Measuring perinatal complications: methodologic issues related to gestational age

Table 3 Appropriate Denominator* when Considering Pregnancy Outcomes and Complications by Week of Gestation

Pregnancies Delivered (PD)	Mixed	Ongoing Pregnancies (OP)
Forceps delivery	Antepartum stillbirth	Abruption
Vacuum delivery	Oligohydramnios (if measured)	Chorioamnionitis
Epidural use	Preeclampsia/Eclampsia	Primary cesarean
3^rd and 4^th degree lacerations	Onset of labor	Uterine rupture
Cesarean in labor	Antepartum hemorrhage
Postpartum hemorrhage	Premature rupture of membranes
Shoulder dystocia	Preterm birth
Neonatal outcomes

*The type of denominator denotes the population at risk for the outcome or complication

ISSN: 1471-2393