When CTG monitoring is used in labour, abnormal patterns are common. Maternity professionals sometimes use another test of some sort to try to distinguish between a fetus who is coping ok but happens to have an abnormal heart rate pattern and one who is really not ok and would prefer to be out right about now, please and thanks. The problem is that we don’t have really great research to know what test to do. Two of the options are fetal blood sampling (I have written about this here, here, and here) and fetal scalp stimulation (I have written about this here).
A team of researchers based in Ireland have recently published their trial protocol for what they are calling FIRSST – the Fetal Intrapartum Randomised Scalp Stimulation Trial, and I’m excited! The plan is to include 2,500 women, having their first baby after 37 weeks, who have an abnormal CTG pattern and where an additional test of fetal wellbeing would be useful. Half the group will be randomly assigned to either digital stimulation of the scalp (to see what change in the heat heart rate this prompts) or fetal blood sampling for pH testing.
The primary goal of the trial is to see what the impact of the second line test is on the overall caesarean section rate. They also plan to look at why the caesarean sections are being done (when they are), the rate of assisted vaginal births (that’s forceps and vacuum extractions), and the rate of spontaneous vaginal births. Perinatal deaths, Apgar scores, cord blood gas results, admission to the nursery, neonatal encephalopathy, complications of fetal blood sampling, and neurological assessment at the time of hospital discharge are also included, so we can be sure whether option is performing better or worse than the other when it comes to the health of the baby.
I’m really excited that the research team has gone one step beyond what more fetal monitoring researchers have done in the past. They are taking women’s outcomes into consideration in a broader sense than just which way the baby comes out. They will also collect data about postpartum haemorrhage, severe perineal trauma, referral to perinatal mental health services, and ask women about whether the test was acceptable to them or not.
The research team have runs on the board already in relation to research in this field and have pilot tested the plan to work out the kinks. The paper is available for free so you can see what steps they have taken to make sure the research is ethical and safe. They plan to finish recruitment in 2025, so it will be some years before we get to see the outcome of their labours.