Foetal monitoring

This about making sure that the foetus is OK. This basically consists of cardiotocography (CTG) and if foetal distress is suspected, foetal blood sampling. It is also important to look after babies after birth. Mothers tend to get annoyed if you let them die. So some clever chap came up with something called an APGAR score which is detailed at the bottom of this page.

Foetal distress is a poorly defined term but essentially means signs that the foetus's life is compromised unless something is done soon.

Cardiotocography

All mothers who have babies in hospital have periodic foetal heart rate monitoring. This is using a Doppler ultrasound. Continuous fetal heart rate monitoring is NOT indicated in normal labour with no associated risk factors and is only used when there is a reason to. It is only an indirect guide to the health of the foetus but since it is one of the few ways of being able to tell, many treat it as a direct monitor.

Indications

Having said this, there are a variety of indications for CTG and they can be split into three different sections: risks in the mother, risk to the foetus and risks during labour.

• Mother
  • Medical - pre-eclampsia; diabetes; antepartum haemorrhage; any significant maternal disease
  • Iatrogenic - induced labour; previous Caesarean section
  • Other - post-term pregnancy; prelabour rupture of the membranes
• Foetus - IUGR; prematurity; multiple pregnancy; breech presentation; meconium
• Labour - augmentation; epidural; vaginal bleeding; fever; meconium

Classification of findings

Obviously, management is affected by CTG findings. The findings are classified into reassuring, non-reassuring and abnormal which in turn are used to describe the CTG as normal, suspicious or pathological The following table classifies CTG findings:

	Baseline Heart Rate	Heart Rate Variability	Decelerations	Accelerations
Reassuring	110-160	>/=5	Absent	Present
Non-reassuring	100-109/161-180	<5 for 40-90 mins	Early/variable/single prolonged <3mins	Absence in presence of other findings
Abnormal	<100/>180/sinusoid (S-shaped) >10 minutes	<5 for >90mins	Late/atypical variable/single prolonged >3mins	As above

Essentially, a normal CTG means that all four categories are normal. Suspicious CTGs have 1 non-reassuring feature and pathological is anything else i.e. >1 non-reassuring/1 or >1 abnormal.

Suspicious CTGs have four main causes: poor quality, uterine hypercontractility, infection and other maternal adverse factors. These factors have to be considered before deciding that the foetus is distressed. A pathological CTG requires the following:

Foetal Scalp Blood Sampling

Essentially, blood is taken from the presenting head of the foetus. I can't put a copyrighted image on the website but I can link to it and this one gives you and idea of what's going on. The tube is called an amnioscope which gives access to the foetal scalp. The value that you get is a pH measurement which is normally >7.25.

• pH <7.20 - deliver
• pH 7.20-7.25 - repeat in 30 minutes. If still abnormal, deliver.

APGAR Score

The APGAR score is a set of criteria to measure a newborn's wellbeing and was developed over 50 years ago. It is done at 1 minute and 5 minutes following birth.

	Score of 0	Score of 1	Score of 2	Component of Acronym
Skin color	blue all over	blue at extremities body pink	no cyanosis body and extremities pink	Appearance
Heart rate	absent	<100	>100	Pulse
Reflex irritability	no response to stimulation	grimace/feeble cry when stimulated	sneeze/cough/pulls away when stimulated	Grimace
Muscle tone	none	some flexion	active movement	Activity
Breathing	absent	weak or irregular	strong	Respiration

The score is (and you'll have figured this out already if you're sharp on your arithmetic) out of 10.