- Objective: To assess the importance of birth order and advanced maternal age on maternal and peripartum complications. Study design: The study population consisted of 12 296 multiparous women (six deliveries or more) with singleton gestation. Patients were classified into two groups according to the birth order: grand multiparous (between six and nine deliveries) and huge multiparous (ten or more deliveries). Peripartum complication was defined when at least one of the following conditions occurred: massive hemorrhage, uterine rupture, abruptio placentae, dysfunctional labor or malpresentations. Logistic regression analysis was used to evaluate the relationship between birth order and maternal age and peripartum complications. Results: Among the study population, 9587 (78%) were grand multiparous and the remaining 2709 were huge multiparous women. The rate of peripartum complications was higher in huge multiparous than in grand multiparous women: malpresentation (6.2% versus 5%, P<.005), massive hemorrhage (0.7% versus 0.4%, P<.001) and dysfunctional labor (6.4% versus 3.5%, P<.001). Huge multiparous women also had a higher rate of the following complications than grand multiparous women: cesarean section (14.4% versus 10.4%, P<.01), chronic hypertension (7.9% versus 3%, P<.001), severe pregnancy induced hypertension (2.6% versus 1.1%, P<.01), diabetes class A (10.7% versus 7.5%, P<.005), diabetes class B–R (4.3% versus 2%, P<.01) congenital anomalies (3.3% versus 2.6%, P<.05) and large for gestational age infant, (17% versus 12.4%, P<.01). When adjusted for maternal age, high birth order remained strongly associated with the occurrence of peripartum complications. Conclusions: Huge multiparity was associated with a higher rate of maternal and peripartum complications than grand multiparity. Higher birth order remained an independent risk factor for peripartum complications after adjustment for maternal age.