Table 3.

Hazard ratios (95% confidence intervals) for preterm delivery in first pregnancy and cardiovascular events (MI and stroke), among women without hypertensive disorders of pregnancy in first pregnancy

	Non-HDP Term: ≥37 weeks (n=51,343)	Non-HDP Preterm: <37 weeks (n=4,487)	Non-HDP Moderate Preterm: ≥32 to <37 weeks (n=3,372)	Non-HDP Very Preterm: <32 weeks (n=1,115)
Cases/Person-Years*	613/1,641,456	76/141,478	46/105,585	30/35,893
Model 1†	1.00 (ref)	1.44 (1.13, 1.82)	---	---
Model 2†	1.00 (ref)	1.38 (1.08, 1.75)	---	---
Model 3†	1.00 (ref)	1.35 (1.06, 1.72)	---	---
Model 1‡	1.00 (ref)	---	1.17 (0.87, 1.58)	2.21 (1.53, 3.18)
Model 2‡	1.00 (ref)	---	1.15 (0.85, 1.55)	2.02 (1.39, 2.95)
Model 3‡	1.00 (ref)	---	1.12 (0.83, 1.52)	2.01 (1.38, 2.93)

Model 1 is adjusted for age at first birth, age in 1989, race/ethnicity, and parental education

Model 2 is additionally adjusted for pre-pregnancy BMI, pre-pregnancy smoking, pre-pregnancy Alternative Healthy Eating Index (AHEI) score (in quintiles), pre-pregnancy alcohol intake, physical activity at age 18, and pre-pregnancy oral contraceptive use

Model 3 is additionally adjusted for pre-pregnancy chronic hypertension, pre-pregnancy hypercholesterolemia, pre-pregnancy type 2 diabetes mellitus, and family history of MI or stroke before age 60

^*Sample size and total case numbers differ from Table 2 due to additional exclusion criterion: did not complete 2009 reproductive wrap up. The 2001 questionnaire did not include questions regarding HDP.

^†Compares non-HDP preterm (<37 weeks) to Non-HDP term (≥37 weeks)

^‡Non-HDP preterm category is split into non-HDP moderate preterm (≥32 to <37 weeks) and non-HDP very preterm (<32 weeks)