2009-2010usuhs msiii ob/gyn clerkship self directed studies multiple gestation ch 14 2009-2010...
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2009-2010 USUHS MSIII Ob/GynClerkship Self Directed Studies
Multiple GestationCh 14
2009-2010 Academic Year
MSIII Ob/Gyn Clerkship
Self-Directed Study
2009-2010 USUHS MSIII Ob/GynClerkship 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.
2009-2010 USUHS MSIII Ob/GynClerkship 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!!!!!!!
2009-2010 USUHS MSIII Ob/GynClerkship 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.
2009-2010 USUHS MSIII Ob/GynClerkship 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
2009-2010 USUHS MSIII Ob/GynClerkship Self Directed Studies
Timing of Monozygotic Twinning
Time of Cleavage Membranes0-72 hours Diamniotic
Dichorionic
4-8 days Diamniotic
Monochorionic
9-12 days Monoamniotic
MonochorionicAdapted from Essentials of Obstetrics and Gynecology, 4th ed; Hacker et al, page 183.
2009-2010 USUHS MSIII Ob/GynClerkship 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
2009-2010 USUHS MSIII Ob/GynClerkship Self Directed Studies
MonoamnioticMonochorionic
DiamnioticDichorionic
Twin Peak Sign
http://www.obgyn.net/us/galleryUSUHS Radiology
2009-2010 USUHS MSIII Ob/GynClerkship Self Directed Studies
Maternal Physiologic Adaptations
Blood Vol 40% (2L) 3L or more
Infection risk Increases
Pre-E, GHTN X 2
Uterine Size is much larger
Resp compromise orthostatic
Renal function
System Singleton Multiples riskFor anemiaAnd low FeAnd Folate
CompressesLungs.Compresses
Vena Cave.
Compressedureters
2009-2010 USUHS MSIII Ob/GynClerkship Self Directed Studies
Associated Complications
Anemia Malpresentation
Hydramnios Placenta Previa
Hypertension Abruption
Premature Labor P(P)ROM
Postpartum atony Prematurity
PP Hemorrage Cord Prolapse
Pre-eclampsia IUGR
Cesarean Delivery Congenital anomalies
Maternal Fetal
Adapted from Hacker et al, 4th ed.
2009-2010 USUHS MSIII Ob/GynClerkship 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