Intrauterine pressure during the second stage of labor in obese women

OBJECTIVE: The perception that obese women have longer labors and a higher frequency of operative delivery because they are "poor pushers" persists despite the absence of objective study. We tested the hypothesis that obese women generate inadequate intrauterine pressure during the second stage of labor. METHODS: Intrauterine pressure was prospectively measured in 71 women during the second stage of labor. Obesity was defined as a body mass index (BMI) greater than 29 (n = 17). A BMI below 25 was normal (n = 40). Women with a BMI between 26 and 29 (n = 14) were considered overweight. All women labored with epidural analgesia and were alert and responsive throughout the study. After recording the baseline contractility, a standardized Valsalva maneuver was performed during contractions. The area under the intrauterine pressure curve (integral) was used as an estimate of uterine contractility. RESULTS: All women delivered vaginally. There were no significant differences in baseline uterine contractility among obese, overweight, and normal women either before (obese 1,787 mm Hg/s; 95% confidence interval [CI] 1,164, 2,742 versus normal 1,569 mm Hg/s; 95% CI 718, 2,371 versus overweight 1,770 mm Hg/s; 95% CI 1,305, 2,835; P =.223) or during Valsalva maneuver (obese 2,831 mm Hg/s; 95% CI 1,771, 4,599 versus normal 2,637 mm Hg/s; 95% CI 1,240, 4,390 versus overweight 2,813 mm Hg/s; 95% CI 1,209, 4,982; P =.742). A BMI greater than 25 was associated with a higher frequency of oxytocin augmentation (P =.037). Univariate analysis revealed a relationship between labor duration and BMI (r = 0.299, P =.018). Obese women labored longer during the active phase (one-way analysis of variance, P =.02), but second-stage duration was similar among groups (one-way analysis of variance P =.44). Obesity did not increase the incidence of perineal lacerations (P =.82) or frequency of operative delivery (relative risk obese versus nonobese = 0.212; 95% CI 0.04, 1.05). CONCLUSION: Obese women produce second-stage intrauterine pressures equivalent to women with a normal BMI, although they may require oxytocin augmentation more often. LEVEL OF EVIDENCE: II-2     

Effects of sublingual nitroglycerin on human uterine contractility during the active phase of labor

Nitroglycerin is administered intravenously in acute obstetric emergencies to relax the uterus. However, complications (eg, hypotension, acute uterine bleeding) are frequent, which prompted a search for alternative routes of administration. We hypothesized that the sublingual administration of nitroglycerin would reduce uterine tone and contractility with few complications. Intrauterine pressure was measured in 12 women who were actively laboring (>4 cm dilatation, regular contractions) with epidural analgesia and who were alert and responsive throughout the study. In a double-blind fashion, subjects were randomized to receive either placebo or sublingual nitroglycerin (3 doses, 800 microg each) 10 minutes apart. The obstetric anesthesiologist continuously monitored maternal blood pressure and fetal heart rate. Cervical dilatation was assessed at the beginning and the end of the protocol. The area under the intrauterine pressure curve (integral) was used to estimate uterine contractility. Intrauterine pressure was analyzed before the randomization code was broken. Nitroglycerin did not alter the intrauterine pressure integral after the first dose (placebo, 3147 mm Hg x s [95% CI, 2206-4088] vs nitroglycerin, 4146 mm Hg x s [95% CI, 2451-5841]; P =.22), second dose (placebo, 3123 mm Hg x s [95% CI, 2447-3799] vs nitroglycerin, 3611 mm Hg x s [95% CI, 2723-4499]; P =.28), or third dose (placebo, 3303 mm Hg x s [95% CI, 2616-3990] vs nitroglycerin, 3810 mm Hg x s [95% CI, 2306-5314]; P =.45). Cervical dilation, basal uterine tone, duration and frequency of uterine contractions, or fetal heart rhythm remained unaffected. Maternal mean arterial pressure decreased significantly after nitroglycerin was administered. All women were delivered vaginally without intervention. Three doses of sublingual nitroglycerin (800 microg per dose) reduce neither uterine activity nor tone, despite lowering maternal blood pressure. If a clinical option, sublingual nitroglycerin will require a higher dose, which would place mother and fetus at risk for complication.     

Randomized Controlled Trial of Hands‐and‐Knees Positioning for Occipitoposterior Position in Labor

ABSTRACT: Background: Hands‐and‐knees positioning during labor has been recommended on the theory that gravity and buoyancy may promote fetal head rotation to the anterior position and reduce persistent back pain. A Cochrane review found insufficient evidence to support the effectiveness of this intervention during labor. The purpose of this study was to evaluate the effect of maternal hands‐and‐knees positioning on fetal head rotation from occipitoposterior to occipitoanterior position, persistent back pain, and other perinatal outcomes. Methods: Thirteen labor units in university‐affiliated hospitals participated in this multicenter randomized, controlled trial. Study participants were 147 women laboring with a fetus at ≥37 weeks’ gestation and confirmed by ultrasound to be in occipitoposterior position. Seventy women were randomized to the intervention group (hands‐and‐knees positioning for at least 30 minutes over a 1‐hour period during labor) and 77 to the control group (no hands‐and‐knees positioning). The primary outcome was occipitoanterior position determined by ultrasound following the 1‐hour study period and the secondary outcome was persistent back pain. Other outcomes included operative delivery, fetal head position at delivery, perineal trauma, Apgar scores, length of labor, and women's views with respect to positioning. Results: Women randomized to the intervention group had significant reductions in persistent back pain. Eleven women (16%) allocated to use hands‐and‐knees positioning had fetal heads in occipitoanterior position following the 1‐hour study period compared with 5 (7%) in the control group (relative risk 2.4; 95% CI 0.88–6.62; number needed to treat 11). Trends toward benefit for the intervention group were seen for several other outcomes, including operative delivery, fetal head position at delivery, 1‐minute Apgar scores, and time to delivery. Conclusions: Maternal hands‐and‐knees positioning during labor with a fetus in occipitoposterior position reduces persistent back pain and is acceptable to laboring women. Given this evidence, hands‐and‐knees positioning should be offered to women laboring with a fetus in occipitoposterior position in the first stage of labor to reduce persistent back pain. Although this study demonstrates trends toward improved birth outcomes, further trials are needed to determine if hands‐and‐knees positioning promotes fetal head rotation to occipitoanterior and reduces operative delivery. (BIRTH 32:4 December 2005)     

One-blade rotation of a persistent posterior vertex

Fifteen women in labor at term with no evidence of protraction or arrest disorder successfully underwent a single-blade rotation of the fetus from occipitoposterior to occipitoanterior position. There were no failures, no fetal injuries, and no significant maternal trauma. This method of forceps rotation appears to be a safe alternative to current methods of managing occipitoposterior positions.     

Myometrial thickness during human labor and immediately post partum

OBJECTIVE: Morphologic studies suggest dramatic, asymmetric uterine growth during pregnancy that is caused by muscle cell hypertrophy. This growth is most marked at the fundus. Our objective was to evaluate sonographically the in vivo changes in myometrial thickness during active labor, second-stage labor, and after delivery. STUDY DESIGN: Abdominal ultrasound scans were performed on 52 term pregnant women to investigate the dynamic changes in myometrial thickness during the active and second stages of labor and immediately after delivery. Twenty-six women (mean +/- SEM gestational age, 39.09 +/- 0.3 weeks) were in active labor (cervical dilatation >4 cm with regular uterine contractions). An additional 26 nonlaboring women (gestational age, 39.8 +/- 0.2 weeks) provided control measurements. The myometrium was defined sonographically as the echo homogeneous layer between the serosa and the decidua. Myometrial thickness was measured at the low segment and mid anterior, fundal, and posterior uterine walls by the same observer. Myometrial thickness was also measured during uterine contractions and after artificial rupture of the amniotic membranes. All laboring women had uncomplicated labor patterns when studied and were delivered spontaneously. RESULTS: The myometrium was significantly thinner during active labor compared with nonlabor at each site studied: midanterior (mean [+/-SEM] myometrial thickness, 5.8 +/- 0.27 vs 8.83 +/- 0.51 mm; t test, P <.001), fundus (mean myometrial thickness, 6.78 +/- 0.32 vs 8.49 +/- 0.35 mm; P =.0015), and posterior (mean myometrial thickness, 6.22 +/- 0.34 vs 8.12 +/- 0.30 mm; P <.001). However, myometrial thickness did not differ among sites within the two groups. The thickness of the low segment was not affected by labor status (nonlabor, 4.68 +/- 0.48 vs labor, 4.66 +/- 0.37 mm; P =.97). Similarly, the myometrial thickness of the anterior uterine wall was unaffected by contractions (no contractions, 5.56 +/- 0.2 vs contractions, 5.68 +/- 0.22 mm; t test, P =.654). There was no change in myometrial thickness measured immediately before and after rupture of the amniotic membranes, despite a significant decrease of the amniotic fluid index. There was significant thickening of the anterior and fundal myometrium during the second stage of labor after the fetal head descended to +3 station by digital examination (anterior, 12.99 +/- 0.60 vs 5.8 +/- 0.27 mm; t test, P <.001; fundus, 10.61 +/- 1.63 vs 6.78 +/- 0.32 mm; t test, P =.04). Valsalva maneuver (pushing) during contractions did not affect myometrial thickness at the fundus (between contractions, 10.61 +/- 1.63 vs pushing, 10.76 +/- 1.95 mm; t test, P =.99). Immediately after delivery, the myometrial thickness at the placental insertion site was the thinnest. After completion of the third stage of labor, the uterine fundus remained significantly thinner than the anterior and posterior walls (fundus, 27.37 +/- 3.5 mm vs anterior, 40.94 +/- 3.5 vs posterior, 42.34 +/- 2.44; one-way analysis of variance, P =.02). CONCLUSION: There is significant and widespread thinning of the myometrium during active labor. Descent of the fetal head during the second stage of labor is associated with a significant relative thickening of the anterior and fundal myometrium. After delivery, the relationship reverses. These findings suggest the directionality of the expulsive force vectors (fundal dominance) is not determined by asymmetric myometrial growth but, rather, may be a function of increased "myometrial mass" that results from increased surface area at the fundus.     

Does fetal head position at the term plus 12 scan influence induction, labor and delivery outcome?

AIMS: To assess the influence that fetal head position has on induction, labor and delivery outcome for both mother and baby. METHODS: During a one month period, in November 1999, all women attending for a post-dates scan were enrolled as the study population. In total, 91 women formed our study population for analysis of data. The sonographic, induction and labor details of all women were recorded on a dedicated data sheet. As well as documenting the maternal age, parity, liquor volume (mm) and BPS, the position of the fetal head was noted by the sonographer as occipitoanterior, occipitotransverse or occipitoposterior. All women had gestation confirmed by ultrasound early during the course of their pregnancy. Maternal, ultrasonographic, induction and labor variables were correlated with fetal head presentation at scan. RESULTS: There was no positive correlation found between fetal head position at the term plus 12 scan and associated induction, labor or delivery complications in the 91 women studied. CONCLUSIONS: Our study shows no positive correlation between fetal head position and induction, labor or delivery complications.     

Life-table analysis of the success of thermal balloon endometrial ablation in the treatment of menorrhagia

OBJECTIVE: To evaluate the change in intrauterine pressure during thermal balloon endometrial ablation and to identify risk factors associated with treatment failure. DESIGN: Prospective observational study. SETTING: University-affiliated teaching hospital. PATIENT(S): Seventy two consecutive patients with idiopathic menorrhagia refractory to medical treatment. INTERVENTION(S): Thermal balloon endometrial ablation under patient-controlled sedation. MAIN OUTCOME MEASURE(S): Change in intrauterine pressure during the treatment cycle and risk factors associated with treatment failure. RESULT(S): A spontaneous decrease in intrauterine pressure occurred in most patients (93%). The mean (+/-SD) decrease was 34.1 +/- 14.9 mm Hg, or 19.5% +/- 9.1%. The treatment failed in 10 patients (13.9%), and the mean end pressure was significantly lower in this group (131.1 +/- 14.1 mm Hg vs. 145.1 +/- 18.0 mm Hg; P=.02). The chance of success of treatment was significantly lower when the end pressure was <140 mm Hg (odds ratio, 0.42 [95% CI, 0.27 to 0.68]; P=.01), the intrauterine volume was >10 mL (odds ratio, 0.43 [95% CI, 0.22 to 0.83]; P=.058) and the uterus was retroverted (odds ratio, 0.36 [95% CI, 0.20 to 0.65]; P=.008). CONCLUSION(S): Maintaining high intrauterine pressure during the treatment cycle and correction of the retroversion may help to improve treatment success in thermal balloon endometrial ablation.     

Uterine and umbilical artery velocimetry during normal labor

Twelve normal parturients were studied with a continuous wave Doppler unit to assess changes in uterine and umbilical velocity waveforms during labor. The analysis of these waveforms included the peak systolic/end-diastolic ratio and the evaluation of a diastolic notch. Each woman served as her own control, and all fetal heart rate tracings were normal. In latent phase labor and intact membranes, the umbilical artery systolic/end diastolic ratios before, during, and after a contraction were 2 +/- 0.2, 2 +/- 0.3 and 1.95 +/- 0.3 (N.S.). Similar results were obtained in the active phase, after rupture of membranes, or during oxytocin stimulation. This stability of the fetal cardiovascular system ensures an uninterrupted gas exchange process during the contractions (on the fetal side), enabling the great majority of term fetuses to tolerate labor with minimal if any metabolic changes. The uterine artery end-diastolic velocity fell progressively during the contraction, reaching 0 when the intrauterine pressure exceeded 35 mm Hg. Despite intrauterine pressure of greater than 60 mm Hg, the diastolic notch did not appear. Thus at term, the umbilical artery velocity waveform does not change over a wide range of uterine pressures. The changes seen in the uterine artery waveforms suggest that the end-diastolic component is primarily determined by changes in the arcuate and spiral arteries, both of which are affected during the uterine contraction.     

Evaluation of fetal heart rate in relation to the intrauterine 20 mm Hg level

The purpose of the author's study was to investigate whether any changes in fetal heart rate (FHR) and in fetal acid-base status could be observed when the intrauterine pressure rises above 20 mm Hg.16 primigravidae were studied. In 11 out of 16 patients labor was induced by amniotomy, in 9 cases oxytocin was given, and in 12 patients pethidine and promethazine (Phenergan) was administered. Two new parameters were introduced into the study of the collected material: (a) the peak variation in FHR (bpm) i.e. the difference between the highest and lowest FHR over a given period of time; (b) the contraction energy, i.e. the product of duration and intensity of intrauterine contractions as measured from the 20 mm Hg level.In 15 out of 16 women the mean peak variation in FHR was highest during a uterine contraction (> 20 mm Hg). After a uterine contraction (< 20 mm Hg) the mean peak variation did not immediately return to control values.It is suggested that in the 16 patients studied, the increase in FHR peak variation during uterine contraction is basically caused by a slight transient fetal hypoxia, exaggerated during the expulsion period of labor by cord entanglement.     

The influence of uterine motility upon cervical dilatation in labor

Intrauterine tocometry was used to study the influence of uterine motility on the relationship between the frequency and strength of contractions upon cervical dilatation. As it was not possible to collect sufficient material for valid conclusions on a series of patients with similar uterine activity, fetal size, uterine volume, cervical resistance, and lower uterine segment development; only women in normal labor without disproportion and delivered of infants in the occipitoanterior vertex presentation were included in the study. The average intensity and frequency of contractions and the average uterine activity were calculated for each woman. The patients were divided with regard to parity and ruptured or unruptured membranes. It was learned that the most rapid cervical dilatation occurs, for unchanged uterine activity, at the frequency of 21-23 contractions per hour. The observation is important for understanding the 1st stage of labor for proper treatment, by drugs, of dystocia.     

Efficacy and safety of nifedipine tablets for the acute treatment of severe hypertension in pregnancy

OBJECTIVE: The purpose of this study was to determine whether the slower- and longer-acting nifedipine tablets were as effective and safe as the rapid onset and short-acting nifedipine capsules for the treatment of acute severe hypertension in pregnancy. STUDY DESIGN: Sixty-four women in the second half of pregnancy who were not in labor randomly received 10 mg nifedipine tablets (n = 55 studies) or 10 mg nifedipine capsules (n = 74 studies) if blood pressure was > or =170/110 mm Hg. Blood pressure, heart rate, and cardiotocography were monitored over the subsequent 90 minutes. Successful treatment was a target blood pressure of 110 to 169/80 to 109 mm Hg after 90 minutes; unsuccessful treatment included fetal distress at any stage, the requirement for additional treatment (intravenous hydralazine), or the development of hypotension by 90 minutes after treatment. RESULTS: Nifedipine capsules lowered blood pressure further (28/19 vs 21/13 mm Hg; P =.03) than nifedipine tablets, but more than three quarters of each group had a successful treatment. Twice as many women (28%) who received nifedipine tablets required a second dose to achieve successful treatment (P =.05), but fewer women had hypotensive episodes (P =.001). Fetal distress was uncommon in both groups (3%-4%), and both groups were delivered an average of 4 days after the study. CONCLUSION: Nifedipine tablets, although of slower onset, are as effective as nifedipine capsules for the rapid treatment of severe hypertension in pregnancy.     

Mifepristone for preinduction cervical ripening beyond 41 weeks' gestation: a randomized controlled trial

OBJECTIVE: To compare the effect of mifepristone with placebo on cervical ripening before labor induction in prolonged pregnancies. METHODS: One hundred eighty women with pregnancies beyond 41 weeks and undilated, uneffaced cervices were assigned randomly to receive mifepristone 200 mg or placebo and observed for 24 hours. We then gave intravaginal misoprostol 25 microg every 4 hours or intravenous oxytocin. We expected 60% of placebo-treated and 80% of mifepristone-treated women to deliver vaginally within 48 hours. RESULTS: Among 180 subjects, 97 received mifepristone and 83 received placebo. The mean interval (+/- standard deviation [SD]) from start of induction to delivery was 2209 +/- 698 minutes for mifepristone-treated subjects and 2671 +/- 884 minutes for placebo-treated subjects (P <.001, log-transformed data). Twelve (13. 6%) mifepristone-treated women and seven (10.8%) placebo-treated women delivered vaginally on day 1 (P =.60). After 24 hours, the median Bishop score for both groups was 3 (0-11) (P =.51). One hundred thirty-one subjects required misoprostol, 65 (67.0%) were mifepristone-treated women, and 66 (79.5%) placebo-treated women (P =.06). The median (range) oxytocin dose was 871.5 (0-22,174) mU for mifepristone-treated women and 2021.0 (0-24,750) mU for placebo-treated women (P =.02). Seventy-seven (87.5%) mifepristone-treated women and 46 (70.8%) placebo-treated women delivered vaginally 48 hours after the start of treatment (P =.01). There were nine cesareans in the mifepristone group and 18 in the placebo group (P =.02). More nonreassuring fetal heart rate patterns and uterine contractile abnormalities occurred in mifepristone-treated subjects. There were no statistically significant differences in neonatal outcomes between groups. CONCLUSION: Mifepristone had a modest effect on cervical ripening when given 24 hours before labor induction, appearing to reduce the need for misoprostol and oxytocin compared with placebo.     

Effects of sitting position on uterine activity during labor

To determine which components of uterine activity are affected by different positions of labor, 116 intrauterine pressure records in the sitting and supine positions were analyzed in order to measure resting, contraction, and bearing down pressures. The resting pressure in the sitting position showed consistent elevation compared to the supine position, while the contraction pressure did not differ strikingly in the two positions. The bearing down pressure in the sitting position for nulliparas during the second stage and for multiparas at the time of the 8- to 10-cm dilation was significantly higher than that in the supine position. Also, the sitting position led to a significantly shorter duration of the second stage in nulliparas and the 5- to 10-cm dilation period in multiparas. These findings suggest that the maternal position does not affect uterine contractility, that the increased resting pressure in the sitting position is of some importance in supplementing the downward delivery force, and that the increased bearing down pressure in the sitting position could help to significantly shorten the duration of labor.     

Monitoring contractions in obese parturients: electrohysterography compared with traditional monitoring

OBJECTIVE: To compare electrohysterogram-derived contractions with both tocodynamometry and intrauterine pressure monitoring in obese laboring women. METHODS: From a large database of laboring patients with electrohysterogram monitoring, obese subjects were selected in whom data were recorded for at least 30 minutes before and after intrauterine pressure catheter placement for obstetric indication. Using a contraction detection algorithm, the relationship between the methods was determined with regard to both frequency and contraction duration. RESULTS: Of the 25 subjects (median body mass index 39.6 [25th percentile 36.5, 75th percentile 46.3]), seven underwent amniotomy at the time of intrauterine pressure catheter placement. Tocodynamometry identified 248 contractions compared with 336 by electrohysterography, whereas intrauterine pressure catheter monitoring identified 319 contractions compared with 342 by electrohysterography. Using the Contractions Consistency Index, electrohysterogram contraction detection correlated better with the intrauterine pressure catheter (0.94+/-0.06) than with tocodynamometry (0.77+/-0.25), P=.004. Electrohysterogram-derived contraction lengths closely approximated those calculated from the intrauterine pressure catheter signal. CONCLUSION: Contraction monitoring routinely is employed for managing labor, and tocodynamometry may be unreliable in obese parturients. In the obese women in this study, the electrohysterogram-derived contraction pattern correlated better with the intrauterine pressure catheter than tocodynamometry. Electrohysterography may provide another noninvasive means of monitoring labor, particularly for those women in whom tocodynamometry is inadequate.     

Use of intrathecal analgesia in a rural hospital Case studies

A woman's experience of unrelenting back pain with a fetus in an occipitoposterior position and the escalating interventions culminating in a cesarean birth is every midwife's nightmare. Intrathecal analgesia is a relatively simple and rapid method to provide maternal relaxation and relief from severe back labor. This article describes the use of intrathecal opioid analgesia in labor complicated by failure to progress in first-stage labor due to persistent occipitoposterior position of the fetus. Intrathecal analgesia has the advantage of being inexpensive and providing rapid onset of adequate pain relief for the first stage of labor. It does not cause motor blockade, so it allows the mother to be mobile and feel the urge to push. Consequently, there is no associated risk of an increased need for forceps or vacuum-assisted delivery. The authors note a decreased incidence of operative delivery for fetal occipitoposterior position with the use of intrathecal narcotics.     

两种体侧卧位法纠正枕后位的临床观察

目的探讨产程中产妇采用两种不同体侧卧位纠正枕后位的临床效果.方法选择潜伏期经内诊或B超确诊为枕后位的初产妇100例,按随机表法分成同侧卧位组和对侧卧位组(各50例),分别采用同侧和对侧卧位法纠正胎方位,观察两组阴道分娩率、第1产程时间.结果(1)同侧卧位组阴道分娩34例(68%),胎儿转至枕前位27例(54%),对侧卧位组阴道分娩为22例(44%),胎儿转至枕前位12例(24%),两组比较,差异有显著性(P＜0.005).(2)同侧卧位组平均第1产程时间为(13.5±6.5)h;对侧卧位组平均第1产程时间为(17.1±7.2)h,两组比较,差异有极显著性(P＜0.01).结论产程中指导产妇取同侧卧位矫正枕后位,是提高阴道分娩率、缩短第1产程的有效方法.     

Qualitative assessment of maternal uterine and fetal umbilical artery blood flow and resistance in laboring patients by Doppler velocimetry

The purpose of this study is to evaluate the effect of uterine contractions during labor on both the uterine and the umbilical circulations. Twenty-seven patients in active labor were studied by continuous-wave Doppler velocimetry. Umbilical, left uterine, and right uterine arterial waveforms were obtained before, during, and after peak uterine contractions, and the ratio of maximum systolic and minimum diastolic velocities was calculated. Fifteen patients showed absent flow in end diastole on the uterine artery waveform and had significantly higher intra-amniotic pressures (64.5 +/- 3.5 mm Hg) during the peak amplitude of the uterine contraction compared with the 12 patients with maintained end diastolic flow (46.5 +/- 2.6 mm Hg; p less than 0.05). During the peak amplitude of the uterine contractions the 12 patients maintaining end-diastolic flow had significantly higher systolic/diastolic ratios in the uterine artery (6.5 +/- 1.5) compared with either before or after a contraction (2.1 +/- 0.15 and 2.0 +/- 0.2, respectively; p less than 0.05). Also, these 12 patients showed a linear relationship between the systolic/diastolic ratio and the intrauterine pressure. However, no differences were observed in the umbilical artery systolic/diastolic ratios before, during, or after a contraction in the intensity range studied. On the contrary, during contractions an increase in uterine artery resistance occurs with decreased or absent end-diastolic flow, which bears an inverse linear relationship to the intensity of the contraction. This suggests that during uterine contractions the human fetus continues to have uninterrupted fetoplacental blood flow, whereas the degree of interruption or reduction in uteroplacental blood flow is dependent on the intensity of uterine contraction.     

USE OF INTRATHECAL ANALGESIA IN A RURAL HOSPITAL: Case Studies

A woman's experience of unrelenting back pain with a fetus in an occipitoposterior position and the escalating interventions culminating in a cesarean birth is every midwife's nightmare. Intrathecal analgesia is a relatively simple and rapid method to provide maternal relaxation and relief from severe back labor. This article describes the use of intrathecal opioid analgesia in labor complicated by failure to progress in first-stage labor due to persistent occipitoposterior position of the fetus. Intrathecal analgesia has the advantage of being inexpensive and providing rapid onset of adequate pain relief for the first stage of labor. It does not cause motor blockade, so it allows the mother to be mobile and feel the urge to push. Consequently, there is no associated risk of an increased need for forceps or vacuum-assisted delivery. The authors note a decreased incidence of operative delivery for fetal occipitoposterior position with the use of intrathecal narcotics.     

Fetal adrenal gland volume and cortisol/dehydroepiandrosterone sulfate ratio in inflammation-associated preterm birth

OBJECTIVE: Fetal adaptation to stress is regulated in part by the pituitary-adrenocortical system. The stress hormones dehydroepiandrosterone sulfate (DHEAS) and cortisol have opposing effects: cortisol suppresses while DHEAS enhances immune functions. We sought to estimate the impact of intraamniotic inflammation on fetal adrenal gland volume and cortisol-to-dehydroepiandrosterone sulfate ratio (fetal stress ratio) in pregnancies complicated by preterm birth. METHODS: Fifty-one consecutive singleton fetuses of mothers who had an indicated amniocentesis to rule out infection were analyzed. Intraamniotic inflammation was assessed by proteomic profiling of amniotic fluid for the biomarkers of the Mass Restricted score. The Mass Restricted score ranges from 0 (biomarkers absent) to 4 (all biomarkers present), with Mass Restricted scores of 3 or 4 indicating severe intraamniotic inflammation. Fetal adrenal gland volume was assessed by three-dimensional ultrasonography and corrected for estimated fetal weight. Interleukin-6 (IL-6), cortisol, and DHEAS were measured by immunoassay. RESULTS: Women with intraamniotic inflammation delivered earlier (27.8+/-3.4 weeks, n=16, compared with 32.3+/-3.0 weeks, n=35, P<.001), and their fetuses had higher cord blood IL-6 (P=.011) and higher corrected adrenal gland volumes (P=.027). Cord blood IL-6 levels were in direct relationship with corrected adrenal volume (r=0.372, P=.019), fetal cortisol (r=0.428, P=.010), and DHEAS (r=0.521, P<.001). However, fetuses exposed to intraamniotic inflammation had an overall lower fetal stress ratio (P=.034). These results maintained after adjusting for gestational age, uterine contractions, and steroid exposure. CONCLUSION: Fetuses exposed to intraamniotic inflammation have higher adrenal gland volumes and lower cortisol-to-DHEAS ratios, suggesting that the fetal adrenocortical axis plays a role in the intrauterine adaptation to inflammation.     

产程中应用度冷丁对胎心率及宫缩的影响

目的探讨度冷丁对胎心率及宫缩的影响。方法对潜伏期精神紧张或休息、进食不佳的３０例产妇肌内注射度冷丁１００ｍｇ,用胎儿内监护仪监测胎心率及宫腔压力,观察用药后３０分钟、１小时、２小时的胎心率变化及宫缩情况。结果用药３０分钟后胎心率基线有所下降,１～２小时下降明显但仍在正常范围。用药３０分钟后宫腔静止压力下降。用药１小时后,不协调宫缩得以改善,同时,度冷丁对宫缩频率及强度有加强作用。结论潜伏期使用度冷丁能改善产妇一般情况,虽胎心率有所下降但不造成胎儿窘迫;并有增强宫缩频率与强度和调整不协调宫缩的作用