Table 5.
Clinical characteristics and obstetric interventions among multiparous women with OASIS and women without OASIS. Data are presented in frequencies (and numbers). p-Values from χ2 test
| 2003–2005 |
2008–2010 |
|||
|---|---|---|---|---|
| Multiparous women | OASIS | Non-OASIS | OASIS | Non-OASIS |
| Deliveries | n=102 | n=6634 | n=53 | n=8032 |
| Incidence OASIS | 1.5 (102/6634) | 0.7 (53/8032) | ||
| Risk factors | % | % | ||
| Age (years) | p=0.79 | p=0.71 | ||
| 15–29 | 24.5 (n=25) | 27.5 (n=1824) | 17 (n=9) | 21.4 (n=1721) |
| 30–34 | 44.1 (n=45) | 41.9 (n=2778) | 41.5 (n=22) | 40.6 (n=3265) |
| 35–51 | 31.4 (n=32) | 30.6 (n=2032) | 41.5 (n=22) | 37.9 (n=3046) |
| Birthweight (g) | p<0.001 | p<0.001 | ||
| 720–2999 | 2.9 (n=3) | 11.9 (n=791) | 9.4 (n=5) | 11.6 (n=933) |
| 3000–3499 | 17.6 (n=18) | 32.8 (n=2173) | 18.9 (n=10) | 32.1 (n=2581) |
| 3500–3999 | 32.4 (n=33) | 36.4 (n=2414) | 35.8 (n=19) | 37.5 (n=3010) |
| 4000–4499 | 33.3 (n=34) | 15.3 (n=1015) | 17 (n=9) | 15.4 (n=1238) |
| 4500–5850 | 13.7 (n=14) | 3.6 (n=241) | 18.9 (n=10) | 3.4 (n=270) |
| Delivery method | p<0.001 | p<0.001 | ||
| Spontaneous | 89.2 (n=91) | 96.3 (n=6388) | 84.9 (n=45) | 96.5 (n=7748) |
| Ventouse | 7.8 (n=8) | 3.4 (n=226) | 15.1 (n=8) | 3.3 (n=265) |
| Forceps | 2.9 (n=3) | 0.3 (n=20) | 0 (n=0) | 0.2 (n=19) |
| Episiotomy, all vaginal deliveries | p=0.33 | p<0.001 | ||
| 9.8 (n=10) | 7.3 (n=482) | 22.6 (n=12) | 8 (n=644) | |
| Episiotomy, spontaneous deliveries | p=0.80 | p=0.43 | ||
| 5.5 (n=5) | 6.1 (n=391) | 13.3 (n=6) | 6.1 (n=471) | |
| Episiotomy, instrumental deliveries | p=0.57 | p=0.42 | ||
| 45.5 (n=5) | 37 (n=91) | 75 (n=6) | 60.9 (n=173) | |
| Duration second stage (min) | p<0.001 | p < 0.001 | ||
| 0–09 | 19.6 (n=20) | 34.9 (n=2315) | 18.9 (n=10) | 29.6 (n=2380) |
| 10–29 | 49 (n=50) | 49.9 (n=3311) | 39.6 (n=21) | 55.8 (n=4484) |
| 30–59 | 23.5 (n=24) | 12.3 (n=815) | 30.2 (n=16) | 11.7 (n=941) |
| 60–205 | 6.9 (n=7) | 2.5 (n=167) | 9.4 (n=5) | 2.7 (n=214) |
| Missing data (n=4/n=27) | 1 (n=1) | 0.4 (n=26) | 1.9 (n=1) | 0.2 (n=13) |
| Epidural | p=0.21 | p=0.36 | ||
| 19.6 (n=20) | 14.9 (n=988) | 22.6 (n=12) | 17.5 (n=1407) | |
| Shoulder dystocia | p=0.001 | p<0.001 | ||
| 4.9 (n=5) | 1.2 (n=82) | 5.7 (n=3) | 0.9 (n=70) | |
| Occiput posterior presentation | p=0.39 | p=0.046 | ||
| 1 (n=1) | 2.2 (n=149) | 7.5 (n=4) | 2.9 (n=233) | |
| Induced labour | p=0.62 | p=0.80 | ||
| 11.8 (n=12) | 13.4 (n=891) | 17 (n=9) | 15.7 (n=1260) | |
OASIS, obstetric anal sphincter injuries.