TY - JOUR AU - Ursem, N TC; Struijk, P C; Hop, W CJ; Clark, E B; Keller, B B; Wladimiroff, J W TI - Heart rate and flow velocity variability as determined from umbilical Doppler velocimetry at 10-20 weeks of gestation JO - Clin Sci (Lond) IS - 05 VL - 95 PY - 1998 L3 - PubMed-ID: 9791039 SP - 539 EP - 545 ER -