Table 1 Background characteristics and delivery details

Maternal age in years: median (range)

25 (17–37)

24 (18–39)

0.58

Parity: median (range)

1 (0–4)

1 (0–4)

0.96

Gravidity: median (range)

2 (1–7)

2 (1–6)

0.69

Gestational age in weeks: median (range)

39 (28–43)

39 (28–43)

0.62

Nulliparous: % (n)

47.3 (213)

48.9 (220)

0.69

Pre-delivery hemoglobin: median (range)

11.2 (6.1–15.3)^b

11.3 (5.5–16.3)^c

0.27

Type of delivery: % (n)

0.90

Vaginal

91.8 (413)

92.2 (415)

Forceps

8.2 (37)

7.8 (35)

Delivery outcome: % (n)

> 0.99

Singleton (live birth)

99.3 (447)

99.1 (446)

Twins (live birth)

0.2 (1)

0.4 (2)

Triplets (live birth)

0.2 (1)

0.0 (0)

Singleton (stillborn)

0.2 (1)

0.2 (1)

Twins (stillborn)

0.0 (0)

0.2 (1)

One or more complications (including vaginal or perineal tears): % (n)

1.1 (5)

2.4 (11)

0.21