Multiple gestation Flashcards
what is multiple gestation
presence of more than one fetus in the uterus at the same time
how is multiple gestation classified (4)
- Number of fetuses (twins, triplets, quadriplets)
- Number of fertilized eggs: Zygosity
- Number of placentae: Chorionicity
- Number of amniotic cavities: Amnionicity
what are the 2 types of twin pregnancy
- Dizygotic twins (70 – 80%), resulting from fertilization of two ova leading to fraternal twin.
- Monozyogotic twins (20 – 30%), resulting from fertilization of one ovum followed by splitting of developing zygote leading to identical twin.
what are the types of monozygotic (3)
- Monochorionic diamniotic 70-75% (MCDA)
- Dichorionic diamniotic 25-30% (DCDA)
- Monochorionic monoamniotic 1-2% (MCMA)
all monochorionic pregnancies are what
monozygotic
not all dichorionic pregnancies are what
dizygotic
In M-DCDA when does the egg split
day 1-3
In M-MCDA when does the egg split
day 4-8
In M-MCMA when does the egg split
day 9-12
for conjoint twins when does the egg split
day 13-15
what are risk factors for multiple gestation (5)
- Assisted reproductive techniques
- In vitro fertilisation
- Use of fertility medications (clomiphene) - Maternal family history
- Race
- High in African women - High parity (5 gravida onwards)
- Increased maternal age (30 – 35 yrs)
what in the history can help you diagnose multiple gestation (6)
- Hx of ovulation inducing drugs
- Maternal family hx of twins
- Increase nausea and vomiting in early months
- Palpitations or SOB (anemia)
- Leg swelling and/or hemorrhoids
- Unusual rate of abdominal enlargement
what things on your clinical exam can help you diagnose multiple gestation (5)
- Signs of anemia
- Barrel shape abdomen
- SF size/GA discrepancy
- Palpation of too many fetal parts
- Two distinct fetal heart sounds at separate spots with a silent area in between
how can you tell multiple gestation on sonography (5)
- different fetuses genders
- number of placentae
- placenta location
- T sign
- lambda sign/ twin peak signwh
when is it most reliable to do a scan for twin gestation to see the gestational sacs
6-10 weeks
when is the lambda/twin peak sign best seen
11-14 weeks
why is it hard to see dividing membranes as gestation increases
the dividing membranes get thinner
in twin pregnancy what is a major determinant of pregnancy outcome
chorionicity
T sign (monochorionic shared placenta) is seen in what type of twin
MCDA
what type of twin do you see the lambda sign (fused dichorionic placenta)
DCDA
what are ddx for multiple pregnancy (5)
- inaccurate menstrual hx
- macrosomic baby
- polyhydraminos
- molar pregnancy
- fibroid in pregnancy
what are possible maternal complications of multiple gestation (7)
- Hyperemesis
- Abortion
- Anaemia
- Abruption
- Hypertensive disorders of pregnancy
- Thromboembiolism
- PPH
what are the fetal complications of D-DCDA and M-DCDA (6)
- Preterm birth
- Growth restriction
- Mal presentation
- Vanishing twin
- IUFD of one twin
- Perinatal mortality
what are the fetal complications of M-MCDA (8)
- Preterm birth
- Growth restriction
- Mal presentation
- Vanishing twin
- IUFD of one twin
- Perinatal mortality
- Twin -twin transfusion syndrome
- Fetal anomalies (all organ systems)
what are fetal complications of M-MCMA (10)
- Preterm birth
- Growth restriction
- Mal presentation
- Vanishing twin
- IUFD of one twin
- Perinatal mortality
- Twin -twin transfusion syndrome
- Fetal anomalies (all organ systems)
- Cord entrapment
- Conjoining
fetal growth restriction in multiple gestation can be what (2)
- discordant
- concordant
what is the risk of IUGR in DCDA
25%
what is the risk of IUGR in MC
50%
what things should you think of in the management of FGR (3)
- Balance the risk of iatrogenic preterm delivery for a single growth restricted fetus.
- Generally, avoid delivery before 28-30weeks
- For MC twins, IUFD may lead to death or severe handicap of the co-twin
- Prefer delivery before IUFD of growth restricted twin
what causes twin to twin transfusion syndrome (2)
- Due to abnormal placental vascular anastomoses
- Unbalanced AV connections in one direction result in TTTS
who does TTTS occur in
Unique to MC twins
- 10% MCDA
- 5% MCMA
in TTTS the donor twin has predominantly what
arteries
in TTTS the recipient twin has predominantly what
veins
what risks can occur to the donor twin (5)
- anemic
- growth restricted
- hypovolemic
- oligohydraminos
- renal failure
what risks can happen to the recipient twin (4)
- polycythemic
- polyhydraminos
- heart strain (congestive HF)
- high blood pressure
what is the criteria for dx TTTS (5)
- Single placenta mass
- Same gender
- Oligohydramnios in one twin and polyhydramnios in the other
- Discordant bladder appearences
- Haemodynamic and cardiac compromise
what is the quintero severity grading for TTTS (5)
Stage 1
- Oligohydramnios and polyhydramnios sequence
- Bladder of donor twin visible
- Dopplers normal in both twins
Stage 2
- Oligohydramnios and polyhydramnios sequence
- Bladder of donor twin not visible
- Dopplers normal in both twins
Stage 3
- Oligohydramnios and polyhydramnios sequence
- Bladder of donor twin not visible
- Abnormal dopplers
AEDF/REDF in UAD
Stage 4
- Signs of hydrops in one or both fetuses
Stage 5
- Death of one or both fetuses
how can you manage TTTS (6)
- Expectant
- Amnioreduction
- Septostomy
- Selective feticide
- Laser ablation of anastomoses
- Definitive Rx for TTTS stage 2 and above - Preterm delivery (above 28weeks
what is the antenatal care for multiple gestation (5)
- order uss
- for dating, chorionicity and amnionicity as early as possible .
- for anatomy and/or anomalies at 18-20 wks gestation
- every 2-3 weeks after 28 wks gestation for growth, Doppler if discordant growth
- For growth discordance > 20%, refer to Central Hospital. - frequency of ANC visits
- Same as for singleton in first trimester
- More frequent after 20weeks
- DC twins
- 4 weekly until 28 weeks
- 2 weekly 28-36weeks
- Weekly 36-38 weeks - MC twins
- Refer to Central Hospital
- Steroids at 28weeks
- Inpatient care with daily CTG from 28weeks till delivery
- Plan delivery at 32-34 weeks - Nutrition and medications
- extra daily caloric needs of 600 kcal
- Encourage normal balanced diet
- Ensure iron supplementation
- Prophylactic dexamethasone between 28 and 34 weeks - One antenatal fetal death
- Admit to inpatient ward for expectant management
- Monitor for maternal complications of IUFD including infection or DIC
- Monitor fetal well-being of surviving twin
when is c/s indicated in multiple gestation (5)
- If breech or transverse
- Cord prolapse of the leading twin
- Previous caesarean section
- Triplets (or higher order pregnancy)
- Twin with complications: IUGR, conjoint twins
- MC twins
