Table 1 Background, obstetric and neonatal variables among women who had their first child between 2006 and 2016

Age (mean, standard deviation, 1–99% percentiles)

30.0, ± 5.9, 18–43

28.5, ± 5.2, 18–41

n

%

n

%

Artificial reproductive technologies

892

8.0

17,408

5.7

 < 0.001

Psychiatric disorder before or during first pregnancy^a

3065

27.6

31,316

10.2

 < 0.001

Psychiatric disorder five years following first delivery^a

550

5.0

9781

3.2

 < 0.001

Medium level of education

4507

40.6

128,046

41.8

0.008

High level of education

4747

42.7

134,133

43.8

0.024

Married or cohabiting

9207

81.3

26,465

86.1

 < 0.001

Migrant origin

973

8.8

29,621

9.7

0.001

Premature birth before gestational age 37 weeks + 0

643

5.8

18,251

6.0

0.448

Birthweight < 2500 g

301

2.7

12,204

4.0

 < 0.001

Congenital anomalies diagnosed at birth

773

7.0

17,980

5.9

 < 0.001

Spontaneous vaginal delivery^c

4179

37.6

197,541

64.5

 < 0.001

Assisted vaginal delivery^c

1331

12.0

49,681

16.2

 < 0.001

Planned caesarean section^c

3509

31.6

13,488

4.4

 < 0.001

Emergency caesarean section^c

2089

18.8

45,390

14.8

 < 0.001

Spinal, epidural, or combined anaesthesia^b

4787

86.9

189,109

76.5

 < 0.001

Other analgesia^b

4813

87.4

207,084

83.8

 < 0.001

Manual placenta removal^b

143

2.6

5179

2.5

0.001

Third -or fourth degree perineal tear^b

116

2.1

4950

2.3

 < 0.001

Uterine curettage

51

0.5

2373

0.8

 < 0.001

Blood transfusion

411

3.7

9882

3.2

0.006

Infant treated in neonatal intensive care unit

1342

12.1

40,078

13.1

0.002

Apgar score at 5 min < 7

311

2.8

8686

2.8

0.814

Umbilical artery pH < 7.05

101

0.9

4795

1.6

 < 0.001