3. Results
The total number of deliveries in the study period was 45,166, of which 1.92% (n = 869) were twin pregnancies. Of these 295 twin pregnancies with the first twin in vertex presentation and meeting the study criteria, 30.16% (n = 89) were in the VB group, while the remaining 69.84% (n = 206) were in the CB group. In the VB group, all the first twins with vertex presentation were delivered via VB, while of the second twins, 82.03% (n = 73) were delivered by VB, and the remaining 17.97% (n = 16) were delivered via CB. The distribution of all births that included twins during this period is summarized in Figure 1.
A comparison of the demographic characteristics of the two groups is shown in Table 1. The VB and CB groups presented the following average respective results: maternal age 32.28±5.19 and 32.36±5.24; gravida 2.55±1.12 and 2.58±1.90; parity 1.57±1.13 and 1.61±1.91; BMI (kg/m2) 23.7 ± 4.7 and 24.7 ± 4.6; in vitro fertilization 47.19% (n = 42) and 49.5% (n = 102).  The failure of intrauterine maneuvers was most frequently observed for cesarean indication of the second twin (n=6, 37.5%) (Table 2).
A comparison of the clinical characteristics of the two groups is shown in Table 3. When comparing the groups, VB and CB presented the following respective results; birth weight of first twin 2370±441 g and 2362±374 g; birth weight of second twin 2363±414 g and 2361±403 g; five-minute APGAR of first twin 9.13±0.74 and 9.11±0.89; five-minute APGAR of second twin 8.81±1.77 and 8.90±1.18; rate of second twin’s five-minute APGAR<7 5.6% (n = 5) and 3.9% (n = 8); birth trauma 1.12% (n = 1) and 1.45% (n =3) (p˃0.05). For the remaining characteristics, the VB and CB groups presented the following respective results: ENMR 2.24% (n = 2) and 0.97% (n = 2). These results were considered statistically significant (p = 0.006). When considering the distribution of early neonatal death cases in the two death cases in both the VB and the CB group occurred in the preterm groups. In addition, these four neonatal death cases were the vertex presentation, dichorionic diamniotic, did not have intrauterine growth retardation and inter-twin weight discordance too.