1. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Multiple Gestation Ch 14 2009-2010 Academic Year MSIII Ob/Gyn Clerkship Self-Directed Study

2. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Case Study A 41 year old Lt. Colonel, G1, presents to the OB clinic for her initial OB visit. She is very happy to have undergone IVF treatment with the military and was told by her reproductive doctor that she had twins.

3. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Questions to Consider 1. What are the patient’s risk factors for twins? –IVF (Ovarian stimulation, multiple embryo transfer) –Age (>35 yo with double risk of a 25 yo) 2. Are assisted reproductive techniques associated with twinning? –YES!!!!!!!

4. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies APGO Educational Topic 20 A. Discuss the etiology of monozygotic, dizygotic, and multizygotic gestation. B. Describe the altered physiologic state with multifetal gestation. C. Describe the potential complications associated with multifetal gestation.

5. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Etiology of Twinning Monozygotic Twinning: splitting of 1 embryo Dizygotic Twinning: fertilization of 2 eggs in a single menstrual cycle. Multizygotic: fertilization of more than 2 eggs

6. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Timing of Monozygotic Twinning Time of CleavageMembranes 0-72 hoursDiamniotic Dichorionic 4-8 daysDiamniotic Monochorionic 9-12 daysMonoamniotic Monochorionic Adapted from Essentials of Obstetrics and Gynecology, 4th ed; Hacker et al, page 183.

7. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Figure 14-1 Diagrammatic representation of the major types of twin placentas found with monozygotic twins. Redrawn from Benirschke K, Driscoll SG: Pathology of the Human Placenta. New York, Springer-Verlag, 1974, p 263. Downloaded from: StudentConsult (on 15 June 2009 09:55 PM) © 2005 Elsevier

8. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Monoamniotic Monochorionic Diamniotic Dichorionic Twin Peak Sign http://www.obgyn.net/us/gallery USUHS Radiology

9. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Maternal Physiologic Adaptations Blood Vol 40%  (2L) 3L or more Infection riskIncreases  Pre-E, GHTN  X 2 Uterine Size is much larger  Resp compromise  orthostatic Renal  function SystemSingletonMultiples  risk For anemia And low Fe And Folate Compresses Lungs. Compresses Vena Cave. Compressed ureters

10. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Associated Complications AnemiaMalpresentation HydramniosPlacenta Previa HypertensionAbruption Premature LaborP(P)ROM Postpartum atonyPrematurity PP HemorrageCord Prolapse Pre-eclampsiaIUGR Cesarean DeliveryCongenital anomalies MaternalFetal Adapted from Hacker et al, 4th ed.

11. 2009-2010USUHS MSIII Ob/Gyn Clerkship Self Directed Studies Other Tidbits of Info Twins = 1% of all births in USA Dizygotic twinning is dependant on FMHx, ethnicity (  Nigeria), and maternal age (  with age >35 yo is 2x’s that of 25 yo) while monozygotic twinning rates is constant. ART (Assisted Reproductive Technology) increases multifetal gestation. –Clomid = 6-8% incidence of multiples –Gonadotropins = 20-30% incidence of multiples