Reference Ranges of Amniotic Fluid Index in Late Third Trimester of Pregnancy: What Should the Optimal Interval between Two Ultrasound Examinations Be?

Table 4

Values of AFI (in cm) by different authors.

Authors	AFI values	34 W	35 W	36 W	37 W	38 W	39 W	40 W
	5th centile	7.6	7.4	7.2	7.0	6.8	6.1	5.9
Khadilkar et al. 2003 [16]	50th centile	14.2	13.8	13.5	12.8	12.2	11.5	11.3
	95th centile	19	18.5	18.3	18.2	17.6	16.8	16.6
	Mean (St. Dev)	13.7 (3.1)	12.6 (2.2)	11.1 (2.6)	12.1 (2.4)	11.4 (2.1)	11.8 (1.7)	11.0 (1.0)
Hinh and Ladinsky 2005 [22]	Min	8.5	8.6	7.1	6.7	6.3	8.4	9.4
	Max	18.8	16.8	16.3	15.9	15.4	14.8	12.7
	10th centile	10.2	9.7	9.1	8.4	7.7	7	6.2
MacHado et al. 2007 [23]	50th centile	14.4	14.1	13.9	13.5	13.2	12.8	12.4
	90th centile	19.5	19.4	19.3	19.1	18.9	18.6	18.3
	Mean (St. Dev)	13.8 (1.18)	12.9 (0.60)	12.7 (1.55)	12.8 (0.84)	12.8 (0.89)	12.8 (1.19)	12.5 (0.98)
Birang 2008 [24]	5th centile	8.3	7.3	7.1	7.1	7.1	7.0	6.6
	95th centile	23.7	23.2	22.8	22.1	20	18.7	18
	Mean	17.1	16.9	16.3	16.2	15.7	15.3	14.8
Singh et al. 2013 [25]	5th centile	11.0	10	9.7	10.1	9.9	8.1	8.8
	95th centile	24.5	24.1	24.8	24.2	24.1	23.7	18
	Mean	14.59 (1.79)	14.25 (1.57)	13.17 (1.56)	12.48 (1.52)	12.2 (1.7)	11.37 (1.71)	10.99 (1.55)
Present study	5th centile	11.7	11.1	10.6	10.1	9.8	8.8	8.7
	95th centile	17.3	16.4	15.7	15.1	14.7	14.4	13.7