What is the Impact of Abnormal Amniotic Fluid Volumes on Perinatal Outcomes in Normal Compared with At-Risk Pregnancies?

Figures & data

Figure 1 Study flow.

Table 1 Descriptive Statistics

Measure	Groups
	Normal + Normal Fluid (Group 1) N=2198	Normal + Oligo (Group 2) N=80	Normal + Poly (Group 3) N=74	At Risk + Normal Fluid (Group 4) N=917	At Risk +Oligo (Group 5) N=21	At Risk + Poly (Group 6) N=75	p-value
Age, mean ± SD	26.8 ± 5.7	24.7 ± 6.3	27.3 ± 6.0	29.5 ± 6.1	27.3 ± 6.1	28.7 ± 6.3	<0.0001
Race, N (%)							<0.0001
White	1006 (45.8%)	29 (36.3%)	57 (77.0%)	478 (52.1%)	7 (33.3%)	57 (76.0%)
Black	682 (31.0%)	26 (32.5%)	7 (9.5%)	248 (27.0%)	8 (38.1%)	8 (10.7%)
Other	509 (23.2%)	25 (31.2%)	10 (13.5%)	191 (20.8%)	6 (28.6%)	10 (13.3%)
Gravidity, median [Q1, Q3]	2 [1, 4]	2 [1, 4]	2 [1, 4]	2 [1, 4]	2 [1, 3]	2 [2, 4]	0.2875^a
Parity, median [Q1, Q3]	1 [0, 2]	0 [0, 2]	1 [0, 2]	1 [0, 2]	1 [0, 2]	1 [0, 2]	0.4543^a
BMI at 1st Visit, mean ± SD	30.5 ± 6.6	31.2 ± 6.7	27.9 ± 5.5	34.2 ± 9.7	35.4 ± 8.2	34.8 ± 7.1	<0.0001

Note: ^aDenote statistical test using Kruskal-Wallis.

Table 2 Association Between Maternal Groups and Categorical Infant Outcomes (Adjusted)

Group	Amnioinfusion	p-value	Variables Influencing Delivery	p-value	Lates Influencing Delivery	p-value	Meconium	p-value	NICU Admission	p-value
1	Ref	0.143	Ref	0.076	Ref	0.060	Ref	0.395	Ref	<0.0001
2	1.83 (0.64, 5.22)		0.86 (0.45, 1.64)		2.06 (1.14, 3.73)		1.51 (0.76, 2.99)		1.69 (0.81, 3.55)
3	0.86 (0.20, 3.59)		1.08 (0.60, 1.94)		1.04 (0.47, 2.33)		1.42 (0.69, 2.92)		1.65 (0.85, 3.23)
4	1.69 (1.12, 2.55)		1.33 (1.09, 1.63)		1.33 (1.04, 1.70)		0.82 (0.61, 1.10)		2.06 (1.63, 2.60)
5	1.92 (0.25, 14.6)		1.27 (0.42, 3.82)		1.93 (0.63, 5.87)		0.50 (0.07, 3.79)		2.11 (0.65, 6.86)
6	0.46 (0.06, 3.39)		0.71 (0.36, 1.39)		1.08 (0.51, 2.29)		1.18 (0.56, 2.52)		2.74 (1.54, 4.87)

Notes: Groups 1 (Normal+Normal Fluid); 2 (Normal+Oligo Fluid); 3 (Normal+Poly Fluid); 4 (At-Risk+Normal Fluid); 5 (At-Risk+Oligo Fluid); 6 (At-Risk+Poly Fluid); Analyses adjusted for maternal age, race, parity, gravidity, BMI at first visit, estimated gestational age at last assessment.

Table 3 Association Between Maternal Groups and Continuous Infant Outcomes (Adjusted)

Group	Least Squares Means Difference with Group 1 as the Reference Group
	Birthweight	p-value^a	Umbilical Artery pH	p-value^a	Bases Excess	p-value^a
2 vs 1	−92.39 (−218.0, 33.22)	<0.0001	−0.001 (−0.019, 0.017)	0.148	−0.121 (−0.762, 0.519)	0.757
3 vs 1	345.77 (214.6, 476.9)		−0.026 (−0.055, 0.004)		0.390 (−0.682, 1.461)
4 vs 1	−121.68 (−167.1, −76.3)		−0.008 (−0.016, −0.001)		0.027 (−0.249, 0.304)
5 vs 1	−513.30 (−754.0, −272.6)		−0.017 (−0.051, 0.017)		0.695 (−0.552, 1.942)
6 vs 1	507.87 (378.3, 637.5)		−0.007 (−0.033, 0.019)		0.438 (−0.515, 1.391)

Notes: Groups 1 (Normal+Normal Fluid); 2 (Normal+Oligo Fluid); 3 (Normal+Poly Fluid); 4 (At-Risk+Normal Fluid); 5 (At-Risk+Oligo Fluid); 6 (At-Risk+Poly Fluid); ^aDenote overall F-test p-value; Analyses adjusted for maternal age, race, parity, gravidity, BMI at first visit, estimated gestational age at last assessment.