II. Epidemiology

  1. 1 in 80 white pregnancies

III. Definitions

  1. Dizygotic Twins (66% U.S. twins)
    1. Fertilization of 2 ova (egg) by 2 sperm
    2. Dichorionic: Separate chorion (placenta)
    3. Diamniotic: Separate amnion (amniotic sac)
  2. Monozygotic Twins (33% U.S twins, identical)
    1. Division of 1 ova (eggs) fertilized by same sperm
    2. Ova division <72 hours: Dichorionic, diamniotic
    3. Ova division 4-8 days: monochorionic, diamniotic
    4. Ova division 8-13 days: monochorionic, monoamniotic
    5. Ova division >13 days: Conjoined twins
  3. Fetus Papyraceous
    1. One twin does not develop
    2. Amorphous, shriveled, and flattened twin

IV. Risk factors for Dizygotic twins

  1. Older mother
  2. Multiparous mother
  3. Family History of dizygotic Twin Gestation

V. Differential Diagnosis Multiple Gestation (early)

  1. Misdated pregnancy
  2. Polyhydramnios
  3. Uterine Fibroid tumors
  4. Cyst
  5. Hydatiform mole

VI. Intrapartum Associated Complications

  1. Large Placenta
    1. Placenta Previa
    2. Postpartum Hemorrhage
  2. Large Fetal Demand
    1. Iron Deficiency Anemia
    2. Megaloblastic Anemia
  3. Large bulk or polyhydramnios
    1. Preterm Labor or Premature Infant
    2. Pyelonephritis
  4. Placental Insufficiency
    1. Growth retardation
  5. Miscellaneous associated conditions
    1. Pregnancy Induced Hypertension
    2. Conjoined twins
    3. Hyperemesis Gravidarum
    4. Congenital defect risk doubles in twins

VII. Peripartum Complications

  1. Umbilical Cord Prolapse
  2. Fetal Malpresentation
  3. Placental Abruption
  4. Postpartum Hemorrhage
  5. Locked twins
    1. Description: Twins lock heads
      1. First twin Breech
      2. Second twin vertex
    2. Management
      1. Push second twin's head from Pelvis
      2. Frees first fetus
  6. Transfusion Syndrome
    1. Placental AV shunt in monozygotic twins
    2. Arterial twin
      1. Pumps blood to other twin
      2. Starves self
    3. Other twin
      1. Bulky and plethoric
      2. Polycythemic

VIII. Presentation

  1. First twin presents vertex: 75%
  2. Both twins vertex: 45%
  3. One twin vertex, one twin Breech: 37%
  4. Both twins Breech: 10%

IX. Management: Pregnancy

  1. General Measures
    1. Good diet
    2. Supplement iron and Folic Acid
    3. Reduce activity and increase rest
  2. Clinic visits at least every 2 weeks after 24 weeks
    1. Cervical checks each visit after 24 weeks
    2. Preterm Labor Education
    3. Fetal Movement Counts daily after 32 weeks
  3. Obstetric Ultrasound every 4-6 weeks after diagnosis
    1. Assess for Placenta Previa
    2. Assess Fetal Growth
    3. Follow Fetal Presentation
  4. Weekly Nonstress Tests after 32 weeks
    1. Assess fetal well-being
    2. Predict cord compression
  5. Perinatology Consultation as needed

X. Management: Cesarean Delivery Indications

  1. Twin A (first twin) not vertex presentation
  2. Twin B (second twin) not vertex
    1. External Cephalic Version of second twin fails
    2. Second twin experiences Fetal Distress
    3. Breech Delivery not an option
      1. Mother not willing to undergo Breech Delivery
      2. Physician discretion
      3. Fetus <2 kg
      4. Twin B larger than Twin A

XI. Management: Vaginal Delivery if First Twin Vertex

  1. Monitor first twin by Internal scalp electrode
  2. Monitor second twin by External fetal monitor
  3. Deliver first twin vaginally (vertex)
  4. Second Twin Delivery (Do not delay)
    1. Consider external version of second twin if Breech
    2. Consider vaginal Breech Delivery for infant >2 kg
    3. Consider cesarean delivery of second twin

Images: Related links to external sites (from Bing)

Related Studies