Problems of Multiple Pregnancy
- Two of more pregnancies
- Pregnancies with 3 or more fetuses are referred to as ‘higher multiples’
- Twins account of 1.5% of all pregnancies
Risk factors
- Assisted reproduction
- Increasing maternal age
- High parity
- Black race
- Maternal family hstory
Classification
- Based on;
- Number of fetuses – twins, triplets, quadruplets etc
- Number of fertilised eggs – zygosity
- Number of placentas – chorionicity
- Number of amniotic cavities – amnionicity
- Number of fetuses – twins, triplets, quadruplets etc
Complications
- Miscarriage and severe preterm delivery – average gestation is 37 weeks. Increased risk for monochorionic twins
- Perinatal mortality – six times higher for twins compared with singletons
- Death of one fetus in a twin pregnancy – may be associated with a poorer outcome of the remaining twin
- IUGR
- Twin-twin transfusion syndrome
- Can occur in monochorionic twin pregnancies when then in an imbalance in the flow of blood across the placental vascular anastomoses
- Can be mild, moderate or severe depending on the degree of imbalance
- Donor fetus suffers from hypovolaemia and hypoxia and may become growth restricted and oligouric
- Recipient twin may develop polycythaemia, cardiac failure and polyhydramnios
- Treatment is via therapeutic amniocentesis or laser coagulation to disrupt flow between anatomising vessels
- Can occur in monochorionic twin pregnancies when then in an imbalance in the flow of blood across the placental vascular anastomoses
- Monochorionic twins are at increased risk of cord accidents predominately entanglement
- Increased maternal complications such as anaemia, diabetes,antepartum haemorrhage, thrombolembolism and pre-eclampsia
Antenatal Management
- Screening for hypertension and gestational diabetes
- Supplementation of iron and folic acid
- Minor symptoms of pregnancy more common and severe
- Generally management as with singleton
- Determination of chorionicity via ultrasound in the last first trimester
- Screening for fetal abnormalities
- Monitoring fetal growth and well-being via ultrasound
- Threatened pre-term labour
Intrapartum Management
- Twin CTG machine should be used for fetal monitoring
- Oxytocin may be required for augmentation of delivery of the second twin
- Caesarean section may be performed if the first twin is breech or transverse lie or if there are triplets
- Common practice to induce at 38 weeks
- Delivery of second twin is normally easier than the first, taking about 20 mins
- Prophylactic oxytocin may be required to prevent postpartum haemorrhage (PPH is more common due to uterine over distension an a larger placental site)
- Locked twins – a rare complication whereby the first twin is breech and the second is cephalic. Caesarean section must be performed
Fetal Reduction
- Ultrasound guided puncture of the fetal heart and injection of potassium chloride
- Usually delayed until 12 weeks to allow for spontaneous reduction to occur and the diagnosis of fetal abnormalities and chromosomal defects
- Following reduction there is a gradual resorption of the dead fetuses and their placentas