DOCSLIB.ORG

Yolk Sac Diameter in Multiple Gestations

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Yolk Sac Diameter in Multiple Gestations Case Studies Yolk Sac Diameter in Multiple Gestations Chelsea Fox, MD; Karenne Fru, MD, PhD; and Bruce A. Lessey, MD, PhD From the Department of OB/GYN, Greenville Health System, Greenville, SC (C.F., B.A.L.), University of South Carolina School of Medicine Greenville, Greenville, SC (B.A.L.), and Department of Obstet- rics and Gynecology, New Hanover Regional Medical Center, Wilmington, NC (K.F.) Abstract Enlargement of the yolk sacs is an ominous sign even in multi-gestational pregnancies. he yolk sac functions as the primary route ity conceived after placement of 2 embryos on of exchange between the embryo and post-retrieval day 3. Quantitative hCG levels were Tmother prior to the establishment of the higher than expected and transvaginal ultrasound placental circulation. It is well established that an at 6 weeks’ gestation demonstrated a triplet preg- abnormally large yolk sac serves as a prognostic nancy with a singleton sac and a separate mono- indicator for early pregnancy failure in singleton chorionic-monoamniotic versus conjoined twin gestation. However, no studies have been per- pregnancy with symmetrically enlarged yolk sacs, formed to describe normal versus abnormal yolk each with cardiac activity present (Figs. 1A and B). sac diameters (YSD) in multiple gestations. In this The yolk sacs associated with the twin pregnancy case, we describe a patient with triplet pregnancy were 6.15 mm and 7.37 mm, respectively, while the consisting of monochorionic-monoamniotic singleton had a normal yolk sac. A repeat ultra- twins both with enlarged yolk sacs in addition to sound 10 days later confirmed absence of fetal car- singleton pregnancy in a separate sac with a nor- diac activity in the monochorionic-monoamni- mal yolk sac. The monochorionic-monoamniotic otic sac, with increased crown rump length of the twins were later diagnosed with a fetal demise singleton pregnancy, which maintained persistent suggesting large YSD may serve as a poor prog- cardiac activity. This embryo went on to normal nostic indicator in multiple gestations as well. development and delivery. A second example of a twin pregnancy with normal yolk sacs is shown in Case Description Figure 1C. In this example, these twins went on to A 34-year-old woman opting for in vitro fertil- sustain normal development and were delivered ization (IVF) as treatment for primary infertil- successfully. Figure 1 (A and B) Yolk sac size in a multi-gestational pregnancy predicted an adverse outcome of the affected mono- mono twins of a triplet pregnancy. (C) Another twin pregnancy with dichorionic-diamniotic embryos with reassuring normal appearing yolk sacs continued and developed normally. GHS Proc. May 2016; 1 (1): 47-48 47 Correspondence Discussion While it is widely accepted that monoamniotic twins share a yolk sac, recent evidence shows Address to: The routine use of ultrasound is a key feature in the monoamniotic twins with 2 yolk sacs.4,5 This case Chelsea Fox, MD modern management of early pregnancy. In par- Greenville Health also challenges the previously held idea that the ticular, the yolk sac has been studied as a prognos- System, Dept of number of yolk sacs is equal to amnionicity in tic indicator for pregnancies. The secondary yolk OB/GYN sac is the primary source of exchange between the both monochorionic-monoamniotic and mono- 890 W Faris Rd 4 embryo and the mother during organogenesis.1 It chorionic-diamniotic twin pregnancies. While Greenville, SC 29605 the question of amnionicity may require further ([email protected]) is first visualized at 5 weeks’ gestation, or when the gestational sac reaches 10 mm2, and regresses by study, this case bears out the fact that abnormally the 12th week of gestation in normal pregnancies.2,3 large yolk sacs are predictive of abnormal preg- A normal range of yolk sac diameters has been nancy even in multiple gestations. Moreover, only described, particularly in singleton pregnancies the affected sacs with enlarged yolk sacs suffered with abnormal outcome in all cases where YSD the expected adverse sequelae. The singleton preg- was greater than 5.6 mm.1 Lindsay et al followed nancy was carried to term with no further evi- 486 first-trimester pregnancies and found a YSD dence of the twin pregnancy following embryonic >2SDs (standard deviations) above the mean was demise. This is, to the best of our knowledge, the associated with abnormal outcomes with a sensi- first case report demonstrating that enlarged yolk tivity of 15.6%, specificity of 97.4%, and a positive sacs in twins may be associated with adverse out- predictive value of 60.0%.1 There is a paucity of comes similar to singleton pregnancies; the case data for normal versus abnormal YSD in multiple also adds to the growing body of literature sug- gestations. However, there is no reason to suspect gesting yolk sac number does not always correlate that similar guidelines regarding enlarged yolk with amnionicity in first-trimester monochori- sacs and poor prognosis would not apply. onic multiple gestations.6-10 References 1. Lindsay DJ, Lovett IS, Lyons EA, Levi CS, Zheng XH, H, Torii Y. Monochorionic monoamniotic twin preg- Holt SC, Dashefsky SM. Yolk sac diameter and shape nancies with two yolk sacs may not be a rare finding: at endovaginal US: predictors of pregnancy outcome a report of two cases. Ultrasound Obstet Gynecol. in the first trimester. Radiology. 1992;183:115-8. 2010;36:384-6. 2. Jauniaux E, Jurkovic D, Henriet Y, Rodesch F, Hustin 7. Malinowski W. Yolk sacs in twin pregnancy. Acta J. Development of the secondary human yolk sac: cor- Genet Med Gemellol (Roma). 1998;47:177-81. Hum relation of sonographic and anatomic features. 8. Shen O, Samueloff A, Beller U, Rabinowitz R. Num- Reprod . 1991;6:1160-6. ber of yolk sacs does not predict amnionicity in early 3. Berdahl DM, Blaine J, Van Voorhis B, Dokras A. first-trimester monochorionic multiple gestations. Detection of an enlarged yolk sac on early ultrasound Ultrasound Obstet Gynecol. 2006;27:53-5. Fertil if associated with adverse pregnancy outcomes. 9. Corbett S, Shmorgun D. Yolk sac number does not Steril . 2010;94:1535-7. predict reliably amnionicity in monochorionic twin 4. Levi CS, Lyons EA, Dashefsky SM, Lindsay DJ, Holt pregnancies: a case of monochorionic monoamniotic SC. Yolk sac number, size and morphologic features in twin pregnancy with two distinct yolk sacs on early monochorionic monoamniotic twin pregnancy. Can first-trimester ultrasound. Ultrasound Obstet Gyne- Assoc Radiol J. 1996;47:98-100. col. 2012;39:607-8. 5. Bishop DK. Yolk-sac number in monoamniotic twins. 10. Meller C, Wojakowski A, Izbisky G, Aiello H, Otaño Obstet Gynecol. 2010;116:504-7. L. Number of yolk sacs in the diagnosis of monoamni- 6. Murakoshi T, Ishii K, Matsushita M, Shinno T, Naruse onicity. J Ultrasound Med. 2014;33:1091-7. 48 GHS Proc. May 2016; 1 (1): 47-48.
Load more

Recommended publications
  • 3 Embryology and Development
    BIOL 6505 − INTRODUCTION TO FETAL MEDICINE 3. EMBRYOLOGY AND DEVELOPMENT Arlet G. Kurkchubasche, M.D. INTRODUCTION Embryology – the field of study that pertains to the developing organism/human Basic embryology –usually taught in the chronologic sequence of events. These events are the basis for understanding the congenital anomalies that we encounter in the fetus, and help explain the relationships to other organ system concerns. Below is a synopsis of some of the critical steps in embryogenesis from the anatomic rather than molecular basis. These concepts will be more intuitive and evident in conjunction with diagrams and animated sequences. This text is a synopsis of material provided in Langman’s Medical Embryology, 9th ed. First week – ovulation to fertilization to implantation Fertilization restores 1) the diploid number of chromosomes, 2) determines the chromosomal sex and 3) initiates cleavage. Cleavage of the fertilized ovum results in mitotic divisions generating blastomeres that form a 16-cell morula. The dense morula develops a central cavity and now forms the blastocyst, which restructures into 2 components. The inner cell mass forms the embryoblast and outer cell mass the trophoblast. Consequences for fetal management: Variances in cleavage, i.e. splitting of the zygote at various stages/locations - leads to monozygotic twinning with various relationships of the fetal membranes. Cleavage at later weeks will lead to conjoined twinning. Second week: the week of twos – marked by bilaminar germ disc formation. Commences with blastocyst partially embedded in endometrial stroma Trophoblast forms – 1) cytotrophoblast – mitotic cells that coalesce to form 2) syncytiotrophoblast – erodes into maternal tissues, forms lacunae which are critical to development of the uteroplacental circulation.
    [Show full text]
  • The Derivatives of Three-Layered Embryo (Germ Layers)
    HUMANHUMAN EMBRYOLOGYEMBRYOLOGY Department of Histology and Embryology Jilin University ChapterChapter 22 GeneralGeneral EmbryologyEmbryology FourthFourth week:week: TheThe derivativesderivatives ofof trilaminartrilaminar germgerm discdisc Dorsal side of the germ disc. At the beginning of the third week of development, the ectodermal germ layer has the shape of a disc that is broader in the cephalic than the caudal region. Cross section shows formation of trilaminar germ disc Primitive pit Drawing of a sagittal section through a 17-day embryo. The most cranial portion of the definitive notochord has formed. ectoderm Schematic view showing the definitive notochord. horizon =ectoderm hillside fields =neural plate mountain peaks =neural folds Cave sinks into mountain =neural tube valley =neural groove 7.1 Derivatives of the Ectodermal Germ Layer 1) Formation of neural tube Notochord induces the overlying ectoderm to thicken and form the neural plate. Cross section Animation of formation of neural plate When notochord is forming, primitive streak is shorten. At meanwhile, neural plate is induced to form cephalic to caudal end, following formation of notochord. By the end of 3rd week, neural folds and neural groove are formed. Neural folds fuse in the midline, beginning in cervical region and Cross section proceeding cranially and caudally. Neural tube is formed & invade into the embryo body. A. Dorsal view of a human embryo at approximately day 22. B. Dorsal view of a human embryo at approximately day 23. The nervous system is in connection with the amniotic cavity through the cranial and caudal neuropores. Cranial/anterior neuropore Neural fold heart Neural groove endoderm caudal/posterior neuropore A.
    [Show full text]
  • What Is the Role of the Placenta—Does It Protect Against Or Is It a Target for Insult?
    Teratology Primer, 3rd Edition www.teratology.org/primer What Is the Role of the Placenta—Does It Protect Against or Is It a Target for Insult? Richard K. Miller University of Rochester School of Medicine & Dentistry Rochester, New York The placenta is not just a barrier but has many functions that are vital to the health of the embryo/fetus. The placenta is the anchor, the conduit, and the controller of pregnancy—and it can also be a target for toxicant action. The placenta encompasses not only the chorioallantoic placenta but all of its extraembryonic membranes (chorion/amnion) and the yolk sac. (Figure 1). The placenta and its membranes secure the embryo and fetus to the decidua (uterine lining) and release a variety of steroid and protein hormones that characterize the physiology of the pregnant female. Figure 1. Placental Structure in the Mouse. Figures depict early development of the mouse conceptus at embryonic days (E3.5, E7.5, E12.5). In the fetus, the visceral yolk sac (vYS) inverts and remains active throughout the entire gestation providing for transfer of selective large molecules, e.g., immunoglobulins IgG and vitamin B12. Abbreviations: Al, allantois; Am, amnion; Ch, chorion; Dec, decidua; Emb, embryo; Epc, ectoplacental cone; ICM, inner cell mass; Lab, Labyrinth; pYS, parietal yolk sac; SpT, spongiotrophoblast; TCG, trophoblast giant cell; Umb Cord, umbilical cord; vYS, visceral yolk sac; C-TGC, maternal blood canal trophoblast giant cell; P-TGC, parietal trophoblast giant cell; S-TGC, sinusoidal trophoblast giant cell; SpA-TGC, Spiral artery-associated trophoblast giant cell; Cyan-trophectoderm and trophoblast lineage, Black- inner cell mass and embryonic ectoderm; Gray -endoderm, Red-maternal vasculature, Purple-mesoderm, Yellow- decidua, Pink-fetal blood vessels in labyrinth.
    [Show full text]
  • Human Embryologyembryology
    HUMANHUMAN EMBRYOLOGYEMBRYOLOGY Department of Histology and Embryology Jilin University ChapterChapter 22 GeneralGeneral EmbryologyEmbryology DevelopmentDevelopment inin FetalFetal PeriodPeriod 8.1 Characteristics of Fetal Period 210 days, from week 9 to delivery. characteristics: maturation of tissues and organs rapid growth of the body During 3-5 month, fetal growth in length is 5cm/M. In last 2 month, weight increases in 700g/M. relative slowdown in growth of the head compared with the rest of the body 8.2 Fetal AGE Fertilization age lasts 266 days, from the moment of fertilization to the day when the fetal is delivered. menstrual age last 280 days, from the first day of the last menstruation before pregnancy to the day when the fetal is delivered. The formula of expected date of delivery: year +1, month -3, day+7. ChapterChapter 22 GeneralGeneral EmbryologyEmbryology FetalFetal membranesmembranes andand placentaplacenta Villous chorion placenta Decidua basalis Umbilical cord Afterbirth/ secundines Fusion of amnion, smooth chorion, Fetal decidua capsularis, membrane decidua parietalis 9.1 Fetal Membranes TheThe fetalfetal membranemembrane includesincludes chorionchorion,, amnion,amnion, yolkyolk sac,sac, allantoisallantois andand umbilicalumbilical cord,cord, originatingoriginating fromfrom blastula.blastula. TheyThey havehave functionsfunctions ofof protection,protection, nutrition,nutrition, respiration,respiration, excretion,excretion, andand producingproducing hormonehormone toto maintainmaintain thethe pregnancy.pregnancy. delivery 1) Chorion: villous and smooth chorion Villus chorionic plate primary villus trophoblast secondary villus extraembryonic tertiary villus mesoderm stem villus Amnion free villus decidua parietalis Free/termin al villus Stem/ancho chorion ring villus Villous chorion Smooth chorion Amniotic cavity Extraembyonic cavity disappears gradually; Amnion is added into chorionic plate; Villous and smooth chorion is formed.
    [Show full text]
  • Embryology and Teratology in the Curricula of Healthcare Courses
    ANATOMICAL EDUCATION Eur. J. Anat. 21 (1): 77-91 (2017) Embryology and Teratology in the Curricula of Healthcare Courses Bernard J. Moxham 1, Hana Brichova 2, Elpida Emmanouil-Nikoloussi 3, Andy R.M. Chirculescu 4 1Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, Wales, United Kingdom and Department of Anatomy, St. George’s University, St George, Grenada, 2First Faculty of Medicine, Institute of Histology and Embryology, Charles University Prague, Albertov 4, 128 01 Prague 2, Czech Republic and Second Medical Facul- ty, Institute of Histology and Embryology, Charles University Prague, V Úvalu 84, 150 00 Prague 5 , Czech Republic, 3The School of Medicine, European University Cyprus, 6 Diogenous str, 2404 Engomi, P.O.Box 22006, 1516 Nicosia, Cyprus , 4Department of Morphological Sciences, Division of Anatomy, Faculty of Medicine, C. Davila University, Bucharest, Romania SUMMARY Key words: Anatomy – Embryology – Education – Syllabus – Medical – Dental – Healthcare Significant changes are occurring worldwide in courses for healthcare studies, including medicine INTRODUCTION and dentistry. Critical evaluation of the place, tim- ing, and content of components that can be collec- Embryology is a sub-discipline of developmental tively grouped as the anatomical sciences has biology that relates to life before birth. Teratology however yet to be adequately undertaken. Surveys (τέρατος (teratos) meaning ‘monster’ or ‘marvel’) of teaching hours for embryology in US and UK relates to abnormal development and congenital medical courses clearly demonstrate that a dra- abnormalities (i.e. morphofunctional impairments). matic decline in the importance of the subject is in Embryological studies are concerned essentially progress, in terms of both a decrease in the num- with the laws and mechanisms associated with ber of hours allocated within the medical course normal development (ontogenesis) from the stage and in relation to changes in pedagogic methodol- of the ovum until parturition and the end of intra- ogies.
    [Show full text]
  • Organogenesis Part 2 ______
    Organogenesis Part 2 ___________________________________ ___________________________________ V. Lateral Plate Mesoderm VI. Endoderm ___________________________________ VII. Development of the Tetrapod Limb VIII. Sex Determination ___________________________________ ___________________________________ ___________________________________ ___________________________________ V. Lateral Plate Mesoderm ___________________________________ ___________________________________ paraxial mesoderm chordamesoderm intermediate mesoderm ___________________________________ ___________________________________ ___________________________________ lateral plate mesoderm ___________________________________ ___________________________________ Lateral Plate Mesoderm ___________________________________ Terminology: - Somatopleure: somatic mesoderm plus ectoderm ___________________________________ - Splanchnopleure: splanchnic mesoderm plus endoderm - Coelom: body cavity forms between them ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Lateral Plate Mesoderm ___________________________________ • The Coelom: ___________________________________ – eventually left and right cavities fuse into one ___________________________________ – runs from neck to anus in vertebrates – portioned off by folds of somatic mesoderm ___________________________________ • pleural cavity: surrounds the thorax and lungs • pericardial cavity: surrounds the
    [Show full text]
  • Unit 3 Embryo Questions
    Unit 3 Embryology Clinically Oriented Anatomy (COA) Texas Tech University Health Sciences Center Created by Parker McCabe, Fall 2019 parker.mccabe@@uhsc.edu Solu%ons 1. B 11. A 21. D 2. C 12. B 22. D 3. C 13. E 23. D 4. B 14. D 24. A 5. E 15. C 25. D 6. C 16. B 26. B 7. D 17. E 27. C 8. B 18. A 9. C 19. C 10. D 20. B Digestive System 1. Which of the following structures develops as an outgrowth of the endodermal epithelium of the upper part of the duodenum? A. Stomach B. Pancreas C. Lung buds D. Trachea E. Esophagus Ques%on 1 A. Stomach- Foregut endoderm B. Pancreas- The pancreas, liver, and biliary apparatus all develop from outgrowths of the endodermal epithelium of the upper part of the duodenum. C. Lung buds- Foregut endoderm D. Trachea- Foregut endoderm E. Esophagus- Foregut endoderm 2. Where does the spleen originate and then end up after the rotation of abdominal organs during fetal development? A. Ventral mesentery à left side B. Ventral mesentery à right side C. Dorsal mesentery à left side D. Dorsal mesentery à right side E. It does not relocate Question 2 A. Ventral mesentery à left side B. Ventral mesentery à right side C. Dorsal mesentery à left side- The spleen and dorsal pancreas are embedded within the dorsal mesentery (greater omentum). After rotation, dorsal will go to the left side of the body and ventral will go to the right side of the body (except for the ventral pancreas).
    [Show full text]
  • Ultrasound in the First Trimester
    ULTRASOUND IN THE 4 FIRST TRIMESTER INTRODUCTION First trimester ultrasound is often done to assess pregnancy location and thus it overlaps between an obstetric and gynecologic ultrasound examination. Accurate performance of an ultrasound examination in the first trimester is important given its ability to confirm an intrauterine gestation, assess viability and number of embryo(s) and accurately date a pregnancy, all of which are critical for the course of pregnancy. Main objectives of the first trimester ultrasound examination are listed in Table 4.1. These objectives may differ somewhat based upon the gestational age within the first trimester window, be it 6 weeks, 9 weeks, or 12 weeks, but the main goals are identical. In this chapter, the approach to the first trimester ultrasound examination will be first discussed followed by the indications to the ultrasound examination in early gestation. Chronologic sequence of the landmarks of the first trimester ultrasound in the normal pregnancy will be described and ultrasound findings of pregnancy failure will be presented. The chapter will also display some of the major fetal anomalies that can be recognized by ultrasound in the first trimester. Furthermore, given the importance of first trimester assignment of chorionicity in multiple pregnancies, this topic will also be addressed in this chapter. TABLE 4.1 Main Objectives of Ultrasound Examination in the First Trimester - Confirmation of pregnancy - Intrauterine localization of gestational sac - Confirmation of viability (cardiac activity in embryo/fetus) - Detection of signs of early pregnancy failure - Single vs. Multiple pregnancy (define chorionicity in multiples) - Assessment of gestational age (pregnancy dating) - Assessment of normal embryo and gestational sac before 10 weeks - Assessment of basic anatomy after 11 week TRANSVAGINAL ULTRASOUND EXAMINATION IN THE FIRST TRIMESTER There is general consensus that, with rare exceptions, ultrasound examination in the first trimester of pregnancy should be performed transvaginally.
    [Show full text]
  • First, Do No Harm . . . to Early Pregnancies
    295jum_online.qxp:Layout 1 4/25/10 3:04 PM Page 685 Editorial First, Do No Harm . to Early Pregnancies Peter M. Doubilet, MD, PhD Carol B. Benson, MD Department of Radiology Brigham and Women’s Hospital Harvard Medical School Boston, Massachusetts USA hen a woman of childbearing age presents to a physician or other care- giver complaining of vaginal bleeding and/or pelvic pain, a pelvic ultra- sound examination is often performed to assess the etiology of her symptoms.1,2 If she has a positive pregnancy test, the major role of ultra- Wsound is to assess whether she has a normal intrauterine pregnancy (IUP), an abnor- mal IUP, or an ectopic pregnancy. The information provided by ultrasound can be of great value in guiding management decisions and improving outcome. Errors in ultrasound interpretation, however, can lead to mismanagement and, there- by, to bad pregnancy outcome. Potential interpretation errors include: (1) failure to conclude that there is a definite or probable IUP despite ultrasound images depicting such a finding; and (2) failure to conclude that there is a definite or probable ectopic pregnancy despite ultrasound images depicting such a finding. This editorial focuses on the former error. Definition and Scope of the Problem The issue addressed here involves the situation in which a woman with a positive preg- nancy test and symptoms of bleeding and/or pain undergoes a pelvic ultrasound examination, and the scan demonstrates a nonspecific intrauterine fluid collection (Figure 1). By “nonspecific,” we mean a fluid collection with curved edges in the central echogenic portion of the uterus (ie, in the decidua) with no visible embryo or yolk sac, that does not demonstrate one of the published signs of early IUP (double sac sign3 or intradecidual sign4).
    [Show full text]
  • Development of the Genital System Development of the Gonads
    Development of the Genital System Development of the gonads Dr Ahmed Salman The gonads develop form three sources (the first two are mesodermal, the third one is endodermal ) . 1.Proliferating coelomic epithelium on the medial side of the mesonephros. 2. Adjacent mesenchyme dorsal to the proliferating coelomic epithelium. 3. Primordial germ cells (endodermal), which develop in the wall of the yolk sac and migrate along the dorsal mesentery to reach the developing gonad. DR AHMED SALMAN The indifferent stage of the developing gonads - The coelomic epithelium (on either side of the aorta) proliferates and becomes multi layered and forms a longitudinal projection into the coelomic cavity called the genital ridge. - The genital ridge forms a number of epithelial cords called the primary sex cords that invade the underlying mesenchyme, which separate the cords from each other. - Up to the 6th or 7th week, the developing gonad cannot be differentiated into testis or ovary. DR AHMED SALMAN DR AHMED SALMAN Development of the testis and its descent Under the effect of the testis determining factor (T.D.F) present on the short arm of Y - chromosome, the undifferentiated gonad is switched to form a testis. 1. The coelomic epithelium. - The primary sex cords elongate to form testis cords (future seminiferous tubules) which undergo three important events : • Ventrally, they lose contact with the surface epithelium by the developing tunica albuginae. • Dorsally, they communicate with each other to form rete testis. • Internally, they are invaded by the primitive germ cells. DR AHMED SALMAN The testis cords become lined by two types of cells: A.
    [Show full text]
  • 26 April 2010 TE Prepublication Page 1 Nomina Generalia General Terms
    26 April 2010 TE PrePublication Page 1 Nomina generalia General terms E1.0.0.0.0.0.1 Modus reproductionis Reproductive mode E1.0.0.0.0.0.2 Reproductio sexualis Sexual reproduction E1.0.0.0.0.0.3 Viviparitas Viviparity E1.0.0.0.0.0.4 Heterogamia Heterogamy E1.0.0.0.0.0.5 Endogamia Endogamy E1.0.0.0.0.0.6 Sequentia reproductionis Reproductive sequence E1.0.0.0.0.0.7 Ovulatio Ovulation E1.0.0.0.0.0.8 Erectio Erection E1.0.0.0.0.0.9 Coitus Coitus; Sexual intercourse E1.0.0.0.0.0.10 Ejaculatio1 Ejaculation E1.0.0.0.0.0.11 Emissio Emission E1.0.0.0.0.0.12 Ejaculatio vera Ejaculation proper E1.0.0.0.0.0.13 Semen Semen; Ejaculate E1.0.0.0.0.0.14 Inseminatio Insemination E1.0.0.0.0.0.15 Fertilisatio Fertilization E1.0.0.0.0.0.16 Fecundatio Fecundation; Impregnation E1.0.0.0.0.0.17 Superfecundatio Superfecundation E1.0.0.0.0.0.18 Superimpregnatio Superimpregnation E1.0.0.0.0.0.19 Superfetatio Superfetation E1.0.0.0.0.0.20 Ontogenesis Ontogeny E1.0.0.0.0.0.21 Ontogenesis praenatalis Prenatal ontogeny E1.0.0.0.0.0.22 Tempus praenatale; Tempus gestationis Prenatal period; Gestation period E1.0.0.0.0.0.23 Vita praenatalis Prenatal life E1.0.0.0.0.0.24 Vita intrauterina Intra-uterine life E1.0.0.0.0.0.25 Embryogenesis2 Embryogenesis; Embryogeny E1.0.0.0.0.0.26 Fetogenesis3 Fetogenesis E1.0.0.0.0.0.27 Tempus natale Birth period E1.0.0.0.0.0.28 Ontogenesis postnatalis Postnatal ontogeny E1.0.0.0.0.0.29 Vita postnatalis Postnatal life E1.0.1.0.0.0.1 Mensurae embryonicae et fetales4 Embryonic and fetal measurements E1.0.1.0.0.0.2 Aetas a fecundatione5 Fertilization
    [Show full text]
  • RNA-Seq Reveals Conservation of Function Among the Yolk Sacs Of
    RNA-seq reveals conservation of function among the PNAS PLUS yolk sacs of human, mouse, and chicken Tereza Cindrova-Daviesa, Eric Jauniauxb, Michael G. Elliota,c, Sungsam Gongd,e, Graham J. Burtona,1, and D. Stephen Charnock-Jonesa,d,e,1,2 aCentre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, United Kingdom; bElizabeth Garret Anderson Institute for Women’s Health, Faculty of Population Health Sciences, University College London, London, WC1E 6BT, United Kingdom; cSt. John’s College, University of Cambridge, Cambridge, CB2 1TP, United Kingdom; dDepartment of Obstetrics and Gynaecology, University of Cambridge, Cambridge, CB2 0SW, United Kingdom; and eNational Institute for Health Research, Cambridge Comprehensive Biomedical Research Centre, Cambridge, CB2 0QQ, United Kingdom Edited by R. Michael Roberts, University of Missouri-Columbia, Columbia, MO, and approved May 5, 2017 (received for review February 14, 2017) The yolk sac is phylogenetically the oldest of the extraembryonic yolk sac plays a critical role during organogenesis (3–5, 8–10), membranes. The human embryo retains a yolk sac, which goes there are limited data to support this claim. Obtaining experi- through primary and secondary phases of development, but its mental data for the human is impossible for ethical reasons, and importance is controversial. Although it is known to synthesize thus we adopted an alternative strategy. Here, we report RNA proteins, its transport functions are widely considered vestigial. sequencing (RNA-seq) data derived from human and murine yolk Here, we report RNA-sequencing (RNA-seq) data for the human sacs and compare them with published data from the yolk sac of and murine yolk sacs and compare those data with data for the the chicken.
    [Show full text]