You are on the labour ward and called to see a 33-year-old woman in labour as the mid- wife is concerned about the cardiotocograph (CTG).
She is 41 + 2 weeks’ gestation and this is her first baby. The pregnancy was uncompli- cated until 2 days ago when she developed mild hypertension, without proteinuria. In view of the gestational age a decision was made for induction of labour yesterday. She had 2 mg prostaglandin gel administered into the vagina at 18.00 last night and again at 06.00 this morning. Spontaneous rupture of membranes occurred at 10.00 today after which contractions commenced.
Blood pressure is 135/68 mmHg, heart rate 90/min and temperature is 37.1°C.
On abdominal palpation the fetus is cephalic, 1/5 palpable, and strong contractions are felt. Vaginally the cervix is fully effaced and 6 cm dilated. The fetus is cephalic at ischial spines with mild caput but no moulding. Grade 1 meconium is noted.
· How would you interpret the CTG and fetal blood sample result?
· How would you manage the patient?
The CTG shows a baseline of 155 beats/min with reduced variability (5–10 beats/min) and late decelerations. No accelerations are seen. The CTG is therefore classified as abnormal. Contractions are 5 in 10.
The fetal pH should normally be between 7.25 and 7.35. This fetal blood sample suggests an acidotic baby (low pH and high negative base excess).
In cases of an abnormal CTG, the fetus may not be compromised, and it is therefore important to assess the fetal wellbeing with a fetal blood sample before progressing to operative intervention (unless fetal blood sampling is contraindicated or in cases of per- sistent fetal bradycardia). In this case the fetal blood sample confirmed that the fetus was significantly compromised.
The meconium-stained liquor may be a sign of fetal compromise, but at 41 weeks’ gesta- tion meconium may be an incidental finding and is therefore difficult to interpret.
If the cervix were fully dilated and the head below the ischial spines then instrumental delivery, by ventouse or forceps, would be appropriate. As this is not the case, then imme- diate delivery by Caesarean section is essential. The important points for an emergency Caesarean section are:
· the midwife in charge, theatre staff, obstetric consultant, specialist registrar, anaesthetist and paediatrician should be informed
· the reasons for the proposed procedure should be explained to the woman and informed consent obtained
· metoclopramide and ranitidine should be given in case of the need for general anaesthetic
· intravenous access is needed with full blood count and group and save sent
· a urethral catheter should be inserted
· the baby should be delivered within a maximum 30 min after the decision