TABLE 4.

Risks of severe maternal morbidity by maternal fertility status

	Intensive care		Blood transfusion		Ruptured uterus		Unplanned hysterectomy		Hysterectomy after cesarean		Third- or fourth-degree perineal lacerationa
N, Pregnancies	1,477,522		1,477,522		1,477,522		1,477,522		522,691		942,742
Outcomes, %	2130	0.14%	3608	0.24%	506	0.03%	611	0.04%	493	0.09%	12,327	1.31%
	AOR	95% CI	AOR	95% CI	AOR	95% CI	AOR	95% CI	AOR	95% CI	AOR	95% CI
Fertile	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference	1.00	Reference
Subfertile	0.87	0.58–1.31	1.58b	1.23–2.02b	1.47	0.67–3.23	1.08	0.55–2.11	0.91	0.43–1.96	2.08b	1.79–2.43b
IVF autologous-fresh	0.88	0.74–1.06	1.33b	1.14–1.54b	1.62b	1.14–2.29b	1.04	0.74–1.48	0.86	0.58–1.28	1.37b	1.26–1,49b
IVF autologous-thawed	1.22	0.95–1.57	1.94b	1.60–2.36b	1.39	0.80–2.45	2.80b	1.96–4.00b	2.76b	1.88–4.04b	2.10b	1.84–2.40b
IVF donor-fresh	1.13	0.84–1.52	2.16b	1.69–2.75b	0.60	0.20–1.78	2.14b	1.33–3.44b	1.75b	1.02–3.01b	2.11b	1.66–2.69b
IVF donor-thawed	1.08	0.67–1.72	2.01b	1.38–2.92b	0.33	0.04–2.50	2.46b	1.33–4.54b	2.05b	1.03–4.09b	1.28	0.79–2.08

Models adjusted for maternal fertility status, age, parity, race and ethnicity, hypertension and diabetes (pregestational and gestational), plurality at birth, length of gestation, and mode of delivery, as well as state and year of birth and infant sex.

AOR, adjusted odds ratio; CI, confidence interval; IVF, in vitro fertilization.

^aLimited to singleton vaginal births only, adjusted for all factors in original model, as well as length of gestation

^bSignificantly increased compared to reference group.

Luke et al. Risk of severe maternal morbidity. Am J Obstet Gynecol 2019.