Impact of preterm premature rupture of membranes and oligohydramnios on in-hospital outcomes of very-low-birthweight infants

Figures & data

Figure 1. The enrollment scheme of the included infants. NICU: neonatal intensive care unit; PPROM: preterm premature rupture of membrane; VLBW: very-low-birthweight

Table 1. Baseline characteristics of the included infants based on the presence of PPROM.

	Non-PPROM (N = 178)	PPROM (N = 141)	p-value
Gestational age (at birth) (weeks)	28.1 [26.1–30.4]	26.8 [25.4–28.9]	<.001
Birthweight (g)	1,041 [840–1273]	968 [763–1230]	.208
SGA	39 (21.9)	8 (5.7)	<0001
Male sex	86 (48.3)	75 (53.2)	.387
Multiple birth	83 (46.6)	43 (30.5)	.003
Cesarean delivery	153 (86.0)	124 (87.9)	.602
1-min Apgar	3 [2–4]	3 [1–4]	.076
5-min Apgar	6 [5–7]	6 [4–7]	.017
Mother age	34 [31–36]	33 [30–36]	.216
Primiparity	106 (59.6)	80 (56.7)	.613
Maternal diabetes	15 (8.4)	11 (7.8)	.839
Histologic chorioamnionitis	48 (27.6)	76 (53.9)	<.001
Placental abruption	9 (5.1)	4 (2.8)	.310
ACS administration	122 (68.9)	106 (75.2)	.219
ART	38 (21.3)	28 (19.9)	.744
PPROM duration (h)	–	50.5 [9.0–103.0]	–
PPROM onset (weeks)	–	26.6 [24.1–28.5]	–
PPROM onset <25 weeks	–	48 (34.0)	–
Oligohydramnios	20 (11.2)	34 (24.1)	<.001

SGA: small for gestational age; ACS: antenatal corticosteroid; ART: assisted reproductive technology; ACS: antenatal corticosteroid; PPROM: preterm premature rupture of membrane.

Figure 2. Distribution of PPROM latency groups depending on the presence of oligohydramnios. PPROM: preterm premature rupture of membrane

Table 2. Characteristics concerning PPROM based on the presence of oligohydramnios.

	Only PPROM (N = 107)	PPROM and oligohydramnios (N = 34)	p-value
PPROM latency (h)	48 [7–70]	67 [14–221]	.013
PPROM onset (weeks)	26.7 [24.5–28.7]	25.6 [22.7–28.4]	.029
PPROM at <25 weeks	32 (29.9)	16 (47.1)	.066
GA at delivery (weeks)	26.9 [25.4–29.0]	26.5 [24.6–28.9]	.142

PPROM: preterm premature rupture of membrane; GA: gestational age.

Table 3. Neonatal outcomes of the included infants depending on the presence of PPROM.

	Non-PPROM (N = 178)	PPROM (N = 141)	p-value
Air leak syndrome	18 (10.1)	16 (11.3)	.723
Massive pulmonary hemorrhage	39 (21.9)	20 (14.2)	.078
Pulmonary hypertension	32 (18.0)	32 (22.7)	.296
Respiratory distress syndrome	161 (90,4)	134 (95.0)	.123
Moderate to severe BPD	94 (63.5)	83 (70.3)	.241
Severe BPD	57 (38.5)	47 (39.8)	.827
Invasive MV duration (days)**	13 [3–39]	14 [3–51]	.379
HS-PDA	50 (28.1)	34 (24.1)	.448
Sepsis	59 (33.1)	50 (35.5)	.665
NEC ≥ stage 2	15 (8.4)	10 (7.1)	.492*
Severe IVH	40 (24.5)	39 (29.3)	.335
Cystic PVL	49 (30.1)	43 (32.6)	.643
ROP needing treatment	18 (11.9)	18 (14.5)	.525
Death before discharge	30 (16.9)	24 (17.0)	.968
Length of stay (days)**	61 [47–88]	66 [48–98]	.148
Body weight at discharge (g)**	2485 [2155–2850]	2590 [2278–2958]	.103

BPD: bronchopulmonary dysplasia; MV: mechanical ventilation; hsPDA: hemodynamically significand patent ductus arteriosus; NEC: necrotizing enterocolitis; IVH: intraventricular hemorrhage; PVL: periventricular leukomalacia; ROP: retinopathy of prematurity.

*Fisher’s exact test.

** Infants who expired before discharge excluded from the analysis.

Table 4. Neonatal outcomes of the included infants based on the presence of oligohydramnios.

	Non-oligohydramnios (N = 265)	Oligohydramnios (N = 54)	p-value
Air leak syndrome	23 (8.7)	11 (20.4)	.011
Massive pulmonary hemorrhage	46 (17.4)	13 (24.1)	.247
Pulmonary hypertension	46 (17.4)	18 (33.3)	.008
Respiratory distress syndrome	245 (92.5)	50 (92.6)	.972
Moderate to severe BPD	152 (66.7)	25 (65.8)	.916
Severe BPD	89 (39.0)	15 (39.5)	.959
Invasive MV duration (days)**	15 [3–44]	1 [3–63]	.897
HS-PDA	73 (27.5)	11 (20.4)	.186
Sepsis	88 (33.2)	21 (38.9)	.422
NEC ≥ stage 2	21 (7.9)	4 (7.4)	.355
Severe IVH	67 (26.8)	12 (26.1)	.920
Cystic PVL	80 (32.0)	12 (26.1)	.477
ROP needing treatment	28 (12.0)	8 (19.0)	.214
Death before discharge	37 (14.0)	17 (31.5)	.002
Length of stay (days)**	65 [48–92]	61 [47–112]	.828
Body weight at discharge (g)**	2550 [2230–2950]	2485 [2110–2958]	.584

BPD: bronchopulmonary dysplasia; MV: mechanical ventilation; hsPDA: hemodynamically significand patent ductus arteriosus; NEC: necrotizing enterocolitis; IVH: intraventricular hemorrhage; PVL: periventricular leukomalacia; ROP: retinopathy of prematurity.

*Fisher’s exact test.

** Infants who expired before discharge excluded from the analysis.

Table 5. Subgroup analysis of neonatal outcomes of the included infants depending on the presence of oligohydramnios in infants affected by PPROM.

	Non-oligohydramnios (N = 107)	Oligohydramnios (N = 34)	p-value
Air leak syndrome	10 (9.3)	6 (17.6)	.154*
Massive pulmonary hemorrhage	14 (13.1)	69 (17.6)	.340*
Pulmonary hypertension	19 (17.8)	13 (38.2)	.013
Respiratory distress syndrome	103 (96.3)	31 (91.2)	.221*
Moderate to severe BPD	66 (71.0)	17 (68.0)	.773
Severe BPD	34 (36.6)	13 (52.0)	.161
Invasive MV duration (days)**	15 [3–45]	11 [2–80]	.683
HS-PDA	26 (25.0)	8 (25.0)	>.99
Sepsis	35 (32.7)	15 (44.1)	.226
NEC ≥ stage 2	7 (6.7)	3 (9.1)	.443*
Severe IVH	30 (29.1)	9 (30.0)	.926
Cystic PVL	34 (33.0)	9 (31.0)	.841
ROP needing treatment	10 (10.3)	8 (29.6)	.018*
Death before discharge	14 (13.1)	10 (29.4)	.027
Length of stay (days)**	68 [48–96]	62 [49–119]	.777
Body weight at discharge (g)**	2570 [2290–2955]	2625 [2183–2959]	.898

BPD: bronchopulmonary dysplasia; MV: mechanical ventilation; hsPDA: hemodynamically significand patent ductus arteriosus; NEC: necrotizing enterocolitis; IVH: intraventricular hemorrhage; PVL: periventricular leukomalacia; ROP: retinopathy of prematurity.

*Fisher’s exact test.

** Infants who expired before discharge excluded from the analysis.

Table 6. Logistic regression analysis for the association of PPROM and oligohydramnios with neonatal outcomes.

	Air leak syndrome	Pulmonary hypertension	ROP needing treatment	Death before discharge
	OR (95%CI)	OR (95%CI)	OR (95%CI)	OR (95%CI)
PPROM	1.138	1.339	1.255	1.012
	(0.558–2.321)	(0.773–2.320)	(0.622–2.530)	(0.562–1.824)
PPROM onset <25 weeks	3.816	4.821	5.671	11.531
	(1.294–11.253)	(2.092–11.110)	(1.976–16.273)	(3.952–33.644)
PPROM latency group
<24 h	Ref	Ref	Ref	Ref
≥24 and <72 h	0.855	2.710	1.119	1.620
	(0.225–3.240)	(0.963–7.628)	(0.316–3.965)	(0.502–5.229)
≥72 and <168 h	0.556	2.333	1.567	2.778
	(0.062–4.985)	(0.586–9.286)	(0.275–8.924)	(0.676–11.416)
≥168 h	1.984	3.706	2.798	3.070
	(0.545–7.220)	(1.195–11.488)	(0.741–10.561)	(0.914–10.313)
Oligohydramnios	2.692	2.380	1.723	2.831
	(1.224–5.921)	(1.244–4.555)	(0.725–4.093)	(1.447–5.539)
PPROM + oligohydramnios	1.967	2.840	3.308	2.282
	(0.750–5.158)	(1.335–6.044)	(1.325–8.259)	(1.021–5.103)

PPROM: preterm premature rupture of membrane; ROP: retinopathy of prematurity; OR: odds ratio; 95% CI: 95% confindece interval.