Table 3. Risk of SMM or death arising between 23 weeks’ gestation up to 42 days postpartum among all women (upper) and those without known prepregnancy DM (lower), each in association with preconception A1c cut-points for prediabetes (5.8% to 6.4%) and diabetes (>6.4%), relative to an A1c <5.8% (Additional analysis 7).

RRs were adjusted for maternal age and world region of origin—each at the time of the A1c test—as well as drug or tobacco dependence <1 year before conception and multifetal pregnancy. This analysis comprises 31,225 pregnancies in the preconception sub-cohort, and 28,075 women without known prepregnancy diabetes therein.

	A1c category: Number (%) in that category	Number (%) with SMM or death	Unadjusted RR (95% CI)	p-Value	aRR (95% CI)	p-Value
All women (N = 31,225)	<5.8%: 25,012 (80.1)	468 (1.9)	1.00 (referent)		1.00 (referent)
	5.8% to 6.4%: 4,250 (13.6)	104 (2.6)	1.31 (1.06–1.61)	0.01	1.31 (1.06–1.62)	0.01
	>6.4%: 1,963 (6.3)	110 (5.6)	3.00 (2.45–3.67)	<0.001	2.84 (2.31–3.49)	<0.001
Women without known prepregnancy DM (N = 28,075)	<5.8%: 24,406 (86.9)	453 (1.9)	1.00 (referent)		1.00 (referent)
	5.8% to 6.4%: 3,517 (12.5)	77 (2.2)	1.18 (0.93–1.50)	0.18	1.15 (0.90–1.47)	0.25
	>6.4%: 152 (0.54)	10 (6.6)	3.54 (1.93–6.50)	<0.001	3.25 (1.76–6.00)	<0.001

Abbreviations: aRR, adjusted relative risk; A1c, hemoglobin A1c; DM, diabetes mellitus; RR, relative risk; SMM, severe maternal morbidity