The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Sonia S. Hassan - One of the best experts on this subject based on the ideXlab platform.

  • presence of an umbilical artery notch in monochorionic Monoamniotic Twins
    Fetal Diagnosis and Therapy, 2014
    Co-Authors: Alma Auriolesgaribay, Roberto Romero, Maynor Garcia, Faisal Qureshi, Suzanne M. Jacques, Hyunyoung Ahn, Lami Yeo, Tinnakorn Chaiworapongsa, Edgar Hernandezandrade, Sonia S. Hassan
    Abstract:

    Objective: To examine the association between an umbilical artery notch and fetal deterioration in monochorionic/Monoamniotic (MC/MA) Twins. Methods: Six MC/MA twin pregnancies were admitted at 24-28 weeks of gestation for close fetal surveillance until elective delivery at 32 weeks or earlier in the presence of signs of fetal deterioration. Ultrasound (US) examinations were performed twice weekly. The presence of cord entanglement, umbilical artery notch, abnormal Doppler parameters, a non-reassuring fetal heart rate pattern, or an abnormal fetal biophysical profile were evaluated. Results: Umbilical cord entanglement was observed on US in all pregnancies. The presence of an umbilical artery notch was noted in four out of six pregnancies and in two of them an umbilical artery notch was seen in both Twins. The umbilical artery pulsatility index was normal in all fetuses. Doppler parameters of the middle cerebral artery and ductus venosus, fetal biophysical profile and fetal heart rate monitoring remained normal until delivery in all pregnancies. All neonates experienced morbidity related to prematurity; however, all were discharged home in good condition. Conclusion: The presence of an umbilical artery notch and cord entanglement, without other signs of fetal deterioration, are not indicative of an adverse perinatal outcome.

  • Presence of an Umbilical Artery Notch in Monochorionic/Monoamniotic Twins
    Fetal Diagnosis and Therapy, 2014
    Co-Authors: Alma Aurioles-garibay, Roberto Romero, Edgar Hernandez-andrade, Maynor Garcia, Faisal Qureshi, Suzanne M. Jacques, Hyunyoung Ahn, Lami Yeo, Tinnakorn Chaiworapongsa, Sonia S. Hassan
    Abstract:

    Objective: To examine the association between an umbilical artery notch and fetal deterioration in monochorionic/Monoamniotic (MC/MA) Twins. Methods: Six MC/MA twin pregnancies were admitted at 24-28 weeks of gestation for close fetal surveillance until elective delivery at 32 weeks or earlier in the presence of signs of fetal deterioration. Ultrasound (US) examinations were performed twice weekly. The presence of cord entanglement, umbilical artery notch, abnormal Doppler parameters, a non-reassuring fetal heart rate pattern, or an abnormal fetal biophysical profile were evaluated. Results: Umbilical cord entanglement was observed on US in all pregnancies. The presence of an umbilical artery notch was noted in four out of six pregnancies and in two of them an umbilical artery notch was seen in both Twins. The umbilical artery pulsatility index was normal in all fetuses. Doppler parameters of the middle cerebral artery and ductus venosus, fetal biophysical profile and fetal heart rate monitoring remained normal until delivery in all pregnancies. All neonates experienced morbidity related to prematurity; however, all were discharged home in good condition. Conclusion: The presence of an umbilical artery notch and cord entanglement, without other signs of fetal deterioration, are not indicative of an adverse perinatal outcome.

Mark P Umstad - One of the best experts on this subject based on the ideXlab platform.

  • the significance of yolk sac number in Monoamniotic Twins
    Fetal Diagnosis and Therapy, 2019
    Co-Authors: Christine Fenton, Karen Reidy, Marina Demyanenko, Ricardo Palmadias, Stephen Cole, Mark P Umstad
    Abstract:

    Background Detection of a single yolk sac on early first trimester ultrasound was previously thought to be a reliable diagnostic feature of monochorionic Monoamniotic (MCMA) twin pregnancies. Objectives To determine the frequency of two yolk sacs in MCMA twin pregnancies and the association of yolk sac number with pregnancy outcomes. Methods A retrospective cohort analysis of MCMA Twins managed at a tertiary obstetric centre from January 2003 until February 2017. All MCMA twin pregnancies were diagnosed on tertiary centre ultrasound and, where possible, placental histopathology postnatally. All MCMA twin pregnancies, including conjoined Twins, with available first trimester ultrasounds from 5 to 11 weeks' gestation were included in the analysis. MCMA pregnancies without available first trimester ultrasounds and triplet pregnancies which included a MCMA pair were excluded from the study. Results Sixty-seven MCMA cases were identified over 14 years. Thirty-eight cases were included in the analysis. There was one yolk sac identified in 26 cases (68%) and two yolk sacs in 12 cases (32%). Two yolk sacs were associated with a higher proportion of male fetuses (33%, 4 out of 12, vs. 8%, 2 out of 26; p = 0.01). There were no other significant differences between one and two yolk sacs for maternal or neonatal outcomes. Conclusions Two yolk sacs are present in up to a third of all MCMA twin pregnancies, dispelling the original concept that a single yolk sac is diagnostic of MCMA pregnancies. Yolk sac number should not be used to determine amnionicity. The presence of two yolk sacs on first trimester ultrasound is associated with an increased rate of male fetuses. The number of yolk sacs has no other significant impact on perinatal outcomes.

Arthur T. Evans - One of the best experts on this subject based on the ideXlab platform.

  • Umbilical artery flow velocity waveforms in Monoamniotic Twins with cord entanglement.
    Obstetrics & Gynecology, 1995
    Co-Authors: Alfred Z. Abuhamad, Giancarlo Mari, Joshua A. Copel, Catherine J. Cantwell, Arthur T. Evans
    Abstract:

    Background Monoamniotic Twins with ultrasonographic evidence of umbilical cord entanglement present a management challenge in the antepartum period. Cases We report two pregnancies with Monoamniotic Twins and ultrasonographic evidence of cord entanglement in which longitudinal Doppler flow velocity waveforms of the umbilical and middle cerebral arteries were obtained. A notch in the umbilical artery velocity waveform was noted in one twin member at 33 weeks' gestation and in both twin members of the other pregnancy at 31 weeks' gestation. Worsening of the umbilical artery velocity waveform notch with advancing gestation was noted in one fetus. Conclusion The presence of a notch in the umbilical artery velocity waveform may reflect hemodynamic alterations in the fetal-placental circulation secondary to narrowing of the umbilical vessels involved in cord entanglement. This Doppler finding may be useful in the antepartum management of these pregnancies.

  • Umbilical artery flow velocity waveforms in Monoamniotic Twins with cord entanglement.
    Obstetrics and gynecology, 1995
    Co-Authors: Alfred Z. Abuhamad, Giancarlo Mari, Joshua A. Copel, Catherine J. Cantwell, Arthur T. Evans
    Abstract:

    Monoamniotic Twins with ultrasonographic evidence of umbilical cord entanglement present a management challenge in the antepartum period. We report two pregnancies with Monoamniotic Twins and ultrasonographic evidence of cord entanglement in which longitudinal Doppler flow velocity waveforms of the umbilical and middle cerebral arteries were obtained. A notch in the umbilical artery velocity waveform was noted in one twin member at 33 weeks' gestation and in both twin members of the other pregnancy at 31 weeks' gestation. Worsening of the umbilical artery velocity waveform notch with advancing gestation was noted in one fetus. The presence of a notch in the umbilical artery velocity waveform may reflect hemodynamic alterations in the fetal-placental circulation secondary to narrowing of the umbilical vessels involved in cord entanglement. This Doppler finding may be useful in the antepartum management of these pregnancies.

Donald K Bishop - One of the best experts on this subject based on the ideXlab platform.

  • Yolk-sac number in Monoamniotic Twins.
    Obstetrics and gynecology, 2010
    Co-Authors: Donald K Bishop
    Abstract:

    It has been accepted practice to use yolk-sac number to predict amnionicity in twin pairs. Two yolk sacs in a single chorionic sac were thought to confirm diamniotic pregnancy, and a single yolk sac with two fetal poles was thought to indicate Monoamniotic Twins. Thus, basic ultrasonography could confirm amnionicity early in pregnancy and avoid invasive testing or the more difficult tasks of demonstrating the absence of a dividing membrane or presence of entwined cords later in the pregnancy. We present a case of Monoamniotic twin gestation in which early ultrasonography confirmed the presence of two yolk sacs. Doppler showed entwined umbilical cords. After elective cesarean delivery, the Twins did well in the neonatal intensive care unit and continue to thrive. Yolk-sac number does not predict amnionicity. The diagnosis of Monoamniotic Twins requires demonstration of entwined cords or an invasive procedure.

  • Yolk-sac number in Monoamniotic Twins.
    Obstetrics & Gynecology, 2010
    Co-Authors: Donald K Bishop
    Abstract:

    Background It has been accepted practice to use yolk-sac number to predict amnionicity in twin pairs. Two yolk sacs in a single chorionic sac were thought to confirm diamniotic pregnancy, and a single yolk sac with two fetal poles was thought to indicate Monoamniotic Twins. Thus, basic ultrasonography could confirm amnionicity early in pregnancy and avoid invasive testing or the more difficult tasks of demonstrating the absence of a dividing membrane or presence of entwined cords later in the pregnancy. Case We present a case of Monoamniotic twin gestation in which early ultrasonography confirmed the presence of two yolk sacs. Doppler showed entwined umbilical cords. After elective cesarean delivery, the Twins did well in the neonatal intensive care unit and continue to thrive. Conclusion Yolk-sac number does not predict amnionicity. The diagnosis of Monoamniotic Twins requires demonstration of entwined cords or an invasive procedure.

S Shen-schwarz - One of the best experts on this subject based on the ideXlab platform.

  • Prenatal diagnosis of an unusual nuchal cord complication in Monoamniotic Twins.
    Obstetrics & Gynecology, 1994
    Co-Authors: Westover T, E R Guzman, S Shen-schwarz
    Abstract:

    BACKGROUND Monoamniotic twin pregnancies are frequently associated with cord entanglement, but such entanglement rarely involves the co-twin's trunk, extremities, or neck. CASE We report a set of Monoamniotic Twins in which color Doppler imaging revealed that the cord of twin B was wrapped around the neck of its dead co-twin. This knowledge allowed us to avoid clamping and dividing twin A's nuchal cord during vaginal delivery, preventing asphyxia of twin B. This is the fifth reported incidence of this particular Monoamniotic complication and the first to be diagnosed prenatally. CONCLUSION Color Doppler imaging facilitates the diagnosis of rare cord complications in Monoamniotic twin pregnancies.

  • Prenatal diagnosis of an unusual nuchal cord complication in Monoamniotic Twins.
    Obstetrics and gynecology, 1994
    Co-Authors: T Westover, E R Guzman, S Shen-schwarz
    Abstract:

    Monoamniotic twin pregnancies are frequently associated with cord entanglement, but such entanglement rarely involves the co-twin's trunk, extremities, or neck. We report a set of Monoamniotic Twins in which color Doppler imaging revealed that the cord of twin B was wrapped around the neck of its dead co-twin. This knowledge allowed us to avoid clamping and dividing twin A's nuchal cord during vaginal delivery, preventing asphyxia of twin B. This is the fifth reported incidence of this particular Monoamniotic complication and the first to be diagnosed prenatally. Color Doppler imaging facilitates the diagnosis of rare cord complications in Monoamniotic twin pregnancies.