Multifetal Pregnancy
Multifetal Pregnancy
Multifetal Pregnancy
Multifetal Pregnancy
Objectives
• To discuss the different types of multifetal pregnancy and
pathophysiology
• To discuss the antepartum and intrapartum assessment of multifetal
pregnancy
• To discuss the complications of multifetal pregnancy on the fetuses
and the mothers
• To discuss management principles of the possible complications of
multifetal pregnancy.
Sources
• William’s Textbook of Obstetrics 25th edition. Chapter 45
• https://www.nice.org.uk/guidance/ng137
Incidence and Epidemiology
• 1-3% of all pregnancies
• Incidence in Philippines: 0.72% of all pregnancies
• As much as 10% of perinatal mortality, morbidity,
neurodevelopmental problems
• Increased incidence in developed countries
• Increased incidence with the advent of assisted reproductive
techniques
25%
• Prenatally- By Ultrasound
Antenatal :
1.Hyperemesis gravidarum
2.↑chances of abortion
3.hydramnios
4.Increased incidence of Hypertensive disorders of
pregnancy, Diabetes during pregnancy
5.Placenta previa, abruptio
6.Anemia
• Intrapartum :
1.Prolonged labor (uterine inertia)
2.Malpresentation
3.Cord prolapse
4.Abruptio placenta for 2nd twin
5.Postpartum Hemorrhage
Fetal complications
1.Preterm delivery
2.IUGR
3.Congenital Abnormalities
4.Cord abnormalities :
1. Single umbilical artery
2. Velamentous insertion
3. Cord entanglement
4. Cord prolapse
5.Monochorionic twins :
1. Discordant growth
2. Twin to twin syndrome
3. Single fetal Demise
Fetal Complications Unique
to Monochorionic Twins
Twin to Twin Trasfusion Syndrome
Twin to Twin Transfusion Syndrome
Occur in 10-15% of monochorionic twins
Mostly during 2nd trimester
Due to imbalance of blood flow across placental AV
anastomosis
Associated with a tense uterus with excessive
amniotic fluid volume
Ultrasound : Polyhydramnios in recipient twin and
oligohydramnios in donor twin
Introduction
• Vascular communications exist between the two
placentas in ALL monochorionic twins, which are
usually artery to artery vein to vein.
• As the pressure is equal on both sides with no
gradient, the blood supply to the fetuses is not
compromised.
• But in TTTS the artery of one fetus communicates
with the vein of the other fetus,giving rise to
pressure gradient.
• Thus blood flows unidirectionally from one fetus to
the other resulting in hyperperfusion of the recipient
twin and hypoperfusion of the donor twin.
• The donor becomes
anemic and its growth
maybe restricted, while
the recipient becomes
polycythemic and may
develop circulatory
overload manifest as
hydrops.
L A S E R A B L AT I O N
Video of fetoscopic laser ablation for TTTS
• https://www.youtube.com/watch?v=bhzlJzujISM
https://www.youtube.com/watch?v=bhzlJzujISM
Twin Reversed Arterial Perfusion (TRAP)
Steenhaut, P. et al. Perinatal Mortality in Multiple Pregnancy. St. Luc University Hospital. Belgium.2012
Fetal growth discordance
• Intrapair difference in birth weight >20% of larger twin`s
weight
• Growth Discordance
= (wt of bigger twin – wt of smaller twin) X 100
wt of bigger twin
Discordancy
Mild <15%
Moderate 15-30%
Severe >30%
Sumpaico et al. Obstetrics and Gynecology Ultrasound for Practicing Clinician. Second Edition. 2006
Selective Intrauterine Growth Restriction
Steenhaut, P. et al. Perinatal Mortality in Multiple Pregnancy. St. Luc University Hospital. Belgium.2012
IUGR and Discordancy
Steenhaut, P. et al. Perinatal Mortality in Multiple Pregnancy. St. Luc University Hospital. Belgium.2012
Velamentous cord insertion
Congenital Anomalies
• 2% in the population of 15,000 babies
• Monozygotic 1 or 2 in a million pregnancies
• Dizygotic 14/15 in a million
• Philippines 4th most common birth defect 114 per 10,000
First Trimester Screening in Twins
• Serum biochemical marker concentrations in twin pregnancies reflect
the presence of two fetuses rather than one.
• 11–13 weeks maternal serum concentrations are approximately
double those found in singleton pregnancies.
• monochorionic twins the average of the two NT measurements can
be used to calculate the pregnancy risk
• dichorionic twins the individual NT measurements can be used to
calculate the fetus-specific risk
• first-trimester NT and maternal serum biochemistry markers can
improve the overall DR to around 80% at a 5% FPR
• PAPP-A, the median MoM values are higher in dichorionic twins than in
monochorionic twins, approaching 2.1 MoM and 1.6 MoM, respectively, at week
13.
• Free β-hCG-MoM values in dichorionic and monochorionic twins increase to a
similar level with gestation, approaching 2.0 MoM at 13 weeks’ gestation
• In twins the levels of serum PAPP-A and free β- hCG change with gestation and
these levels are lower in monochorionic twins than in dichorionic twins.
• dichorionic twins both markers increase from approximately 1.5 MoM of the
singleton median in gestational weeks 8–9 to approximately 2.0 MoM at 13–14
weeks.
• In monochorionic twins the levels of both biochemical markers are approximately
equal to the singleton median at 8–9 weeks and increase at 13–14 weeks to 2.0
MoM for free β-hCG and 1.5 MoM for PAPP-A.
• Trisomy 21-affected singletons, with decreased PAPP-A-MoM and
increased free β- hCG-MoM.
• dichorionic twins affected by trisomy 21, the mean logMoM fitted
well with the model assuming half the level of that in singleton
pregnancies with trisomy 21.
Cervical Assessment in Multiple Gestation
• Despite the lack of precision, clinical cervical assessment
appears to be safe and may be effective in monitoring twin
gestations, if transvaginal ultrasound is not available or
determined to be too expensive. However, compared to
transvaginal sonography, digital examination is more subjective
and less reproducible.
Antenal Corticosteroids to Prevent Respiratory Distress Syndrome. Royal College of Obstetrics and
Gynecology. 2004
Single Fetal Demise
• > in Monochorionic twin
• If one twin dies after 14wk,there is high risk of neurological
damage to survivor twin :
• This is due to thromboplastin release resulting to possible
thrombotic arterial occlusion of anterior & middle cerebral
arteries causing multicystic encephalomalacia
Important Points in the manangement of
single fetal demise
• Determine the chorionicity
• Evaluate fro fetal anomalies/ do fetal surveillance
• Steroid prophylaxis for lung maturity if preterm delivery
• Conservative management unti 37 weeks
• Post-mortem examination of the stillborn. Send placenta for histological
examination
• Counselling and support
• Pediatric assessment and long-term follow-up
Conjoined twin
Conjoined (siamese twin)
• Result of late incomplete embryonic division
• Only in monochorionic –monoamniotic twins
• Incidence -1 in 50,000 to 100,000 births
• Mostly female sex
• Most common –thoracopagus
• Serial Ultrasound required for fetal anatomy and
management
• Ex utero intrapartum treatment(EXIT):procedure for
delivery of co-twin when one twin is not likely to
survive
Prenatal Care
• OPD visits:
• Monthly until 24th week
• Starting 24th week: periodic cervical assessment for dilatation
• Every 2-3 weeks until 30-32 weeks
• Ultrasound every 4 weeks from 24 weeks
Objective Examination
Diagnose twin AC difference of 20mm
discordance EFW difference (based on BPD&AC or
AC&FL) >20%
Assess fetal well-being BPP
NST
AFV
Single overall AFI
Individual AFI per sac
Largest 2-diameter pocket per sac
Subjective assessment
Doppler velocimetry
-Structural anomaly scan at 20-22wk -US surveillance for TTTS and discordant
growth at 16wk and then 2weekly
-Serial fetal growth scan eg:24,28,32 then -Structural anomaly scan 20-22wk
2-4weekly (including fetal ECHO)
-BP monitoring and urinalysis at 20,24,28 -fetal growth scan 2wkly interval until
and then 2weekly delivery
-Discussion of mother’s/family needs -BP monitoring and urinalysis at 20,24,28
relating to twins then 2weekly
-34-36wk : discussion of mode of delivery Discussion
and intrapartum care - 32-34wk :discussion of mode of delivery
and intrapartum care
Timing of delivery
• Uncomplicated dichorionic – by
38 week
• Uncomplicated monochorionic –
by 34 to 37 6/7 week
• TTTS – depend on current
situation
• MCMA – 32-34 week, by
Cesarean Section
Mode of delivery
Depend on presentation of 1st twin
Both vertex / 1st twin vertex –
vaginal delivery
Indication for Cesarean Sectio
-More than 2 fetuses
-1st twin malpresentation, CPD
-Scarred uterus
-MCMA
-Conjoined twin
-IUGR in dichorionic twin
-TTTS
Mode of Delivery
Delivery of the First Twin
Breech
Cephalic
Vaginal delivery,
Cesarean followed by
delivery immediate
clamping of cord
Clinical Practice Guidelines on Multiple Pregnancy (2nd ed.). (2011).
Delivery of the Second Twin
Transverse/
Vertex or Breech Oblique Lie
Delivery by vacuum
or forceps extraction,
Delivery by cephalic
breech extraction Breech extraction
or breech extraction
Clinical Practice Guidelines on Multiple Pregnancy (2nd ed.). (2011).
Thank You