This study shows that vaginal deliveries in twin pregnancies are safe and its success rate and safety can be enhanced through structured and regular updates of obstetrical concepts and procedures in obstetric departments. To lower the rate of cesarean deliveries in twin pregnancies, it is key to prevent the first cesarean birth. |
Introduction
Materials and methods
Study population and period
Standardized delivery management of twin pregnancies
Statistical analysis
Ethics statement
Results
Descriptive analysis
Variable | Period I Mean (range)/n (%) | Period II Mean (range)/n (%) | p-value |
---|---|---|---|
Maternal age (years) | 33.1 (18–49) | 32.4 (18–46) | 0.14 |
Gravidity | 1.9 (1–8) | 2.0 (1–9) | 0.18 |
Parity | 1.5 (1–6) | 1.6 (1–7) | 0.09 |
Maternal BMI (initial) | 24.1 (17–47) | 23.9 (16–51) | 0.76 |
Maternal BMI (at birth) | 29.4 (21–55) | 29.1 (19–62) | 0.74 |
Fetal weight (g) | |||
1st twin | 2442 g (1440–3575 g) | 2431 g (660–3670 g) | 0.74 |
2nd twin | 2397 g (890–3610 g) | 2358 g (870–3530 g) | 0.46 |
Fetal weight difference between 1st and 2nd twin (g) | 0.85 | ||
308 g (0–1015 g) | 307 g (0–1870 g) | ||
Fetal sex | |||
1st twin | Female 47.4% | Female 45.5% | 0.73 |
Male 52.6% | Male 54.5% | ||
2nd twin | Female 43.5% | Female 50.1% | 0.14 |
Male 56.5% | Male 49.9% | ||
Planned delivery mode | < 0.001 | ||
Planned cesarean delivery | 146 (63.5%) | 142 (44.0%) | |
Planned vaginal delivery | 84 (36.5%) | 181 (56.0%) | |
Actual delivery mode | < 0.001 | ||
Primary/secondary/emergency cesarean delivery | 186 (80.9%) | 200 (61.9%) | |
Vaginal delivery | 44 (19.1%) | 123 (38.1%) | |
Vaginal delivery success | 0.02 | ||
Secondary/emergency cesarean delivery | 40 (47.6%) | 58 (32.0%) | |
Sucessful vaginal delivery | 44 (52.4%) | 123 (68.0%) | |
Emergency cesarean at trial of vaginal labor | 0.01 | ||
Yes | 14 (16.7%) | 12 (6.6%) | |
No | 70 (83.3%) | 169 (93.4%) | |
Maternal age (years) | 0.09 | ||
> 40 | 12 (5.2%) | 7 (1.3%) | |
≤ 40 | 218 (94.8%) | 316 (97.8%) | |
Previous deliveries | 0.29 | ||
Primiparity | 142 (61.7%) | 173 (53.6%) | |
Previous vaginal delivery | 60 (26.1%) | 101 (31.3%) | |
Previous cesarean delivery | 25 (10.9%) | 43 (13.3%) | |
Previous consecutive vaginal and cesarean delivery | 3 (1.3%) | 6 (1.9%) | |
Gestational age (weeks) | 0.20 | ||
32–34 | 27 (11.7%) | 44 (13.6%) | |
34–36 | 90 (39.1%) | 145 (44.9%) | |
≥ 37 | 113 (49.1%) | 134 (41.5%) | |
Mode of conception | 0.75 | ||
Natural | 150 (65.2%) | 216 (66.9%) | |
ART | 80 (34.8%) | 107 (33.1%) | |
Chorionicity | 0.17 | ||
Monochorionic | 52 (22.6%) | 91 (28.2%) | |
Dichorionic | 178 (77.4%) | 232 (71.8%) | |
Presentation of the fetuses | 0.13 | ||
Vertex/vertex | 161 (70.0%) | 223 (69.0%) | |
Vertex/breech | 47 (20.4%) | 82 (25.4%) | |
Vertex/transverse | 22 (9.6%) | 17 (5.3%) | |
Breech of 1st fetus | 0 (0%) | 1 (0.3%) | |
Fetal weight difference (percentage) | 0.69 | ||
< 20% | 187 (81.7%) | 268 (83.0%) | |
≥ 20% | 43 (18.3%) | 55 (17.0%) |
Predictive factors
Yes, n (%) | No, n (%) | Odds ratio | 95% confidence interval | p-value | |
---|---|---|---|---|---|
Planned cesarean delivery* | |||||
Period I | 146 (63.5%) | 84 (36.5%) | 2.78 | 1.86–4.15 | < 0.0001 |
Period II | 142 (44.0%) | 181 (56.0%) | 1.00 | ||
Successful vaginal delivery** | |||||
Period I | 40 (47.6%) | 44 (52.4%) | 0.49 | 0.28–0.89 | 0.02 |
Period II | 58 (32.0%) | 123 (68.0%) | 1.00 |
Variable | Planned cesarean delivery n = 288 (52.1%) | Planned vaginal delivery n = 265 (47.9%) | Odds ratio | 95% confidence interval | p-value |
---|---|---|---|---|---|
Maternal age (years) | |||||
≤ 40 | 271 (50.8%) | 263 (49.3%) | 0.13 | 0.03–0.62 | 0.01 |
> 40 | 17 (89.5%) | 2 (10.5%) | 1.00 | ||
Parity | |||||
Primiparity | 183 (58.1%) | 132 (41.9%) | 3.12 | 1.97–4.95 | < 0.0001 |
Multiparity | 105 (44.1%) | 133 (55.9%) | 1.00 | ||
Previous deliveries | |||||
Previous cesarean birth | 59 (76.6%) | 18 (23.4%) | 13.01 | 6.49–26.1 | < 0.001 |
No previous cesarean birth | 229 (48.1%) | 247 (51.9%) | 1.00 | ||
Gestational age (weeks) | |||||
32–33 | 55 (77.5%) | 16 (22.5%) | 5.65 | 2.79–11.4 | < 0.0001 |
34–36 | 130 (55.3%) | 105 (44.7%) | 2.04 | 1.35–3.09 | 0.0008 |
≥ 37 | 103 (41.7%) | 144 (58.3%) | 1.00 | ||
Chorionicity | |||||
Monochorionic | 86 (60.1%) | 57 (39.9%) | 1.94 | 1.21–3.13 | 0.006 |
Dichorionic | 202 (49.3%) | 208 (50.7%) | 1.00 | ||
Presentation of the fetuses | |||||
Vertex/vertex | 186 (48.6%) | 197 (51.4%) | 0.74 | 0.48–1.15 | 0.18 |
Other | 102 (60.0%) | 68 (40.0%) | 1.00 | ||
Mode of conception | |||||
Natural | 180 (49.2%) | 186 (50.8%) | 0.68 | 0.44–1.06 | 0.08 |
ART | 108 (57.8%) | 79 (42.3%) | 1.00 | ||
Maternal BMI (at birth) | |||||
Ø 28.9 | Ø 29.5 | 0.99 | 0.95–1.02 | 0.45 | |
Fetal weight difference (continuous per 100 g) | |||||
Ø 341 g | Ø 272 g | 1.17 | 1.07–1.27 | 0.0005 | |
Fetal weight difference (categorical) | |||||
≥ 20% | 72 (73.5%) | 26 (26.5%) | 2.95 | 1.68–5.16 | 0.0002 |
< 20% | 216 (47.6%) | 239 (52.5%) |
Variable | Planned vaginal delivery: secondary cesarean delivery n = 98 (37.0%) | Planned vaginal delivery: succesful vaginal delivery n = 167 (63.0%) | Odds ratio | 95% confidence interval | p-value |
---|---|---|---|---|---|
Maternal age (years) | |||||
≤ 40 | 96 (36.5%) | 167 (63.5%) | > 999.9 | < 0.001–> 999.9 | 0.98 |
> 40 | 2 (100%) | 0 (0%) | 1.00 | ||
Parity | |||||
Primiparity | 69 (52.3%) | 63 (47.7%) | 1.29 | 0.41–4.07 | 0.67 |
Multiparity | 29 (21.8%) | 104 (78.2%) | 1.00 | ||
Previous deliveries | |||||
Previous vaginal delivery | 21 (17.8%) | 97 (82.2%) | 7.88 | 2.38–26.04 | 0.0007 |
No previous vaginal delivery | 77 (52.4%) | 70 (47.6%) | |||
Gestational age (weeks) | |||||
32–33 | 6 (37.5%) | 10 (62.5%) | 1.14 | 0.34–3.82 | 0.83 |
34–36 | 31 (29.5%) | 74 (70.5%) | 1.84 | 1.00–3.39 | 0.049 |
≥ 37 | 61 (42.4%) | 83 (57.6%) | 1.00 | ||
Chorionicity | |||||
Monochorionic | 20 (35.1%) | 37 (64.9%) | 0.88 | 0.44–1.76 | 0.72 |
Dichorionic | 78 (37.5%) | 130 (62.5%) | 1.00 | ||
Presentation of the fetuses | |||||
Vertex/vertex | 71 (36.0%) | 126 (64.0%) | 1.87 | 0.96–3.66 | 0.06 |
Other | 27 (39.7%) | 41 (60.3%) | 1.00 | ||
Mode of conception | |||||
Natural | 65 (35.0%) | 121 (65.1%) | 0.91 | 0.48–1.74 | 0.78 |
ART* | 33 (41.8%) | 46 (58.2%) | 1.00 | ||
Maternal BMI (at birth) | |||||
Ø 30.0 | Ø 29.2 | 0.98 | 0.93–1.03 | 0.44 | |
Fetal weight difference (OR continuous per 100 g) | |||||
Ø 266 g | Ø 274 g | 1.06 | 0.92–1.22 | 0.44 | |
Fetal weight difference (categorical) | |||||
≥ 20% | 8 (30.8%) | 18 (69.2%) | 1.79 | 0.66–4.85 | 0.25 |
< 20% | 90 (37.7%) | 149 (62.3%) |
Neonatal outcome
Twin | Planned cesarean delivery n = 576 (%) n = 310 for ≥ 36 + gestational weeks | Planned vaginal delivery, secondary cesarean delivery n = 170 (%) n = 131 for ≥ 36 + gestational weeks | Planned vaginal delivery, successful vaginal delivery n = 360 (%) n = 261 for ≥ 36 + gestational weeks | p-value |
---|---|---|---|---|
Umbilical artery pH < 7.2 | ||||
1st | 4 (1.4%) | 3 (4.2%) | 6 (3.1%) | 0.26 |
2nd | 16 (5.6%) | 15 (15.3%) | 47 (28.3%) | < 0.0001 |
APGAR score at 5 min < 7 | ||||
1st | 22 (7.6%) | 7 (9.7%) | 14 (7.3%) | 0.79 |
2nd | 20 (6.9%) | 14 (14.3%) | 25 (15.0%) | 0.01 |
Transfer to NICU | ||||
1st | 104 (36.1%) | 9 (12.5%) | 39 (20.2%) | < 0.0001 |
2nd | 116 (40.3%) | 28 (28.6%) | 31 (18.6%) | < 0.0001 |
Transfer to NICU (≥ 36 + gestational weeks) | ||||
1st | 6 (3.9%) | 3 (5.2%) | 7 (5.1%) | 0.86 |
2nd | 12 (7.7%) | 9 (12.3%) | 8 (6.5%) | 0.34 |
Monochorionic | Dichorionic | |||||||
---|---|---|---|---|---|---|---|---|
Twin | Planned cesarean delivery n = 172 (%) | Secondary cesarean delivery n = 36 (%) | Vaginal delivery n = 78 (%) | p-value | Planned cesarean delivery n = 404 (%) | Secondary cesarean delivery n = 134 (%) | Vaginal delivery n = 282 (%) | p-value |
Umbilical artery pH < 7.2 | ||||||||
1st | 2 (2.3%) | 1 (6.3%) | 0 (0.0%) | 0.33 | 2 (1.0%) | 2 (3.6%) | 6 (4.0%) | 0.17 |
2nd | 5 (5.8%) | 3 (15.0%) | 6 (16.2%) | 0.14 | 11 (5.5%) | 12 (31.8%) | 12 (15.4%) | < 0.0001 |
APGAR score at 5 min < 7 | ||||||||
1st | 10 (11.6%) | 3 (18.8%) | 4 (9.8%) | 0.64 | 12 (5.9%) | 4 (7.1%) | 10 (6.6%) | 0.94 |
2nd | 6 (7.0%) | 2 (10.0%) | 5 (13.5%) | 0.51 | 14 (6.9%) | 12 (15.4%) | 20 (15.4%) | 0.02 |
Transfer to NICU | ||||||||
1st | 42 (48.8%) | 6 (37.5%) | 7 (17.1%) | 0.003 | 62 (30.7%) | 3 (5.4%) | 32 (21.1%) | 0.0003 |
2nd | 45 (52.3%) | 9 (45.0%) | 6 (16.2%) | 0.0009 | 71 (35.2%) | 19 (24.4%) | 25 (19.2%) | 0.005 |
Transfer to NICU (≥ 36 + gestational weeks) | ||||||||
1st | 2 (5.4%) | 2 (22.2%) | 2 (6.5%) | 0.22 | 4 (3.4%) | 1 (2.0%) | 5 (4.7%) | 0.69 |
2nd | 3 (8.1%) | 1 (10.0%) | 4 (12.9%) | 0.81 | 9 (7.6%) | 8 (12.7%) | 4 (4.4%) | 0.16 |
Twin | Interval < 30 min n = 50 (%) | Interval ≥ 30 min n = 32 (%) | p-value |
---|---|---|---|
Umbilical artery pH < 7.2 | |||
1st | 1 (4.0%) | 2 (13.3%) | 0.64 |
2nd | 8 (32.0%) | 7 (47.7%) | 0.55 |
APGAR score at 5 min < 7 | |||
1st | 0 (0.0%) | 2 (12.5%) | 0.28 |
2nd | 4 (16.0%) | 5 (31.3%) | 0.45 |
Transfer to NICU | |||
1st | 5 (20.0%) | 7 (43.75%) | 0.20 |
2nd | 5 (20.0%) | 6 (37.5%) | 0.38 |
Transfer to NICU (≥ 36 + gestational weeks) | |||
1st | 1 (5.9%) | 1 (11.1%) | 1.00 |
2nd | 2 (11.8%) | 0 (0%) | 0.77 |