Table 1 Patient characteristics

Baseline characteristics, mean (range)

 Age (years)

37.1 (23–53)

 Gravidity

2.2 (0–6)

 Parity

2.0 (0–5)

 Weight (kg)

72.0 (49.2–131)

 Cycle day

23.1 (1–66)

Method of contraception, number (%)

 Hormonal

42 (50%)

 Oral contraceptive pill

31

 Evra patch

4

 Depo-Provera

6

 Mirena

1

Non-hormonal

42 (50%)

 Barrier

24

 Other

4

 None

11

 Not recorded

3

 Cycle day

Number (%)

 0–10^a

30 (36%)

 11–20

22 (26%)

 >20

32 (38%)

Method of sedation, number (%)

 Oral

26 (31%)

 Intravenous

58 (69%)