Amniotic fluid index at admission in labour as predictor of intrapartum fetal status

Summary

To re-examine the value of amniotic fluid index at admission in labour (aAFI) as a predictor of intrapartum fetal status, in 326 term pregnancies at their admission in labour, labour admission test (LAT) and antepartum risk status were recorded. The different categories were correlated with fetal/neonatal outcome. There were 68.7% women at low risk on the Minnesota scale for antepartum status. The proportion of women with low aAFI (≤5 cm) was higher in the high-risk group (8 of 12, 64%, p = 0.0001) and occurrence of significantly higher non-reassuring fetal status (NRFS; 10 of 12 with low AFI, 83%, p = 0.0001). Number recording LAT as non-reactive trace (41 cases) was similar irrespective of the pregnancy status (24 and 17 in low- and high-risk cases, respectively) and fetal status through labour (21 and 20 in fetuses with NRFS and otherwise, respectively). Negative predictive value was similar between the groups (88% for aAFI and 89% for LAT), and LAT was found to be more specific (91%) than 64% for aAFI. Sensitivity and positive predictive values were poor in both. It is concluded that aAFI is not a reliable screening test to predict intrapartum fetal compromise.

Keywords:

• Amniotic fluid index
• antepartum risk score
• intrapartal fetal compromise
• labour admission test
• non-reassuring status

Acknowledgement

The authors are thankful to Dr Prashanth K Adiga, Associate Professor in Obstetrics-Gynecology at Kasturba Medical College, Manipal for help in recording the amniotic fluid index of parturients.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.