Multiple Pregnancy Flashcards
Predisposing factors for multiple pregnanc
Increasing maternal age + parity
Personal / fhx
Assisted conception
Risks of multiple pregnancy
Mat: hyperemesis, miscarriage, htn, pre-eclampsia, gestDM, polyhydramnios, anaemia, APH, PPH, placenta praevia
Fetal: incr perinatal mortality, congenital abnormality, preterm labour, placental insufficiency, IUGR, malpresentation, TTTS, bp vanishing twin syndrome
Twin-twin transfusion
Anastomosis of vessels in monochorionic twin pregnancy -> unequal haemodynamics
Donor: anaemic, hypovolaemic, oligohydramniotic, growth restricted
Recipient: policythaemia, hypervolaemia, polyuria, polyhydramnios
Occurs in up to 35% monochorionic twins
Accounts for 15% perinatal mortality
Managing TTTS
Frequent Us monitoring
Therapeutic amniocentesis to reduce amniotic fluid pressure
Laser ablation of placental vessels (risk demise/congenital abn)
Vanishing twin syndrome
Fetus in multiple gestation pregnancy dies in utero
Subsequently resorted by mother, partially or completely
Delivery
1st twin cephalic: trial of labour
1st twin breech/transverse lie: Caesarean section
Risks: cord prolapse, entanglement/knotting, locking, PPH, thrombosis, fetal distress, inefficient uterine activity after 1st twin delivered
Monozygotic twins
Due to mitotic division of single fertilised ovum
40%
Monozygotic, monochorionic, monoamniotic twins
Mitotic division after 8 days
3%
Prior to formation of primitive streak= single amniotic cavity and chorion
1%
After formation of primitive streak= conjoined twins
Monozygotic, monochorionic, diamniotic twins
Mitotic division between 4 -7 days 66% During formation of inner cell mass Single placenta Own amniotic membrane
Monozygotic, dichorionic, diamniotic twins
Mitotic divison
Dizygotic twins
Fertilisation of two different ova by two different sperm
60%
Not identical
