Fetal head position during the second stage of labor: comparison of digital vaginal examination and transabdominal ultrasonographic examination.
ABSTRACT To study the correlation between digital vaginal and transabdominal ultrasonographic examination of the fetal head position during the second stage of labor.
Patients (n = 110) carrying a singleton fetus in a vertex position were included. Every patient had ruptured membranes and a fully dilated cervix. Transvaginal examination was randomly performed either by a senior resident or an attending consultant. Immediately afterwards, transabdominal ultrasonography was performed by the same sonographer (OD). Both examiners were blind to each other's results. Sample size was determined by power analysis. Confidence intervals around observed rates were compared using chi-square analysis and Cohen's Kappa test. Logistic regression analysis was performed.
In 70% of cases, both clinical and ultrasound examinations indicated the same position of the fetal head (95% confidence interval, 66-78). Agreement between the two methods reached 80% (95% CI, 71.3-87) when allowing a difference of up to 45 degrees in the head rotation. Logistic regression analysis revealed that gestational age, parity, birth weight, pelvic station and examiner's experience did not significantly affect the accuracy of the examination. Caput succedaneum tended to diminish (p = 0.09) the accuracy of clinical examination. The type of fetal head position significantly affected the results. Occiput posterior and transverse head locations were associated with a significantly higher rate of clinical error (p = 0.001).
In 20% of the cases, ultrasonographic and clinical results differed significantly (i.e., >45 degrees). This rate reached 50% for occiput posterior and transverse locations. Transabdominal ultrasonography is a simple, quick and efficient way of increasing the accuracy of the assessment of fetal head position during the second stage of labor.
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ABSTRACT: Objective To determine risk factors for the occurrence of third degree perineal tears during vaginal delivery.Design A population-based observational study.Population All 284,783 vaginal deliveries in 1994 and 1995 recorded in the Dutch National Obstetric Database were included in the study.Methods Third degree perineal rupture was defined as any rupture involving the anal sphincter muscles. Logistic regression analysis was used to assess risk factors.Main outcome measures An overall rate of third degree perineal ruptures of 1.94% was found. High fetal birthweight, long duration of the second stage of delivery and primiparity were associated with an elevated risk of anal sphincter damage. Mediolateral episiotomy appeared to protect strongly against damage to the anal sphincter complex during delivery (OR: 0.21, 95% CI: 0.20–0.23). All types of assisted vaginal delivery were associated with third degree perineal ruptures, with forceps delivery (OR: 3.33, 95%-CI: 2.97–3.74) carrying the largest risk of all assisted vaginal deliveries. Use of forceps combined with other types of assisted vaginal delivery appeared to increase the risk even further.Conclusions Mediolateral episiotomy protects strongly against the occurrence of third degree perineal ruptures and may thus serve as a primary method of prevention of faecal incontinence. Forceps delivery is a stronger risk factor for third degree perineal tears than vacuum extraction. If the obstetric situation permits use of either instrument, the vacuum extractor should be the instrument of choice with respect to the prevention of faecal incontinence.BJOG An International Journal of Obstetrics & Gynaecology 02/2003; 110(1):90; author reply 90. · 3.76 Impact Factor
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ABSTRACT: To assess the feasibility of transabdominal ultrasound for determining fetal head position in laboring women and compare it to digital examination, and to study ultrasonographically the rotation of the fetal head in normal and obstructed labor. This was an observational prospective study of 148 women in active labor. Ultrasound examinations were performed longitudinally in the first and second stages of labor. Assessment of the fetal head position by digital examination was not possible in 60.7% (122/201) of cases in the first stage and 30.8% (41/133) in the second stage of labor. Difficulty in assessing the position was more likely if the occiput was posterior in comparison to anterior and in the maternal right in comparison to the left side. In the second stage, it was three times more likely for the assessment not to be possible digitally if the occiput was posterior. In the cases when assessment by vaginal examination was possible, the correlation with ultrasound was average in the first stage (kappa = 0.59) and good in the second stage (kappa = 0.77). Overall fetal head position assessment by digital examination was accurate in 31.28% of the cases in the first stage and 65.7% of the cases in the second stage of labor. Rotation of the fetal head is highly unlikely when labor begins in the occipital anterior position. Persistent occipital posterior position developed through failure to rotate from an initial occipital posterior or transverse position. Duration of the first stage of labor was independently related to parity and position of the fetal spine at presentation, and duration of the second stage of labor was independently related to parity, birth weight, position of the fetal head at the beginning of the second stage, rotation and position of the head at delivery. Ultrasound assessment of the fetal head position in labor is feasible in a busy labor ward. Digital examination is less accurate than ultrasound, in particular in cases of obstructed labor when medical intervention is more likely to be needed. Ultrasound assessment may prove useful in the prediction and diagnosis of difficult and prolonged labor.Journal of Maternal-Fetal and Neonatal Medicine 02/2003; 13(1):59-63. · 1.52 Impact Factor
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ABSTRACT: To investigate the accuracy of intrapartum transvaginal digital examination in defining the position of the fetal head before instrumental delivery. In 64 singleton pregnancies undergoing instrumental delivery the fetal head position was determined by transvaginal digital examination by the attending obstetrician. Immediately after or before the clinical examination, the fetal head position was determined by transabdominal ultrasound by a trained sonographer who was not aware of the clinical findings. The digital examination was considered to be correct if the fetal head position was within +/- 45 degrees of the ultrasound finding. The accuracy of the digital examination was examined in relation to maternal and fetal characteristics. Digital examination failed to define the correct fetal head position in 17 (26.6%) cases. In 12 of 17 (70.6%) errors the difference was >/= 90 degrees and in five (29.4%) the difference was between 45 degrees and 90 degrees. The accuracy of vaginal digital examination was 83% for occiput-anterior and 54% for occiput-lateral + occiput-posterior positions. Logistic regression analysis demonstrated significant independent contributions in explaining the variance in the accuracy of vaginal examination for the station of the fetal head, the position of the fetal head and the experience of the examining obstetrician. Digital examination during instrumental delivery fails to identify the correct fetal head position in about one quarter of cases.Ultrasound in Obstetrics and Gynecology 05/2003; 21(5):437-40. · 3.56 Impact Factor