Table 1:

Age-standardized baseline characteristics of Nurses’ Health Study II participants^* by time period of follow-up

	Time Period of Follow-up
	1989–1993n=11,776(11.1%)	1994–2003n=31,395(29.6%)	2004–2013n=63,059(59.3%)
Age, years, mean (SD)†	41.5 (0.9)	43.7 (2.3)	50.0 (4.6)
Total cholesterol, mg/dL, mean (SD)	188.8 (8.1)	193.0 (14.9)	202.0 (21.3)
HDL-C, mg/dL, mean (SD)	61.1 (3.9)	60.1 (6.6)	62.2 (9.5)
Systolic blood pressure, mm Hg, mean (SD)	115.7 (5.9)	114.7 (9.0)	117.2 (11.8)
Anti-hypertensive medication use	8	7	8
Current smoker	13	11	7
Diabetes	0	1	2
Hypertensive disorder of pregnancy status
Normotension	92	91	89
Gestational Hypertension	3	3	4
Preeclampsia	5	6	7
Parity
Nulliparous	17	18	17
1 birth	15	15	13
2 births	43	40	40
≥3 births	26	27	30
Hypertensive disorder of pregnancy and parity
Nulliparous	17	18	17
Normotensive pregnancy and para 1	13	13	11
Normotensive pregnancies and para 2	39	36	35
Normotensive pregnancies and para ≥3	23	24	26
History of HDP and para 1	2	2	2
History of HDP and para 2	4	5	5
History of HDP and para >3	3	3	4

Abbreviations: HDL-C: high-density lipoprotein cholesterol. HDP: hypertensive disorder of pregnancy. Values are means (SD) or percentages and are standardized to the age distribution of the study population. Percentages unless otherwise noted. Values of polytomous variables may not sum to 100% due to rounding.

* n=38,324 women contributed person-time to the analysis drawn from one time period, n=19,340 contributed person-time from two time periods, and n=9,742 contributed person-time from all three time periods.

^† Value is not age adjusted