Patients often ask me : “Will I have normal delivery?”
I had thought, and Suzie had thought, she would have a normal delivery. It was her third pregnancy. She had had vaginal deliveries with the first two. Her second labour was only 2.5 hrs duration. This pregnancy had been uncomplicated. It did not appear her baby was large and so it was logical to conclude she would have an uncomplicated labour and normal delivery.
That proved not to be the case.
Suzie was keen to be induced early. I agreed to this and booked the induction for when she was 39 weeks gestation.
The midwife who was assigned to Suzie was very experienced. She phoned me to say baby’s head was a bit too high for her to safely do an ARM. So, I agreed to start a Syntocinon infusion first. With contractions the baby’s head would be better applied to the cervix and so an ARM would be safer. The risks of an ARM with a high head are umbilical cord prolapse and the baby’s lie changing to traverse and so necessitating a Caesarean section delivery. It is not that unusual to have a higher head situation at term gestation when a woman had had previous babies. That is because the uterus is laxer because of stretching from previous pregnancies and does not grip the baby as tightly as it did in the first pregnancy. It is quite common for a baby’s head not to be engaged at onset of labour when a woman has had previous labours.
She wanted a pain free labour and so an epidural was inserted at the time of induction of labour.
The plan worked. The midwife was later able to safely do and ARM as the baby’s head became better applied to the cervix because of the driving force of uterine contractions. First stage labour was progressing uneventfully.
I was phoned when Suzie’s cervix was about 6cm dilated. The midwife said Suzie’s baby had a face presentation, mento-anterior (chin to Suzie’s front and back of head facing Suzie’s back). I attended. On vaginal examination I found it now a vertex (top of baby head) presentation. Baby was in an occipito-posterior position. The head was still not very well applied to the cervix. I advised the midwife to increase the Syntocinon infusion rate to optimise contraction strength and so optimise progress in labour. At the next examination Suze’s cervix was about 8cm. The baby’s head was better applied and so the labour seemed to be back on track. At the next examination Suzie’s cervix was still 8cm dilated. There had not been progress despite the Syntocinon infusion. This time the midwife found the baby had a brow presentation.
I attended and confirmed the vaginal examination findings. I confirmed a brow presentation with the back of baby’s head facing Suzie’s back. Baby’s head was well applied to the cervix.
I advised Suzie and her husband that as it was brow presentation in advanced labour she would need a Caesarean section delivery. A brow presentation prevents a normal delivery as the diameter of the baby’s head presenting in this position is too great for normal delivery. They were upset.
Suzie had an uncomplicated Caesarean section delivery under the epidural anaesthetic. The baby had fluid swelling of the skin over the baby’s brow which I showed Suzie and her husband when baby was delivered. This was consistent with a brow presentation. Suzie’s daughter was born in good condition and had birth weight of 3066gms. Suzie had an uncomplicated postnatal course and went home the third post-operative day as she had requested.
A brow presentation is reported to occur in about 1 in 1,000 labours. While a brow presentation can be transient in early labour, in an advanced prolonged labour with baby’s occiput being posterior and baby’s head being well applied to the cervix there was an obstructed labour scenario. The engagement diameter of a brow presentation in a normal sized baby is the mento-vertical diameter of about 13.5 cm which is longer than any diameter of the inlet, so labour is obstructed. A Caesarean section is indicated.
When I am asked: “Will I have normal delivery?” I answer: “Probably”, if there is no obvious reason why not and so that scenario looks likely. But a normal delivery can’t be guaranteed. As Suzie found out there can be unexpected developments in labour which prevent that outcome.
