Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Labor Onset”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed2001

The relationship between oligohydramnios and the onset of preterm labor in preterm premature rupture of membranes.

OBJECTIVE: The objective of this study was to determine whether a reduced amniotic fluid volume was associated with the onset of preterm parturition in patients with preterm premature rupture of membranes. STUDY DESIGN: An amniotic fluid index was determined before transabdominal amniocentesis in 129 patients with preterm premature rupture of membranes (gestational age < or = 35 weeks). Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Survival techniques were used for analysis. RESULTS: Amniotic fluid index was < or = 5 cm in 29% of patients (38/129). Patients with an amniotic fluid index of < or = 5 cm had a significantly higher rate of positive amniotic fluid culture than those with an amniotic fluid index of >5 cm (42% [16/38] vs 18% [16/91]; P<.01). Spontaneous preterm delivery within 24 hours and 48 hours was more frequent among patients with an amniotic fluid index of < or = 5 cm than those with an amniotic fluid index of >5 cm (for 24 hours, 29% vs 12%; for 48 hours, 42% vs 21%; P<.05 for each). The amniocentesis-to-delivery interval was significantly shorter in patients with an amniotic fluid index of < or = 5 cm than in patients with an amniotic fluid index of >5 cm (median, 38 hours; range, 0.2-1310 hours; vs median, 100 hours; range 0.1-2917 hours; P<.01). Moreover, Cox proportional hazards model analysis indicated that an amniotic fluid index of < or = 5 cm was a significant predictor of the duration of the pregnancy after adjustment for gestational age and the results of amniotic fluid culture (odds ratio, 2.4; 95% confidence interval, 1.4-3.9; P<.001). CONCLUSION: Patients with preterm premature rupture of membranes and an amniotic fluid index of < or = 5 cm are at increased risk for a shorter interval to delivery.

Adult↗
PubMed2003

Intervention rates after elective induction of labor compared to labor with a spontaneous onset. A matched cohort study.

INTRODUCTION: Elective induction of labor has become a widely used procedure in obstetrics. A number of studies have shown an increased incidence of operative deliveries. The objective of this study was to evaluate the rate of interventions in our hospital, including operative delivery. METHODS: A matched cohort study in which labor of 122 electively induced women and 122 women with labor with a spontaneous onset were analyzed retrospectively. These women were matched for parity and gestational age. RESULTS: Pain relief, fetal scalp blood sampling and operative deliveries were recorded more frequently in the electively induced labor group. Cesarean delivery was found in 15% of women with induced labor, and in 1% of labors with a spontaneous onset (relative risk 18 (95% CI 2.4-132.7)). No differences were found in neonatal outcomes. CONCLUSIONS: Elective induction of labor leads to increased intervention rates during labor. The rate of cesarean delivery is high, particular in nulliparous women and multiparous women without a previous vaginal birth.

Adult↗
PubMed1999

[The permeability of the cell membrane in the human uterine smooth muscle at term pregnancy].

OBJECTIVE: To study the changes of the permeability of the uterine smooth muscle cell membrane at the various stages of labor, and comparing with the onset of labor. METHODS: 18 women (38 to 41 gestational weeks) were divided into three groups: late pregnancy not in labor, prelabor, active labor, and six cases in each group. The myometrium tissues in the corpus and lower segment of the uterus were studied by the Lanthanum tracing method under transmission electron microscopy (TEM). RESULTS: Lanthanum entered into the smooth muscle cells, deposited in the mitochondria. The positive rates of the smooth muscle cells of lower segment by lanthanum tracing were markedly higher than that of corpus in late pregnancy group (P < 0.05), the difference were not found between lower segment and corpus in prelabor group (P > 0.05). The positive rates in corpus were significant higher than that of lower site in the active labor group (P < 0.05); Comparing corpus to corpus, the positive rates were not significantly different between late pregnancy and prelabor group (P > 0.05), then in active labor group it were markedly higher than those in the other two groups (P < 0.05, respectively); but in lower segment, the positive rates in late pregnancy group were significant higher than that in prelabor and active labor group (P < 0.05 respectively), no difference was found between prelabor and active labor (P > 0.05). The lanthanum deposition in the late pregnancy and prelabor groups was mainly showed in larger mitochondria within the smooth muscle cell while in active labor group, it laid on the outer and inner membrane and cristae of all the mitochondria. CONCLUSION: The permeability of uterine smooth muscle cell membrane at term, pregnancy increases, especiany in uterine corpus, which showed a close correlation with the onset of labor.

Adult↗
PubMed1975

Prophylactic antibiotics in cesarean section.

Using a random selection procedure, 100 patients were evaluated in order to determine the value of prophylactic antibiotics in cesarean section. All patients were evaluated for febrile morbidity, and specific infection sites were recorded. Significant differences were found between the treated and control groups and between cesarean sections performed prior to the onset of labor and after the onset of labor.

Bacterial Infections↗
PubMed1997

Lung liquid production rates and volumes do not decrease before labor in healthy fetal sheep.

Previous studies have suggested that the volume and production rate of fetal lung liquid decrease late in gestation, before the onset of labor, in preparation for the clearance of lung liquid at birth. In contrast, our earlier studies have not shown a decrease in lung liquid volume near term, although these studies were not continued to the onset of labor. Our aim was to determine the changes in lung liquid volume and production rate in fetal sheep during the last 2 wk of gestation up to the onset of labor at term (approximately 147 days). In eight chronically catheterized fetal sheep, the volume and production rate of fetal lung liquid were measured at 130, 135, and 140 days of gestation and then on every 2nd day until the onset of labor. Labor was detected by monitoring uterine muscle activity and intrauterine pressure changes. On the day of labor onset, which occurred at 147 +/- 1 days of gestation, fetuses weighted 5.0 +/- 0.2 kg. The volume of fetal lung liquid was 40.4 +/- 2.7 ml/kg at 19 +/- 1 days before labor onset and had not significantly changed by 0.7 +/- 0.2 days (44.8 +/- 5.1 ml/kg) before labor. Similarly, lung liquid production rates at 19 +/- 1 days before labor (5.1 +/- 1.8 ml.h-1.kg-1) were not significantly different from those at 0.7 +/- 0.2 days before labor (3.4 +/- 0.7 ml.h-1.kg-1). We conclude that, in healthy ovine fetuses, lung liquid volumes and production rates do not decrease before the onset of labor. Our results indicate that the entire volume of fetal lung liquid (approximately 222.5 +/- 36.6 ml) must be cleared after the onset of labor.

Animals↗
PubMed1984

[Changes in steroids in amniotic fluid in relation to the initiation of labor].

To study the changes in steroid concentrations in amniotic fluid (AF) in relation to the initiation of parturition, eleven steroids in AF which included cortisol(F), progesterone (P4), 20 alpha-dihydroprogesterone, free(f-) and conjugated(c-) pregnenolone, DHA, estradiol(E2) and estriol(E3) were measured by RIA. Experiment 1: Samples were obtained at I) elective cesarean section (not in labor, n = 9), II) vaginal delivery after the spontaneous onset of labor (in labor, n = 13). Experiment 2: AF were collected serially from each individual at A) the artificial rupture of the membrane before the onset of labor, B) the initiation of labor and C) second stage of delivery. Samples of B and C were obtained with a catheter which was placed in the uterine cavity at the rupture of the membrane. The mean concentrations of F,c-E2,f- and c-E3,DHA in I were significantly higher than those in II. In experiment 2, except for P4, all steroid concentrations tended to increase during the course of labor. The levels of F increased significantly from A to C but not from A to B. Free DHA increased from B to C. The percentage increase in steroid levels was also caliculated and it was found that the steroid increase from A to B was f-E2 while P4 decreased. E2/P4 ratio increased significantly from A to B. These results suggested that the increase in F and DHA may be due to the fetal response to the stress of labor. A possible role of increased E2 and decreased P4, and subsequently increased E2/P4 ratio, in AF on the onset of labor is suggested.

20-alpha-Dihydroprogesterone↗
PubMed1987

Changes in the plasma prostaglandin F2 alpha metabolite before and during spontaneous labor and labor induced by amniotomy, oxytocin and prostaglandin E2.

To elucidate the role of endogenous prostaglandin F2 alpha in spontaneous and induced labor, plasma concentrations of 13, 14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were determined before the onset of labor, at onset of labor, during active labor, at the crowning of the fetal head, and 1 and 2 hours after delivery. Patients in spontaneous labor and labor induced by amniotomy, oxytocin, and prostaglandin E2 were studied. The levels of plasma PGFM in patients who entered spontaneous labor fell 2 to 3 weeks before delivery, whereas those in the induced labor group did not change until the time of induction. Although the levels of PGFM rose gradually with the progress of labor in all cases, the levels in the spontaneous labor were significantly lower in each stage than in the corresponding stage of induced labor. These results suggest that endogenous prostaglandin F2 alpha (PGF2 alpha) production decreases 2-3 weeks prior to the spontaneous onset of labor and is increased again as labor progresses, that the patterns of PGF2 alpha production are similar to each other during spontaneous labor and labor induced by various methods. Therefore, it is felt that endogenous PGF2 alpha may participate in the progress of all kinds of labor.

Adult↗
PubMed2005

Diagnosis of labor: a prospective study.

Accurate diagnosis of the onset of labor remains a problem in obstetrics. Criteria commonly used to diagnose labor have never been scientifically evaluated. This prospective study involved 423 pregnant women who presented themselves with uterine contractions to 2 Italian hospitals (248 nulliparous patients total and 175 multiparous total) and who were either admitted or advised to return home. The obstetrician on duty collected data using a standardized form that listed common criteria for labor diagnosis. Multivariate analysis showed that a reduction of the interval between consecutive uterine contractions, odds ratio [OR] = 1.42; 95% confidence interval [95%CI] 1.06-1.90); abdominal pain of increasing intensity (OR = 1.42; 95% CI 1.01-2.02); cervical effacement (OR = 1.4; 95%CI 1.12-1.77); and cervical dilation (OR = 1.91; 95% CI 1.53-2.38) were significant markers of the onset of labor. On the other hand, backache had a negative diagnostic value (OR = 0.78; 95% CI 0.61-0.99). The value of criteria such as regular uterine contractions, loss of mucous plug, changes in intestinal habits, vomiting, pain that is relieved by walking, and changes in breathing pattern did not reach statistical significance.

Diagnostic Techniques, Obstetrical and Gynecologic↗
PubMed2006

Acute onset headache complicating labor epidural caused by intrapartum pneumocephalus.

BACKGROUND: Epidural placement for obstetric anesthesia is a common procedure. Pneumocephalus, the introduction of air into the cranial cavity after epidural placement, is a rare complication encountered when air is used for identification of the epidural space. CASE: A 42-year-old primipara undergoing epidural placement reported sudden onset of severe headache with associated neurologic symptoms and nuchal rigidity. Emergent CT scan revealed pneumocephalus. With conservative management, her symptoms resolved with interval resumption of the air collection evidenced on interval CT. CONCLUSION: Acute onset headache after epidural placement can present with impressive neurologic signs and symptoms. Prompt identification of the cause of this pathology is of vital importance to delineate pneumocephalus from potentially treatable or life-threatening disorders.

Acute Disease↗
PubMed2002

[Comparison study on transvaginal ultrasonographic measurement and cytokine in prediction of the cervical ripening and the onset time of term labor].

OBJECTIVE: To compare the level of interleukin-6 (IL-6), interleukin-8 (IL-8), human chorionic gonadotropin (hCG) with transvaginal ultrasonographic measurement in prediction of the cervix ripening and the time of term labor. METHODS: The 79 cases of primiparous women of term pregnancy were chosen as the research subjects. The maternal level of IL-6, IL-8, hCG in cervicovaginal secretions were measured. The cervical length, internal cervical os wedge width and forebag length were measured by transvaginal ultrasonography. The cervical Bishop score was also determined. RESULTS: (1) The levels of IL-6, IL-8, hCG in cervicovaginal secretions were significantly higher in women they are in labor than that of women at term not in labor (782 +/- 508) ng/L, (10,539 +/- 8 680) ng/L, (114 +/- 86) IU/L, versus (155 +/- 75) ng/L, (7,113 +/- 6 050) ng/L, (35 +/- 21) IU/L, respectively. (2) The levels of cervicovaginal secretions IL-6, IL-8, hCG and the length of cervical, forebag were significant correlation with the cervical Bishop score (P < 0.05, r = 0.42, 0.24, 0.44, -0.56, 0.35) respectively. (3) The levels of cervicovaginal secretions IL-6, IL-8, the length of cervical, forebag measured by transvaginal ultrasonography and the cervical Bishop score were significant correlation to the onset time of term labor (P < 0.01, r = -0.42, -0.46, 0.64, -0.52, -0.41) respectively, and all these markers also could predict the onset of term labor in < or = 7 days, The predictive value on onset labor within < or = 7 days by cervical length < or = 30 mm: the sensitivity, specificity, positive values and negative value are 0.83, 0.89, 0.91 and 0.81 respectively. (4) Among the several markers in predicting cervix ripening and onset of labor, the best one was the transvaginal ultrasonographic measurement of cervical length. CONCLUSIONS: The levels of cervicovaginal secretions IL-6, IL-8, the length of cervical and forebag measured by transvaginal ultrasonography and the Bishop score are valuable in prediction of cervix ripening and onset of labor. The cervical length measured by transvaginal ultrasonography is the best one.

Adult↗
PubMed1976

Primary prostaglandins in amniotic fluid in pregnancy and spontaneous labor.

Primary prostaglandins have been measured by radioimmunoassay in the amniotic fluid of 80 patients. In late pregnancy, PGE2 was higher than PGF2alpha with an increase around 36 weeks (378 +/- 71 pg. per milliliter) without significant modification until term. PGF2alpha increased too, but only significantly at term. During spontaneous labor, PGE2 and PGF2alpha were higher than before the onset of labor. Through serial determinations in five patients, two steps can be distinguished: the first one with stable levels but large oscillations of PGE2 and PGF2alpha and the second one starting at a variable stage of cervical dilatation with inversion of PGE2/PGF2alpha ratio (less than 1 and followed by an increase of both compounds more pronounced for PGF2alpha. It appears that PGE2 is concerned with the initiation of parturition while both PG's and mainly PGF2alpha are in relation to the contractions and the duration of labor.

Amniotic Fluid↗
PubMed2006

Cumulative economic implications of initial method of delivery.

OBJECTIVE: To examine the cumulative costs of hospital care in the first and subsequent pregnancies associated with different methods in the initial delivery of nulliparous women. METHODS: An 18-year population-based cohort study (1985-2002) using the Nova Scotia Atlee Perinatal Database compared cumulative delivery costs in the first and subsequent pregnancies. Women were identified by initial method of delivery for nulliparous women with singleton cephalic presentation at term undergoing spontaneous or induced labor for planned vaginal delivery, and for nulliparous women undergoing cesarean delivery without labor. Costs that were assessed included nursing hours in antepartum, labor and delivery, postpartum and neonatal intensive care units, physician costs, labor induction agents, consumables, and costs for postpartum hysterectomy, tubal ligation, and dilatation and curettage. RESULTS: A total of 27,613 pregnancies satisfied inclusion and exclusion criteria. When cumulative costs by type of labor at first delivery were considered, induction of labor (7,220 dollars) was more costly than spontaneous onset of labor (6,919 dollars, P = .006). The cumulative costs of assisted vaginal delivery at first delivery (7,288 dollars) and cesarean delivery in labor at first delivery (9,524 dollars) were similar in magnitude and were higher than spontaneous vaginal delivery at first delivery (P < .001). Cesarean delivery in labor in the first delivery was the most costly type of delivery (9,524 dollars), and the differences in cost increased with increasing number of deliveries (P < .05). CONCLUSION: Cesarean delivery in labor in the first delivery is associated with increased cumulative costs compared with other methods of delivery, regardless of the number or type of subsequent deliveries.

Adult↗
PubMed1988

[Changes in N-acetyl-beta-glucosaminidase activity in the maternal plasma and utero-placental tissues during normal pregnancy and parturition].

In the ripening of the uterine cervix during parturition, glycosaminoglycan (GAG) in the cervical extracellular matrix has been reported to undergo drastic changes i.e. the increase in hyaluronic acid, and the decrease in dermatan sulfate and chondroitin sulfate. N-acetyl-beta-glucosaminidase (NAG; EC3.2.1.30), one of marker enzymes of lysosome, may also degrade extracellular GAG in the uterine cervix. This study is undertaken to determine if NAG plays a role in the ripening of the cervix during parturition. The maternal plasma were collected from 252 women with normal pregnancy (5-41 weeks gestation). Amnion, chorion and parietal decidua were obtained from 20 patients at more than 36 gestational weeks who had undergone cesarean section (CS) prior to labor, and from 24 who had undergone CS after the onset of labor. NAG activity in the maternal plasma gradually increased with the advance of gestation, and increased drastically after the onset of labor. The activity in the amnion and decidua, but not in the chorion, decreased significantly in the women who had undergone CS after the onset of labor compared with those who had undergone CS prior to labor. It is concluded that NAG is released into the maternal circulation from lysosomes in amnion and decidua, and it is also estimated that NAG plays a role in the ripening of the uterine cervix during parturition by degrading GAG in the cervical extracellular matrix.

Acetylglucosaminidase↗
PubMed1986

Labor in humans: 1. Progesterone, 20 alpha-dihydro-progesterone, estrone and 17 beta-estradiol in near placental and most distant human amnion and chorion laeve in various stages of labor at term.

In some species the onset of labor is regulated by changes in the estrogen/progesterone ratio. The same change in fetal membranes has been suggested to be one of the triggering mechanisms of labor in humans. In order to examine if a gradient in steroid concentration existed in fetal membranes and if changes in concentrations could be observed with the onset and advancing labor, the concentration of progesterone (P), 20 alpha-dihydro-progesterone (20 alpha-OHP), estrone (E1) and 17 beta-estradiol (E2) were determined by specific radioimmunoassay in the near placental and most distant regions of human amnion and chorion laeve obtained at term, before, at the onset and in advanced labor. Both estrogen and progestin concentrations in the chorion were higher than in the amnion. No gradient in the concentration of steroids was found. No statistically significant differences in estrogen and progestin levels were associated with the onset of labor.

20-alpha-Dihydroprogesterone↗
PubMed1998

[Morphometric analysis of gap junctions of the cell membrane in human uterine smooth muscle at term].

OBJECTIVE: To study the changes of the gap junctions (GJS) in the uterine smooth muscle cells at various stages of labor, and its relationship with the onset of labor. METHODS: 18 women (38 to 41 gestational weeks) were divided into three groups: not-in-labor, pre-labor, active in labor and six cases in each group. The uterine myometrium tissues were observed by transmission electron microscopy (TEM) and lanthanum tracing method. RESULTS: The lengths and areas of GJS in uterine corpus and lower segment in the active in labor group were significantly larger than that of the other 2 groups, but there was no significant difference between the not-in-labor and pre-labor groups. The area but not the lengths of GJS in corpus was significant larger than that in the lower segment in the active in labor group. CONCLUSION: The great increase of length and areas of GJS in all parts of the uterine smooth muscle was closely correlated with onset of labor.

Adult↗
PubMed1982

Simultaneous determinations of plasma oxytocin and serum placental leucine aminopeptidase (P-LAP) during late pregnancy.

1. Plasma oxytocin concentrations were measured by radioimmunoassay in 231 normal pregnant patients. The mean level of the maternal plasma oxytocin increases gradually with advancing pregnancy, culminating in a marked increase during the last two months. 2. Serum placental leucine aminopeptidase (P-LAP) activities and oxytocinase were measured serially in 78 obstetrically normal pregnant patients during late pregnancy. The daily mean P-LAP activity rises progressively during late pregnancy, reaching a relatively high level at 11 days prior to the onset of labor, then fluctuates slightly until the onset of labor. 3. Simultaneous serial measurements of plasma oxytocin levels and serum P-LAP activities in 9 normal pregnant women during late pregnancy show that the onset of labor is preceded by either an increase in the oxytocin level or a decrease in the P-LAP activity.

Adult↗
PubMed1996

A randomized controlled trial of membrane stripping at term to promote labor.

OBJECTIVE: To determine the effectiveness of membrane stripping at term to promote the onset of labor. METHODS: One hundred twenty gravidas at 38 weeks' gestation, who were attending an antenatal clinic and planned to deliver at Maharaj Nakorn Chiang Mai University Hospital in northern Thailand, were assigned randomly to one of two groups. One group had weekly pelvic examinations only, and the other also had membrane stripping, beginning at 38 weeks' gestation and continuing until the onset of labor or until 42 completed weeks' gestation. Outcome measures included the proportion of patients who delivered with 7 days after the first examination, Bishop scores among those who did not deliver, days from the first examination to delivery, incidence of postterm pregnancy, and maternal and fetal complication. RESULTS: Twenty-five of 61 patients (41%) assigned to membrane stripping delivered within 1 week, compared with 12 of 59 controls (20.3%), a statistically significant difference (P = .014). There was also a statistically significant difference (P = .013, Mann-Whitney U test) in the Bishop scores among those who did not deliver within 1 week (4 +/- 2.5 versus 2.6 +/- 1.7 in the study and control groups, respectively). A significant difference was also observed with respect to the mean number of days to delivery (8.8 +/- 6.7 versus 13.6 +/- 7.5, respectively; P < .001). The incidence of postterm pregnancy was one of 61 (1.6%) and three of 59 (5.1%) in the stripping and control groups, respectively. No significant differences were observed in maternal and fetal complications. CONCLUSION: Membrane stripping is safe and effective in promoting the onset of labor at term.

Adult↗
PubMed1976

Plasma cortisol levels in human fetus during parturition.

In several mammalian species, the fetal adrenal cortex plays an important role in the spontaneous onset of labor. No conclusive evidence has yet been presented that a similar mechanism is active in humans. Although in some previous studies the cortisol concentration in human cord blood has been found higher after spontaneous labor than after induced labor, it has not been possible to determine whether this rise in the fetal cortisol level precedes the onset of parturition or is a consequence of labor. In the present study, starting at the earliest possible stage of labor, fetal scalp blood samples were taken sequentially during 16 spontaneous and 13 induced vaginal deliveries. Cortisol levels in these 2 goups of samples were compared with each other and also with cord blood cortisol levels in 11 patients undergoing elective cesarean section. The initial fetal cortisol levels did not differ between groups with different modes of labor onset. A pronounced rise of plasma cortisol levels occurred during labor in simultaneously sampled maternal and fetal blood. These results do not support the concept of a role for the fetal adrenal cortex in the initiation of labor in humans; they invalidate the use of cortisol concentration in cord blood for the estimation of prelabor fetal cortisol level. The origin of the cortisol surge in fetal plasma during labor and also whether the fetal adrenocortical function responds to the stress of labor are discussed. It is concluded that the rise of fetal cortisol levels during labor might mainly be a reflection of the maternal response to stress.

Amniotic Fluid↗