The optimal gestational age to deliver patients with chronic hypertension on antihypertensive therapy

Figures & data

Table 1. Baseline characteristics.

	37 weeks			38 weeks
	Planned delivery 37–37.6 weeks n = 94	Expectant delivery beyond 37.0 weeks n = 461	p Value	Planned delivery 38–38.7 weeks n = 113	Expectant delivery beyond 38 weeks n = 277	p Value
Age	34.68 ± 5.12	34.74 ± 4.87	.92	35.16 ± 4.63	34.56 ± 4.81	0.26
Race			0.002			0.41
White	21 (22.3)	191 (41.4)		43 (38.0)	124 (44.8)
Black	37 (39.4)	122 (26.5)		33 (29.2)	66 (23.8)
Other/Unknown	36 (38.3)	148 (32.1)		37 (32.7)	87 (31.4)
Ethnicity			0.43			0.71
Hispanic	13 (13.8)	56 (12.2)		12 (10.6)	33 (11.9)
Not Hispanic	70 (74.5)	368 (79.8)		94 (83.2)	221 (79.8)
Unknown	11 (11.7)	37 (8.0)		7 (6.2)	23 (8.3)
Parity			0.60			0.61
0	33 (35.1)	156 (33.8)		34 (30.1)	99 (35.7)
1	38 (40.4)	169 (36.7)		47 (41.6)	94 (33.9)
>1	23 (24.5)	136 (29.5)		32 (28.3)	84 (30.3)
Insurance			0.23			0.33
Public Insurance	26 (27.7)	157 (34.1)		33 (29.2)	95 (34.3)
Private Insurance	68 (72.3)	304 (66.0)		80 (70.8)	182 (65.7)
BMI > 30	81 (86.2)	359 (77.9)	0.07	93 (82.3)	209 (75.5)	0.14
Tobacco Use	2 (2.1)	4 (0.9)	0.28	0 (0.00)	4 (1.4)	0.20
Proteinuria			0.61			0.36
Present	10 (10.6)	55 (11.9)		14 (12.4)	29 (10.5)
Not present	56 (59.6)	291 (63.1)		75 (66.4)	170 (61.4)
Unknown	28 (29.8)	115 (25.0)		24 (21.2)	78 (28.2)
Creatinine	0.60 ± 0.12	0.62 ± 0.15	0.21	0.63 ± 0.17	0.61 ± 0.13	0.32
Steroid	9 (9.6)	17 (3.7)	0.01	2 (1.8)	7 (2.5)	0.65
Aspirin	38 (40.4)	159 (34.5)	0.27	38 (33.6)	84 (30.3)	0.52
Prior Preeclampsia	19 (20.2)	72 (15.6)	0.27	13 (11.5)	47 (17.0)	0.17
GDMA	25 (26.6)	85 (18.4)	0.07	23 (20.4)	53 (19.1)	0.78
Maternal Comorbidities^a	8 (8.5)	40 (8.7)	0.96	12 (10.6)	21 (7.6)	0.33
Medication
Labetalol	71 (75.5)	352 (76.4)	0.86	83 (73.4)	211 (76.2)	0.57
Nifedipine	23 (24.5)	57 (12.4)	0.002	15 (13.3)	28 (10.1)	0.37
Amlodipine	2 (2.1)	18 (3.9)	0.40	7 (6.2)	10 (3.6)	0.27
Methyldopa	5 (5.3)	70 (15.2)	0.01	19 (16.8)	42 (15.2)	0.68
Hydralazine	0 (0)	5 (1.1)	0.31	1 (0.9)	1 (0.4)	0.51
Number of antihypertensive medications			0.80			0.12
1	87 (92.6)	423 (91.8)		102 (90.3)	262 (94.6)
>1	7 (7.5)	38 (8.2)		11 (9.7)	15 (5.4)

Data are mean (standard deviation) number (frequency).

^aMaternal comorbidities include autoimmune, cardiovascular, hematological, neurological disorders.

Table 2. Outcomes of planned delivery by gestational age for patients with chronic hypertension on antihypertensive medications.

Outcomes of Planned Delivery 37^0/7 to 37^6/7 weeks Gestation versus Expectant Management beyond 37 weeks
	Planned delivery 37.0–37.6 weeks n = 94	Expectant delivery beyond 37.0 weeks n = 461	aOR with 95% CI
Primary Outcomes	14 (14.8)	48 (10.4)	1.49 (0.77, 2.88)
Ph < 7.0	1 (0.2)	0 (0)
Respiratory Disorder	13 (13.8)	37 (8.0)
Mechanical Vent	2 (2.1)	3 (0.6)
Non-Invasive Resp Support	8 (8.5)	39 (8.5)
Apgar <5	2 (2.1)	4 (0.9)
Neonatal Death	0 (0)	0 (0)
Seizure	0 (0)	0 (0)
Primary C-Section	30 (31.9)	116 (25.1)	1.45 (0.87, 2.41)
Preeclampsia	30 (31.9)	146 (31.7)	0.92 (0.56, 1.52)
Eclampsia	0 (0)	0 (0)	n/a
Postpartum Readmit	11 (11.7)	34 (7.4)	1.53 (0.74, 3.19)
Neonatal Days > =5	8 (8.5)	32 (6.9)	1.25 (0.55, 2.86)
Outcome of Planned Delivery 38^0/7 to 38^6/7 weeks Gestation versus Expectant Management beyond 38 weeks
	Planned delivery 38–38.7 weeks n = 113	Expectant delivery beyond 38 weeks n = 277	aOR with 95% CI
Primary Outcomes	11 (9.7)	28 (10.1)	0.84 (0.39, 1.78)
Ph < 7.0	0 (0)	0 (0)
Respiratory Disorder	7 (6.2)	23 (8.3)
Mechanical Vent	1 (0.9)	1 (0.4)
Non-Invasive Resp Support	11 (9.7)	21 (7.6)
Apgar <5	1 (0.9)	0 (0)
Neonatal Death	0 (0)	0 (0)
Seizure	0 (0)	0 (0)
Primary C-Section	28 (24.8)	64 (23.1)	0.98 (0.58, 1.66)
Preeclampsia	28 (24.8)	75 (27.1)	0.83 (0.50, 1.40)
Eclampsia	0 (0)	0 (0)	n/a
Postpartum Readmit	5 (4.4)	22 (7.9)	0.54 (0.20, 1.46)
Neonatal Days > =5	4 (3.5)	19 (6.9)	0.48 (0.16, 1.46)

OR: Odds Ratio.