RESUMO
To know the normal umbilical artery waveform pattern and to establish the A/B ratio during the 2nd and 3rd trimester. From this knowledge to detect the abnormal waveform and A/B ratio and its application to diagnose the I.U.G.R. Design: A study of 150 normal and twenty abnormal patients presented through indoor or outdoor basis over a period of about six months. Setting: Department of diagnostic radiology Lahore General Hospital and Park View Clinic, Lahore. Subjects: 150 normal pregnant cases and twenty cases of pregnancy associated with some obstetrical problem from indoor or outdoor. Main outcome measures: Waveform pattern study and A/B ratio calculation. Normal value of A/B ratio decreased from 20th week to 40th week with significant increase in diastolic flow. These normal results were compared with twenty cases of pregnancy associated with some obstetrical problem. Among these three cases were normal, fourteen cases showed reduced diastolic velocity, there showed absent diastolic phase while reverse diastolic phase was not noted in any case which is a sign of severe I.U.G.R. and in these cases A/B ratio was also high as compared to normal cases. Study of pattern of umbilical artery Doppler flow velocity waveform and from it calculation of A/B ratio is very helpful in detecting the cases of I.U.G.R and is also helpful in deciding the time and mode of delivery depending upon the severity of I.U.G.R