Positive End-diastolic Flow Research Articles

A case of type III selective intrauterine growth restriction in a monochorionic twin pregnancy with a myriad of Doppler changes of the umbilical and vitelline arteries

Monochorionic twins have higher mortality rates than dichorionic twins. Selective intrauterine growth restriction (sIUGR) is a common complication found in monochorionic twins. We report such a case of type III sIUGR monochorionic twins. There was positive end-diastolic flow of umbilical arteries, which corresponded to type I sIUGR at 15 weeks. Then, the umbilical arteries showed persistently absent end-diastolic flow at 17 weeks which corresponded to type II sIUGR. Finally, the umbilical artery showed intermittent absent/reversed end-diastolic flow which corresponded to type III sIUGR. This case demonstrated a unique myriad of Doppler changes during the pregnancy, indicating its significance in being reported. The twins were delivered by caesarean section at 32 weeks and were developing well. Placental examination showed unequal placental sharing and the presence of an arterio-arterial anastomosis. These are characteristic findings of a type III sIUGR. Type III sIUGR may not be obvious at the initial examination but may only be obvious at later examinations.

Perinatal outcome of monochorionic diamniotic twin pregnancy complicated by selective intrauterine growth restriction according to umbilical artery Doppler flow pattern: single-center study using strict fetal surveillance protocol.

To determine the perinatal outcome of monochorionic diamniotic (MCDA) twin pregnancies complicated by selective intrauterine growth restriction (sIUGR), which were classified according to the umbilical artery (UA) Doppler flow pattern of the IUGR twin. This was a retrospective cohort study of all MCDA twin pregnancies diagnosed with sIUGR and managed at a single tertiary referral center between 2012 and 2018. Cases were classified according to the UA Doppler flow pattern of the IUGR twin as Type I (positive end-diastolic flow), Type II (persistently absent/reversed end-diastolic flow) or Type III (intermittently absent/reversed end-diastolic flow). Patients with Type-II or -III sIUGR were hospitalized at 26-28 weeks of gestation for increased fetal surveillance. Perinatal and immediate and long-term neurodevelopmental outcomes were stratified according to the UA Doppler flow pattern at the final examination. Intact survival rate was defined as the number of infants surviving without neurological impairment, divided by the total number of fetuses. Composite adverse outcome, defined as any mortality, presence of severe brain lesions on postnatal transcranial ultrasound or severe neurological morbidity, was also assessed. Of 88 MCDA twin pregnancies with sIUGR included in the study, 28 underwent selective termination by cord occlusion using radiofrequency ablation, resulting in a perinatal survival rate of 89.3% and a median gestational age (GA) at delivery of 33.8 (interquartile range (IQR), 28.8-38.2) weeks for the large cotwin. Expectant management was employed in 60 cases. In 26 (43.3%) cases in the expectant-management group, the classification according to the UA Doppler flow pattern changed during gestation, resulting in 26 (43.3%) cases of Type-I, 22 (36.7%) cases of Type-II and 12 (20.0%) cases of Type-III sIUGR at the final examination. The perinatal survival rate of both twins with sIUGR Types I, II and III at the final examination was 100%, 81.8% and 75.0%, respectively (P = 0.04). Two cases of double fetal death and one case of single fetal death occurred 1-4 weeks after the Doppler pattern had changed from Type I or Type II to Type III. The median GA at delivery was 34.8 (IQR, 33.1-35.7) weeks in Type I, 30.3 (IQR, 28.6-32.1) weeks in Type II and 32.0 (IQR, 31.3-32.6) weeks in Type III (P < 0.01). The total intact survival rate was 100% for Type I, 77.3% for Type II and 75.0% for Type III (P < 0.001). Multivariate analysis demonstrated that early GA at diagnosis (odds ratio (OR), 0.83 (95% CI, 0.69-0.99); P = 0.04) and the presence of Type II or III vs Type I at the last examination (OR, 13.16 (95% CI, 1.53-113.32); P = 0.02) were associated with preterm birth < 32 weeks' gestation. Early GA at diagnosis was also associated with the composite adverse outcome (OR, 0.60 (95% CI, 0.36-0.99); P = 0.04). The classification system of MCDA pregnancy complicated by sIUGR, according to the UA Doppler flow pattern of the IUGR twin at final examination, is associated with perinatal outcome. Importantly, the UA Doppler flow pattern can change during gestation, which has an impact on the risk of fetal death. Nevertheless, under strict fetal surveillance, the perinatal outcome of these pregnancies is favorable. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Umbilical Artery Doppler Indices at the Perivesical Segment in Growth-Restricted Fetuses

AbstractTo compare perinatal outcomes of growth-restricted fetuses with bilateral positive end-diastolic (PED) flow at the perivesical segment (PVC) and growth-restricted fetuses with unilateral or bilateral absent/reverse end-diastolic (ARED) flow at the PVC segment. A total of 119 growth-restricted fetuses with PED flow at the free loop of the umbilical artery were enrolled in this cross-sectional study. Methods The patients were separated into three groups according to presence or absence of the end-diastolic flow at the perivesical segment. Patients with bilateral PED flow at the PVC segment were enrolled in Group1, patients with unilateral and bilateral (ARED) flow at the PVC segment were enrolled in Group 2 and 3, respectively. The perinatal outcomes of the groups were investigated. There were no significant differences between groups in terms of maternal age, gravida, parity, the gestational age at ultrasound examination and the pulsatility index of free umbilical artery. The gestational age at delivery, the birth weight and the interval between the diagnosis and delivery were found significantly higher in Group 1 than the other groups, there were no significant differences between Group 2 and 3 in terms of these parameters. More adverse pregnancy outcomes were observed in the unilateral and bilateral ARED flow groups than the bilateral PED flow group. In addition to the free loop Doppler indices, measuring the umbilical arteries Doppler indices at the PVC segment could contribute to the determination of more growth-restricted fetuses at risk of hypoxia.

Umbilical Artery Doppler Patterns and Right Ventricular Outflow Abnormalities in Twin-Twin Transfusion Syndrome.

To evaluate the association of abnormal Doppler velocimetric patterns in the umbilical arteries (UAs) and right ventricular outflow tract abnormalities (RVOTAs) in twin- twin transfusion syndrome (TTTS) cases. This retrospective study involved women who had laser surgery for TTTS between January 2012 and May 2018 at a single institution. The prevalence of an RVOTA in either twin was compared among TTTS cases in which both twins had positive end-diastolic flow (EDF) in the UA and those in which either twin had intermittent or persistent absent/reversed UA EDF. Nonparametric tests were used for comparisons. Logistic regression was performed to identify variables associated with an RVOTA in either twin, adjusted for moderate or severe tricuspid regurgitation, right ventricular hypertrophy, right ventricular systolic or diastolic dysfunction, the Quintero stage, and other confounders. P < .05 was considered significant. A total of 126 consecutive TTTS cases were included. Right ventricular outflow tract abnormalities were seen in 8.7% (11of 126) of cases, all in recipient twins. Significant differences in the rate of RVOTAs in the recipient twin were seen between TTTS cases with intermittent absent/reversed UA EDF and those with positive UA EDF (26.9% [7 of 26] versus 3.7% [3 of 82]; P = .002]. However, no significant differences were noted among the other study groups. Intermittent absent/reversed UA EDF was associated with a significantly increased risk for an RVOTA (adjusted odds ratio, 20.6 [95% confidence interval, 3.1-138]; P = .002) after adjusting for confounders. Intermittent changes in vascular impedance to UA flow may contribute to the pathogenesis of acquired right-sided cardiac lesions in the recipient twin affected with TTTS.

Management and perinatal outcome of selective intrauterine growth restriction in monochorionic pregnancies

Introduction Selective intrauterine growth restriction (sIUGR) is a complication observed in about 10–15% of all monochorionic (MC) pregnancies, causing a significant increase in perinatal mortality and morbidity. Objective To evaluate clinical management options and perinatal outcomes of sIUGR in MC pregnancies monitored in a single tertiary center. Methods A retrospective study was performed on 55-MC pregnancies with sIUGR between January 2012 and May 2018 at the Fetal Medicine Unit of La Paz Hospital. Cases were classified according to the umbilical artery (UA) Doppler pattern as type I (positive end-diastolic flow; n = 25), type II [persistently absent or reversed end-diastolic flow (AREDF); n = 5] and type III [intermittently absent or reversed end-diastolic flow (iAREDF); n = 25]. Types II and III were then merged together as severe sIUGR cases. Subsequently, two possible approaches were considered: expectant management (EM) with elective preterm delivery in case of fetal deterioration, or in-utero therapy via fetoscopic laser photocoagulation (FLP) of intertwin anastomosis or selective umbilical cord occlusion (CO) of the growth-restricted fetus. Results Gestational age (GA) at diagnosis was progressively lower with each type. Severe sIUGR cases delivered significantly earlier than type I, showing lower birth weights and higher intertwin biometric discordance. Unintended fetal demise occurred in 14% (6/25) of severe sIUGR pregnancies as opposed to 0% (0/19) in type I, p = .028. A significantly higher proportion of twins was admitted in NICU in severe cases when compared to type I [87% (33/38) versus 47% (18/38), p < .001]. In addition, brain damage at birth was also found to be more prevalent in this group [21% (8/38) versus 11% (4/38), p = .346], especially in the larger twin, when comparing any short-term neurological sequel [30% (7/23) versus 0% (0/19), p = .011] or specifically periventricular leukomalacia [PVL; 22% (5/23) versus 0% (0/19), p = .053]. Although the overall mortality rate was significantly higher in severe sIUGR that underwent CO instead of EM [58% (7/12) versus 11% (4/36), p = .002], NICU admissions were higher in the latter [94% (17/18) versus 40% (2/5), p = .021]. Neurological sequels at birth were similar in both groups [39% (7/18) versus 40% (2/5), p = 1.000], similarly when considering only the larger twin for any brain lesion [28% (5/18) versus 40% (2/5), p = .621] or just PVL [22% (4/18) versus 20% (1/5), p = 1.000]. Conclusion Given the good prognosis of type I sIUGR, expectant management is the first approach to consider. However, due to the poorer clinical evolution of types II and III sIUGR, the decision-making is challenging and needs to be individualized depending on the UA Doppler pattern, GA at diagnosis, severity of growth restriction and biometric discordance, technical issues and parents’ preferences.

Successful Management of Takayasu’s Arteritis with Pulmonary Hypertension in Pregnancy: A Rare Case

Introduction: Takayasu’s arteritis (TA) is a rare systemic, chronic inflam-matory, progressive, idiopathic disease of aorta and its main branches. Taka-yasu’s arteritis causes narrowing, occlusion and aneurysm of arteries. The eti-ology of TA is still unknown. It may be autoimmune or genetic in origin or infective diseases. It is commonly found in Asia and oriental countries. Worldwide annual incidence is 1.2 - 2.6 cases/million. Women are affected in 80% - 90% of cases with age of onset below 40 years. TA does not worsen or improve with pregnancy but has adverse effect on pregnancy in the form of abortion, Intrauterine fetal death, superimposed preeclampsia, Intrauterine growth restriction, abruption and congestive heart failure. Because the disease is common in women of childbearing age, management of pregnancy in these patients becomes important; however optimal management for pregnant pa-tients with this disease has not yet been established. Due to the manifold car-diovascular complications that can occur in the course of the disease, man-agement of pregnancies in TA patients is a challenge for the clinician. An in-terdisciplinary collaboration of obstetrician, rheumatologist, cardiologist and anaesthetist is necessary to improve maternal and fetal prognosis. This was the first reported case of TA in pregnancy in Hasan Sadikin Hospital with superimposed preeclampsia and pulmonary hypertension. Materials and Methods: The patient, G1P0A0 was diagnosed as TA since one year ago, and when the patient was pregnant, the patient routinely came to obstetric and rheumatology clinics. Angiographic examination showed dilatation of aorta ascendant, narrowing of aorta descendent at 8 thoracal vertebrae, and arcus aorta, abdominal aorta and the branches were without abnormalities that lead to type IIb TA. On physical examination blood pressure was 200/100 mmHg on the right arm, and 140/100 mm Hg on the left arm, right hand pulse 120 x/m, left hand pulse 113 x/m, respiration rate 20 x/m, temperature 36°C. Laboratory values showed Elevated C-reactive protein 6.8 Mg/dl, anemia hemoglobin 10.5 g/dL, elevated rate of sedimentation of blood 36 mm/hours, and proteinuria + 2. The results of other examinations: Glucose, Ureum, Creatinine, GOT, GPT and electrolytes were in normal limits. Thoracal examination/rontgen showed revealed cardiomegaly. Echocardiogram at 20 - 21 weeks gestational age showed an ejection fraction of 55%, hypertensive heart disease and pulmonal hypertension. The ultrasound examination at 36 - 37 weeks’ gestation showed a 2066 g estimated weight (IUGR simetris). Doppler of the umbilical artery showed a resistance index (RI) of 0.49, pulsatility index (PI) 0.70 with a positive end diastolic flow (EDF). Doppler of the median cerebry media artery showed a resistance index (RI) of 0.72, pulsatility index (PI) 1.26. Amniotic Fluid Index 11, 43 cm, Placenta anterior. The pregnancy was controlled tightly in our clinic. During pregnancy in the first trimester, the patient got methylprednisolone 1 × 4 mg, Azathioprin 1 × 50 mg, folic acid 1 × 1 mg. Additional therapy at second trimester were calcium 1000 mg, multivitamin 1 x/day, methyldopa 3 × 250 mg and Acetylsalicylic acid 1 × 80 mg. She was scheduled for a cesarean section at 37 - 38 weeks of pregnancy. Results: According to the American College of Rheumatology (ACR) 1990, our patient fulfilled 4 of 6 TA criteria: age Conclusions: The management of TA in pregnancy is still a challenge. A multidisciplinary team involving obstetrician, cardiologist, rheumatologist and anaesthetist is absolutely needed to get an optimal development of the pregnancy. The risk of complication on the mother and fetus might occur any time. Adequately controlled blood pressure and fetal monitoring might result for better outcome. Birth delivery (pervaginam or perabdominal) is still a problem according to obstetrical condition, general condition of the mother and other additional factors. Careful assessment, treatment of TA complication, and regular antenatal follow-up improve maternal and fetal outcome.

184: Natural history of referred monochorionic diamniotic twins complicated by selective intrauterine growth restriction Type III

There is a paucity of data regarding the optimal management of selective intrauterine growth restriction (SIUGR) Type III. We describe the natural history of a referred population of SIUGR Type III patients and examine risk factors for progression to twin-twin transfusion syndrome (TTTS) or SIUGR Type II. Retrospective study of monochorionic diamniotic twins diagnosed with SIUGR Type III from 2006 to 2017. SIUGR was diagnosed when one twin had an estimated fetal weight of <10% and umbilical artery end- diastolic flow (EDF) waveforms: Type I (positive EDF), Type II (persistent absent or reversed EDF), and Type III (intermittent absent or reversed EDF). SIUGR Type III patients were divided into two groups: those who did and did not progress to TTTS or SIUGR Type II (Groups A and B). Patient characteristics and 30-day perinatal survival are compared by Group, and continuous data are reported as median (range). Of 53 referred patients diagnosed with SIUGR Type III, data were available for 48 (90.6%). The gestational age (GA) at diagnosis was 20.9 (17.0-26.3) weeks, and the delivery GA was 33.6 (26.0-39.1) weeks. Survivorship was 45/48 (93.8%) for the appropriate for GA (AGA) twin and 40/48 (83.3%) for the SIUGR twin, with dual survivorship at 39/48 (81.3%). Group A patients [26 (54.2%)] progressed to TTTS or SIUGR Type II, and Group B patients [22 (45.8%)] did not. No risk factors for progression were identified. In Group A, 9 patients progressed to TTTS [latency 1.9 (0.9-4.0) weeks] and 17 patients developed SIUGR Type II [latency 2.1 (0.7-11.2) weeks]. (Figure) Two SIUGR Type II patients underwent laser surgery and the remaining 15 were managed expectantly. Expectant management reasons were largely due to diagnosis by outside providers without referral back. The delivery GA did not differ between Groups A and B [31.8 (26.0-39.1) vs. 33.8 (28.1-37.0) weeks, p=0.0976], and survivorship for the AGA twin (88.5% vs. 100%, p=0.2394), and for the SIUGR twin (73.1% vs. 95.5%, p=0.0551), by Group A vs. B did not reach statistical significance. However, the dual survivorship was lower in Group A compared to Group B (69.2% vs. 95.4%, p=0.0276). Greater than half of referred cases of SIUGR Type III patients progressed to TTTS or SIUGR Type II. This antenatal progression was associated with a lower dual survivorship.

ISUOG Practice Guidelines: role of ultrasound in twin pregnancy.

ISUOG Practice Guidelines: role of ultrasound in twin pregnancy.

Effect of antenatal betamethasone administration on Doppler velocimetry of fetal and uteroplacental vessels: a prospective study.

To examine the effect of antenatal betamethasone administration on Doppler parameters of fetal and uteroplacental circulation. Seventy-six singleton pregnancies that received betamethasone therapy were prospectively evaluated. Doppler measurements of pulsatility indices (PI) in fetal umbilical artery (UA), middle cerebral artery (MCA), ductus venosus and maternal uterine arteries were performed before (0 h) and 24, 48, 72 and 96 h after the first dose of betamethasone. Women with positive end-diastolic flow (EDF) in UA and those with absent or reversed EDF in UA were evaluated separately. Fifty-two women with EDF in UA and 24 women with absent or reversed flow in UA were examined. Administration of maternal betamethasone was followed by a significant decrease in the PI of the MCA at 24 h (P<0.05). Additionally, return of absent to positive, reversed to absent or from reversed to positive diastolic flow in UA was detected within 24 h in 19 (79.2%) fetuses with absent or reversed UA-EDF. All alterations were transient and maintained up to 72 h. Antenatal administration of betamethasone is associated with significant but transient changes in the fetal blood flow. Hence, intensive surveillance of fetuses with Doppler ultrasonography is warranted following betamethasone therapy.

Hemodynamic Impact of Absent or Reverse End-Diastolic Flow in the Two Umbilical Arteries in Growth-Restricted Fetuses

ObjectiveTo determine if bilateral absent or reverse end-diastolic (ARED) flow in the two umbilical arteries (UAs) at the perivesical (PVC) segment represents a more severe degree of hemodynamic compromise than unilateral ARED flow at the PVC segment in singleton pregnancies complicated by intrauterine growth restriction (IUGR).MethodsThis was a prospective observational study. One hundred nine fetuses with IUGR underwent a total of 225 ultrasound (US) examinations. We measured the pulsatility index (PI) from the two UAs at the PVC segment, UA in the free floating cord (FFC), middle cerebral artery (MCA), ductus venosus (DV) and the aortic isthmus blood flow index (IFI). Three groups were classified according to bilateral positive end-diastolic (PED) flow, unilateral ARED flow or bilateral ARED flow in the UAs at the PVC segment.ResultsThe proportions of US examinations with PED flow, unilateral ARED flow and bilateral ARED flow in the UAs were 54.7%, 20.4%, and 24.9%, respectively. At the last US examination, the IFI z-scores were significantly lower in the bilateral ARED group (-6.28±4.30) compared to the unilateral ARED group (-1.72±3.18, p<0.05) and the bilateral PED group (-0.83±2.36, p<0.05), the DV-PI z-scores were significantly higher in the bilateral ARED group (2.15±3.79) compared to the bilateral PED group (0.64±1.50, p<0.05). Before 32 weeks of gestation, the interval between US examination and delivery was significantly shorter in the bilateral ARED group (8.9 days ±8.2) than the unilateral ARED group (15.9 days ±13.4, p<0.05) and the bilateral PED group (30.3 days±25.7, p<0.05).ConclusionThere are significant differences in fetal blood fluxes between left and right UA. Doppler examination at the PVC segment significantly improves the comparability of UA-PI between two successive US examinations and allows a longitudinal and independent hemodynamic investigation of each UA. Examination of a single UA in free floating cord may miss a large fraction of unilateral ARED flow. In singleton IUGR fetuses, a bilateral ARED flow in the UAs at the PVC segment indicates more severe hemodynamic compromise and worse fetal conditions than unilateral ARED flow.

Placenta Share Discordance and Umbilical Artery Doppler Change After Antenatal Betamethasone Administration in Monochorionic Twins With Selective Intrauterine Growth Restriction: Is There a Link?

This study was designed to evaluate the degree of placenta share discordance in relation to the betamethasone-induced return of positive end-diastolic flow in monochorionic twin pregnancies with selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery Doppler. Monochorionic twins with sIUGR was defined as one twin having an estimated fetal weight below the 10th percentile combined with an estimated fetal weight discordance >25%. The umbilical artery Doppler directly prior to (D0) and 24 hours (D1) and 48 hours (D2) after the first dose of betamethasone administration was recorded. The estimated individual placental weight in monochorionic twins was obtained by cutting the placenta along the vascular equator into two territories; the placenta share discordance was calculated as [(estimated individual placental weight of appropriated for gestational age twin- estimated individual placental weight of growth restricted twin)/estimated individual placental weight of appropriated for gestational age twin] × 100%. Six (23.1%) of the 26 included cases achieved betamethasone-induced return of positive umbilical artery end-diastolic flow. The difference of placenta share discordance and birth weight discordance were not significantly different between twins with and without betamethasone-induced return of positive umbilical artery end-diastolic flow. Thus, according to our study results, it was proposed that although the placenta share discordance correlated with the abnormal umbilical artery Doppler in the IUGR fetus in monochorionic twin, the betamethasone-induced return of positive umbilical artery end-diastolic flow, however, did not reveal the similar relationship with the severity of placenta share discordance.

Predicting pH at birth in pregnancies with abnormal pulsatility index and positive end-diastolic velocity in the umbilical artery

Objectives: To identify potential associations between fetal surveillance tests and acidosis at birth in pregnancies with abnormal but positive end-diastolic velocity in the umbilical artery. Methods: A prospective case–control study [group 1: pH < 7.2; group 2: pH ≥ 7.2] including 46 fetuses with abnormal but positive end-diastolic velocity in the umbilical artery was conducted between February 2007 and March 2009. Outcome variables were evaluated by univariate analysis and compared between the two groups. Clinically relevant and statistically significant variables were analyzed by logistic regression. Results: Abnormal nonstress test, presence of deceleration, and absent fetal breathing movements were statistically significant. Logistic regression analysis revealed that fetal heart rate (FHR) deceleration in the nonstress test is the only predictor of fetal acidosis at birth (p = 0.024; OR = 8.2; 95%CI: 1.2–52). Conclusions: In fetuses with positive end-diastolic flow velocity, acute variables of the antenatal surveillance tests are correlated with acidosis at birth and FHR deceleration in the nonstress test is the only predictor of fetal acidosis.

P32.10: Abnormal uterine Doppler velocimetry: Prenatal Doppler evaluation of very preterm fetuses and cerebral neonatal outcome

To evaluate neonatal mortality and brain damage in a group born prior to 32 weeks' gestation. The last prenatal feto-maternal Doppler evaluation was considered for the analysis. The absence (AEDV) or reversal (REDV) and the presence (PEDV) of end-diastolic velocity in UA were recorded. In PEDV fetuses a pulsatility index at the level of the MCA lower or equal-higher than the 10th percentile defined the “Brain spared fetuses” (BSF) and the “Non brain” (non BSF). AREDV and PEDV fetuses differed in birthweight and in the rate of SGA; no differences were found as to neonatal mortality and the prevalence of IVH, RDS, NEC and sepsis. The only case of periventricular leukomalacia occurred in the PEDV group. REDV fetuses were characterized by a low birthweight and a high prevalence of mortality. Non BSF fetuses were characterized by a similar rate of neonatal mortality and IVH when compared to REDV fetuses. The prevalence of preeclampsia in non BSF fetuses was 87%. In very preterm fetuses AEDV condition, if compared to PEDV, is not a major risk factor in predicting perinatal mortality and neurological complications, while REDV appears to be a relevant Doppler feature for neonatal mortality. Fetuses born prior to 32 weeks because of preeclampsia, characterized by positive end-diastolic flow in umbilical artery and no vasodilation in the middle cerebral artery, resulted to be a high risk group. Surprisingly, the neonatal mortality and neurological morbidity of these fetuses was similar to those of REDV ones.

Reversed end‐diastolic flow in the umbilical artery at 10–14 weeks of gestation is associated with absent pulmonary valve syndrome

To determine the incidence of reversed end-diastolic flow (REDF) in the umbilical artery in high-risk first-trimester pregnancies and evaluate associated conditions. This was a prospective evaluation of the umbilical artery Doppler waveforms of 614 consecutive high-risk pregnancies between 10 and 14 weeks of gestation, to determine those with REDF. The associated anomalies and characteristics of these fetuses were then investigated. In 278/614 (45.3%) fetuses, there was positive end-diastolic flow in the umbilical artery; in 331/614 (53.9%) end-diastolic flow was absent and in 5/614 (0.8%) there was REDF. Three of the five fetuses with REDF had tetralogy of Fallot (TOF) with absent pulmonary valve syndrome (APVS) and a patent ductus arteriosus, and all three showed signs of cardiac failure, with reversed blood flow in the ductus venosus during atrial systole and generalized skin edema. Another fetus had a large ventricular septal defect and the remaining fetus had agenesis of the ductus venosus. Three fetuses had trisomy 18 and one had trisomy 13. REDF in the umbilical artery is very rare in early pregnancy and mostly occurs in association with major fetal vascular anomalies and cardiac defects, particularly TOF with APVS and patent arterial duct. We propose that the patency of the arterial duct in TOF with APVS leads to heart failure with subsequent demise early in pregnancy. Therefore, the frequent absence of the arterial duct observed in APVS in later pregnancy is more likely to be a result of early selection than a prerequisite for the development of this lesion as has been proposed previously.

Perinatal outcome in monochorionic twin pregnancies complicated by amniotic fluid discordance without severe twin–twin transfusion syndrome

To assess the natural history and perinatal outcome in monochorionic diamniotic twin pregnancies with discordant amniotic fluid volume without signs of severe twin-twin transfusion syndrome (TTTS). This was an observational study of 84 consecutive monochorionic twin pregnancies which did not meet the criteria for severe TTTS and endoscopic laser coagulation of placental anastomoses at initial presentation. The population was subdivided into two groups. Group 1 consisted of 64 pregnancies (median gestational age, 20.1 (range, 15.6-24.7) weeks) with amniotic fluid discordance and no signs of congestive heart failure in the twin with the larger amniotic fluid volume (Twin 1) and positive end-diastolic flow in the umbilical artery of the twin with the smaller amniotic fluid volume (Twin 2). Group 2 (median gestational age, 19.1 (range, 16.0-24.4) weeks) consisted of 20 pregnancies with amniotic fluid discordance and intrauterine growth restriction (IUGR) (abdominal circumference < 5th percentile) in combination with absent or reversed end-diastolic (ARED) flow in the umbilical artery of Twin 2. After exclusion of one patient from Group 1, who opted for termination of pregnancy, nine patients in Group 1 and one in Group 2 developed severe TTTS, and laser coagulation was offered. The remaining 54 pregnancies of Group 1 were compared with the remaining 19 pregnancies of Group 2. Fetuses in Group 1 showed significantly higher survival rates (overall survival, 100/108 (92.6%) vs. 23/38 (60%), P < 0.0001; survival of both fetuses, 49/54 (90.7%) vs. 9/19 (47.4%), P = 0.0002) and median gestational age at delivery (33.6, (range, 27.6-37.8) weeks vs. 32.0 (range, 26.9-36.3) weeks, P = 0.0457). Overall, there was a significantly higher incidence of complications, defined as necessity for intrauterine intervention, fetal or neonatal death or delivery prior to 32 weeks, in Group 2 (Group 1: 30/63 (47.6%); Group 2: 16/20 (80%), P = 0.0188). Our data suggest that amniotic fluid discordance in monochorionic diamniotic twin pregnancies in combination with IUGR and umbilical artery ARED flow in one fetus represents an extremely high-risk constellation for adverse pregnancy outcome.

Effect of antenatal corticosteroid administration on Doppler flow velocity parameters in pregnancies with absent or reverse end‐diastolic flow in the umbilical artery

Evaluation of alterations of Doppler flow velocity waveforms after antenatal corticosteroid therapy. Pulsatility index of the umbilical artery, middle cerebral artery and ductus venosus waveforms was measured in high-risk pregnancies complicated by umbilical AREDV directly prior to and within 24 or 48 hours after application of the first dose of a steroid treatment course. Return of a positive end-diastolic flow after umbilical AREDV or conversion of REDV into zero-flow was detected in 9 of 20 (45%) pregnancies after steroid application. Neither in the group which showed altered umbilical end-diastolic flow nor in the total of patients investigated was there any significant change in the PI of the umbilical artery or the ductus venosus waveforms. In contrast, there was an overall drop of pulsatility in the middle cerebral artery. Antenatal corticosteroid administration could increase cerebral perfusion but has no influence on umbilical and venous blood flow.

Umbilical Doppler Waveforms and Placental Villous Angiogenesis in Pregnancies Complicated by Fetal Growth Restriction

In Brief Objective To test the hypothesis that the characteristics of umbilical artery Doppler flow velocity waveforms in growth-restricted fetuses indicate angiogenesis within placental stem and gas-exchanging villi. Methods We examined 18 placentas from singleton fetuses that were normal structurally and chromosomally but were growth-restricted, preterm, and complicated by preeclampsia. Ten cases with positive end-diastolic flow and eight with absent or reverse end-diastolic flow were compared with six gestational age-matched controls. Sections of villous placenta were examined to determine structural composition (percentage of fibrinoid, intervillous space, and villous tissue), relative proportion of villous types (stem, immature intermediate, and gas-exchanging villi), and the frequency distribution of stem arterial vessel calibers and their branching pattern. Results Placentas with positive end-diastolic flow had a significantly (P < .05) higher percentage of gas-exchanging villi (median 69.6%, range 62.5–80.8%) than those with absent or reverse end-diastolic flow (58.3%, 29.9–71.9%) or controls (60.8%, 43.1–65.6%). The gas-exchanging villi from placentas with absent or reverse end-diastolic flow were slender, elongated, poorly branched, and poorly capillarized. There was a progressive trend toward reduced branching of the stem arteries from the controls (median 22%, range 2–38%), through the positive end-diastolic group (17%, 11–20%), to the absent or reverse end-diastolic group (13%, 4–23%). Conclusion Compared with absent or reverse end-diastolic flow, the placentas from growth-restricted fetuses with positive end-diastolic flow showed a normal pattern of stem artery development, accompanied by increased capillary angiogenesis and terminal villous development. These features suggest an adaptive pathway for the placenta in the face of uteroplacental ischemia. Different patterns of umbilical artery Doppler flow velocity waveforms identify characteristic placental lesions that can explain different outcomes in growth-restricted fetuses.

Umbilical doppler waveforms and placental villous angiogenesis in pregnancies complicated by fetal growth restriction

Objective: To test the hypothesis that the characteristics of umbilical artery Doppler flow velocity waveforms in growth-restricted fetuses indicate angiogenesis within placental stem and gas-exchanging villi. Methods: We examined 18 placentas from singleton fetuses that were normal structurally and chromosomally but were growth-restricted, preterm, and complicated by preeclampsia. Ten cases with positive end-diastolic flow and eight with absent or reverse end-diastolic flow were compared with six gestational age-matched controls. Sections of villous placenta were examined to determine structural composition (percentage of fibrinoid, intervillous space, and villous tissue), relative proportion of villous types (stem, immature intermediate, and gas-exchanging villi), and the frequency distribution of stem arterial vessel calibers and their branching pattern. Results: Placentas with positive end-diastolic flow had a significantly ( P < .05) higher percentage of gas-exchanging villi (median 69.6%, range 62.5–80.8%) than those with absent or reverse end-diastolic flow (58.3%, 29.9–71.9%) or controls (60.8%, 43.1–65.6%). The gas-exchanging villi from placentas with absent or reverse end-diastolic flow were slender, elongated, poorly branched, and poorly capillarized. There was a progressive trend toward reduced branching of the stem arteries from the controls (median 22%, range 2–38%), through the positive end-diastolic group (17%, 11–20%), to the absent or reverse end-diastolic group (13%, 4–23%). Conclusion: Compared with absent or reverse end-diastolic flow, the placentas from growth-restricted fetuses with positive end-diastolic flow showed a normal pattern of stem artery development, accompanied by increased capillary angiogenesis and terminal villous development. These features suggest an adaptive pathway for the placenta in the face of uteroplacental ischemia.

Maternal and fetal plasma concentrations of endothelin, lipidhydroperoxides, glutathione peroxidase and fibronectin in relation to abnormal umbilical artery velocimetry

Objective: To study plasma concentrations of endothelin (ET), lipidhydroperoxides (LOOH), glutathione peroxidase (GSHpx) and fibronectin in relation to abnormal umbilical artery velocimetry. Study design: Plasma concentrations of ET, LOOH, GSHpx and fibronectin were measured in fetal and maternal venous blood in: (i) a control group ( n=10); (ii) in pregnancies complicated by intrauterine growth retardation (IUGR) ( n=6) or preeclampsia ( n=5) with positive end diastolic flow; and in (iii) pregnancies complicated by absent or reversed end diastolic (ARED) flow in the umbilical artery ( n=18). All children were delivered by primary caesarean section. Results: The significantly highest maternal and fetal ET concentrations were found in plasma collected in pregnancies complicated by ARED flow in the umbilical artery. Maternal fibronectin levels were significantly raised in the ARED flow group. Maternal plasma ET levels were lowest in pregnancies complicated by IUGR. The maternal and fetal plasma concentrations of LOOH and GSHpx did not differ significantly between the groups. Conclusion: Abnormal Doppler velocimetry, especially ARED flow is associated with elevated maternal and fetal plasma levels of ET. The exact mechanism causing the placental vasoconstriction is unknown yet, but oxidative stress seems not to be involved.