Table 1.
Baseline values and observed changes related to fluids given until birth. Group differences analysed using Kruskal–Wallis nonparametric ANOVA and Mann–Whitney U test
| Control group elective caesarean (n = 26) | Total fluids given until birth | Kruskal–Wallis P value | Mann–Whitney P value | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Fluid group 1 <1000 ml (n = 113) | Fluid group 2 1000–2500 ml (n = 87) | Fluid group 3 >2500 ml (n = 61) | ||||||||
| Median | Q1–Q3 | Median | Q1–Q3 | Median | Q1–Q3 | Median | Q1–Q3 | |||
| Mother | ||||||||||
| Age | 32 | 27–35 | 31 | 28–34 | 30 | 27–33 | 30 | 26–33 | 0.117 | |
| Weight before pregnancy (kg) | 67 | 58–78 | 66 | 59–73 | 67 | 60–77 | 66 | 60–77 | 0.750 | |
| Body mass index before pregnancy | 26.2 | 22.6–28.1 | 23.7 | 21.0–25.5 | 24.1 | 21.5–27.9 | 23.9 | 22.1–27.1 | 0.066 | |
| Weight at term (kg) | 83 | 72–89 | 79 | 71–89 | 80 | 74–90 | 83 | 74–91 | 0.399 | |
| Weight increase | 12 | 10–18 | 13 | 11–16 | 14 | 10–17 | 15 | 11–19 | 0.466 | |
| Gestational weeks | 38.5 | 38.3–38.7 | 39.7 | 39.0–40.6 | 40.0 | 39.1–40.9 | 40.3 | 39.6–41.0 | 0.087 | |
| Cervical dilatation at admission (cm) | — | — | 5.0 | 4.0–7.0 | 4.0 | 3.0–4.0 | 3.0 | 2.0–4.0 | <0.001 | <0.001 |
| Duration of labour (hours) | — | — | 1.6 | 0.9–3.0 | 5.9 | 4.3–8.9 | 12.2 | 9.8–14.7 | <0.001 | <0.001 |
| Duration second stage (hours) | — | — | 0.2 | 0.1–0.5 | 0.5 | 0.2–1.0 | 0.6 | 0.4–1.0 | <0.001 | <0.001 |
| Oral fluids (ml/hour) | 0 | 0–0 | 185 | 79–316 | 196 | 136–305 | 196 | 154–263 | 0.429 | |
| Intravenous fluid (ml/hour) | Not measured | Not measured | 0 | 0–0 | 52 | 3–102 | 94 | 53–144 | <0.001 | <0.001 |
| Total fluid (ml/hour) | Not measured | Not measured | 194 | 100–325 | 291 | 201–362 | 314 | 260–360 | <0.001 | <0.001 |
| Total fluid (ml) | Not measured | Not measured | 400 | 200–575 | 1680 | 1355–2050 | 3570 | 2925–4355 | — | |
| Oxytocin (ml) | — | — | 0 | 0–0 | 50 | 0–166 | 200 | 100–400 | <0.001 | <0.001 |
| Oxytocin (units) | — | — | 0.0 | 0.0–0.0 | 1.0 | 0.0–3.3 | 4.0 | 2.0–8.0 | <0.001 | <0.001 |
| Oxytocin (maximum rate mU/minute)* | — | — | 10 | 5–20 | 20 | 10–30 | 40 | 20–60 | <0.001 | <0.001 |
| Duration epidural (hours) | — | — | 1.7 | 1.7–1.7 | 4.3 | 2.9–6.1 | 8.8 | 6.8–10.6 | — | |
| Osmolality at baseline (mOsm/kg) | 279 | 277–281 | 280 | 277–282 | 280 | 276–282 | 279 | 277–281 | 0.501 | |
| Osmolality postpartum (mOsm/kg) | 280 | 277–282 | 282 | 279–284 | 277 | 276–281 | 274 | 272–277 | <0.001 | <0.001** |
| Na at baseline (mmol/l) | 137 | 136–138 | 137 | 136–137 | 136 | 135–137 | 136 | 135–138 | 0.238 | |
| Na postpartum (mmol/l) | 137 | 137–138 | 136 | 135–137 | 135 | 133–136 | 133 | 130–135 | <0.001 | <0.001** |
| Na change (mmol/l) | 0.0 | −1.0 to 1.0 | 0.0 | −1.0 to 1.0 | −2.0 | −3.0 to −1.0 | −3.0 | −5.0 to −1.0 | <0.001 | <0.001** |
| Glucose at baseline (mmol/l) | 5.0 | 4.5–5.5 | 5.1 | 4.7–5.8 | 5.2 | 4.9–5.9 | 5.3 | 4.8–6.2 | 0.133 | |
| Glucose postpartum (mmol/l) | 4.8 | 4.2–5.1 | 6.7 | 5.9–7.9 | 7.7 | 6.5–9.4 | 7.8 | 6.9–9.4 | <0.001 | <0.001** |
| Umbilical cord | ||||||||||
| Arterial BE | −2.0 | −3.0 to −1.0 | −4.0 | −6.0 to −3.0 | −5.0 | −7.0 to −3.0 | −6.0 | −9.0 to −3.0 | <0.001 | 0.006** |
| Arterial pH | 7.27 | 7.24–7.29 | 7.26 | 7.22–7.31 | 7.24 | 7.19–7.29 | 7.24 | 7.17–7.29 | 0.042 | 0.014*** |
| Arterial Na (mmol/l) | 139 | 138–140 | 139 | 137–140 | 137 | 136–139 | 136 | 134–138 | <0.001 | <0.001** |
| Arterial–venous Na difference (mmol/l) | 1.0 | 0.0–1.0 | 1.0 | 0.0–2.0 | 1.0 | 0.0–2.0 | 1.0 | 0.0–2.0 | 0.736 | |
| Arterial glucose (mmol/l) | 3.4 | 3.0–3.7 | 4.2 | 3.6–5.0 | 5.2 | 4.2–6.1 | 5.4 | 4.7–6.6 | <0.001 | <0.001** |
| Infant | ||||||||||
| Birthweight (g) | 3415 | 3120–3790 | 3535 | 3305–3850 | 3670 | 3360–4160 | 3805 | 3580–4040 | 0.001 | 0.001** |
All group differences are compared with Kruskal–Wallis nonparametric analysis of variance (ANOVA). When significant differences are found, Mann–Whitney U test is performed to analyse differences between fluid groups 1 and 3.
Including only subjects who received oxytocin. Maximum rate mU/minute: maximum rate of oxytocin infusion during first stage of labour.
Differences between control group elective caesarean and fluid group 3: P < 0.001 (Mann–Whitney) (additional significant test).
Difference between control group elective caesarean and fluid group 3: P = 0.14 (Mann–Whitney) (additional significant test).