OP10.12: Intrauterine growth rate in pregnancies complicated by isolated two-vessel cord

16th World Congress on Ultrasound in Obstetrics and Gynecology

patients who had normal placental parenchyma. The groups were matched for maternal age, gestational age, parity, race, and smoking. Transverse and sagittal scans in real time were used to evaluate the degree and severity of thrombosis. The mean of the two largest lesion diameters was used for severity classification. Results: Mean gestational age at delivery was 39.1 wks (± 1.8) for the control group, 37.9 wks (± 2.8) for mild thrombosis and 35.2 wks (± 5.8) for severe thrombosis, (p < 0.0001). Mean birth weight was 3348 g (± 492) for the control, 3134 g (± 657) for the mild thrombosis and 2524 g (± 1339) for the severe thrombosis group, (p = 0.0005). The presence of IUGR was more frequent in patients with thrombotic lesions: 9.6% in mild thrombosis and 38.4% in severe thrombosis, in comparison to 3.1% in the control group (p = 0.0003; OR = 5.7; p = 0.0151). Pre-eclampsia was also more frequent in patients with thrombosis: control group, 0.0%; the mild group, 7.7%; and severe group, 15.4% (p < 0.0214; OR = 14.3, p = 0.0139). Conclusions: There is a strong association between placental thrombosis and adverse perinatal outcomes. Increased size and/or number of thrombotic lesions is associated with more adverse perinatal outcomes. Ultrasound may be useful in identifying patients with pro-thrombotic abnormalities associated with placental thrombosis.

OP10.11 Correlation of ultrasound placental grading and a stereological estimate of placental function T. T. Yin1 , S. S. Ong2 , J. Padfield3 , T. M. Mayhew4 , P. V. Loughna1 Nottingham City Hospital, United Kingdom, 2 Birmingham Women’s Hospital, United Kingdom, 3 Queen’s Medical Centre, Nottingham, United Kingdom, 4 School of Biomedical Science, University of Nottingham, United Kingdom

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Objective: To provide a rationale for obtaining a stereological estimate of the oxygen diffusive conductance (Dp) of the placental villous membrane. The ultimate aim is to correlate this surrogate measure of placental function with ultrasound placental grading (Grannum system). Methods: Placentas were graded (0, I, II or III) at 31–34 weeks gestation and we aim for n = 10 patients per grade. Placentas were collected immediately after delivery and trimmed weights and volumes measured. Multistage systematic uniform random sampling was applied to obtain tissue images. Full-thickness pieces of tissue were fixed in formalin and sections were stained. Thirty micrograms per placenta were recorded. Test point counting allows estimation of the volumes of functioning villi and fetal capillaries. Surface areas were estimated by counting intersections with test lines. The harmonic mean thickness of the villous membrane (an effective diffusion distance) was obtained by measuring random intercept lengths. Finally, villous membrane Dp was calculated for each placenta from surface areas and diffusion distances. So far, 8 placentas have been analysed and, here, we provide a summary of data obtained for a set of n = 4 placentas graded I on the Granny scale. Results: Mean (SEM) gestational age was 39 (0.7) week, birth weight 2.99 (0.25) kg and placental volume 530 (108) ml. Within the placenta, functioning villi accounted for 101 (12) ml and had a surface of 11 (3) m2 . Corresponding figures for fetal capillaries were 46 (12) ml and 10 (2) m2 . The harmonic mean thickness of the villous membrane was 4.8 (0.2) µm. These values yielded a total Dp of 39 (12) ml/min/kPa. Conclusion: Findings are consistent with earlier estimates for normal term pregnancies. With further analysis, we expect to correlate grading with Dp and, in addition, assess whether or not individuals have values of Dp matched to birth weight.

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Oral poster abstracts

OP10.12 Intrauterine growth rate in pregnancies complicated by isolated two-vessel cord R. Neiger1 , D. S. McKenna1 , A. Bombrys2 , S. Wiegand1 , C. S. Croom1 , G. Ventolini1 , J. D. Sonek1 Wright State University, United States, 2 SouthView Hospital, United States

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Objective: Pregnancies complicated by isolated 2 vessel cord are often followed closely because of concerns regarding possible intrauterine growth impairment. To assess whether the practice of serial sonographic assessments is beneficial, we studied the rate of intrauterine growth in such pregnancies. Methods: Our diagnostic perinatal center is a large referral center staffed by four Maternal-Fetal Medicine specialists. Pregnant women are referred to us at the discretion of their private physicians. We collected serial data regarding fetal growth on all pregnancies that were diagnosed with 2 vessel cord. Inclusion criteria included a minimum of three sonographic studies. We excluded multiple gestations and pregnancies complicated by fetal anomalies or maternal complications. Rate of growth was compared to normal values according to Hadlock data. Results: Between January 2004 and December 2005 we detected 2 vessel cords in 86 pregnancies. Thirty six were excluded from analysis: twenty three had less than two ultrasound studies, two were twin gestations, and 11 had associated fetal anomalies. The growth rate of biometric measurements, estimated fetal weight and amniotic fluid volumes of the remaining 50 pregnancies were analyzed. The fetal growth rate in 48 (96%) of these pregnancies fell within normal range. The estimated weight of one fetus fell below the 10th percentile at 31.6 weeks’ gestation, and second fell to the 10th percentile at 37.9 weeks’. Conclusion: The risk of growth restriction in association with the ultrasound finding of an isolated two vessel cord does not appear to be increased. Therefore, in otherwise uncomplicated pregnancies, serial ultrasound assessments of intrauterine growth in such pregnancies do not appear to be indicated.

OP10.13 Prognosis of threatened abortion by embryonic/fetal heart beat rate I. Y. Park, J. C. Shin, C. Y. Kim The Catholic University of Korea, Republic of Korea Objectives: We try to evaluate the prognosis of threatened abortion by embryonic/fetal heart rate. Methods: Study population are composed of 481 threatened abortion cases. Successful pregnancy was noticed in 424 cases and 57 spontaneous abortion was occured in study population. Embryonic/fetal heart rate was analysed for prognosis. The equipment for sonographic evaluation was ACCUVIX (Medison, Seoul, Korea). Results: The average fetal heart beat of successful pregnancy group was 152.7 bpm and The average fetal heart beat of spontaneous abortion group was 142.9 bpm (p-value < 0.01). Especially, during gestational age 8–10 weeks, the fetal heart rate of successful pregnancy group was 164.9 bpm and the fetal heart rate of spontaneous abortion group was 146.1 bpm (p-value < 0.05) Conclusions: The embryonic/fetal heart rate of threatened abortion was useful prognostic factor. We need more evaluation about fetal heart physiology.

Ultrasound in Obstetrics & Gynecology 2006; 28: 412–511