Presentation on theme: "Problems in Twin Pregnancy Findings of Prenatal Sonography and Pathology Jeong-Ah Kim, Jeong Yeon Cho, Mi Jin Song, Jee-Yeon Min, Soo-Hyun Lee, Young Ho."— Presentation transcript:
Problems in Twin Pregnancy Findings of Prenatal Sonography and Pathology Jeong-Ah Kim, Jeong Yeon Cho, Mi Jin Song, Jee-Yeon Min, Soo-Hyun Lee, Young Ho Lee, Hak Jong Lee, Yi-Kyeong Chun 1, Ei-Jeong Kim 1, Sung Ran Hong 1 Department of Radiology, Diagnostic Pathology 1, Samsung Cheil Hospital Sungkyunkwan University School of Medicine Multiple births have increased with development in assisted reproductive technology and increased aging maternal population. Multifetal gestations are high-risk pregnancies with higher perinatal morbidity and mortality. Multifetal gestations are subject to unique complications including conjoined twins, twin-to-twin transfusion syndrome (TTTS), acardiac twins, twin emblization of co-twin demise and heterotopic pregnancies. Prenatal sonographic diagnosis of types and complications of multefetal gestations is important for antenatal care and prediction of fetal outcome. The purpose of this exhibition is to present the prenatal ultrasonographic findings and pathologic findings of the unique complicaitons of twin pregnancy. Twin-to-Twin Transfusion Syndrome TTTS occurs in 4-35 % of monochorionic pregnancies and is responsible for as much as 17% of prenatal mortality. In TTTS, there is unbalanced shunting in the deep arteriovenous anastomoses within the monochorionic placenta. Doppler sonography demonstrates antepartum transfusion from the umbilical artery of donor twin into the umbilical vein of the recipient. Twin Oligohydramnios Polyhydramnios Sequence In monochorionic twin pregnancies, weight discordance of 20% or more and a major difference in fluid volume between amniotic sacs with severe oligohydramnios of one sac (stuck twin) has been termed TOPS. Fig 3. MCDA twin pregnancy showing twin-to-twin transfusion syndrome. A. US on GA 21w shows smaller fetus with oligohydramnios (B) and larger one (A). B. Significant discrepancy of fetal sizes. Fetus A is larger than fetus B by more than 2 SD. C, F. CDUS shows approximate insertion of umbilical cords D, E. Umbilical arterial duplex US of smaller fetus (D) shows increased vascular resistance and that of larger fetus (E) shows normal flow pattern. Conjoined Twins Conjoined twins are a rarest form of monozygotic twinning, always associated with MCMA. They results from incomplete division of inncer cell mass more than 13 days after fertilization. Early prenatal diagnosis of conjoined twin is essential for pregnancy termination. Fig 1. US and autopsy findings of craniothoracoomphalopagus. A. US performed on GA 21w shows one cranium with fused cerebrum and one cerebellum. B. Fused anterior chest with fused two hearts (H). C. Fused cranium with V shaped two spines (arrows). D. Fused anterior abdomen with two ischiums (ISC). E.F.Specimen radiographs(E) and autopsy (F) show a craniothoracoomphalopagus. Fig 2. Prenatal US findings of twin oligohydramnios/polyhydramnios sequence. A. US on GA 14w shows single placenta with intertwin membrane (arrow). B. US on GA 22w shows stuck twin (B, arrow) of 20w size with severe oligohydramnios. (A: fetus A of 22w size, M: intertwin membrane) C, D. Cord insertions of fetus A (C) and fetus B (D) are separated without anastomosis. Introduction AB C D EF B A A B A BC DEF A B C D
B A A B UA AO A B C D E F G H Fig.5. Sonographic findings of MCDA twins with co-twin demise A. US performed on GA 14w shows thin intertwin membrane (arrow) with single placenta and IUFD of one fetus with diffuse soft tissue edema (double head arrow). B. US on GA 23w shows cystic hygroma of the dead fetus. C. Enlarged umbilical cord was noted in the surviving fetus in the US on 23w. D. Cardiomegaly with thickened biventricular walls in surviving fetus. Acardiac Twins Acardia is a lethal anomaly occurring in 1% of monozygotic twin. Acardia develops during early embryogenesis as a result of extensive artery-to-artery and vein-to-vein anastomosis through monochorionic placenta with reverse umbilical arterial circulation. The acardiac twin has a parasitic existence and depends on the donor (pump) twin for its blood supply via placental anastomoses and retrograde perfusion of umbilical cord. Perfusion of malformed fetus occurs via artery-to-artery anastomosis between the fetuses. This twin reversed arterial perfusion (TRAP) sequence is a most extreme manifestation of the TTTS. Depending on the state of disruption, acardiac anomalies are divided into four categories: acardius anceps, acardius acephalus, acardius acormus and acrdius amorphus. Doppler verification of reversed flow in umbilical cord of the acardiac twin confirms the diagnosis. The incidence of spontaneous single intrauterine loss is 2.6-6.8 %. The complications of single fetal demise are preeclampsia, preterm labor and intrauterine growth retardation. In monochorionic pregnancies, increased risk of cerebral necrotic lesion due to thromboemblic material, anemia in a twin transfusion syndrome or premature delivery have been reported. Fig.4. Sonographic diagnosis and autopsy findings of acardiac twins in monochorionic pregnancy. A. US performed on GA 19w shows significant discrepancy of fetal sizes. Absence of heart and diffuse soft tissue edema are demonstrated in the larger fetus B. B. No head in fetus B(arrowhead) with rudimentary bony upper extremities (arrow). C. Multiseptated cystic mass suggesting large cystic hygroma is noted along back of fetus. D. CDUS demonstrates interfetal anastomoses of umbilical veins and arteries. Fetus B have singe umbilical artery and vein. E. Duplex US verify the reversed flow in umbilical artery (UA) of acardiac fetus B. F. Reversed flow downside up is noted in descending aorta (AO) of acardiac fetus B. G.Autopsy specimen of another acardiac twins shows absent head, thorax and upper extremities with knotting of umbilical cord (arrow). H. Monochorionic placental tissue shows artery-to-arterial anastomosis of umbilical vessels including single umbilical arteries of both fetuses. Co-Twin Demise Treatment for ovulation induction and assisted reproductive technology have dramatically increased the incidence of heterotopic pregnancy. The incidence of heterotopic pregnancy is 1% in ovulation induction procedure.Sonographic detection of an extrauterine gestational sac with or without a fetal pole with an IUP confirm the diagnosis. Most frequent location is tube (ampulla >isthmic >fimbria). The prognosis of IUP is similar to that without heterotopia. Fig.7. Cornual heterotopic pregnancy. A. Gestational sac is seen within the uterine cavity (arrow). B. Another gestational sac (yellow arrow) with embryo (red arrow) in the cornual portion of uterus. Heterotopic Pregnancy AB CD AB Fig.6. Tubal heterotopic pregnancy. A. US on GA 8w shows fetal pole (calipers) within the intrauterine gestational sac (arrow). B. Simultaneous extrauterine gestational sac (arrow) located between uterus (UT) and left ovary (LO). C. Left salpingectomy verified ectopic pregnancy demonstrating the hemorrhagic mass (arrow) within the dilatated left fallopian tube. AB C
Your consent to our cookies if you continue to use this website.