Multifetal Gestation

1. Multifetal Gestation

2. singleton septuplets …… twin triplets

3. Factors that Influence Twinning • Race • Heredity • Maternal Age and Parity • Nutritional Factors • Pituitary Gonadotropin • Infertility Therapy • Assisted Reproductive Technology (ART)

4. Fetal malformations placental vascular anastomosis (twin-twin transfusion syndrome, TTTS) fetal-growth restriction preterm delivery perinatal mortality …… Maternal preeclampsia postpartum hemorrhage maternal death …… Complications

5. Labor and delivery complications • preterm labor • uterine contractile dysfunction • abnormal presentation • umbilical cord prolapse • premature separation of the placenta • immediate postpartum hemorrhage

6. ova–dizygotic or fraternal twins maturation and fertilization of two ova monozygotic or identical twins Etiology

7. Genesis of Monozygotic Twins

8. "Vanishing Twin" • one twin is lost or "vanishes" • maternal serum alpha-fetoprotein level ↑ • amnionic fluid alpha-fetoprotein level ↑ • amnionic fluid acetylcholinesterase assay+

9. Determination of Chorionicity • Sonographic Evaluation • Placental Examination • Infant Sex and Zygosity

10. Diagnosis • History and Clinical Examination • Sonography • Radiological Examination • Biochemical Tests

11. large uterus for gestational age • Multiple fetuses • Elevation of the uterus by a distended bladder • Inaccurate menstrual history • Hydramnios • Hydatidiform mole • Uterine leiomyomas • A closely attached adnexal mass • Fetal macrosomia (late in pregnancy)

12. Duration of Gestation

13. Unique Complications

15. Vascular Anastomoses between Fetuses

17. Antepartum Management of Twin Pregnancy • Delivery of markedly preterm neonates be prevented • Fetal-growth restriction be identified and afflicted fetuses be delivered before they become moribund • Fetal trauma during labor and delivery be avoided • Expert neonatal care be available

18. Recommendations for intrapartum management • An appropriately trained obstetrical attendant should remain with the mother throughout labor. Continuous external electronic monitoring is employed. If membranes are ruptured and the cervix dilated, then simultaneous evaluation of both the presenting fetus by internal electronic monitoring and the remaining sibling(s) by external monitors is typically used • Blood transfusion products are readily available • An intravenous infusion system capable of delivering fluid rapidly is established. In the absence of hemorrhage, lactated Ringer or an aqueous dextrose solution is infused at a rate of 60 to 125 mL/hr

19. Recommendations for intrapartum management • An obstetrician skilled in intrauterine identification of fetal parts and in intrauterine manipulation of a fetus should be present • A sonography machine is made readily available to help evaluate position and status of the remaining fetus(es) after delivery of the first • Experienced anesthesia personnel are immediately available in the event that intrauterine manipulation or cesarean delivery is necessary • For each fetus, two attendants, one of whom is skilled in resuscitation and care of newborns, are appropriately informed of the case and remain immediately available • The delivery area should provide adequate space for all team members to work effectively. Moreover, the site must be appropriately equipped to provide maternal and neonatal resuscitation

20. Presentation and Position • admission for delivery: cephalic-cephalic, cephalic-breech, and cephalic- transverse

21. Vaginal delivery • When • How • Evaluation

22. Internal podalic version

23. Cesarean Delivery • Complications • Secondary • Rare situation

24. Twin-Twin Transfusion Syndrome (TTTS) • blood is transfused from a donor twin to its recipient sibling • the donor becomes anemic and its growth may be restricted • the recipient becomes polycythemic and may develop circulatory overload manifest as hydrops • donor twin is pale, and its recipient sibling is plethoric

25. Diagnosis--sonographic suspedted • Monochorionicity • same-sex gender • hydramnios defined if the largest vertical pocket is > 8 cm in one twin and oligohydramnios defined if the largest vertical pocket is < 2 cm in the other twin • umbilical cord size discrepancy • cardiac dysfunction in the recipient twin with hydramnios • abnormal umbilical vessel or ductus venosus Doppler velocimetry • significant growth discordance.

26. Quintero staging system • Stage I–discordant amnionic fluid volumes as described above, but urine still visible sonographically within the donor twin's bladder • Stage II–criteria of stage I, but urine is not visible within the donor's bladder • Stage III–criteria of stage II and abnormal Doppler studies of the umbilical artery, ductus venosus, or umbilical vein • Stage IV–ascites or frank hydrops in either twin • Stage V–demise of either fetus

27. Disorders of Amnionic Fluid Volume

28. The role of amnionic fluid • a physical space • promotes normal fetal lung development • avert compression of the umbilical cord

29. Permitting fetal movement and the development of the musculoskeletal system. • Swallowing of amniotic fluid enhances the growth and development of the gastrointestinal tract. • The ingestion of amniotic fluid provides some fetal nutrition and essential nutrients. • Amniotic fluid volume maintains amniotic fluid pressure thereby reducing the loss of lung liquid - an essential component to pulmonary development. (Nicolini, 1989). • Protects the fetus from external trauma. • Protects the umbilical cord from compression. • It's constant temperature helps to maintain the embryo's body temperature. • It's bacteristatic properties reduces the potential for infection.

30. Pathway

31. Normal Amnionic Fluid Volume • 1 L by 36 weeks, decreases thereafter to less than 200 mL at 42 weeks • Diminished fluid is termed oligohydramnios • more than 2 L of amnionic fluid is termed hydramnios or polyhydramnios

32. Measurement of Amnionic Fluid • amnionic fluid index, AFI • adding the vertical depths of the largest pocket in each of four equal uterine quadrants • hydramnios : ＞24 cm

34. Sonogram of a pocket of amniotic fluid in a patient with hydrops fetalis and polyhydramnios. Two small segments of umbilical cord (arrows) are seen traversing the measured pocket of amniotic fluid. The placenta (P), which appears normal to prominent in this case, is, in fact, abnormally thickened.

35. Hydramnios

36. Causes • fetal malformations • gastrointestinal anomalies • nonimmune hydrops • chromosomal abnormalities • central nervous system • TTTS • fetal pseudohypoaldosteronism • fetal Bartter or hyperprostaglandin E syndrome • fetal nephrogenic diabetes insipidus • placental chorioangioma • fetal sacrococcygeal teratoma • maternal substance abuse

37. Oligohydramnios

38. Associated Conditions • Fetal • Chromosomal abnormalities • Congenital anomalies • Growth restriction • Demise • Postterm pregnancy • Ruptured membranes

39. Associated Conditions • Placenta • Abruption • Twin-twin transfusion • Maternal • Uteroplacental insufficiency • Hypertension • Preeclampsia • Diabetes

40. Associated Conditions • Drugs • Prostaglandin synthase inhibitors • Angiotensin-converting enzymeinhibitors • Idiopathic

41. The End