Pregnancy Bliss | Reproductive Health Answers
A knot in the umbilical cord. Such a development may lead to compromised blood flow to the baby. This is likely to be manifest through passage of meconeum and abnormal CTG features. When the knot gets tighter, the features may be such that immediate delivery is required. The discovery of the knot will only happen after the delivery.
Is CTG diagnostic?
No. All it does is point towards the probability of fetal distress.
A normal CTG is always reassuring whilst a suspicious or frankly abnormal CTG is not always significant. In fact, the majority of CTGs classified as unsatisfactory or suspicious will turn out to be false scares, with babies being born perfectly healthy with no hint of distress.
Does this high rate of false scares on the part of CTG not lead to increased, unnecessary intervention?
Indeed it does. Nobody doubts that the CTG has single-handedly increased the rate of caesarean section quite substantially. However, one needs to remember that this technology has also saved the lives of millions of babies. The increased rate of intervention is probably a small price to pay for the greater good.
Is there any way of verifying the findings of a suspicious CTG?
Yes. The standard next step is to obtain a small sample of blood from the baby to have it analyzed for oxygen saturation. This is much more definitive. The blood is obtained by scratching the leading part of the baby (usually the scalp). A drop of blood is collected in a fine capillary tube and put in a machine which gives results in less than one minute.
In the majority of cases, the results are reassuring but in some, the results will confirm the fetal distress suspected earlier, therefore calling for expedited or immediate delivery.
Will every abnormal result following a fetal blood sample lead to caesarean section or instrumental delivery?
Not really. The action taken will depend on the degree of abnormality. If the reflected distress is only mild, action such as changing the position of the mother, stopping or reducing the rate of oxytocin infusion and giving oxygen to the mother may be all that is required. With that, improvement on the CTG may soon be apparent and, if need be, a repeat sample is taken after some time to reassure everybody concerned.
If there is significant distress, then delivery by the quickest means possible will be carried out. This may be a caesarean section but it may also be by forceps or ventouse vaginal delivery, if this is feasible.
What is the significance of the baby opening his or her bowels (meconeum) during labour?
When the fetus opens its bowels, passing the green stuff called meconeum, there is usually some concern as to whether it might be significant.
Passing meconeum before labour is uncommon but becomes more common, the further the
pregnancy advances beyond 40 weeks. In fact, for those pregnancies reaching 42 weeks,
roughly half of the babies will be found to have already passed meconeum when the
‘water
s’ (membranes) are broken.This old meconeum tends to have a yellow tinge and
any midwife will distinguish old from fresh meconeum. It is the latter that is usually
(but not always) significant.
So, what happens when the fetus passes meconeum during labour?
This may indicate some degree of fetal distress. It is therefore regarded as a wise measure to do continuous CTG monitoring for a baby that has passed meconeum, particularly so if the meconeum is thick and fresh.
If the CTG is normal, the doctor may opt to do nothing other than continued monitoring and observation. If the CTG is equivocal, fetal blood sampling for analysis may be carried out.