Multiple pregnancies presentation

1. Multiple Pregnancies

2. DEFINITION :
• Any pregnancy which two or more embryos or
fetuses present in the uterus at same time.
• It is consider as a complication of pregnancy due
to ;
 The mean gestational age of delivery of twins is
approximately 36w.
 The perinatal mortality &morbidity increase.

3. Terminology vs. number
• Singletons  one fetus
• Twins  tow fetuses.
• Triplets  three fetuses.
• Quadruplets  four fetuses.
• Quintuplets  five fetuses.
• sextuplets  six fetuses.
• Septuplets  seven fetuses.

4. Incidence & epidemiology
• The incidence of multiple pregnancy in US is
approximately 3% (increase annually due to Assisted
Reproductive Technology ART ).
• Monozygotic twins ( approx. 4 in 1000 births ).
• Triplet pregnancies ( approx. 1 in 8000 births ).
• Multiple gestation increase morbidity & mortality for
both the mother & the fetuses.
• Hellin's Law: is the principle that one in about 89
natural pregnancies ends in the birth of twins, triplets
once in 892 births, and quadruplets once in 893 births.

5. Overview

6. Definitions:
• ZYGOSITY:
- Refers to the Type of Conception.
-only determined by DNA testing.
• CHORIONICITY:
- Type of Placentation/ Sharing the placenta.
- prenatally by ultrasound.
- postnatally by examining membranes.

7. A- Dizygotic twins
•Most common represents
2/3 of cases.
•Fertilization of more than
one egg by more than one
sperm
•Non identical ,may be of
different sex.
•Two chorion and two
amnion.
•Placenta may be separate or
fused.

8. Cont.
• The incidence of dizygotic twins is higher in:
1. Certain families.
2. Race; African American.
3. Increases with maternal age, parity, weight
and height.
4. Ovulation Induction.

9. B- Monzygotic twins
• Constitutes 1/3 of twins
• These twins are multiple gestations resulting
from cleavage of a single, fertilized ovum.
• The timing of cleavage determines the
placentation of the pregnancy.
• Not affected by heredity.
• Not related to induction of ovulation

10. B- Monzygotic twins
1. If separation occurs before the differentiation
of the trophoblast, two chorions and two
amnions (Di-Di) result.

11. B- Monzygotic twins
• 2. After trophoblast differentiation and before
amnion formation (days 3 to 8), separation
leads to a single placenta, one chorion, and
two amnions (Mo-Di).
Blastocyct

12. B- Monzygotic twins
3.Division after amnion formation leads to a
single placenta, one chorion, and one amnion
(Mo-Mo) (days8 to 13).

13. B- Monzygotic twins
• 4. Rarely, conjoined or “Siamese” twins (days
13to 15).

14. Conjoined twins

15. Which is more important – zygosity or
chorionicity??
• Dichorionic twins can be either
mono/dizygotic.
• Dichorionic twins develop as two distinct
organs. – so no risk.
• Monochorionic twins have increased vascular
anastomoses between the two circulation
– so high risk!!

16. Diagnosis:
• History:
-Family hx of dizygotic twins.
-Use of fertility drugs.
-sensation of excessive fetal movements.
-Exaggerated symptoms of pregnancy (hyperemesis gravidarum ).
• Examination:
-GPE ( weight gain, Pre-eclampsia signs ).
-Abdominal examination (excessive uterine fundal growth, and auscultation of
fetal heart rates in separate quadrants of the uterus are suggestive but not
diagnostic).
• Sonographic examination ( diagnostic )

17. Ultrasound differentiation of chorionicity

18. Ultrasound differentiation of chorionicity

19. Ultrasound differentiation of zygocity
US

20. Complications
1. Maternal Complications.
2. Fetal Complications.

21. 1.Maternal Complications

22. Cont.

23. 2.Fetal Complications

24. 2.Fetal Complications
• Prematurity :
Single most important cause of perinatal
mortaility and morbidity.
Ensure delivery in a tertiary care centre.

25. 2.Fetal Complications
• IUGR:
 Can affect one or both fetuses.
Monochorionic > Dichorionic.
Up to30-32 Weeks twins grow with same velocity
, after that reduction in abdominal
circumference.
Poor growth – poor placentation , unequal
placental sharing, fetal anomalies.

26. 2.Fetal Complications
• Single Fetal Demise

27. Single Fetal Demise cont.
Monochorionic - 25% risk of twin death, 25%
risk of neurological damage in surviving twin.
• Dilemma exists whether to deliver early or not
• Terminated as soon as other twin is capable of extra uterine
survival
Dichorionic – no such risk
• Conservative management

28. 2.Fetal Complications
• Twin-Twin Transfusion Syndrome
• The presence of unbalanced anastomosis in the placenta
(typically arterial-venous connections) leads to a syndrome
in which one twin’s circulation perfuses the other Twin.
• Complications:
 Donor : anemic HF, hypovolemia, hypotension, anemia,
oligohydramnios, growth restriction.
 Recipient : hypervolemic HF , hypervolemia, hypertension,
polyhydramnios, thrombosis, hyperviscosity,cardiomegaly,
polycythemia, hydrops fetalis.

29. Twin-Twin Transfusion Syndrome Cont.

30. Twin-Twin Transfusion Syndrome Cont.
• Management :
 Repeated amniocentesis from ( recipient).
Intrauterine transfusion of the anemic (donor)
twin is of no benefit in this condition.
Fetoscopy and laser ablation of
communicating vessels.

31. 2.Fetal Complications
• Vanishing Twin & Abortion
Incidence of abortion more in multiple pregnancy
Spontaneous cessation of cardiac activity in a previously
viable fetus of a multiple gestation. – VANISHING TWIN
When fetal death occur after the first trimester, results in a thin
parchment – like body called FETUS PAPYRACEOUS
Diagnosis made after delivery
No effect on mother or the viable fetus.

32. Vanishing Twin & Abortion

33. 2.Fetal Complications
• Congenital Anomalies
STRUCTURAL MALFORMATIONS
• Unique to twins – conjoined twins , Acardiac fetus
• Non specific but common in twins – CHD , Anencephaly
• Postural deformities – Talipes & Congenital dislocation of Hip
CHROMOSOMAL ANOMALIES
• Dizygotic – independent risk, but both will not be involved
• Monozygotic – same risk as that of singleton, both affected
• Down’s syndrome

34. Congenital Anomalies Cont.
Conjoined Twins

35. Congenital Anomalies Cont.
• Acardiac Foetus
Very rare
Bizarre form of monochorionic twinning
One fetus is normal
The other twin is severely malformed – no heart , absent development
of upper part of body

36. Acardiac Foetus Cont.

37. Management
• Antepartum :
 Adequate nutrition.
-Adequacy of maternal diet is assessed due to the
increased need for overall calories, iron, vitamins,
and folate.
-The Institute of Medicine (IOM) recommends
women with twins gain a total of 16.0 to 20.5 kg
during the pregnancy.
 More frequent prenatal visits.
 Periodic U/S assessment “ every 3-4 weeks from23weeks’
gestation “ to monitor the growth and detection of discordant
growth or TTTS.
 Amniocentesis
.

38. Management Cont.
• Intrapartum
 Delivery should be considered if:
1. Fetal lung maturity is demonstrated
2. If compromise of the remaining fetus
develops.
3. If evidence of disseminated intravascular
coagulation in the mother is present

39. Management Cont.
 The route of delivery depends on:
1. Presentation of the twins.
2. Gestational age.
3. Presence of maternal or fetal complications.
4. Experience of obstetrician.
5. Availability of anesthesia & neonatal intensive care.

40. Management Cont.
• postpartum :
 Active management of PPH:
By giving oxytocin in the 3nd stage of labor
just after delivery of both fetuses and
placentas.