Fetal Growth and Abnormal Lie

Question 1

What are causes of perinatal mortality?

Answer 1

Preterm delivery
IUGR
Congenital abnormalities
Intra-partum (hypoxia)
Placental abruption

Question 2

What is cerebral palsy associated with?

Answer 2

Prematurity
IUGR
Infection
Pre-eclampsia
Congenital abnormalities
Intra-partum fetal distress

Question 3

What is the definition of small for dates?

Answer 3

Weight of fetus is less than tenth centile

Question 4

What is the definition of intrauterine growth restriction?

Answer 4

Failure to meet growth potential

Question 5

What is the definition of fetal distress?

Answer 5

Acute situation which may result in fetal damage or death

Mainly used in labour

Question 6

What is the definition of fetal compromise?

Answer 6

Chronic situation when conditions for normal growth and neurological development are not optimal
Poor nutrient transfer through placenta
IUGR

Question 7

What are pre-pregnancy risk factors?

Answer 7

Mother’s age
Previous medical and obstetric history

Not a specific or sensitive screening test

Question 8

What are the benefits and limitations of serial growth scans?

Answer 8

Safe and shows consistent growth in high-risk and multiple pregnancies

Inaccurate measurements common, misleading and potentially harmful

Question 9

What are the benefits and limitations of Doppler umbilical artery waveforms

Answer 9

High resistance circulation (reduced flow in fetal diastole compared to systole) suggests placental dysfunction

Identifies which small fetuses are IUGR

Less effective identifying normal weight, compromised fetus

Question 10

What are the benefits and limitations of Doppler waveforms of the fetal circulation?

Answer 10

Esp middle cerebral arteries (reduced resistance) and ductus venosus

Used in high risk pregnancy and with suspected anaemia

Question 11

What are causes of IUGR?

Answer 11

Pre-existing maternal disease
Maternal pregnancy complications
Multiple pregnancy
Smoking
Drug usage
Infection
Extreme malnutrition

Question 12

What is a prolonged pregnancy?

Answer 12

More than 42 weeks are completed

More common in nulliparous women

Question 13

What are risks of a prolonged pregnancy?

Answer 13

Stillbirth
Encephalopathy
Meconium passage

Question 14

How is prolonged pregnancy managed?

Answer 14

Induce labour between 41 to 42 weeks

Sweep cervix

Question 15

What are causes of an abnormal lie?

Answer 15

Polyhydramnios
High parity
Fetal/uterine abnormalities
Twin pregnancies

Question 16

What are complications of an unstable lie?

Answer 16

Umbilical cord may prolapse when membranes rupture

May cause uterine rupture

Question 17

How are unstable or transverse lie managed?

Answer 17

After 37 weeks, admit to hospital in case membranes rupture

USS to exclude known causes - polyhydramnios, placenta praevia

ECV unjustified as it turns back

Question 18

What are types of breech presentation?

Answer 18

Extended - 70% both legs extended at knee

Flexed breech - 15% both legs flexed at knee

Footling breech - 15% one or both feet are below the buttocks

Question 19

What are complications of a breech presentation?

Answer 19

Cord prolapse

Head may get trapped

Question 20

What is ECV?

Answer 20

Done from 37 weeks
Success rate of 50%
3% will turn back

Done without anaesthetic but tocolytic given to relax uterus

CTG done afterwards with anti-D if needed

Question 21

What are contraindications to ECV?

Answer 21

Compromised fetus
If vaginal delivery would be contraindicated
Twins
ROM
Recent APH

Question 22

How common are twins and triplets?

Answer 22

1 in 80 are twins

1 in 1000 are triplets

Question 23

What are dizygotic twins?

Answer 23

Fertilisation of different ooxytes by different sperm

May be different sex and as genetically similar as siblings

Question 24

What are monozygotic twins?

Answer 24

Mitotic division of single zygote into identical twins

Whether they share the same amnion and placenta depends on when in division they split

Question 25

What are the different types of monozygotic twins?

Answer 25

Division before day 3 (30%) - separate placentas and amnions (dichorionic diamniotic DCDA) Division between days 4 and 8 (70%) - shared placenta but separate amnions (monochorionic diamnioric MCDA) Later division very rare and causes twins with shared placenta and amnion (monochorionic monoamniotic MCMA)

Question 26

How are multiple pregnancies diagnosed?

Answer 26

Vomiting | Larger uterus than expected for dates

Question 27

What are maternal complications of multiple pregnancy?

Answer 27

Gestational diabetes Pre-eclampsia Anaemia - greater increase in blood volume

Question 28

What are fetal complications of multiple pregnancies?

Answer 28

``` Greater mortality and long term handicap Preterm delivery IUGR TTTS Miscarriage - one twin can vanish with a first trimester death ```

Question 29

What are complications of monochorionicity?

Answer 29

Twin-twin transfusion syndrome IUGR Co-twin death - if one twin dies, the drop in BP allows acute transfusion of blood from the alive twin -> hypovolaemia -> death or neuro damage Monoamniotic twins - cords are tangled -> death

Question 30

What is twin-twin transfusion syndrome?

Answer 30

Only occurs in MCDA twins Unequal blood distribution through anastamoses of shared placenta Donor twin is volume depleted and becomes anaemic, IUGR and oligohydramnios Recipient twin is volume overloaded and develops polycythaemia, cardiac failure and polyhydramnios

Question 31

What are intrapartum complications of twins?

Answer 31

Malpresention of first twin (20%) - indication for c-section Fetal distress - second twin may die of hypoxia, cord prolapse, tetanic uterine contraction or placental abruption PPH

Question 32

How are multiple pregnancies managed antepartum?

Answer 32

Consultant led care Iron and folic acid supplements Normal screen for abnormalities At 12 weeks, selective reduction offered to triplets TV ultrasound to identify short cervix = risk of preterm Serial USS at 28, 32 and 36 weeks to identify IUGR

Question 33

What extra antepartum management is done for monochorionic twins?

Answer 33

USS from 12 weeks - watch out for TTTS (tricuspid regurg and polyhydramnios) Laser photocoagulation of placental anastomoses in fetal medicine centre

Question 34

How are fetal abnormalities managed in twins?

Answer 34

Before 14 weeks - KCl, or can be done after 32 weeks so if delivery happens, remaining twin will survive In MCDA twins, cord must be occluded using bipolar diathermy as circulation is shared

Question 35

How are twins delivered?

Answer 35

C-section - esp if first fetus is breech or transverse lie 34-38 weeks CTG Epidural helpful Contractions diminish after first twin, usually return quickly - check lie of baby and do ECV if needed Normally deliver 2nd twin within 20 mins Can have vaginal delivery if first twin is cephalic