Fetal head progression and regression on maternal pushing at term and labor outcome.

OBJECTIVES: The aim of our study was two-fold. First, to evaluate the association between the change in the angle of progression (AoP) on maternal pushing and labor outcome. Second, to assess the incidence and clinical significance of the reduction of AoP on maternal pushing. METHODS: This was a prospective cohort study of nulliparous women with singleton pregnancy at term. AoP was measured at rest and on maximum Valsalva maneuver before the onset of labor, and the difference between AoP on maximum Valsalva and that at rest (ΔAoP) was calculated for each woman. Following delivery and data collection, we assessed the association between ΔAoP and various labor outcomes, including Cesarean section (CS), duration of the first, second and active second stages of labor, Apgar score and admission to the neonatal intensive care unit (NICU). The prevalence of women with reduction of AoP on maximum Valsalva maneuver (AoP-regression group) was calculated and its association with the mode of delivery and duration of different stages of labor was assessed. RESULTS: Overall, 469 women were included in the analysis. Among these, 273 (58.2%) had spontaneous vaginal birth, 65 (13.9%) had instrumental delivery and 131 (27.9%) underwent CS. Women in the CS group were older, had narrower AoP at rest and on maximum Valsalva, higher rate of epidural administration and lower 1-min and 5-min Apgar scores in comparison with the vaginal-delivery group. ΔAoP was comparable between the two groups. On Pearson's correlation analysis, AoP at rest and on maximum Valsalva maneuver had a significant negative correlation with the duration of the first stage of labor. ΔAoP showed a significant negative correlation with the duration of the active second stage of labor (Pearson's r, -0.125; P = 0.02). Cox regression model analysis showed that ΔAoP was associated independently with the duration of the active second stage (hazard ratio, 1.014 (95% CI, 1.003-1.025); P = 0.012) after adjusting for maternal age and body mass index. AoP reduction on maximum Valsalva was found in 73 (15.6%) women. In comparison with women who showed no change or an increase in AoP on maximum Valsalva, the AoP-regression group did not demonstrate significant difference in maternal characteristics, mode of delivery, rate of epidural analgesia, duration of the different stages of labor or rate of NICU admission. CONCLUSIONS: In nulliparous women at term before the onset of labor, narrower AoP at rest and on maximum Valsalva, reflecting fetal head engagement, is associated with a higher risk of Cesarean delivery. The increase in AoP from rest to Valsalva, reflecting more efficient maternal pushing, is associated with a shorter active second stage of labor. Fetal head regression on maternal pushing is present in about 16% of women and does not appear to have clinical significance. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Transperineal ultrasound assessment of maternal pelvic floor at term and fetal head engagement.

OBJECTIVES: To evaluate the association between pelvic floor dimensions in nulliparous women at term and fetal head engagement, as assessed by transperineal ultrasound. METHODS: This was a prospective observational study of nulliparous women at term. Before the onset of labor, transperineal ultrasound was used to measure the anteroposterior diameter (APD) of the levator hiatus and the angle of progression (AoP) at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver (before and after visual feedback). We assessed the correlation between pelvic floor static and dynamic dimensions (levator hiatal APD and levator ani muscle coactivation) and AoP, which is an objective index of fetal head engagement. RESULTS: In total, 282 women were included in the analysis. Among these, 211 (74.8%) women had a vaginal delivery while 71 (25.2%) had a Cesarean delivery. AoP was narrower in the Cesarean-delivery group at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva, whereas no differences in levator hiatal APD were found between the two groups. We found a negative correlation between levator hiatal APD at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva and the duration of the second stage of labor. There was a positive correlation between AoP and levator hiatal APD on maximum Valsalva maneuver after visual feedback (r = 0.15, P = 0.01). Women with levator ani muscle contraction on Valsalva maneuver (i.e. coactivation), both pre and post visual feedback, had a narrower AoP at rest and on maximum Valsalva. After visual feedback, women with levator ani muscle coactivation had a longer second stage of labor than did those without (80.8 ± 61.4 min vs 62.9 ± 43.4 min (P = 0.04)). CONCLUSIONS: Smaller pelvic floor dimensions and levator ani muscle coactivation are associated with higher fetal head station and with a longer second stage of labor in nulliparous women at term. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

[Interference of hemolysis in plasma urea determination. A comparison of 2 methods: classical Berthelot urease and the modified Berthelot urease]. / Interferenza dell'emolisi sulla determinazione dell'urea plasmatica. Confronto tra due metodiche: ureasi-Berthelot classica ed ureasi-Berthelot modificata.

The authors have tested the interference of the hemoglobin by two routine methods ( Berthelot classic and Berthelot modified) for the determination of plasmatic urea. From their work it appears that Berthelot classic method already presents a very sensible positive interference for hemoglobin at 0.04 g/dl level while for the Berthelot modified method such interference begins to be significant only for those values which are than 1.25 g/dl level. The correlation between these two methods, tested by limpid and lacking in hemolysis plasmas, is very good, so the authors think the Berthelot modified method is more respondent to the exigence of the routine as it is not exceptional the case to have to execute anyhow some determinations of urea and plasmas which have a partial hemolysis.

[Determination of the diagnostic value of erythrocyte discrimination indices (Mentzer and Srivastava) and of glycerol lysis time (GLT 50) in microcytosis]. / Contributo alla precisazione del valore diagnostico di alcuni indici discriminanti eritrocitari (Mentzer e Srivastava) e del tempo di lisi al glicerolo (GLT50) nelle microcitosi.

Many authors proposed erythrocytes discriminating functions to differentiate most common microcythemic hypochromic anemias (beta-thalassemia and iron deficiency). This study considers two of these discriminating functions: 1. Mentzer's index; 2. Srivastava's index; and also test GLT50 proposed by Authors with the same aim. The purpose is to quantify the percent of false positive and false negative results of such tests. As standard the test of measurement HbA2 and HbF was used to classify thalassemic patients. The results prove that the Mentzer test is the best while, not highly specific (20% false positive), but we did not find any false negatives in our study. Srivastava's method for the presence of false negatives (7% of thalassemic patients) is less reliable, and even less so the GLT50 test (30% of thalassemic patients).