Progression of Doppler abnormalities in intrauterine growth restriction.

OBJECTIVE: To identify the sequence of progression of arterial and venous Doppler abnormalities from the onset of placental insufficiency in intrauterine growth restriction (IUGR).

METHODS: Prospective observational study of singletons with IUGR (abdominal circumference < 5(th) percentile) who underwent serial standardized umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV) and umbilical vein (UV) Doppler surveillance. Time intervals between progressive Doppler abnormalities and patterns of deterioration were related to UA Doppler status and gestational age.

RESULTS: Six hundred and sixty-eight longitudinal examinations were performed in 104 fetuses, identifying three patterns of progression: (1) Mild placental dysfunction (n = 34) that remained confined to the UA/MCA. The UA became abnormal at a median of 32 weeks' gestation but the pulsatility index never exceeded 3 SD above normal. Progression took a median of 33 days, requiring delivery at a median of 35 weeks. (2) Progressive placental dysfunction (n = 49). Initially normal UA Doppler PI at 29 weeks' gestation increased beyond 3 SD, progressing to abnormal MCA, absent/reversed UA diastolic flow, abnormal DV, UV pulsations in 9-day intervals requiring delivery by 33 weeks. (3) Severe early-onset placental dysfunction (n = 21). Markedly elevated UA PI established by 27 weeks' gestation was associated with rapid (7-day intervals) progression to abnormal venous Doppler with median delivery at 30.6 weeks. Gestational age at onset, time to delivery and progression intervals were different between patterns (all P < 0.05).

CONCLUSION: The characteristics of cardiovascular manifestations in IUGR are determined by the gestational age at onset and the severity of placental disease. Recognition of these factors is critical for planning fetal surveillance in IUGR.