Antenatal Care 3 Flashcards
What are the different types of identical twins?
DCDA - dichorionic, diamniotic, monozygotic
MCDA - monochorionic, monoamniotic
MCMA (rare)
conjoined twins (v rare)
see notebook for details
What are non identical twins?
dichorionic
diamniotic
dizygotic
What are the causes of twins?
assisted conception
genetic factors
increasing maternal age
increasing parity
What are the risks associated with multiple pregnancy?
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%
How are twin pregnancies managed?
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
When is C-section indicated in twins?
if first fetus is breech
with high order multiple pregnancies
if there have been antepartum complications
all monochorionic twins (some hospitals)
What is the method of labour for twins?
- 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)
What is extended breech?
“frank breech”
both legs extended at the knee
What is flexed breech?
both legs flexed at the knee
What is footling breech?
“knee of footling breech”
one or both feet present below the buttocks
When is breech most common?
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
What are the risks of breech presentation?
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
When is external cephalic version used?
from 37 weeks
success rate about 50%
How is external cephalic version performed?
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
What measures are taken to protect the mum and baby during ECV?
CTG performed straight after and anti-D given to rhesus negative women
When is there lower chance of success for ECV?
nulliparous women causasians engaged breech non palpable head high uterine tone obese women liquor volume reduced
When is ECV contraindicated?
- if fetus is compromised
- if vaginal delivery is contraindicated
membranes ruptured - recent antepartum haemorrhage
- if there is placenta praevia
- abnormal CTG
- previous uterine scar
Why are breech babies normally delivered with a C-section?
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)
What are the causes of a breech presentation?
gestational age placental location uterine abnormalities multiple pregnancy neurological impairment of the fetal limbs (unable to kick itself round to cephalic presentation)
What are the potential complications of ECV?
cord entrapment
placental abruption
rupture of the membranes
persistent fetal bradycardia
When is vaginal delivery risky?
with a fetus over 4kg
with evidence of fetal compromise
with an extended head or footlings legs
When is pregnancy considered prolonged?
if over 42 weeks gestation
risks of perinatal mortality and morbidity starts increasing 41-42 weeks
What are the risks of prolonged pregnancy?
rate of still birth increased neonatal illness encephalopathy meconium passage clinical diagnosis of fetal distress greater in women of south Asian origin
How is prolonged pregnancy managed?
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
What are the principles of fetal monitoring?
- Identify ‘high-risk’ pregnancy using history/events during pregnancy or using specific
investigations - Monitor fetus for growth + well-being (methods vary according to pregnancy risk + events during pregnancy)
- Intervene at appropriate time balancing risks of in utero compromise against those of intervention + prematurity
