Table 2.

Numbers and Proportions of Infant and Maternal Adverse Events, According to Hypertension Status

	No hypertension, n=2 780 267		Chronic hypertension, n=42 349		Chronic hypertension treated during pregnancy, n=22 816		Chronic hypertension untreated during pregnancy, n=19 533		Chronic hypertension vs no hypertension, P value	Treated hypertension vs untreated hypertension, P value
	No.	Percentage	No.	Percentage	No.	Percentage	No.	Percentage
Infant events
Infant death	12 136	0.44	355	0.84	201	0.88	154	0.79	<0.0001	0.2977
Small‐for‐gestational age*	220 449	13.96	5203	24.38	3223	28.77	1980	19.54	<0.0001	<0.0001
Premature delivery threat	277 722	9.99	5514	13.02	3288	14.41	2226	11.40	<0.0001	<0.0001
Preterm birth†	201 767	7.30	8010	19.11	4857	21.52	3153	16.30	<0.0001	<0.0001
Preterm birth stages†									<0.0001	<0.0001
Moderate preterm (≥32 WG)	170 722	6.17	6093	14.54	3682	16.32	2411	12.47
Very preterm (27–31 WG)	24 271	0.88	1569	3.74	983	4.36	586	3.03
Extremely preterm (<27 WG)	6774	0.24	348	0.83	192	0.85	156	0.81
Maternal events
Gestational diabetes	229 593	8.26	7110	16.79	4547	19.93	2563	13.12	<0.0001	<0.0001
Preeclampsia	75 222	2.71	7237	17.09	4124	18.08	3113	15.94	<0.0001	<0.0001
Cesarean delivery	736 920	26.51	20 864	49.27	12610	55.27	8254	42.26	<0.0001	<0.0001
Obstetric hemorrhage	158 957	5.72	2982	7.04	1582	6.93	1400	7.17	<0.0001	0.35
Venous thromboembolism	3281	0.12	121	0.29	62	0.27	59	0.30	<0.0001	0.56
ACS or stroke	770	0.03	45	0.11	16	0.07	29	0.15	<0.0001	0.01
Death postpartum	152	0.01	13	0.03	9	0.04	4	0.02	<0.0001	0.27

ACS indicates acute coronary syndrome; and WG, weeks of gestation.

^*Birth weight was available from 2013; percentages for small for gestational age are calculated for available data for the period from 2013 to 2018.

^†Preterm percentages are calculated for live births.