A comparison of Doppler and biophysical findings between liveborn and stillborn growth-restricted fetuses.

OBJECTIVE: The purpose of this study was to evaluate the surveillance characteristics that precede stillbirth in growth-restricted fetuses that receive integrated Doppler and biophysical profile scoring (BPS). STUDY DESIGN: Nine hundred eighty-seven singleton pregnancies that were complicated by fetal growth restriction had multivessel Doppler scans (umbilical and middle cerebral arteries [MCA], ductus venosus, and umbilical vein) and BPS. Surveillance findings were compared between live births and stillbirths. RESULTS: Forty-seven stillbirths occurred in 2 clusters, 37 at <34 weeks of gestation and 10 thereafter. Before 34 weeks of gestation, stillbirths had parallel escalation of umbilical artery and ductus venosus Doppler findings followed by abnormal BPS. At ≥34 weeks of gestation, only a decline in MCA pulsatility index was observed, and 75% of stillbirths were unanticipated by the BPS. CONCLUSION: Before 34 weeks of gestation, multivessel Doppler abnormality anticipates an abnormal BPS and subsequent stillbirth. After 34 weeks of gestation, stillbirths occur after MCA brain-sparing in a shorter interval than predicted by a normal BPS. Recognition of these differences in clinical behavior requires consideration for the planning of monitoring intervals in preterm and term fetal growth restriction.

Outcome after fetoscopic selective laser ablation of placental anastomoses vs equatorial laser dichorionization for the treatment of twin-to-twin transfusion syndrome.

OBJECTIVE: The objective of the study was to compare the outcome in women with twin-twin transfusion syndrome (TTTS) who were managed by selective laser ablation of placental anastomoses (S-LASER) vs equatorial dichorionization of the anastomoses and chorionic plate (ED-LASER). STUDY DESIGN: We conducted an analysis of 2 consecutive cohorts with TTTS treated with S-LASER and ED-LASER. Preoperative, procedural, delivery, and outcome details were compared between treatment groups. RESULTS: A total of 147 twin pregnancies had laser (S-LASER, n = 71; ED-LASER, n = 76). Obstetric history, Quintero stage, placental location, individual arterial and venous Doppler parameters, and gestational age at laser and delivery did not differ. Use of lens fetoscope (96.1% vs 50.7%), coagulated anastomosis count (11 vs 15, P < .001), complete equatorial plate visualization (77.5% vs 92.1%, P = .019), and amniotic fluid transparency (80.3% vs 94.7%, P = .011) was greater during ED-LASER. Procedure-related complications, gestational age at delivery, and perinatal details were comparable between groups. ED-LASER was associated with significantly lower recurrence of TTTS (3.9% vs 8.5%), twin anemia polycythemia sequence (2.6% vs 4.2%), and amniotic fluid abnormalities (0% vs 5.6%, P < .05 for all comparisons). Logistic regression identified complete visualization of the equator as the primary determinant for successful TTTS treatment and coagulation of the chorionic plate as an independent cofactor. Double survival at age 6 months was significantly higher after ED-LASER (68.4% vs 50.7%, P < .05), attributable to a lower postlaser and neonatal mortality rates. CONCLUSION: In patients with TTTS, photocoagulation of causative anastomoses and the chorionic plate along the vascular equator decreases recurrence without increasing adverse outcome and improves survival compared with the selective technique.

Changes in umbilical venous volume flow after fetoscopic laser occlusion of placental vascular anastomoses in twin-to-twin transfusion syndrome.

OBJECTIVE: To examine effects of fetoscopic laser occlusion of placental vascular anastomoses on umbilical venous volume flow in twin-to-twin transfusion syndrome. STUDY DESIGN: Absolute umbilical venous volume flow, measured preoperatively and 48 hours after fetoscopic laser occlusion was related to Doppler studies, bladder filling in donors, and anastomoses. RESULTS: Among 45 patients, recipients had decreased ductus venosus pulsatility index (ductus venosus-pulsatility index for veins, 1.16 vs 1.01; P < .001) and unchanged umbilical venous volume flow after fetoscopic laser occlusion (74.7 vs 74.5 mL; P = .407). Donors had decreased umbilical artery pulsatility (1.34 vs 1.11; P = .008), increased ductus venous-pulsatility index for veins (0.75 vs 0.91; P < .014), and significantly increased umbilical venous volume flow per kilogram by 52.3% (136.6 vs 208.0 mL/Kg/min; P < .001). Donor bladder filling occurred at higher umbilical venous volume flow per kilogram (142.7 vs 221.4 mL/Kg/min; P < .012). Increase in umbilical venous volume flow per kilogram correlated with the net difference in arteriovenous anastomoses (Pearson r = 0.403, P = .006). CONCLUSION: Fetoscopic laser occlusion in twin-to-twin transfusion syndrome corrects intertwin differences in umbilical venous volume flow by predominant effects in the donor. Reappearance of donor bladder filling correlates with correction of volume flow.

Ductus venosus Doppler for fetal surveillance in high-risk pregnancies.

Doppler evaluation of the fetal ductus venosus has increased our depth of understanding of many fetal conditions. The ductus venosus has an important role in the regulation of nutrient partitioning in the fetus. Alterations in cardiac afterload, contractility compliance, intravascular volume status, and heart rate may significantly impact on the ductus venosus flow velocity waveform. Accordingly, ductus venosus Doppler is useful in the management of conditions that put the fetus at risk for cardiovascular deterioration. The application of DV Doppler in fetal growth restriction, complicated monochorionic multiple gestation, fetal hydrops, and arrhythmia are discussed in this review.

Fetal growth restriction - from observation to intervention.

Fetal growth restriction (FGR) due to placental dysfunction has important short- and long-term impacts that may reach into adulthood. Early-onset FGR before 34 weeks' gestation shows a characteristic sequence of responses to placental dysfunction that evolves from the arterial circulation to the venous system and finally to biophysical abnormalities. In this form of FGR safe prolongation of pregnancy is a primary management goal, as gestational age at delivery, birth weight and iatrogenic premature delivery have an important impact on short-term outcome and neurodevelopment. Surveillance intervals should be adjusted based on umbilical artery and venous Doppler studies. Intervention thresholds need to be based on the balance of fetal vs. neonatal risks and therefore critically depend on gestational age. Late-onset FGR presents with subtle Doppler and biophysical abnormalities and therefore poses a diagnostic dilemma. Often unrecognized, term FGR contributes to a large proportion of adverse perinatal outcome. Monitoring intervals should be adjusted based on middle cerebral artery Doppler and fetal heart rate parameters. Delivery timing thresholds can be low. In both forms of FGR neurodevelopmental impacts of placental disease occur before clinical decisions regarding delivery timing arise. This places special emphasis on future preventative studies.

Predictors of fetal growth in maternal HIV disease.

We sought to determine predictors of fetal growth restriction in maternal HIV disease. Pregnant HIV-positive women on antiretroviral therapy were monitored with serial viral load and CD4 counts. Individualized growth potential (GP) percentile was calculated for birth weight (BW). BW <10th GP percentile defined fetal growth restriction (FGR). Multiple medical and social factors, CD4 count, viral load, and antiretroviral therapy were tested for impact on fetal growth using chi-square and multiple regression analysis. Two hundred eleven women were studied. CD4 count <200 in the first trimester was strongly associated with FGR (odds ratio 8.75, 95% confidence interval 2.88 to 26.52). Maternal age ( P = 0.02) and smoking ( P = 0.03) were independent cofactors for FGR (Nagelkerke R(2) = 0.33). No other factors demonstrated an independent effect. Severity of maternal HIV disease as indicated by the CD4 count, rather than placental exposure to viral load, predicts FGR. Smoking has an independent detrimental effect on fetal growth.

Venous Doppler in the assessment of fetal cardiovascular status.

PURPOSE OF REVIEW: The purpose of this review is to highlight recent developments in the Doppler assessment of the fetal venous circulation with special reference to clinical applications in the human fetus. RECENT FINDINGS: Doppler evaluation of the fetal venous circulation has increased our understanding of fetal cardiovascular function. Examples include the regulatory role of the ductus venosus in fetal nutrient partitioning and the significance of venous and arterial circulatory watershed areas. Alterations in cardiac afterload, contractility compliance, intravascular volume status and heart rate modulate venous and arterial flow velocity waveforms. Concurrent examination of these cardiovascular factors is of great importance in fetal growth restriction, complicated monochorionic multiple gestation, fetal hydrops and arrhythmia. In these conditions, comprehensive Doppler assessment provides critical diagnostic and prognostic information and has a key role in directing interventions. SUMMARY: Venous Doppler has added a critical dimension to the understanding of fetal cardiovascular pathophysiology. In both health and disease, venous Doppler must now occupy a fundamental position in the comprehensive assessment of the fetal circulation.

Arterial and venous Doppler in the diagnosis and management of early onset fetal growth restriction.

Key issues in the management of early onset fetal growth restriction (IUGR<34 weeks) are accurate diagnosis and assessment of fetal well-being to optimize timing of delivery by weighing fetal vs. neonatal risks. Cardiovascular, behavioral and fetal heart rate patterns in IUGR follow a predictable progression that corresponds with the severity of compromise. Umbilical artery (UA) Doppler primarily serves as a placental function test providing insufficient information to solely direct perinatal management. Venosus Doppler is an independent predictor of stillbirth and acidemia and needs to be examined when the UA index is elevated, especially if end-diastolic velocities are absent. Neonatal outcomes are primarily determined by gestational age and their antenatal prediction is too ineffective to guide management. Abnormal venous Doppler, biophysical profile score and mean minute variation of the fetal heart rate are strong predictors of fetal compromise therefore favoring delivery. Randomized trials indicate that delayed delivery has little effects on short-term outcome while producing a trend towards improved early childhood neurodevelopment. This stresses the need for excellent fetal surveillance techniques and their ongoing investigation through randomized management trials.

Pathophysiology of fetal growth restriction: implications for diagnosis and surveillance.

UNLABELLED: Normal fetal growth depends on the genetically predetermined growth potential and is modulated by fetal, placental, maternal, and external factors. Fetuses with intrauterine growth restriction (IUGR) are at high risk for poor short- and long-term outcome. Although there are many underlying etiologies, IUGR resulting from placental insufficiency is most relevant clinically because outcome could be altered by appropriate diagnosis and timely delivery. A diagnostic approach that aims to separate IUGR resulting from placental disease from constitutionally small fetuses and those with other underlying etiologies (e.g., aneuploidy, viral infection, nonaneuploid syndromes) needs to integrate multiple imaging modalities. In placental-based IUGR, cardiovascular and behavioral responses are interrelated with the disease severity. Ultrasound assessment of fetal anatomy, amniotic fluid volume, and growth is complementary to the Doppler investigation of fetoplacental blood flow dynamics. A diagnostic approach to IUGR combining these modalities is presented in this review. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader should be able to describe the development of the placental interface, to outline the mechanisms of placental insufficiency, and to list the manifestations of placental insufficiency and the tests that can be used to diagnose fetal growth restriction.

Venous Doppler evaluation of the growth-restricted fetus.

Evaluation of venous Doppler parameters has significantly contributed to the understanding of the vascular mechanisms that lead to fetal growth restriction (FGR) and subsequent fetal deterioration in the setting of progressive placental dysfunction. Venous redistribution of umbilical venous blood flow away from the fetal liver precedes fetal growth delay. Venous Doppler examination allows adjustment of monitoring intervals in recognition of accelerating fetal deterioration. The timing of delivery in early-onset FGR remains challenging because gestational age has an overriding effect on the neonatal outcome until the late second trimester and randomized trials of specific delivery triggers are lacking.