Admission cardiotocography: Its role in predicting foetal outcome in high-risk obstetric patients

Routine and continuous electronic monitoring of foetal heart rate (FHR) in labour has become an established obstetric practice in high-risk pregnancies in industrialised countries. However, the same may not be possible in non-industrialised countries where antenatal care is inadequate with a large number of high-risk pregnancies being delivered in crowded settings and inadequate health care provider to patient ratios.

The objective of this study was to evaluate the predictive value of the admission cardiotocogram (CTG) in detecting foetal hypoxia at the time of admission in labour and to correlate the results of the admission CTG with the perinatal outcome in high-risk obstetric cases.

This was a prospective observational study conducted in the labour and maternity ward of a hospital in Gangtok, India, during the period 2008 to 2010. The study included high-risk pregnant women, admitted via the emergency or outpatient department with a period of gestation ≥36 weeks, in first stage of labour with foetus in the cephalic presentation. All women were subjected to an admission CTG, which included a 20 minute recording of FHR and uterine contractions.

One hundred and sixty patients were recruited. The majority of women were primigravida in the 21-30 years age group. About 42% patients were postdated pregnancy followed by pregnancy-induced hypertension (PIH) (15.6%) and premature rupture of membranes (PROM) (11.3%) as the major risk factors. The admission CTG were 'reactive' in 77%, 'equivocal' in 14.4% and 'ominous' in 8.7% women. Incidence of foetal distress, moderate-thick meconium stained liquor and neonatal intensive care unit (NICU) admission was significantly more frequent among patients with ominous test results compared with equivocal or reactive test results on admission. Incidence of vaginal delivery was more common when the test was reactive.

The admission CTG appears to be a simple non-invasive test that can serve as a screening tool in 'triaging' foetuses of high-risk obstetric patients in non-industrialised countries with a heavy workload and limited resources.