Circadian Variation in the Onset of Placental Abruption

Table 2

Demographic data of each group for the four 6-hour intervals in regard to placental abruption.

	0:00 AM; ~; 6:00 AM	6:00 AM; ~; 0:00 PM	0:00 PM; ~; 6:00 PM	6:00 PM; ~; 0:00 AM
Number	40	26	25	24
Age (yrs.)
Nulliparity (%)	21 (53%)	9 (35%)	12 (48%)	7 (29%)
Smoking	2	2	0	1
Hypertension	9	7	2	3
PROM	2	4	4	0
PPA	2	0	1	0
Gestational age at delivery (wks.)
Cesarean delivery	32 (80%)	22 (85%)	20 (80%)	18 (75%)
(IUFD followed by cesarean delivery)	(7)	(1)	(0)	(0)
Birth weight (g)

Results are expressed as number, mean ± SD, or incidence (%). PROM: premature rupture of the membranes. PPA: prior history of placental abruption. IUFD: intrauterine fetal death. CD: cesarean delivery.