Table 2 Distribution of maternal outcomes comparing women ≥ 35 years to younger women in bivariate analyses

Whole population (elective c-section and trial of labor populations)

Maternal outcomes

< 35 years

(n = 39,496) ^$$

≥ 35 years

(n = 4,799)

RR

95% CI

Pvalue

N (%)

N (%)

Cesarean sections

4472 (11.3)

1116 (23.3)

2.05

1.94–2.18

< 0.0001

Postpartum hemorrhage^@

2720 (9.22)

271 (7.92)

0.86

0.76–0.97

< 0.0001

Maternal length of stay, days (for c-sections)

Mean (SD)

5.87 (6.76)

5.52 (2.56)

Mean difference

-0.35

-0.63- -0.07

0.014

Maternal length of stay, days (for vaginal deliveries)

Mean (SD)

3.82 (2.92)

3.98 (1.75)

Mean difference

0.17

0.06–0.27

0.0018

Trial of labor population (excluding cases of elective c-sections)

< 35 years

(n = 38,595)^$$

≥ 35 years

(n = 4,261)

RR

95% CI

P value

Cesarean sections

3571 (9.3)

578 (13.6)

1.47

1.35–1.59

< 0.0001

Prolonged Second stage ^#

3906(11.01)

317 (8.55)

0.78

0.70–0.87

< 0.0001

Population of vaginal delivery

< 35 years

(n = 35,024)^$$

≥ 35 years

(n = 3,683)

RR

95% CI

P value

Instrumental Delivery

5751 (16.4)

500 (13.6)

0.83

0.76–0.90

< 0.0001

Tears (3rd -and 4th - degree tears)

248 (7.1)

13 (3.5)

0.50

0.29–0.87

0.0122

Induced population

< 35 years

(n = 7,526)

≥ 35 years

(n = 982)

RR

95% CI

P value

Cesarean sections

1064 (14.1)

189 (19.2)

1.36

1.18–1.57

< 0.0001