第三产程中胎盘剥离过程的动态超声观察

目的　探讨第三产程中胎盘剥离的生理过程和适宜时间。方法　应用彩色超声诊断仪 ,观察第三产程中胎盘剥离过程的动态变化 ;以称重法计算产后 2h内的出血量。结果　第三产程中胎盘剥离过程可分为 4个时期 :潜伏期、收缩期、分离期、排出期 ;各期持续时间为 :潜伏期 (4 37±3 78)min ,收缩期 (1 4 8± 0 97)min ,分离期 (0 5 0± 0 0 0 )min ,排出期 (0 6 2± 0 2 3)min。约 85 %的产妇第三产程均在 10min以内结束 ,平均 6 94min。第三产程超过 10min者 ,阴道出血量显著增加 (P <0 0 1) ,发生各种并发症的危险性也相应增加。结论　为预防产后出血 ,第三产程以不超过 10min为宜。     

Length of the third stage of labor at term pregnancies is shorter if placenta is located at fundus: prospective study

AIM: To investigate how the location of the placenta at term pregnancies affects the duration of the third stage of labor and to discuss the possible mechanisms affecting the duration of the third stage. We believe that this is the first prospective study comparing the duration of the third stage of labor according to placental location. METHODS: The placental implantation was determined as anterior (n = 78), posterior (n = 59), or fundal (n = 64) by ultrasound, in 201 women with singleton pregnancies. After delivery of the newborn, oxytocin infusion was routinely given. Duration of the third stage of labor was compared by anova. P < 0.05 was determined as significant. RESULTS: The duration of the third stage of labor was 10.36 +/- 5.94 min, 10.44 +/- 5.35 min, and 8.12 +/- 4.25 min with placentas located anteriorly, posteriorly, and fundal, respectively. The length of the third stage was significantly shorter in the fundal placenta group. CONCLUSION: In this study, the length of the third stage of labor was approximately 2 min shorter with placentas located at the fundus compared to the other two groups. The mechanism responsible for shorter duration may be the bipolar separation of fundal placentas in contrast to usual unipolar down-up separation of anterior or posterior placentas. Another contributing factor may be the use of oxytocin infusion for the management of the third stage, however this should be investigated by further studies by using real time ultrasonography.     

The duration of the third stage of labor is subject to the location of placental implantation

We evaluated the association between placental location and length of the third stage of labor in normal term singleton pregnancies. Two hundred consecutive singleton term live vaginal deliveries following uncomplicated pregnancies were included in a retrospective study. The mean maternal age was 27.5 +/- 5.2 years, and the mean parity was 2.2 +/- 1.4. Patients' charts were reviewed in order to determine the placental implantation site. Anterior location of the placenta was noted in 96 women (48%), posterior in 66 (33%), fundal in 26 (13%), and lateral in 12 (6%). The duration of the third stage was 9.5 +/- 5.5, 9.4 +/- 5.3, 12.8 +/- 9.5, and 7.6 +/- 3.5 min in anterior, posterior, fundal, and lateral groups, respectively (p < 0.05). The duration of the third stage of labor is statistically significantly longer, if the placenta is located in the fundal area of the uterus. Therefore, we believe that the placental location may be important in managing the third stage of labor.     

A randomized controlled trial comparing oxytocin administration before and after placental delivery in the prevention of postpartum hemorrhage

OBJECTIVE: To determine if the timing of the administration of prophylactic oxytocin influences the incidence of postpartum hemorrhage caused by uterine atony, retained placenta, and third-stage duration. STUDY DESIGN: Parturients who presented for vaginal delivery were randomized in a double-blinded fashion to receive oxytocin, 20 units in a 500-mL crystalloid intravenous bolus, beginning upon delivery of either the fetal anterior shoulder or placenta. For all patients, the third stage of labor was managed with controlled cord traction until placental expulsion, followed by at least 15 seconds of fundal massage. Patients were excluded if they had a previous cesarean section, multiple gestation, antepartum hemorrhage, or bleeding disorder. RESULTS: A total of 1486 patients were enrolled: 745 in the before-placenta group and 741 in the after-placenta group. The groups were similar with respect to gestational age, fetal weight, labor duration, maternal age, parity, and ethnicity. The incidence of postpartum hemorrhage did not differ significantly between the two groups (5.4% vs 5.8%; crude OR, 0.92; 95% CI, 0.59 to 1.43). There were no significant differences between the two groups with respect to incidence of retained placenta (2.4% vs 1.6%; OR, 1.49; 95% CI, 0.72 to 3.08), or third-stage duration (7.7 minutes vs 8.1 minutes; P =.23). CONCLUSIONS: The administration of prophylactic oxytocin before placental delivery does not reduce the incidence of postpartum hemorrhage or third-stage duration, when compared with giving oxytocin after placental delivery. Early administration, however, does not increase the incidence of retained placenta.     

Expression of C-type natriuretic peptide in human placenta and myometrium in normal pregnancies and pregnancies complicated by intrauterine growth retardation. Preliminary results.

OBJECTIVE: C-type natriuretic peptide (CNP) is a vasoactive hormone and the endothelial component of the natriuretic peptide system. At present, nothing is known about CNP expression in human reproductive tissue. Since CNP shows antimitogenic and vasodilatative properties, it was the aim of the study to investigate whether CNP expression is altered in placenta and myometrium from pregnancies complicated by intrauterine growth retardation. METHODS: CNP expression was examined by RNase protection assay in human placenta and myometrium from six normal term pregnancies, six pregnancies with preterm delivery and six pregnancies complicated by intrauterine growth retardation (IUGR). RESULTS: In placenta and myometrium, CNP expression levels did not differ between term and preterm pregnancies (40 vs. 28 weeks of gestation). In pregnancies with IUGR (34 weeks of gestation) placental CNP expression was significantly decreased (100.00 +/- 18.6 vs. 67.09 +/- 8.7; p < 0.05). In the myometrium from IUGR pregnancies CNP expression was significantly increased to 191.48 +/- 42.5 (vs. 100.00 +/- 15.4; p < 0.05). CONCLUSIONS: CNP is expressed in human placenta and myometrium with no dependency on gestational age in the third trimester. Pregnancies with IUGR show an opposite regulation of CNP in placenta and myometrium, which indicates an organ-specific function of the peptide in human reproductive tissue.     

MANAGEMENT OF THE THIRD STAGE OF LABOR

The physiology of placental separation, descent, and expulsion is reviewed as a basis for management of third stage. Traditional and active pharmacologic management are described, including techniques for expulsion of the placenta and membranes. The relationship of complications to third stage management decisions is discussed.     

A survey of placental separation by real-time B-mode scanning

Using real-time B-mode Scanning, uteri were observed in 200 cases of delivery focusing on the mechanism of separation and expulsation of the placenta. The following are the main results reported: Ultrasonographically, modes of placental separation and expulsion could be classified into three types, I, II and III. In Type I, soon after the delivery of the fetus, the placenta separated from its bed very smoothly and slid out usually with the first or the second after pains. Blood loss in this type was usually the least, and the duration of the third stage of delivery was the shortest. In Type II, separation of the placenta from its bed began at the marginal site, progressed with each recurring contraction of the uterus. Bleeding was continuous, blood loss tended to be great and expulsation of the placenta was apt to be delayed. In Type III, separation of the placenta started not in the margin but in the central part, and separation progressed as retroplacental hematoma was formed resulting in an increase in the size of the placenta. Blood loss and duration of the third stage of delivery were generally moderate. Among these three types, Type I was the most common, 53 per cent of the cases, and was considered to be the most desirable from the obstetrician's point of view because of the smaller blood loss and the shortening of the third stage of delivery.     

Changes in the isoforms of the sodium pump in the placenta and myometrium of women in labor

OBJECTIVE: We determined whether changes in sodium pump isoform abundance accompanied active human labor. STUDY DESIGN: Specimens of placenta, amniochorion, and myometrium were collected from women in active spontaneous labor and from those not in labor. The abundance of the three sodium pump alpha-isoforms was determined by Western blot analysis. RESULTS: Levels of the alpha1 and alpha2 isoforms were comparable in the three tissues for women in labor and not in labor. However, alpha3 isoform abundance in placenta and myometrium (but not amniochorion) was significantly decreased in women in active labor compared with women not in labor (sodium pump alpha3 in placenta: no labor 91.2 +/- 27.6 vs labor 46.9 +/- 3.6 density units, P =.002. Sodium pump alpha3 in myometrium: no labor 52.3 +/- 7.7 vs labor 19.8 +/- 1.6 density units, P =.0002). CONCLUSION: Because reductions in sodium pump number can result in hormone release from secretory tissues and in contraction of muscle, this suggests that the sodium pump may play a significant role in the initiation or maintenance of human labor.     

胎盘和子宫平滑肌组织中尿皮质素mRNA表达水平变化及其与分娩发动的关系

目的探讨胎盘和子宫平滑肌组织中尿皮质素(urocortin,UCN)对子宫平滑肌收缩功能的影响,及UCN mRNA表达变化在分娩发动、进展中的作用。方法(1)采用半定量RT-PCR技术检测10例未临产妇女(未临产组)及20例临产妇女(临产组,其中10例潜伏期、10例活跃期)的胎盘组织和子宫平滑肌组织中UCN mRNA表达水平;(2)另取24例剖宫产术分娩产妇的子宫平滑肌组织(实验样本)行离体收缩实验,观察不同剂量UCN对子宫平滑肌的收缩作用,以及对由前列腺素F2α(PGF2α)、缩宫素诱发的子宫平滑肌收缩活动的影响,以收缩曲线下面积表示。结果(1)临产组胎盘组织中UCNmRNA的表达水平为1·23±0·52,高于未临产组的0·83±0·38,两组比较,差异有统计学意义(P<0·05);临产组子宫平滑肌组织中UCN mRNA的表达水平为1·32±0·22,高于未临产组的0·94±0·13,两组比较,差异有统计学意义(P<0·05)。临产组活跃期产妇的胎盘组织及子宫平滑肌组织中UCN mRNA表达水平明显高于潜伏期产妇,两者分别比较,差异有统计学意义(P<0·05)。(2)实验样本对不同剂量UCN均无反应,收缩曲线下面积无变化;但在加入UCN的基础上再加入PGF2α,可引起子宫平滑肌收缩曲线下面积由(2·12±0·15)cm2增加到(3·90±0·33)cm2,两者比较,差异有统计学意义(P<0·05);但UCN对缩宫素引起的子宫平滑肌收缩曲线下面积无影响。结论UCN本身对子宫平滑肌收缩功能无影响,但可以增加PGF2α及缩宫素对子宫平滑肌的收缩作用,从而参与分娩的发动和维持。     

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.     

A double-blinded, randomized controlled trial of oxytocin at the beginning versus the end of the third stage of labor for prevention of postpartum hemorrhage

OBJECTIVE: The objective of this study was to compare the administration of oxytocin at the beginning and end of the third stage of labor for the prevention of postpartum hemorrhage. METHODS: Patients with documented singleton pregnancies were randomly assigned to two groups. The first received 10 units of oxytocin intramuscularly at delivery of the anterior shoulder of the fetus and an identical appearing placebo injection following delivery of the placenta. The second received the opposite medication sequence. The study was double blinded. Blood loss was measured by weighing all fluids collected, visual estimation, and serial blood counts. RESULTS: 27 women received oxytocin at the delivery of the fetal shoulder and 24 after the placenta. Oxytocin given after placenta delivery resulted in lower blood loss (345 vs. 400 ml, p = 0.28), lower collection bag weight (763 vs. 833 g, p = 0.55), lower change in HgB (-1.26 vs. -1.32 g, p = 0.86), lower DeltaHCT (-3.43 vs. -3.64%, p = 0.85), and a shorter third stage of labor duration (8.6 vs. 9.2 min, p = 0.75). The incidence of postpartum hemorrhage, defined as estimated blood loss >500 ml (0 vs. 14.8%) was significantly lowered with oxytocin following placental delivery (p = 0.049). CONCLUSIONS: In our study, postpartum hemorrhage was less frequent when oxytocin administration was delayed until after placenta delivery.     

Concentration of annexin V in gestational tissues: placenta, fetal membranes, myometrium and amniotic fluid

THE BACKGROUND: It is believed that annexin V, an anticoagulant protein abundant in trophoblast, prevents circulating blood in the intervillous space from hypercoagulability and fibrin deposition. Distribution and the role of annexin V localized in other gestational tissues like myometrium and fetal membranes, as well as in amniotic fluid is unknown. The aim of this study was to determine the concentration of annexin V in the tissues under consideration. STUDY DESIGN: The study group consisted of 40 healthy women at the 1st stage of labour, 16 of whom delivered by cesarean section. The strips of myometrium, placenta and fetal membranes, as well as the samples of amniotic fluid and the venous blood, were collected during surgery. Homogenates were prepared from the tissues. Annexin V was measured by immunoenzymatic method (ELISA). RESULTS: Concentration of annexin V in the placenta was 122.65 +/- 33,14 ng/mg protein, in fetal membranes 136.31 +/- 49.30 ng/mg protein and in myometrium 65.40 +/- 30.72 ng/mg protein. There was a statistical difference between the concentrations in placenta and fetal membranes vs. myometrium (p<0.05). In amniotic fluid annexin V was found to be in low concentration (4.46 +/- 2.59 ng/ml, i.e., 1.60 +/- 1.21 ng/mg protein) while in blood plasma it was extremely low, over 6000 times lower than in placenta. CONCLUSION: Annexin V is present not only in placenta, but also in fetal membranes and myometrium. Its concentration in fetal membranes is similar to that in placenta, while in myometrium it is 50% lower. Annexin V found in newly discovered sites probably plays a similar role like placental annexin V.     

Active pharmacologic management of the third stage of labor. A comparison of oxytocin and ergometrine.

Postpartum hemorrhage is a common and serious complication of the third stage of labor resulting in anemia and increased morbidity in the puerperium. Administration of uterotonic drugs and suitable mechanical assistance in delivery of the placenta may significantly reduce this hazard. Ergometrine and oxytocin have been used for a long time in markedly different doses and by various routes of administration with varying success. In order to compare these two oxytocics with regard to their hemostatic effects as well as their possible interference with the physiologic placental separation mechanism, three groups (ergometrine, oxytocin, and control) of women have been studied during a 2-year period. Ergometrine (0.2 mg) and oxytocin (10 IU) administered in the stated doses and as single intravenous injections are comparable with regard to hemostatic efficiency, but oxytocin seems to promote placental separation and expulsion better and thereby reduces the risk of partial retention and trapping with bleeding reguiring further emergency measures as a frequent consequence.     

P-selectin in placenta and gestational myometrium: its measurements and hypothetical role in hemostasis of placental bed after labor

AIM: P-selectin is a member of selectin family (E, L- and P-selectins) which plays a crucial role in reproduction and hemostasis as well as in pathogenesis of preeclampsia. There are no regular studies on P-selectin in placenta and it is not clear whether it is present in gestational myometrium. In the present study, we have asked whether P-selectin is present in placenta and myometrium and in what concentration. MATERIAL AND METHODS: The study group consisted of 33 healthy pregnant women at term and/or at the beginning of labor who delivered by cesarean section because of fetal distress or elective reasons. Strips of placenta and myometrium as well as venous blood were obtained during the operation. P-selectin was measured in tissue extracts and plasma with the use of immunoenzymatic assays (ELISA). RESULTS: The median of the level of P-selectin in placenta was 31.65 ng/mg P (total protein), quartiles (Q1-Q3): 24.54-43.35 ng/mg P, and in myometrium 25.54 ng/mg P, quartiles (Q1-Q3): 21.83-35.65 ng/mg P, whereas the median and quartiles (Q1-Q3) of soluble P-selectin in the mother's plasma was 1.14: 0.76-1.63 ng/mg P. The plasma/tissue ratio for placenta was 1:30, and for myometrium -1:25. CONCLUSIONS: P-selectin is present in placenta and gestational myometrium; its concentration is relatively high - respectively 30- and 25-times higher than in plasma. On the basis of our studies, we hypothesize about the role of placental and myometrial P-selectin in hemostasis of placental bed after labor.     

Prolonged third stage of labor: morbidity and risk factors

Although retained placenta is a major cause of postpartum hemorrhage, there is no general agreement regarding when manual placental extraction is indicated to prevent hemorrhage. We sought to determine the following: 1) what duration of the third stage of labor is abnormal, 2) what duration is associated with complications, and 3) what antecedent conditions are associated with prolonged third stage. We studied 12,979 consecutive, singleton vaginal deliveries over an 11-year period. Third-stage duration had a log-normal distribution, with a geometric mean of 6.8 minutes, a median of 6 minutes, and an interquartile range of 4-10 minutes. A third stage of 30 minutes or longer occurred in 3.3% of the deliveries. The incidence of postpartum hemorrhage, transfusion, and D&C remained constant in third stages less than 30 minutes, then rose progressively, reaching a plateau at 75 minutes. The increase in these complications after 30 minutes was observed with both spontaneously delivered and manually extracted placentas. In a logistic regression analysis, factors significantly associated with prolonged third stage included: preterm delivery (odds ratio 3.81), delivery in a labor bed (odds ratio 2.17), preeclampsia (odds ratio 1.76), augmented labor (odds ratio 1.47), and nulliparity (odds ratio 1.45). Because there was no increase in hemorrhage until the third stage exceeded 30 minutes, we suggest that in the absence of bleeding, manual placental extraction is not indicated until 30 minutes have elapsed.     

Epidural analgesia and the course of delivery in term primiparas

OBJECTIVES: Epidural analgesia provides the most effective pain control during labor. Of great concern is its influence on the course of delivery and perinatal complications. DESIGN: The aim of the study was to assess the effect of epidural analgesia on the course of delivery and perinatal outcome. MATERIALS AND METHODS: 609 deliveries among 1334 (323 women with epidural analgesia (53%) and 548 without epidural analgesia (47%)) met the following criteria: primipara, singleton, live pregnancy, > =37 weeks' gestation, cephalic presentation of a fetus, lack of contraindication for vaginal delivery. The incidence of instrumental deliveries and fetal distress, duration of the first, second and third stage of labor, perinatal outcome, perinatal complications and perinatal blood loss and were analyzed. RESULTS: The incidence of fetal distress during second stage of labor was significantly higher in the epidural group (12.69 vs. 6.99%, P=0.02). The incidence of fetal distress during first stage of labor did not differ in both groups (10.53% vs. 8.74%, NS). Cesarean sections rate was similar in epidural and non-epidural group (17.7 vs. 18.2%, NS). Among vaginal deliveries duration of the first and second stage of labor was longer in epidural group (6.5+/-2.4 vs. 5.4+/-2.5 godz., P=0,000003 and 47.3+/-34.8 vs. 29.1+/-25.8 min., P=0.000003) and this was independent of period of time between onset of first stage of labor and epidural analgesia. Oxitocin use was significantly more frequent in the epidural group (20.6 vs. 10.3%, P<0.004). There were no statistically significant differences in the rates of instrumental vaginal deliveries, 1 and 5-minute Apgar scores, length of third stage of labor and perinatal blood loss in patients with and without epidural analgesia. Perinatal outcome did not depend on previous use of epidural analgesia or mode of analgesia for the operation in cesarean section subgroup. CONCLUSION: Epidural labor analgesia is associated with slower progress of labor but has no adverse effect on perinatal outcome and perinatal complications.     

Oral misoprostol for the prevention of primary post-partum hemorrhage during third stage of labor

AIM: To assess the effectiveness of oral misoprostol compared with methylergometrine in the prevention of primary post-partum hemorrhage during the third stage of labor. METHODS: This was a randomized controlled trial of 864 singleton low-risk pregnant women. The outcomes were total blood loss, duration of the third stage of labor and peripartal change in hematocrit. Comparisons were by the chi2-test and Student t-test. Relative risks were calculated for side-effects profile. A P-value of less than 0.05 was statistically significant. RESULTS: The biodata of all the participants were similar. The mean blood loss for the misoprostol and methylergometrine groups was 191.6 +/- 134.5 mL and 246.0 +/- 175.5 mL, respectively (95% CI: -79.3 to -39.5 mL). The mean duration of the third stage of labor was 19.6 +/- 2.4 min and 9.4 +/- 3.3 min in the misoprostol and methylergometrine groups, respectively (95% CI: 9.82-10.58 min). More subjects had blood loss >500 mL, 42 (9.7%) versus 6 (1.4%), and peripartal hematocrit change greater than 10%, 38 (8.8%) versus 5 (1.2%), in the methylergometrine group than in the misoprostol group, respectively. Also, more subjects received additional oxytocic in the methylergometrine group, compared to the misoprostol group (80 [18.5%] versus 33 [7.6%] patients, respectively). CONCLUSIONS: Orally administered misoprostol was more effective in reducing blood loss during the third stage of labor than intramuscular methylergometrine. However, there were more subjects in the misoprostol group in whom duration of the third stage of labor was greater than 15 min and who also had manual placental removal than in the methylergometrine group.     

Effects of induced abortion on the third stage of labor in subsequent pregnancy

The aim of the study was to investigate whether the expulsion of the placenta was delayed among women who had previously undergone induced abortion by suction curettage. We studied the duration of the third stage of labor retrospectively by comparing the third stage of labor, recorded in minutes, between 76 second gravida women with previously induced abortions and 95 second para women with previously uncomplicated pregnancies. The duration of the third stage of labor was also compared among a group of primigravidas and a group of second gravidas with previously induced abortions. We excluded women with previous gynecological disorders (e.g. resulting in curettage of the uterine cavity). All patients included presented normal pregnancies and deliveries resulting in full term (greater than 37 weeks), liveborn infants. By the statistical analysis (analysis of variance and Duncan's test), it could be shown that the 3rd stage of labor lasted significantly longer among women with previously induced abortions (mean: 12 minutes), than among the other groups included in the study (mean: 9 minutes). This discrete difference in length of the third stage of labor need not indicate an altered routine for women, who give birth subsequent to an induced abortion.     

Oral misoprostol for third stage of labor: a randomized placebo-controlled trial.

OBJECTIVE: To investigate whether orally administered misoprostol during the third stage of labor is efficient in reducing postpartum blood loss. METHODS: In a double-masked trial, during vaginal delivery women were randomly assigned to receive a single oral dose of misoprostol (600 microg) or placebo in third stage of labor, immediately after cord clamping. The third stage of labor was managed routinely by early cord clamping and controlled cord traction; oxytocin was administered only if blood loss seemed more than usual. Blood loss was estimated by the delivering physician and differences in hematocrit were measured before and after delivery. RESULTS: Mean (+/- standard error of the mean) estimated blood loss (345 +/- 19.5 mL versus 417 +/- 25.9 mL, P = .031) and hematocrit difference (4.5 +/- 0.9% versus 7.9 +/- 1.2%, P = .014) were significantly lower in women who received misoprostol than those who received placebo. Fewer women in the misoprostol group had postpartum hemorrhage (blood loss of at least 500 mL), but that difference was not statistically significant (7% versus 15%, P = .43). Additional oxytocin before or after placental separation was used less often in the misoprostol group (16% versus 38%, P = .047). There were no differences in the length of third stage of labor (8 +/- 0.9 minutes versus 9 +/- 1 minutes, P = .947). There were no differences in pain during third stage of labor, postpartum fever, or diarrhea, but shivering was more frequent in the misoprostol group. CONCLUSION: Oral misoprostol administered in the third stage of labor reduced postpartum blood loss and might be effective in reducing incidence of postpartum hemorrhage.     

The effect of placental management at cesarean delivery on operative blood loss.

OBJECTIVES: The effect of alternative methods of placental delivery at cesarean section on blood loss has not been reported. The hypothesis of this study was that spontaneous expulsion of the placenta would reduce operative blood loss, compared with that of manual extraction during cesarean delivery. STUDY DESIGN: We prospectively randomized and compared outcomes of 62 gravid women with manual (n = 31) or spontaneous (n = 31) placental delivery at cesarean section. Operative blood loss was measured directly. RESULTS: Blood loss measured at cesarean delivery was greater in the manually delivered group (967 +/- 248 ml) than in the spontaneously delivered group (666 +/- 271 ml, p < 0.0001). The incidence of postpartum endometritis was sevenfold greater in the manual than the spontaneous group (23% vs 3%, respectively; p < 0.05). CONCLUSIONS: We conclude that spontaneous expulsion of the placenta at cesarean delivery results in less operative blood loss and a lower incidence of postoperative endometritis.