Table 1 Characteristics included in definitions of onset of labor
From: Diagnosing onset of labor: a systematic review of definitions in the research literature
| Characteristic included | N (%) |
|---|---|
| Type of labor defined | |
| Latent | 3 (5) |
| First stage | 11 (18) |
| Active | 22 (35) |
| Labor (unspecified) | 15 (24) |
| More than one of the above | 11 (18) |
| Cervical dilation | 42 (68) |
| In latent phase labor | |
| < 2 cm | 1 (2) |
| 3–4 cm | 3 (5) |
| > 4 cm | 7 (11) |
| In active labor | |
| ≥ 2 cm | 2 (3) |
| 3–4 cm | 10 (16) |
| > 4 cm | 14 (23) |
| In first stage labor | |
| 3–4 cm | 4 (6) |
| > 4 cm | 1 (2) |
| In unspecified labor | |
| ≥ 2 cm | 2 (3) |
| 3–4 cm | 2 (3) |
| > 4 cm | 2 (3) |
| Cervical effacement | 12 (19) |
| Regular painful contractions | 44 (71) |
| Frequency of contractions | 12 (19) |
| 1 in 8–10 min | 3 (5) |
| 2 in 10 min or five minutes apart | 3 (5) |
| 3 in 10 min | 5 (8) |
| 1 every 3–5 mins | 2 (3) |
| Other physiological symptoms | 7 (11) |
| Rationale for definition | |
| Referred to women’s reports of onset or routine clinical practice | 11 (18) |
| Cited Friedman | 8 (13) |
| Cited Gross | 4 (6) |
| Cited textbooks | 3 (5) |
| Cited another study | 2 (3) |