Table 2 Risk of operative delivery, fetal distress & low Apgar score in infants with large fetal head circumference relative to average head circumference, Washington State 2003-2009
Outcomes | Large FHC | Average FHC | Unadjusted risk ratio for outcome in large vs. average FHC (95% CI) | ||
|---|---|---|---|---|---|
(N = 10,750) | (N = 10,750) | ||||
n | (%) | n | (%) | ||
Adverse birth outcomes | |||||
Unassisted vaginal delivery | 5160 | (48) | 7271 | (68) | 1.00 (Ref) |
Vacuum extraction | 1067 | (10) | 901 | (8) | 1.55 (1.43, 1.69) |
Forceps delivery | 196 | (2) | 169 | (2) | 1.61 (1.32, 1.97) |
Primary C-section | 4283 | (40) | 2379 | (22) | 1.84 (1.77, 1.92) |
Primary cesarean section a | |||||
Maternal age | |||||
≤ 19 years | |||||
Unassisted vaginal delivery | 798 | (66) | 1490 | (85) | 1.00 (Ref) |
Primary C-section | 416 | (34) | 264 | (15) | 2.28 (1.99, 2.61) |
20-24 years | |||||
Unassisted vaginal delivery | 1702 | (62) | 2413 | (80) | 1.00 (Ref) |
Primary C-section | 1047 | (38) | 621 | (20) | 1.86 (1.71, 2.03) |
25-29 years | |||||
Unassisted vaginal delivery | 1443 | (54) | 1854 | (75) | 1.00 (Ref) |
Primary C-section | 1222 | (46) | 627 | (25) | 1.81 (1.68, 1.96) |
30-34 years | |||||
Unassisted vaginal delivery | 876 | (47) | 1067 | (67) | 1.00 (Ref) |
Primary C-section | 993 | (53) | 536 | (33) | 1.59 (1.47, 1.72) |
35+ years | |||||
Unassisted vaginal delivery | 340 | (36) | 445 | (54) | 1.00 (Ref) |
Primary C-section | 604 | (64) | 329 | (46) | 1.51 (1.37, 1.66) |
Fetal outcomes | |||||
No fetal distress | 9919 | (92) | 9906 | (92) | 1.00 (Ref) |
Fetal distressb | 813 | (8) | 835 | (8) | 0.97 (0.89, 1.07) |
No low Apgar score | 10696 | (99) | 10714 | (99) | 1.00 (Ref) |
Low Apgar score c | 45 | (<1) | 28 | (<1) | 1.61 (1.00, 2.57) |