RESUMEN
OBJECTIVE: Obstetric forceps play an important role in safe childbirth, yet there is a lack of distinction between various forceps types in clinical practice. This study aimed to evaluate and compare perineal pressure and forces on the baby during nonrotational forceps-assisted births using Simpson-Braun forceps, Kielland forceps, and Thierry spatulas on a simulation model. METHODS: This experimental study involved six obstetricians conducting 108 forceps-assisted births on a simulation model. Instruments were assessed for their impact on perineal pressure, traction force, and operator-assessed difficulty. RESULTS: Thierry's spatulas exerted the lowest force on the baby, while Kielland forceps exhibited the lowest perineal pressure, though not statistically significant. An experienced obstetrician demonstrated less perineal pressure with Simpson forceps. Notably, no significant differences in difficulty were observed between instruments. CONCLUSION: This study highlights distinctions in forceps performance, with Thierry spatulas applying the least force on the fetal head, while an experienced obstetrician fared better with Simpson forceps in terms of perineal pressure. Kielland forceps remain a viable alternative for nonrotational forceps births, showing comparable outcomes.
RESUMEN
OBJECTIVE: This study aimed to assess whether intrapartum ultrasound (ITU) measurements in maternal lateral posture are superimposable to ITU measurements in semi-recumbent position. STUDY DESIGN: A single-center, repeated measures design was used. Women in the second stage of labor were randomized to ITU first in semi-recumbent followed by ITU in side-lying posture without and with contraction, or inversely. The angle of progression (AOP) and the head-perineum distance (HPD) between contractions (AOP1 and HPD1) and with contraction (AOP2 and HPD2) were measured in each maternal posture. The differences between AOP1 and AOP2 (dAOP), and between HPD1 and HPD2 (dHPD) were calculated. RESULTS AND CONCLUSIONS: Forty-two women participated in the study. A generalized estimating equation model showed that AOP1 (-3.00°; 95 % CI -5.77 to -0.23; p = 0.03) and AOP2 (-4.14°; 95 % CI -7.20 to -1.08; p = 0.008) were lower in semi-recumbent compared to maternal lateral posture. HPD1 (+1.43 mm; 95 % CI 0.05-2.81; p = 0.042) and HPD2 (+1.53 mm; 95 % CI 0.17-2.89; p = 0.03) were higher in semi-recumbent position. Differences in the ITU measurements in maternal lateral posture compared to semi-recumbent position are small. Monitoring the second stage of labor with ITU in lateral maternal posture is possible.