1. Max Brinsmead PhD FRANZCOG July 2010
THE FETUS AT RISK
Max Brinsmead PhD FRANZCOG
July 2010

2. The fetus is unique because...
He or she cannot signal his or health by way of any history
And we can only examine through his or her mother
We can only...
Document size and growth
Evaluate his or her movements
Listen to his or her heart
Evaluate the fluid around him or her
Assess his or her reaction to stimuli

3. Too big Too small Born too early In utero for too long
This talk will concentrate on fetal problems unrelated to any obvious maternal disease
Too big
Too small
Born too early
In utero for too long
“Not lying straight”
Poor relatives

4. When the uterus is LFD or SFD you first need to know…
What is normal
SFH = Weeks of gestation is valid only between 20 and 32 weeks
Thereafter the mean runs off to 37 cm at 40 weeks
This should be validated in each population
And the 95% confidence limits are not less than +/- 3 cm

6. When the uterus is LFD or SFD you also need to know DATES accurately…
Menstrual history is unreliable when…
The patient is uncertain
She has a good reason to tell lies
Cycles are irregular
Ovulation was delayed >14 days by
Miscarriage
Breast feeding
Hormonal contraception
Quickening is unreliable when…
The placenta is on the anterior uterine wall
The patient is obese
There is something wrong with the fetus or fluid
Ultrasound is unreliable when…
It is done by a non expert or with poor equipment
It is done late in pregnancy
There is something wrong with the fetus e.g. microcephaly

7. If the uterus is LFD think of…
Wrong dates
Hydatidiform mole
Multiple pregnancy
Many small parts
Three poles
Lots of fluid and difficult to feel the baby
Polyhydramnios
Uterus lifted up by
Previous CS
Tumours e.g. Fibroids, Ovarian cyst
A Large Baby

8. If the uterus is LFD then…
Ultrasound is useful because it readily diagnoses:
Hydatidiform mole
Multiple pregnancy
Polyhydramnios
Fibroids and tumours
But ultrasound is poor at:
Diagnosing fetal abnormalities
Estimating fetal weight
If there is a large baby:
Check for maternal diabetes
But macrosomia more commonly due to maternal obesity
+/- Excessive weight gain in pregnancy

9. If there is fetal macrosomia then…
There is a risk of intrauterine death
If the mother is diabetic
And it is poorly controlled
There may be birth difficulties
Cephalopelvic disproportion
Shoulder dystocia
Maternal birth injury and PPH
Vaginal breech birth may not be wise
There may be neonatal problems
From hypoglycaemia
From birth injuries

10. Management of suspected fetal macrosomia…
Exclude maternal diabetes or…
Control maternal blood sugars before and during birth if diabetic
Refer to a place where expert assistance is available
Consider induction of labour but only when it is safe to do so
Watch progress in labour and prepare for complications
Have someone expert stand by for the delivery

11. If the uterus is SFD think of…
Wrong dates
Oligohydramnios
Premature rupture of membranes
Abnormality of the fetal renal tract
Intrauterine growth retardation (IUGR)
Intra uterine growth retardation
There are two major categories
Symmetrical = head, trunk and body reduced proportionaely
Asymmetrical = head-sparing growth restriction

12. Causes of Symmetrical IUGR
Constitutional smallness
Consider maternal size
Ethnic origin
Paternal influence less important
Fetal Infections
TORCH = Toxoplasmosis, Other, Rubella, Cytomegalovirus and Herpes
Remember Syphilis, HIV and Malaria
Fetal Abnormalities
Especially chromosomal abnormalities such as Trisomy 21, 13&16

13. Causes of Asymmetrical IUGR
Anything that reduces Maternal-Uterine-Placental to Fetus transfer of oxygen and nutrients
Maternal smoking and malnutrition
Severe maternal anaemia
Chronic maternal disease
Maternal hypertension especially pre eclampsia
Uterine malformations
Some placental diseases
Maternal thrombophilias congenital or acquired
Recurrent antepartum haemorrhage
An idiopathic group

14. A SFD uterus is more serious when…
The mother was underweight to begin with
She has not gained weight appropriately
There is a past history of IUGR or pregnancy loss
A condition known to be associated with IUGR is also diagnosed
Pre eclampsia
Recurrent APH
Chronic maternal disease or anaemia

15. Management of the SFD baby
Accurate diagnosis
Is the baby salvageable?
Mother at risk?
Steps that improve M-U-P-Fetal transfer of oxygen and nutrients
Stop maternal smoking
Bed rest
Correct anaemia
Improve nutrition
Monitor fetal growth and well being
There is little point in ultrasound at less than 2w intervals
Timely delivery
Must weigh up the risks of induced delivery against the risk of remaining in utero

16. Born too Early
Premature delivery a major cause of perinatal loss
Delivery before 30w almost 100% fatal without neonatal intensive care
Also known as neonatal expensive care
You cannot diagnose threatened preterm delivery unless you know the dates
And diagnosis of labour is difficult
It is a diagnosis in retrospect
To diagnose labour you need to document uterine contractions and find cervical change

17. Causes of Premature Labour
Overdistension of the uterus
Polyhydramnios
Twins
Premature rupture of membranes
Genital tract infection
Antepartum haemorrhage
Cervical incompetence
Maternal diseases like preeclampsia
An idiopathic group
Studies of the mechanism of birth in humans suggest that the fetus and or its placenta determine when labour starts

18. Management of Premature Labour
Is the mother OK?
Is the baby better off in or out?
There is a role for tocolysis
Drugs that relax the uterus
Although studies do not confirm significant prolongation of pregnancy
Administration of high dose corticosteroids to the mother significantly improves neonatal survival
Dexamethasone 6mg Q12H for 2 days
And the few hours bought by tocolysis may allow in utero transfer to a place of optimal birth

19. In Utero too Long
Epidemiological studies show that perinatal mortality begins to rise post term
Beyond 42w completed gestation from LMP
May be earlier in some ethnic/racial groups
But the vast majority of babies (>99%) are still okay
So you need to induce labour in some 450 women to save one baby
We need to identify the fetus at risk. He or she will…
Be not growing well
Not moving well
Surrounded by little fluid (oligohydramnios)
In utero in an unhealthy mother
Weigh up the risks of induction of labour
And always check the dates

20. Babies that do not “Lie Straight”
Breech presentation occurs in 4% women at term
Perinatal mortality is increased 3 – 4 fold
The largest part of the baby is coming last
Risk of hypoxia and trauma is increased
But risk of death or damage from congenital causes are also increased
And 96% of babies born by the breech will be ok
It is desirable to identify breech babies after 36w
Check the dates!
External cephalic version (ECV) shown in RCT’s to reduce the need for Caesarean birth
Consider the need for Caesarean birth

21. Babies that do not “Lie Straight” (2)
Transverse lie occurs in 1-2% women at term
First ask why is the baby lying transverse or oblique
Wrong dates
Placenta previa
Twins or polyhydramnios
Tumour occupying the pelvis
There is a risk of cord prolapse and labour obstruction
So admit to hospital at 37 – 38w and observe
Most will be okay when labour starts
Consider a stabilising induction of labour

22. Babies with Poor Relatives
If there is a history of previous stillbirth or neonatal death
Is there a recurrent cause?
Deal with maternal anxiety
The precious baby
The Previously Infertile Mother
The Poor Obstetric Performer
Previous pre term delivery
The recurrence risk is 30% after one
And 60% after two
Previous low birth weight babies
Risk of meconium and SGA again
The Fetus who is one of Twins (or more)