Table 1

Patient characteristics by line of care at onset for the unmatched (A) and for the matched (B) cohort

(A) Unmatched cohort(B) Matched cohort
Midwife-led care, 
n=46 764
Obstetrician-led care, 
n=10 632
P  value 
before matching
Midwife-led care, 
n=10 632
Obstetrician-led care, 
n=10 632
P value
Maternal age (mean±SD)  30.4±5.0  31.4±5.5<0.0001  31.3±5.3  31.4±5.50.476
Maternal age (years)
 <256060 (13.0%)1305 (12.3%)<0.00011308 (12.3%)1305 (12.3%)0.332
 25–2912 995 (27.8%)2361 (22.2%)2454 (23.1%)2361 (22.2%)
 30–3417 562 (37.5%)3719 (35.0%)3611 (34.0%)3719 (35.0%)
 ≥3510 147 (21.7%)3247 (30.5%)3259 (30.7%)3247 (30.5%)
 Birth weight (mean±SD)  3552±458  3474±500<0.0001  3483±463  3474±5000.142
Parity
 Nulliparous21 074 (45.1%)4376 (41.2%)<0.00014344 (40.9%)4376 (41.2%)0.655
 Multiparous25 690 (54.9%)6256 (58.8%)6288 (59.1%)6256 (58.8%)
Ethnicity
 Non-Western11 406 (24.4%)3226 (30.3%)<0.00013253 (30.6%)3226 (30.3%)0.688
 Western35 358 (75.6%)7406 (69.7%)7379 (69.4%)7406 (69.7%)
 Gestational age, median (range)40 (37–41)40 (37–41)40 (37–41)40 (3–41)0.97
Mean gestational age
 371759 (3.8%)688 (6.5%)<0.0001741 (7.0%)688 (6.5%)0.513
 385079 (10.9%)1459 (13.7%)1450 (13.6%)1459 (13.7%)
 3912 345 (26.4%)2744 (25.8%)2665 (25.1%)2744 (25.8%)
 4016 771 (35.9%)3499 (32.9%)3513 (33.0%)3499 (32.9%)
 4110 810 (23.1%)2242 (21.1%)2263 (21.3%)2242 (21.1%)
SES
 Low11 752 (25.1%)3079 (29.0%)<0.00013023 (28.4%)3079 (29.0%)0.641
 Mid22 973 (49.1%)4785 (45.0%)4796 (45.1%)4785 (45.0%)
 High12 039 (25.8%)2768 (26.0%)2813 (26.5%)2768 (26.0%)
Gender
 Boy23 668 (50.6%)5453 (51.3%)0.2085425 (51.0%)5453 (51.3%)0.701
 Girl23 096 (49.4%)5179 (48.7%)5207 (49.0%)5179 (48.7%)
Intended place of birth
 Home23 329 (49.9%)NA5160 (48.5%)NA
 Hospital18 680 (39.9%)4401 (41.4%)
 Unknown4755 (10.2%)1071 (10.1%)
  • NA, not applicable; SES, socioeconomic status.