Population prevalence of PAS: 20 per 100,000 live births
Presentation of PAS:
(1) neonatal seizures
(2) demonstration of intraventricular hemorrhage or white matter abnormalities on head CT
(3) pathologic handedness (hand preference before 12 months of age) after 2 months of age
(4) other
Risk factors associated with PAS (Table 3, page 727):
(1) infertility (maternal or paternal infertility apparently not distinguished, but with use of ovarian stimulation a risk factor)
(2) pre-eclampsia or pregnancy-induced hypertension
(3) primiparity
(4) chorioamnionitis
(5) prolonged rupture of the membranes (which is a risk factor for chorioamnionitis)
(6) oligohydramnios
(7) prolonged second stage of labor (> 2 hours, which correlates with primiparity)
(8) decreased fetal movements
(9) fetal heart rate abnormalities
total number of risk factors =
= SUM(number of risk factors present)
Interpretation:
• minimum number of risk factors: 0
• maximum number of risk factors: 9
• The presence of 3 or more risk factors was associated with a prevalence of PAS at about 1 in 200 births.
Risk factors that were independent on multivariate analysis (page 727):
(1) history of infertility (especially with use of ovarian stimulation drugs)
(2) pre-eclampsia
(3) chorioamnionitis
(4) prolonged rupture of the membranes
(5) prolonged second stage of labor
Limitations:
• Many of the risk factors are fairly common, while the occurrence of PAS is relatively low. The predictive value of the risk factors for a particular infant is low.
