Antenatal Care 3

Question 1

What are the different types of identical twins?

Answer 1

DCDA - dichorionic, diamniotic, monozygotic
MCDA - monochorionic, monoamniotic
MCMA (rare)
conjoined twins (v rare)

see notebook for details

Question 2

What are non identical twins?

Answer 2

dichorionic
diamniotic
dizygotic

Question 3

What are the causes of twins?

Answer 3

assisted conception
genetic factors
increasing maternal age
increasing parity

Question 4

What are the risks associated with multiple pregnancy?

Answer 4

anaemia 
pre-eclampsia
eclampsia 
antepartum haemorrhage 
postpartum haemorrhage 
fetal growth restriction 
preterm delivery 
caesarean section 
miscarriage 
fetal distress in labour 
congential abnormalities in monochorionic
malpresentation in 20%

Question 5

How are twin pregnancies managed?

Answer 5

early diagnosis 
identification of chorionicity 
consultant care 
iron and folic acid supplements 
anomaly scan 
increased surveillance for pre eclampsia, diabetes and anaemia 
serial US at 28, 32, 36 weeks

MC twins - US fortnightly from 12 weeks for TTTS

Question 6

When is C-section indicated in twins?

Answer 6

if first fetus is breech
with high order multiple pregnancies
if there have been antepartum complications
all monochorionic twins (some hospitals)

Question 7

What is the method of labour for twins?

Answer 7

• Induction/C section at 37/38 weeks (DC) or 34/37 weeks (MC)
• CTG advised as risk of intrapartum hypoxia
  epidural advised if difficult second twin
• contractions diminish after first twin but resume
  oxytocin given if don’t resume
• Lie and ECV if not longitudinal
• Delivery of 2nd twin within 20mins
• If malpresentation = C section
• If fetal distress/cord prolapse, then ventouse of breech extraction (under
  anaesthesia)

Question 8

What is extended breech?

“frank breech”

Answer 8

both legs extended at the knee

Question 9

What is flexed breech?

Answer 9

both legs flexed at the knee

Question 10

What is footling breech?

“knee of footling breech”

Answer 10

one or both feet present below the buttocks

Question 11

When is breech most common?

Answer 11

More common in conditions that prevent movement e.g. fetal/uterine abnormalities/twin

More common in conditions that prevent engagement of head e.g. placenta praevia/pelvic
tumours/pelvic deformities

Question 12

What are the risks of breech presentation?

Answer 12

Perinatal + long-term morbidity + mortality
Fetal abnormalities more common
Higher rates of long-term neurological handicap
Labour has potential hazards – increased rate of cord prolapse, head may become trapped

Question 13

When is external cephalic version used?

Answer 13

from 37 weeks

success rate about 50%

Question 14

How is external cephalic version performed?

Answer 14

performed without anaesthetic
easier and more successful if administer uterine relaxant
if uterine tone is too high or initial attempt failed
both hands on the abdomen, breech disengaged from pelvis, pushed up and to the side, fetus rotated in form of forward somersault

Question 15

What measures are taken to protect the mum and baby during ECV?

Answer 15

CTG performed straight after and anti-D given to rhesus negative women

Question 16

When is there lower chance of success for ECV?

Answer 16

nulliparous women 
causasians 
engaged breech 
non palpable head 
high uterine tone 
obese women 
liquor volume reduced

Question 17

When is ECV contraindicated?

Answer 17

• if fetus is compromised
• if vaginal delivery is contraindicated
  membranes ruptured
• recent antepartum haemorrhage
• if there is placenta praevia
• abnormal CTG
• previous uterine scar

Question 18

Why are breech babies normally delivered with a C-section?

Answer 18

reduced neonatal mortality and short term morbidity
does not affect long term outcomes
more than 1/3 of vaginal breech birth attempts result in emergency C-section (more dangerous than elective)

Question 19

What are the causes of a breech presentation?

Answer 19

gestational age 
placental location 
uterine abnormalities 
multiple pregnancy 
neurological impairment of the fetal limbs (unable to kick itself round to cephalic presentation)

Question 20

What are the potential complications of ECV?

Answer 20

cord entrapment
placental abruption
rupture of the membranes
persistent fetal bradycardia

Question 21

When is vaginal delivery risky?

Answer 21

with a fetus over 4kg
with evidence of fetal compromise
with an extended head or footlings legs

Question 22

When is pregnancy considered prolonged?

Answer 22

if over 42 weeks gestation

risks of perinatal mortality and morbidity starts increasing 41-42 weeks

Question 23

What are the risks of prolonged pregnancy?

Answer 23

rate of still birth increased 
neonatal illness 
encephalopathy 
meconium passage 
clinical diagnosis of fetal distress
greater in women of south Asian origin

Question 24

How is prolonged pregnancy managed?

Answer 24

check gestation correctly
from 41 weeks examine patient vaginally and induce
if no induction - sweep cervix and arrange daily CTG
if abnormal CTG deliver with C-section

Question 25

What are the principles of fetal monitoring?

Answer 25

1. Identify ‘high-risk’ pregnancy using history/events during pregnancy or using specific
   investigations
2. Monitor fetus for growth + well-being (methods vary according to pregnancy risk + events during pregnancy)
3. Intervene at appropriate time balancing risks of in utero compromise against those of intervention + prematurity