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PubMed2002

Fetal blood saturation during the 1st and 2nd stage of labor and its relation to the neonatal outcome.

OBJECTIVE: The aim of this study was to evaluate fetal blood oxygenation (SpO(2)) by means of continuous pulse oximetry during labor and its relation to the neonatal outcome. MATERIALS AND METHODS: Fetal SpO(2) was measured continuously during labor with a noninvasive pulse oximetry for fetal application. The average, minimum and maximum SpO(2) levels were evaluated separately for the 1st and 2nd stage of labor. The average SpO(2) of the fetus was compared to the neonatal outcome assessed by the levels of pH, pO(2) and pCO(2) in the fetus' umbilical blood and to the Apgar score. RESULTS: Twenty-eight patients were monitored by fetal pulse oximetry. All the patients had normal, vaginal delivery. During the 1st stage of labor, the average fetal SpO(2) was 51.78 +/- 8.00%, the minimum SpO(2) level was 37.61 +/- 9.86%, and the maximum level of SpO(2) was 63.82 +/- 7.37%; in the 2nd stage of labor, the average SpO(2) level was 44.91 +/- 8.28%, the minimum level was 35.00 +/- 9.22%, and the maximum SpO(2) was 52.30 +/- 9.36%. A significant decrease in the fetal average and maximum SpO(2) levels was observed between the 1st and the 2nd stages of labor (the average SpO(2) was 51.78 +/- 8.00% vs. 44.91 +/- 8.28%, p = 0.00029; the maximum SpO(2) was 63.82 +/- 7.37% vs. 52.30 +/- 9.36%, p < 0.00001). A significant correlation between the average SpO(2) level during the 1st and 2nd stage of labor and the Apgar score at the first minute of outcome was observed (R = 0.43, p = 0.031). No relationship between the fetal SpO(2) during the 1st and the 2nd stage of labor and the pH, pCO(2), and pO(2) in the fetal umbilical blood were observed. CONCLUSIONS: During the 2nd stage of labor, a significant decrease in the fetus' SpO(2) can be observed. The fetus' SpO(2) level >30% in the 1st and 2nd stage of labor was related to the good neonatal outcome. The assessment of the fetal SpO(2) during the 1st stage of labor seems to be important in predicting neonatal outcome.

Adult↗
PubMed2003

Nitric oxide metabolites in preterm and induced labor.

BACKGROUND: Nitric oxide has potent relaxant effects on the pregnant uterus and has been associated with a quiescent uterus in animal and human studies. Nitric oxide donors have been used to arrest preterm labor and a reduction in nitric oxide production has been reported before the onset of labor. OBJECTIVE: The aim of the study was to estimate the serum levels of nitrate and nitrite in women undergoing spontaneous preterm labor and induced labor. MATERIALS AND METHOD: Venous blood was drawn from 39 patients before the onset of labor (control) and also from 17 patients undergoing induction of labor who were in active labor (study group A), and 24 patients in spontaneous preterm labor (study group B). Serum concentrations of nitrate and nitrite were estimated in the samples using the HPLC method. RESULTS: The maternal age of the patients was similar in all the groups. There was no significant difference in the mean gestational age at delivery between the control and group-A patients (38.86 vs. 38.29 weeks); however, there was a significant difference between the control and group-B patients (38.86 vs. 30.92; p < 0.0001), and between study groups A and B (38.29 vs. 30.92 weeks; p < 0.0001). The mean serum levels of nitrite in groups A and B (0.563 +/- 0.15 and 0.512 +/- 0.13, respectively) were significantly lower than the level in the control group (0.915 +/- 0.13; p < 0.0001). Although the serum nitrate levels in study groups A and B were lower than in the control group, this difference was not significant. The maternal outcome was satisfactory but, as expected, the mean birth weight of the babies in group B (1,665.73 +/- 863.84 g) was significantly lower than the birth weights in the control and group-A patients (p < 0.0001). CONCLUSION: There is a drop in nitric oxide production in active preterm labor and induced labor. These findings need to be confirmed in larger studies to establish the role of nitric oxide in the initiation of labor.

Birth Weight↗
PubMed1996

Elevation of serum creatine phosphokinase and its MB isoenzyme during normal labor and early puerperium.

BACKGROUND: Chest pain or discomfort are infrequent complaints among women during labor and early puerperium, but when present they raise the suspicion of myocardial ischemia. The diagnosis of the latter is based upon serum elevatIon of certain enzymes, such as aspartate amino transferase, lactate dehydrogenase and creatine phosphokinase. Nevertheless, the normal patterns of these enzymes in the serum during labor and early puerperium have not been characterized well. OBJECTIVE: To determine serum creatine phosphokinase, lactate dehydrogenase and aspartate amino transferase levels in late pregnancy, and throughout labor and early puerperium. METHODS: Fifty women having normal pregnancies followed by uneventful vaginal deliveries were prospectively studied for serum lactate dehydrogenase, aspartate amino transferase and creatine phosphokinase including its MB isoenzyme before, during and after labor. Cardiac status was evaluated in all women using serial electrocardiographic and physical examinations. RESULTS: All women were found to have low to normal antepartum serum enzymes levels. However, during labor total creatine phosphokinase increased markedly, reaching a peak of 2-4 fold baseline levels 24 hours postpartum. It then declined gradually back to baseline. Nulliparous women reached substantially higher levels than multiparous women. The MB or so-called cardio-specific isoenzyme was found to be an important contributor to creatine phosphokinase surge in most women. Correlation was demonstrated between length of the active phase of labor and both total and MB creatine phosphokinase activity. There was no clinical or electrocardiographic evidence for cardiac muscle damage in any of the study patients. Serum lactate dehydrogenase and aspartate amino transferase were not altered during or after labor. CONCLUSIONS: Serum total creatine phosphokinase and its MB isoenzyme increase substantially during normal vaginal labor without evidence of myocardial ischemia. The uterus and placenta, two organs which were reported to embody substantial amounts of these enzymes, and which participate actively in the process of labor, are thought to release these enzymes to the circulation during labor. Knowing the normal patterns of these enzymes in the serum during labor and puerperium may prevent erroneous diagnoses of myocardial ischemia or infarction. Lack of electrocardiographic abnormalities and low lactate dehydrogenase and aspartate amino transferase levels may assist in excluding such diagnoses.

Aspartate Aminotransferases↗
PubMed1999

Women's anticipations of and experiences with induction of labor.

BACKGROUND: Although induction of labor is a common procedure, there are limited data on its psychoemotional effects. We studied women's expectations of and experiences with labor induction in a large university hospital. PATIENTS AND METHODS: A total of 296 parturients were recruited, with 270 (91%) taken into the final analysis. Of these, 135 underwent elective induction of labor (44 with amniotomy and 91 with cervical ripening by the use of vaginal prostaglandin gel, followed by amniotomy), whereas the remaining 135 women gave birth spontaneously and served as controls. Each woman was interviewed as to her knowledge, expectations, and feelings about labor before induction or at start of labor (controls) as well as after delivery with the help of questionnaires containing yes/no or multiple-choice questions and visual analog scales. RESULTS: The induction and control groups, in regard to baseline clinical characteristics, did not differ. Labor ended in cesarean section for 24 women in the induction group (18%) and for 12 women in the control group (9%) (p=0.04); these women were included in the data analysis. In the induction group, 67%, and in the control group, 48% of women (p=0.002) reported having received sufficient information on labor induction from medical personnel at prenatal or obstetric clinics. Attitudes towards induction of labor were antenatally positive in 78% of women in the induction group and in 69% in the control group. The induction group reported fear of pain less often (45%) than the control group (57%) (p=0.03). In the induction group, 76 women (56%), and in the control group 94 women (70%) (p=0.02), wanted to participate in the decision on the method of induction, and 74% and 83%, respectively, wished to influence the timing of induction. When interviewed post partum, the labor experience corresponded with the patients' expectations better in the control than in the induction group (p=0.03). Labor induction was a positive experience in 90% of women who underwent immediate amniotomy and in 69% of those who received prostaglandin ripening first. CONCLUSION: Labor induction was a positive experience only seldom eliciting negative feelings. A third of the parturients undergoing induction need more information on the procedure and most want to participate in decision-making concerning the method and timing of induction.

Adolescent↗
PubMed1989

The clinical significance of pain and cognitive activity in latent labor.

We examined the relationship between pain and cognitive activity during the latent (less than or equal to 3 cm), mid-active (5-7 cm), and transition (greater than or equal to 8 cm) phases of labor and the concomitant efficiency of the latent, active, and descent phases in 115 nulliparous women. Patients provided subjective pain ratings and described their thoughts during each of the three phases. Higher levels of pain during the latent phase of labor were predictive of longer latent (r = 0.58) and active (r = 0.50) phases of labor. Distress-related thoughts during latent labor were predictive of longer latent (r = 0.31, P less than .01), active (r = 0.67), and second-stage (r = 0.61) labor. We found no relationships between pain and cognitive activity measured during active labor and efficiency of active labor or second stage of labor. Pain and cognitive activity assessed during the latent phase were also prognostic of obstetric outcome. Thirteen of 19 women (68.4%) who reported "horrible" or "excruciating" pain required instrumental delivery, compared with eight of 27 women (29.6%) in the "discomforting" pain group. Subjects in the "distress-related" cognitive group had 2.6 times the incidence of instrumental delivery, five times the incidence of abnormal fetal heart rate patterns, and four times the requirement for pediatric assistance for the neonate than subjects in the "coping" group. We conclude that latent labor is a critical phase in the psychobiology of labor and that pain and cognitive activity during this phase are important contributors to labor efficiency and obstetric outcome.

Adolescent↗
PubMed1982

[The changes of human plasma ACTH and immunoreactive beta-endorphin during spontaneous or oxytocics induced/maintained labor and delivery (author's transl)].

To evaluate the effects of oxytocics on ACTH and Immunoreactive (IR)-beta-endorphin release, concentrations of these hormones in the plasma of 22 women during spontaneous labor, 22 women in labor who had received oxytocin and 19 women in labor who had received PG.F2 alpha at the time of vaginal delivery, were measured. Maternal ACTH and IR-beta-endorphin concentrations were elevated during spontaneous or oxytocics induced/maintained labor and peaked immediately after delivery and decreased two hours later. There were significant correlations between ACTH and IR-beta-endorphin concentrations during spontaneous labor and delivery (r = 0.921, p less than 0.0001), as well as in oxytocin or PG.F2 alpha induced/maintained labor and delivery (r = 0.833, r = 0.916, p less than 0.0001, respectively). The concentrations of ACTH and IR-beta-endorphin during PG-F2 alpha infusion were slightly higher than those seen in the other two types of labor. However, there was no significant difference in the levels of ACTH and IR-beta-endorphin among the three types of labor. Simultaneous maternal and umbilical cord plasma samples were obtained in 25 cases at delivery. However, there was no significant correlation between ACTH or IR-beta-endorphin concentrations in paired samples. These results suggest that 1) IR-beta-endorphin is secreted in parallel with ACTH, into the peripheral blood by the maternal pituitary gland in response to the stress of labor during all types of labor and delivery; 2) there is no significant difference in the response of ACTH and IR-beta-endorphin between spontaneous and oxytocics induced/maintained labor and delivery: 3) ACTH and IR-beta-endorphin in cord blood are not of maternal origin.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Inflammatory cytokine mRNA in human gestational tissues: implications for term and preterm labor.

OBJECTIVE: To determine if inflammatory cytokine mRNA in gestational tissues is present only in the setting of infection-associated preterm labor or under several other clinical conditions. METHODS: Human gestational tissues were collected from 51 women experiencing 1) term cesarean delivery without labor, 2) normal term vaginal delivery, 3) preterm cesarean delivery without labor, 4) preterm vaginal delivery without chorioamnionitis, and 5) preterm vaginal delivery with concomitant chorioamnionitis. Decidua, chorion, and amnion were isolated, total RNA from each tissue was extracted, and the presence of inflammatory cytokine mRNA was determined by polymerase chain reaction. Interleukin (IL)-1 beta, IL-6, IL-8, and tumor necrosis factor-alpha mRNA was detected using specific oligonucleotide primers. RESULTS: Interleukin-1 beta mRNA was rarely found in tissues preterm without labor but was readily detected in both maternal and fetal tissues after labor, regardless of gestational age. Interleukin-6 mRNA was rare in tissues from the nonlaboring patient but was found in almost all tissues after labor. Interleukin-8 mRNA was detected in all tissues at term, both in nonlaboring and laboring patients. Tumor necrosis factor-alpha mRNA was detected in only 20-50% of tissues after labor, and was rarely detected in the absence of labor. CONCLUSIONS: Inflammatory cytokine mRNA is commonly expressed in human gestational tissues after normal labor and preterm labor with or without associated intrauterine infection. There was no difference in the pattern of expression of mRNA inflammatory cytokine in women who did or did not have clinically evident intrauterine infection.

Adolescent↗
PubMed1991

Maternal serum cortisol and prolactin variations during labor.

Maternal serum cortisol (F) and prolactin (PRL) levels were measured during labor in 20 uncomplicated pregnancies. Four pregnant women were admitted with ruptured membranes (RM group) and 16 were admitted with intact membranes (IM group), ten with spontaneous onset of labor (SL group) and 10 with induced labor (IL group), five with a prolonged for duration labor (PL group) and 15 with a normal for duration labor (NL group). Before the inset of labor F levels were statistically higher (p less than 0.05) in the RM group (x = 975 ng/ml), than in the IM group (x = 664 ng/ml), and also in the SL group (x = 783 ng/ml), than in the IL group (x = 679 ng/ml). During labor, in all twenty pregnant women a marked rise of F (from x = 726 ng/ml before the onset of labor, to x = 911 ng/ml) and a marked fall of PRL (from x = 161 ng/ml to x = 122 ng/ml) were observed (p less than 0.05). In the PL group the F elevation and the PRL drop were more pronounced (p less than 0.001). After placental separation, PRL levels increased slightly while F values remained unchanged. These changes in hormone levels before and during labor could be attributed to the emotional and physical stress of labor.

Female↗
PubMed1988

Factors predisposing to difficult labor in primiparas.

Why do some women have difficult labor whereas other women have relatively easy labor? A study of possible predisposing factors was conducted in 398 and 383 primiparas admitted for uncomplicated spontaneous labor at two hospitals. Psychosocial factors, notably anxiety about childbirth, and physical factors, especially maternal height and body mass index, were measured before the onset of labor. Difficult labor was defined in primiparas admitted to the hospital for spontaneous uncomplicated labor as (1) prolonged labor that was longer than 15 hours from admission until full dilation with vaginal delivery or (2) cesarean section. Anxiety about childbirth as self-reported before the onset of labor did not predispose to difficult labor at either hospital. Short height and heavy body mass index predisposed to difficult labor. Further work is needed to elucidate psychosocial factors predisposing to difficult labor.

Anxiety↗
PubMed1988

Intraamniotic infection and the onset of labor in preterm premature rupture of the membranes.

The purpose of this study was to examine the relationship between intraamniotic infection and the onset of labor in patients with preterm premature rupture of the membranes. Two hundred and thirty consecutive patients were admitted with premature rupture of the membranes to Yale-New Haven Hospital from January 1985 to July 1987. Amniotic fluid was retrieved by amniocentesis from 96% (221/230). Sixty-one patients were in labor on admission (27.6%, 61/221) and 39% of them (24/61) had a positive amniotic fluid culture. Patients in labor on admission were more likely to have a positive amniotic fluid culture than those who were not in labor on admission (24/61 versus 41/160, p = 0.049). Of the 160-patients who were not in labor on admission, 81 subsequently went into spontaneous labor; microbiologic information at the time of labor was known in 48 of these patients (59.2%). Seventy-five percent (36/48) of these patients had a positive amniotic fluid culture. The incidence of intraamniotic infection in quiescent women who subsequently went into labor was higher than that of patients admitted in active labor (75% versus 39%, p = 0.0004). These results provide a basis for the clinical impression that the onset of labor in women with preterm premature rupture of the membranes is associated with a subclinical intraamniotic infection. The mechanisms responsible for the onset of labor in women without an intraamniotic infection may be associated with an extraamniotic infection (e.g., deciduitis) or a noninfectious process.

Amniotic Fluid↗
PubMed1996

The expression of cyclooxygenase-2 (COX-2) in amnion and decidua following spontaneous labor.

OBJECTIVE: Prostaglandins production rises dramatically during term and preterm labor. The source of this production is thought to be the fetal membranes and maternal decidua. The enzyme responsible for the conversion of arachidonic acid to the prostaglandins and related endoperoxides is variously known as prostaglandin synthase or cyclooxygenase (COX). An inducible form of this enzyme, COX-2, has been described in several tissues. The purpose of this study was to investigate a possible role for COX-2 in labor by comparing the COX-2 content in amnion and decidua from laboring and non-laboring patients. STUDY DESIGN: Fetal membranes from seven normal labor and ten elective cesarean sections at term were collected immediately following delivery. The maternal age and gravity were similar between the groups. The amnion and decidua were identified, washed in sterile saline, frozen in liquid nitrogen and stored in -70 degrees C. COX-2 expression was determined using Western Blot analysis with a purified COX-2 antibody. A scanning densitometer was used to quantify the bands. Results were expressed as mean +/-S.D. ng/50 micrograms protein. RESULTS: The concentration of COX-2 in amnion of laboring women showed a twofold increase (240.0 +/- 17.6 vs. 120.7 +/- 5.1) compared to the non-labored group (p < 0.05). The concentration in the decidua showed no significant increase during labor (38.1 +/- 7.5 vs. 26.4 +/- 2.1, p > 0.05). CONCLUSION: We evaluated the role of COX-2 in normal labor. Our study demonstrates that COX-2 is significantly induced in the amnion following spontaneous labor. These findings suggest that the induction of amnion COX-2 may be involved in the process of human labor.

Amnion↗
PubMedDate not supplied

The length of the second stage of labor in uncomplicated, nulliparous African American and Puerto Rican women.

The Friedman Curve of Normal Labor, based on Emanuel Friedman's studies of Caucasian women in 1954 and 1955, remains the "gold standard" for assessing progress in the second stage of labor. Clinical observation by the authors, however, suggests that the second stage of labor is shorter in African American and Puerto Rican women. This descriptive, comparative study examined the duration of the second stage of labor in nulliparous African American and Puerto Rican women with uncomplicated births. The labor and delivery records of 373 African American and 157 Puerto Rican nulliparous women were randomly selected and reviewed, and the mean durations of the second stage of labor for both groups were compared to Friedman's labor curve. The mean length of second stage of labor in the sample of African American women was 31.6 minutes with a standard deviation of +/- 22.5 minutes, significantly shorter than Friedman's duration (P < .01). The mean length of second stage of labor in the sample of Puerto Rican women was 44.32 minutes with a standard deviation of +/- 33.03 minutes. This was also shorter than Friedman's figure for the second stage of labor (P < .01). These findings provide a more appropriate curve for monitoring labor progress in women from different ethnic backgrounds.

Adolescent↗
PubMed2003

Women's recognition of the spontaneous onset of labor.

BACKGROUND: Despite extensive research on the onset of labor, almost no data are available on women's perception of labor onset. We undertook a study to assess how women experience spontaneous onset of term labor. METHODS: A semistructured questionnaire was given to 235 women admitted in spontaneous labor at term. Women noted when labor had started, whether and when membranes had ruptured, and answered an open question about how labor had announced itself. Two investigators independently subdivided women's experiences on how labor had started into 369 sampling units corresponding to 8 predefined categories. RESULTS: Nearly two-thirds of the sampling units (63.4%) related to recurrent and nonrecurrent pain, and the ratio between the two types was higher for multiparas than for nulliparas. The number of women and sampling units were identical for each of the following categories: watery fluid (n = 47), blood-stained loss (n = 33), gastrointestinal symptoms (n = 10) and altered sleep patterns (n = 11); 22 sampling units relating to emotional upheaval were mentioned by 16 women. Although 33.6 percent of women experienced rupture of membranes before admission, only 21.6 percent associated it with their onset of labor, either alone (11.5%) or in association with other categories (10.1%). CONCLUSIONS: Although women experience onset of labor in a variety of ways, for most it is a concrete event. Studies on duration of labor should take women's perception of onset of labor as a starting point rather than rely on surrogate measures.

Adolescent↗
PubMed1999

Utilization of real-time ultrasound on labor and delivery in an active academic teaching hospital.

OBJECTIVE: Ultrasound (US) is currently available on most if not all Labor and Delivery (L+D) services. Our objective was to survey utilization of real-time US on L+D in an active academic teaching hospital. STUDY DESIGN: Between April 1, and July 31, 1998, all US examinations performed for clinical purposes on patients presenting to L+D, were documented. Data collected included: gestational age, whether or not the patient was in labor, number of fetuses, and indication for US. All US examinations were performed by OB/GYN housestaff at the PGY 2-3 level, and fellows in Maternal-Fetal Medicine. Statistical analysis included Student's t-test and chi2 when appropriate, with p < 0.05 considered significant throughout. RESULTS: During the 4-month study period, 1316 patients delivered and 1363 were discharged from L+D, not in labor. Of 630 US examinations 31.64% (192 of 630) and 67.69% (418 of 630) were performed in laboring versus nonlaboring patients, respectively. Of all patients delivered during the study period, 14.5% (192 of 1316) underwent intrapartum US, and of all nonlaboring patients, 30.66% (418 of 1363) underwent US on L+D. The mean gestational age at the time of assessment was 37.32 +/- 4.23 weeks' versus 35.74 +/- 5.76 weeks' gestation, in laboring versus nonlaboring patients respectively, p < 0.05. Main indications for US in patients in labor were; fetal presentation in patients with spontaneous rupture of membranes (SROM) 34.4% (n = 66), confirmation of vertex presentation 20.3% (n = 39), preterm labor 12% (n = 23), multiple gestation 7.3% (n = 14), and malpresentation 7.3% (n = 14). Main indications for patients not in labor were; amniotic fluid index 15.8% (n = 66), SROM 15.6% (n = 65), postdates 9.8% (n = 41) placental location 9.6% (n = 40), and decreased fetal movement 9.3% (n = 39). Ultrasound-guided interventions included: all deliveries of multiple gestations (n = 9), version in nonlaboring patients (n = 10), and postpartum curettage for retained placental tissue in conjuction with severe early postpartum hemorrhage (n = 2). The incidences of each separate indication for US were significantly different between laboring versus nonlaboring patients, p < 0.05, respectively. CONCLUSION: US examination is performed in 15% of patients in labor and 31% of patients not in labor assessed on L+D, constituting a widely applied diagnostic tool in this environment.

Delivery, Obstetric↗
PubMed2000

A randomized controlled trial of the effect of increased intravenous hydration on the course of labor in nulliparous women.

OBJECTIVE: One variable that has the potential to affect the course of labor but has not been evaluated previously is the adequacy of maternal hydration. Typical orders provide for 125 mL of intravenous fluids per hour in patients taking limited oral fluids. Many such patients are clinically dehydrated. Physiologists have shown that increased fluids improve skeletal muscle performance in prolonged exercise. This study was designed to determine whether increased intravenous fluids affect the progress of labor. STUDY DESIGN: Nulliparous women with uncomplicated singleton gestations at term, in spontaneous active labor with dilatation between 2 and 5 cm, and with a cephalic presentation were included. Patients who gave consent were randomly selected to receive either 125 mL or 250 mL of intravenous fluids per hour. RESULTS: One hundred ninety-five patients were randomly selected, 94 to the 125-mL group and 101 to the 250-mL group. Prerandomization variables were well matched between the 2 groups. The mean volume of total intravenous fluids was significantly greater in the 250-mL group (2008 mL vs 2487 mL; P =.002), as was the mean hourly rate (152 mL/h in the 125-mL group vs 254 mL/h in the 250-mL group; P =.001). The frequency of labor lasting >12 hours was statistically higher in the 125-mL group (20/78 [26%] vs 12/91 [13%]; P =.047). In addition, there was a trend favoring longer mean duration of the first stage and total duration of labor in patients delivered vaginally in the 125-mL group, by 70 and 68 minutes, respectively (P =.06). There was a trend toward a lower frequency of oxytocin administration for inadequate labor progress in the higher fluid rate group (61 [65%] in the 125-mL group vs 51 [49%] in the 250-mL group; P =.06). Cesarean deliveries were more frequent in the 125-mL group (n = 16) than in the 250-mL group (n = 10) but did not reach statistical significance. CONCLUSION: This study presents the novel finding that increasing fluid administration for nulliparous women in labor above rates commonly used is associated with a lower frequency of prolonged labor and possibly less need for oxytocin. Thus inadequate hydration in labor may be a factor contributing to dysfunctional labor and possibly cesarean delivery. Consideration of this factor in clinical management and in future studies considering variables that affect labor is warranted.

Adult↗
PubMed2002

Outcome after elective labor induction in nulliparous women: a matched cohort study.

OBJECTIVE: To determine whether elective induction of labor in nulliparous women is associated with changes in fetomaternal outcome when compared with labor of spontaneous onset. STUDY DESIGN: All 80 labor wards in Flanders (Northern Belgium) comprised a matched cohort study. From 1996 through 1997, 7683 women with elective induced labor and 7683 women with spontaneous labor were selected according to the following criteria: nulliparity, singleton pregnancy, cephalic presentation, gestational age at the time of delivery of 266 to 287 days, and birth weight between 3000 and 4000 g. Each woman with induced labor and the corresponding woman with spontaneous labor came from the same labor ward, and they had babies of the same sex. Both groups were compared with respect to the incidence of cesarean delivery or instrument delivery and the incidence of transfer to the neonatal ward. RESULTS: Cesarean delivery (9.9% vs 6.5%), instrumental delivery (31.6% vs 29.1%), epidural analgesia (80% vs 58%), and transfer of the baby to the neonatal ward (10.7% vs 9.4%) were significantly more common (P <.01) when labor was induced electively. The difference in cesarean delivery was due to significantly more first-stage dystocia in the induced group. The difference in neonatal admission could be attributed to a higher admission rate for maternal convenience when the women had a cesarean delivery. CONCLUSION: When compared with labor of spontaneous onset, elective labor induction in nulliparous women is associated with significantly more operative deliveries. Nulliparous women should be informed about this before they submit to elective induction.

Adult↗
PubMed2003

Does labor influence neonatal and neurodevelopmental outcomes of extremely-low-birth-weight infants who are born by cesarean delivery?

OBJECTIVE: The purpose of this study was to examine the influence of labor on extremely-low-birth-weight infants who were born by cesarean delivery with reference to neonatal and neurodevelopmental outcomes. We hypothesized that infants who are born by cesarean delivery without labor will have better outcomes than those infants who are born by cesarean delivery with labor. STUDY DESIGN: This was a retrospective cohort study of extremely-low-birth-weight infants (birth weight, 401-1000 g) who were born by cesarean delivery and cared for in the National Institute for Child Health and Human Development Neonatal Network, during calendar years 1995 to 1997. A total of 1606 extremely-low-birth-weight infants were born by cesarean delivery and survived to discharge. Of these, 1273 infants (80.8%) were examined in the network follow-up clinics at 18 to 22 months of corrected age and had a complete data set (667 infants were born without labor, 606 infants were born with labor). Outcome variables that were examined include intraventricular hemorrhage grade 3 to 4, periventricular leukomalacia, and neurodevelopmental impairment. RESULTS: Mothers in the cesarean delivery without labor group were older (P<.001), more likely to be married (P<.05), less likely to be supported by Medicaid (P<.01), more likely to have preeclampsia/hypertension (P<.001), more likely to receive prenatal steroids (P<.005), and less likely to have received antibiotics (P<.001). Infants who were born by cesarean delivery without labor had higher gestational age (P<.001), lower birth weight (P<.01), and were less likely to be outborn (P<.001). By univariate analysis, infants who were born by cesarean delivery with labor had a higher incidence of grade 3 to 4 intraventricular hemorrhage (23.3% vs 12.1%, P<.001), periventricular leukomalacia (8.5% vs 4.7%, P<.02), and neurodevelopmental impairment (41.7% vs 34.6%, P<.02). Logistic regression analysis that controlled for all maternal and neonatal demographic and clinical variables that were statistically associated with labor or no labor revealed that the significant differences in grade 3 to 4 intraventricular hemorrhage, periventricular leukomalacia, and neurodevelopmental impairment were no longer evident. CONCLUSION: In extremely-low-birth-weight infants who were born by cesarean delivery and after control for other risk factors, labor does not appear to play a significant role in adverse neonatal outcomes and neurodevelopmental impairment at 18 to 22 months of corrected age.

Adult↗
PubMed1994

Changes in lung lipid during spontaneous labor in fetal sheep.

The goals of this study were 1) to examine changes in lung liquid formation and composition during spontaneous labor in fetal lambs and 2) to determine the importance of beta-adrenergic stimulation and transepithelial Na+ flux in removing liquid from the lung lumen near birth. We measured net production of lung liquid (Jv), lung liquid composition, and transpulmonary electrical potential difference (PD) before and during labor in fetal sheep with chronically implanted tracheal and vascular catheters. We determined Jv by measuring rate of change in lung liquid concentration of 125I-albumin, an impermeant tracer that was mixed in lung liquid at the start of each study. In 17 paired experiments, Jv decreased from 11 +/- 2 ml/h (Jv > 0 = secretion) before labor to -1 +/- 2 ml/h (Jv < 0 = absorption) during labor; in 5 paired experiments, PD changed from -7 +/- 1 mV (lumen negative) before labor to -12 +/- 1 mV during labor. To determine whether absorption of lung liquid during labor is the result of beta-adrenergic stimulation, we studied the effect of propranolol on Jv during labor. When propranolol (40 microM) was added to lung liquid during active labor, Jv decreased from -2 +/- 2 to -8 +/- 3 ml/h (n = 9). Thus, propranolol did not inhibit lung liquid absorption during labor. To determine whether transepithelial Na+ movement provides the driving force for lung liquid clearance during labor, we tested the effects of amiloride, an Na+ transport inhibitor, on Jv and PD.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗