Multiple Pregnancy Flashcards
Types of Multiple Pregnancy
Dizygotic (DZ) twins
2/3 of all multiple pregnancies
Fertilisation of different oocytes by different sperm
May be different sexes, no more genetically similar to siblings of same parents
Monozygotic (MZ) twins
Result from mitotic division of a single zygote into identical twins
Depending on timing of division –> sharing of same amnion/placenta
Division before day 3 (30%) –> Dichorionic, diamniotic twins
Day 4-8 (70%) –> shared placenta but two amnions (monochorionic, diamniotic twins)
Very rare to get monochorionic monoamniotic as division would have to occur day -13
Higher rate of fetal loss before 24 weeks with MCMA
Risk Factors for Multiple Pregnancy
Assisted conception (IVF)
Genetic factors
Increasing maternal age
Increasing parity
20% of IVF pregnancies and 5-10% of clomiphene-assisted conceptions are multiple embryo
Clinical Signs of Multiple Pregnancy
Vomiting more (hyperemesis gravidarum)
Uterus larger than expected for dates
Palpable before 12 weeks
Complications of Multiple Pregnancy
All obstetric complications are exaggerated in multiple pregnancy
Maternal Complications
GDM and PET are more frequent
Anaemia is common
Fetal Complications Mortality Long-term handicap Triplets --> 18x handicap IUGR PTD Monochorionicity
All multiples
Antepartum Management of Multiple Pregnancies
Considered high risk pregnancy
Consultant-led care
Iron and folate supplement
Discuss postnatal support at home
Early USS
Chorionicity determined in 2nd trimester
DC: dividing membrane is thick with lambda sign
MC: Thin and perpendicular to placenta = T-sign
Nuchal translucency can predict risk of MC twin complications
Selective reduction Discuss if triples or higher 12 weeks Increased early miscarriage rates Decrease chance of PTD and cerebral palsy
Identify risk of PTD
TVUSS cervical length
Identification of IUGR
More common and more difficult to detect in multiple pregnancy
Serial USS at 28, 32 and 36 weeks
Management of Monochorionic Twins
US surveillance for 12 weeks
TTTS diagnosed between 16 and 22 weeks
Tricuspid regurgitation and polyhydramnios
Laser photocoagulation of placental anastomoses using US and fetoscopy
Fetal Abnormality in Twins
If one twin has congenital abnormality –> selective termination offered
DC: intracardiac injection of KCL before 14 weeks
MC: cord occluded using bipolar diathermy or ablation
If >24 weeks, termination is permitted if will save life of other twin
Intrapartum Management of Multiple Pregnancy
Delivery
C-section increasingly used
Increased risk if death and hypoxia to second twin
IOL or C-section at 37-38 weeks (DC)
34-37 weeks for MC
CTG advised –> increased risk of hypoxia to second twin
Epidural beneficial as likelihood of C-section
Delivery of first twin, cephalic presentation
Oxytocin
ECV of second twin if not longitudinal
Breech extraction if fetal distress
