Effects of hypertensive disorders of pregnancy on the complications in very low birth weight neonates

Figures & data

Figure 1. Study flowchart.

Table 1. Diagnostic criteria for pregnancy-associated hypertension.

Condition

Criteria Required

Gestational hypertension Preeclampsia-Hypertension and: Proteinuria Thrombocytopenia Renal insufficiency Liver involvement Cerebral symptoms Pulmonary edema Eclampsia

BP > 140/90 mmHg after 20 weeks in previously normotensive women • ≥ 300 mg/24 h, or • Protein: Cr ratio ≥ 0.3 or • Dipstick 1+ persistent^a or • Platelets < 100,000/μL • Creatinine >1.1 mg/dL or doubling of baseline^b • Serum transaminase levels^c twice normal • Headache, visual disturbances, convulsions- • In a woman with preeclampsia, a convulsion that cannot be attributed to another cause. The seizures are generalized and may appear before, during, or after labor.

^aRecommended only if sole available test; ^b No prior renal disease; ^cAST (aspartate aminotransferase) or ALT (alanine aminotransferase).

Table 2. Comparison of general information between HDP group and control group.

Variables	HDP group (n = 308)	Control (n = 308)	t/χ^2	P value
Male neonates	148 (48%)	151 (49%)	0.058	0.809
Gestational age, weeks	30.8 ± 2.2	30.7 ± 2.1	0.781	0.435
Birth weight, g	1185.5 ± 217.2	1286.7 ± 177.2	6.331	p < 0.001
Maternal age, yrs	31.5 ± 5.8	29.7 ± 4.6	4.389	p < 0.001
In vitro fertilization-embryo transfer	41 (13.3%)	50 (16.2%)	1.044	0.307
Primiparity	99 (32.1%)	105 (34.1%)	0.264	0.607
Prenatal dexamethasone	279 (90.6%)	283 (91.9%)	0.325	0.569
Neonates delivered by GDM mother	79 (25.6%)	72 (23.4%)	0.430	0.512
PROM	43 (14.0%)	128 (41.6%)	58.487	p < 0.001
Caesarean section	241 (78.2%)	161 (52.3%)	45.827	p < 0.001
Placental abruption	44 (14.3%)	53 (17.2%)	0.991	0.319
Placenta previa	8 (2.6%)	14 (4.5%)	1.697	0.193

HDP, hypertensive disorders of pregnancy; GDM, gestational diabetes mellitus; PROM, premature rupture of fetal membrane. HDP group: VLBW neonates (age <37 weeks; birth weight < 1,500 g) delivered by HDP pregnant women. Control group: VLBW neonates delivered by pregnant women showing a normal blood pressure with matched gestational age.

Table 3. Comparison of major complications in HDP group and control.

Condition	HDP group (n = 308)	Control (n = 308)	t/χ^2	P value
Fetal distress	127 (41.2%)	74 (24%)	20.744	<0.001
Apgar score at 1 min	8.3 ± 2.2	8.9 ± 1.8	-3.212	0.001
SGA	152 (49.4%)	81 (26.3%)	28.161	<0.001
Mechanical ventilation	73 (23.7%)	51 (16.6%)	4.887	0.027
RDS	97 (31.5%)	68 (22.1%)	6.962	0.008
Sepsis	66 (21.4%)	49 (15.9%)	3.090	0.079
BPD	31 (10.1%)	32 (10.4%)	0.894	1.000
ROP	38 (12.4%)	26 (8.4%)	2.511	0.113
NEC, ≥2 stage	24 (7.8%)	11 (3.6%)	5.119	0.024
IVH	78 (25.3%)	86 (27.9%)	1.536	0.215
PVH	4 (1.3%)	3 (0.97%)	0.000	1.000
PPHN	0 (0%)	1 (0.3%)	/	1.000
Cholestasis	17 (5.5%)	11 (3.6%)	1.347	0.246
Death or predicted death	47 (15.3%)	28 (9.1%)	5.481	0.019

SGA, small for gestational age; RDS, respiratory distress syndrome; BPD, bronchopulmonary dysplasia; ROP, retinopathy of prematurity; IVH, intraventricular hemorrhage; PVL, periventricular leukomalacia; PPHN, Persistent pulmonary hypertension in the newborn. HDP group: VLBW neonates (age <37 weeks; birth weight < 1,500 g) delivered by HDP pregnant women. Control group: VLBW neonates delivered by pregnant women showing a normal blood pressure with matched gestational age.

Table 4. Comparison of major complications among the gestational hypertension group, PE group and eclampsia group.

Condition	Gestational hypertension (n = 72)	Pre-eclampsia (n = 222)	Eclampsia (n = 14)	F/χ^2	P value
Fetal distress	11 (15.3%)	109 (49.1%)	7 (50%)	26.130	<0.001
Apgar score at 1 min	8.4 ± 2.0	8.4 ± 2.1	6.4 ± 3.1	5.694	0.004
SGA	16 (22.2%)	128 (57.7%)	8 (57.1%)	27.668	<0.001
Mechanical ventilation	20 (27.8%)	46 (20.7%)	7 (50%)	7.107	0.029
RDS	15 (20.8%)	74 (33.3%)	8 (57.1%)	8.410	0.015
NEC, ≥2 stage	2 (2.8%)	19 (8.6%)	3 (21.4%)	6.324	0.042
Death	10 (13.8%)	33 (14.8%)	4 (28.6%)	2.050	0.359

SGA, small for gestational age; RDS, respiratory distress syndrome; NEC, neonatal necrotizing enterocolitis; HDP, hypertensive disease of pregnancy.

Table 5. Multi-variate regression analysis of major complications between the HDP subgroups.

Variables	Gestational hypertension group			PE group			Eclampsia group
	OR	95% CI	P value	OR	95% CI	P value	OR	95% CI	P value
Fetal distress	0.5	0.220–1.134	0.097	0.729	0.432–1.230	0.236	1.41	0.306–6.489	0.659
Prenatal asphyxia	1.581	0.809–3.089	0.181	0.863	0.492–1.516	0.609	2.192	0.655–7.340	0.203
SGA	0.797	0.432–1.471	0.468	4.123	2.783–6.109	0.000	3.804	1.239–11.681	0.02
Mechanical ventilation	1.214	0.602–2.449	0.588	0.89	0.487–1.626	0.704	1.472	0.426–5.093	0.541
RDS	0.49	0.240–0.099	0.055	1.454	0.879–2.406	0.145	2.578	0.769–8.468	0.125
NEC, ≥2 stage	0.72	0.156–3.318	0.673	2.493	1.161–5.351	0.019	7.264	1.771–29.797	0.006
Death or predicted death	0.902	0.384–2.122	0.814	1.17	0.580–2.360	0.661	1.497	0.370–6.063	0.572

SGA, small for gestational age; RDS, respiratory distress syndrome; NEC, neonatal necrotizing enterocolitis; PE, pre-eclampsia; OR, odds ratio.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.