A 22-year-old woman in her second pregnancy has arrived on the labour ward at 38 weeks 3 days. She had a normal delivery 18 months ago. This pregnancy has been com- plicated by persistent vomiting until 20 weeks, and more recently by anaemia. She reports contractions commencing approximately 4 h ago. She took paracetamol at home and tried to relieve the pain with a bath, but now feels she cannot cope with the pain.
She had a show 2 days ago but has had no bleeding since then and has not noticed any vaginal leak. She has felt the baby moving normally all day.
The blood pressure is 110/58 mmHg and heart rate is 98/min. The presentation is cephalic with 2/5 palpable abdominally. Uterine contractions are palpable and the uterus is non- irritable. On vaginal examination the cervix is 5 cm dilated and the head is 1 cm above the ischial spines. The fetus is right occipitotransverse with mild caput and moulding. The membranes are intact but rupture spontaneously during examination, with clear liquor draining.
The woman requests an epidural for pain relief and is therefore commenced on continu- ous cardiotocograph monitoring. After 20 min you are called in to review the situation.
· Describe the CTG.
· What are the possible causes of this CTG?
· What management would be appropriate now?
The initial 15 min of CTG shows a baseline of 145/min with normal variability (12/min) and no visible acceleration or decelerations. Following this there is a drop in fetal heart rate to 70/min for 7 min before gradual recovery to 125/min. Contractions are 2 in 10 until the tocograph becomes unreadable.
This is a previously low-risk pregnancy and this CTG shows a fetal bradycardia (reduction in baseline heart rate to below 100/min). In many cases no cause is identified.
If a bradycardia continues for more than 5 min, plans should be made to deliver imme- diately by ‘crash’ Caesarean section under general anaesthetic. The labour ward theatre team should be called (including anaesthetist, obstetric registrar, paediatrician, midwife in charge, theatre staff) and the woman transferred to the operating theatre. On occasion the bradycardia recovers as preparation is underway for the Caesarean, in which case the plan may be reviewed. Otherwise the baby should be delivered immediately.
In this case the bradycardia did not recover and the baby was delivered within 12 min of the decision being made. No cause was found for the bradycardia at Caesarean section.
The baby initially made poor respiratory effort and had a heart rate less than 100/min, but recovered quickly with drying and warming. The Apgar score for the baby was 5 at 1 min and 9 at 5 min.