st group was defined as the patients with normal umbilical artery (UA) systolic/diastolic (S/D) ratio, the 2nd group, with increased UA S/D ratio above 95 percentile, and the 3rd, with absent or reversed end-diastolic flow (AREDF). RESULTS:Mean nucleated red blood cell (nRBC) counts per 100 white blood cells (WBCs) were 14.2 (0-150), 91.0 (0-262), 301.4 (6-884) (P<0.001), mean WBC counts were 10.8 (0- 34.1), 9.2(3.4-23.9), 5.9(0.5-15.2) (x1,000/mm(3)) (P=0.007), and mean platelet counts were 215.5+/-69.2, 185.9+/-96.7, 100.2+/-50.3 (x1,000/mL) (Risk factors of early onset thrombocytopenia were AREDF (P=0.037), lower gestational age (P=0.045). Perinatal outcomes were not significantly different except for longer duration of initial antibiotic treatment and hospital stay, more delayed feeding in group 3.

CONCLUSION:

Preterm neonates with abnormal umbilical artery Doppler results had higher nRBC, lower WBC and platelet counts. Lower gestational age and AREDF were risk factors of early onset thrombocytopenia.