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Results for “Labor Onset”

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At least 19 recordsLinked to original sources
PubMed1990

Pregnancy outcome in women with labor-onset hypertension. Similar outcome between labor-onset hypertension and preeclampsia.

Labor-onset hypertension is a poorly documented category, and there is scanty information concerning the outcome of pregnancy in this condition. A retrospective study was performed to compare the pregnancy outcome of 36 patients with labor-onset hypertension (group A) with 36 patients with classical preeclampsia diagnosed before labor (group B) who were matched for parity and age. There was no difference in age, past history of hypertensive pregnancies or family history of hypertension between the two groups. The need for intrapartum hypertensive and anticonvulsant treatment as well as the outcome of pregnancy were similar in both groups. The only significant difference was that group A patients had lower maximum and booking systolic and diastolic pressures. The results indicate that labor-onset hypertension represents a late manifestation of the preeclampsia process, because these patients had lower blood pressure in pregnancy and would not be identified until intrapartum elevation of blood pressure satisfied the diagnostic criteria of preeclampsia.

Apgar Score↗
PubMed1990

Objective tocodynamometry identifies labor onset earlier than subjective maternal perception.

The ability of women instructed in self-detection of uterine contractions to identify the abrupt rise in uterine activity known to precede the onset of labor has not been evaluated. This study was designed to assess the temporal relationship between objective uterine activity monitoring, subjective maternal perception of uterine activity above a commonly used threshold value (four or more contractions per hour), and progressive cervical change. Daily tocodynamometry (7-9 AM) was recorded in 79 women with preterm premature rupture of the membranes from admission until the onset of spontaneous labor (5.3 +/- 6.3 days). The subjects were at bed rest, received no tocolytic therapy, and were instructed in the signs of labor and uterine self-palpation. Patients simultaneously provided a subjective assessment of uterine activity (four or more contractions per hour). The majority of uterine activity recordings (78%) revealed fewer than four contractions per hour, and the patients' subjective reports agreed in almost all instances (97.6%). On 91 days, four or more contractions per hour were recorded objectively, but the patients' subjective reports agreed in only 25 instances (27%). On the day of labor onset, significantly more women had an objective assessment (32%) (P less than or equal to .01). Patients subjectively identified labor onset 10.6 +/- 6.7 hours after objective monitoring indicated increased uterine activity, and when subjectively identified, both cervical dilatation (4.9 +/- 2.5 cm) and effacement (85 +/- 30%) were significantly advanced (P less than or equal to .001) compared with the admission examination (1.1 +/- 1.2 cm; 20 +/- 30%).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiotocography↗
PubMed1989

Purification and characterization of a uterine phospholipase inhibitor that loses activity after labor onset in women.

Gravidin, a protein that inhibits release of arachidonic acid from human decidual cells, was purified from amniotic fluid. The protein has a molecular weight of 58 to 60 kilodaltons, an isoelectric point of 8.4, and physical characteristics that are indistinguishable from those of inhibitor II previously described. Activity was determined in a dispersed decidual cell system that released arachidonic acid in response to either histamine or calcium ionophore and in a cell-free assay of phospholipase A2. Protein purified from incubates of chorion obtained after the onset of labor was significantly less active than that from chorion obtained before the onset of labor.

Chorion↗
PubMed1987

Circadian incidence of labor onset hour in preterm birth and chorioamnionitis.

Normal labor begins most frequently between midnight and 2 AM, presumably because of an unidentified circadian labor-activating mechanism. We used records of the Collaborative Perinatal Project to determine whether such a circadian mechanism is present with intrauterine growth retardation (IUGR) or preterm birth, and whether chorioamnionitis is associated with alternative patterns. In the absence of chorioamnionitis, both preterm births and term births with IUGR demonstrated nocturnal labor onset distributions like those of control term deliveries, which had a peak incidence at 1:45 AM and an amplitude of 35%. With chorioamnionitis, in contrast, there was a different circadian distribution of term labor onset hour, with a peak at 7:45 PM and a 32% amplitude. A similar trend was found among preterm births. These data suggest the presence of the normal nocturnal labor-activating mechanism in both growth-retarded term deliveries and a defined subset of preterm deliveries. Chorioamnionitis appears to be associated with a prominent, unidentified alternative labor-activating mechanism that is maximal in the evening.

Chorioamnionitis↗
PubMed1986

[Anatomical and physiological bases of labor onset].

The induction of labor involves a series of complex mechanisms, the control of which is only partially explained in humans. It is accepted today that the maturing of the uterine cervix is independent of the onset of uterine contractions. These two phenomena are regulated by a complex system where prostaglandins play a key role.

Female↗
PubMedDate not supplied

[Correlation of labor onset, membrane rupture and birth with meteorological events].

UNLABELLED: The birth-physiological events: beginning of labour, rupture of membranes and delivery of 6 539 cases in the years 1976 to 1981 can be correlated with five groups of weather situations: no definite pressure gradient, anticyclonic, meridional, zonal mild maritime, and cyclonic. THE RESULTS: temporary increase of the frequency of births in weather with no definite pressure gradient in summer, in anticyclonic weather in winter and in cyclonic weather in the first half of the year, correspond only partly (namely for the changes within the group of cyclonic weather) with the temporarily increasing number of births during a weather front, as it ist known from experience. The causes of the correlations found out are unknown, and the setting up of a statistical model and consequently an obstestrical-metereological forecast is impossible for the time being.

Austria↗
PubMed1988

Does the onset of spontaneous labor at term influence fetal biophysical test parameters?

Recent data suggest that fetal breathing movement incidence declines while fetal heart rate (FHR) and body movement incidence do not change within 72 hours of spontaneous term labor. We conducted a retrospective study to determine whether the length of time from testing to spontaneous labor onset could influence these biophysical test parameters. Eighty-one normal term fetuses underwent 60-minute tests 1-40 days before the onset of spontaneous labor: 41 were tested within 7 days of labor (19 within 3 days and 22 within 4-7 days) and 40 were tested more than 7 days before labor. We simultaneously acquired and analyzed FHR baseline, frequency of accelerations between ten to 14 beats per minute and more than 15 beats per minute in amplitude, percent of time spent in breathing and moving, and fetal breath rate. These biophysical parameters were not significantly different between the groups, implying that they may continue to provide clinically useful information in the prelabor period.

Female↗
PubMed1991

An evaluation of the pelvic score by the quantification theory for categorical data.

The scoring system for pelvic examination used in Tsukuba University Hospital was evaluated by the quantification theory to investigate the precision in predicting the date of labor onset. The objects of this study were 137 nulliparous gravidae and 142 multiparous gravidae who had spontaneous onset of labor at full-term. In this analysis, we used 15 categories of findings in the examination as independent variables, and as the objective variable we used the interval from the examination to the labor onset. The multiple correlation coefficients in nulliparae was 0.593 and in multiparae 0.598. The following conclusions were reached concerning the assessment of labor onset: (1) The consistency of the cervix and the engagement of the vertex in nulliparous gravidae should be given more consideration. (2) In multiparous gravidae the dilatation of the cervix and the engagement of the vertex are important factors. (3) A different scoring system should be employed for both nulliparae and multiparae.

Evaluation Studies as Topic↗
PubMedDate not supplied

Theories regarding endocrine contributions to the onset of labor.

A review of the literature on endocrine factors influencing labor is presented. Treated separately are oxytocin, the prostaglandins, the fetus, and estrogen/progesterone. Implications for nursing practice and theory are discussed where appropriate, and the reader is encouraged to think of parturition as a complex interplay of factors.

Coitus↗
PubMed1986

[Bradykinin receptor and the mechanism of the onset of labor].

Bradykinin (BK) receptor of uterus and chorionic membrane were studied by radioreceptor assay to clarify the role of BK as theta an agent contracting uterine muscle. Basic examination revealed that incubation at 0 degrees C for 45 minutes with [3H] BK in buffer containing 5mM Mg++ was the most suitable condition for receptor-BK binding. BK receptor assay of several kinds of tissue such as pregnant rat uterus, human chorionic membrane, and placenta was done and the following results were obtained. Specific BK receptor existed in human chorionic membrane and in rat uterus. Ultracentrifugation revealed that it was on the plasma membrane (145 f mole./mg protein: The highest binding in the pellet at 10,000 g centrifugation followed by 600 g centrifugation). Association constant (Ka) and maximal binding capacity (MBC) showed the lowest level at 15 days gestation in rat uterus. These seemed to effectively maintain pregnancy by inhibiting uterine contraction. Both Ka and MBC were increased in the uterus of intrapartum rat compared with that of prepartum, but the former was about 45%, and the latter was almost the same as, that of non pregnant rat.

Animals↗