Prolonged Latent Phase Research Articles

Sonographic evaluation in the second stage of labor to improve the assessment of labor progress and its outcome

Sonographic evaluation in the second stage of labor to improve the assessment of labor progress and its outcome

163: Augmentation of labor for prolonged latent phase at term: A randomized comparison between amniotomy, oxytocin or both

163: Augmentation of labor for prolonged latent phase at term: A randomized comparison between amniotomy, oxytocin or both

The Latent Phase of Labor: Diagnosis and Management

The latent phase of labor is complex and not completely understood by modern science. Studies often ignore evaluation of this phase of labor because determination of onset is subjective. In this article, the definition and time parameters of latent phase labor are discussed, and generalized distinctions between prelabor and labor are evaluated. Outpatient relief measures for latent phase as well as inpatient medical interventions for prolonged latent phase of labor are reviewed. Recommendations for policy development are included along with a discussion about the need to consider the significance of time limits. For optimal outcomes, clinicians are encouraged to individualize a management plan that is made in collaboration with the laboring woman.

Spectrum of epithelial cell abnormalities of uterine cervix in a cervical cancer screening programme: Implications for resource limited settings

Objective (1) To compute the frequencies and peak age incidences of epithelial cell abnormalities (ECA) of uterine cervix in a cytology-based screening programme and (2) to analyze the comparative frequencies of squamous intraepithelial lesions (SIL) and malignancies in age groups <40 and ≥40 years, in order to assess the implications for screening protocol in resource limited settings. Study design Pap smears form 29,475 women were cytologically screened over a 4-year period as a part of hospital-based screening programme. The frequencies, peak age incidences and mean age of various ECA detected were computed. The data was further stratified in to age groups <40 (Gp 1) and ≥40 (Gp 2) and comparative profile of the lesions was analyzed. Results On cytologic screening of the smears 5.6% ECA were detected. Atypical squamous cells-undetermined significance (ASC-US) and low grade SILs (LSIL) were diagnosed more frequently in Gp 1 ( p < 0.001) while atypical glandular cells (AGC) and malignancies were more significantly more frequent in Gp 2 ( p < 0.001). The frequency of HSIL was similar in the two groups. The SILs predominated in the fourth decade while the malignant lesions were most frequent in age >50 years. The mean age for LSIL and HSIL was 34.7 and 37.7 years, respectively, while for malignancy it was 51.8 years thus corroborating the hypothesis that a prolonged latent phase exists between the precursor lesions and the onset of invasive cancer. Conclusions Since the goal of any screening programme should be to pick up majority of the precursor lesions and not frank cancers, it is desirable to initiate screening before 40 years of age. The WHO recommendation of once in a life time screening between 35 and 40 years of age seems appropriate for resource limited settings like ours.

Maternal and fetal outcome after a prolonged latent phase of labour

Context : Prolonged latent phase of labour is reportedly associated with labour dystocia and neonatal morbidity. There are few published work on prolonged latent phase and none from this environment. Objective : To determine if prior labour ward admission with prolonged latent is a predictor of labour dystocia and neonatal morbidity. Methods : The course and outcome of active phase labour in One hundred and twenty-eight patients with a prior prolonged latent phase was compared with 896 patients who went into active phase labour without a prolonged latent phase. Relevant data was retrieved from the departmental obstetric data bank. Outcome measures : Labour augmentation, Caesarean section and instrumental delivery rates, Apgar scores and neonatal hospital admission. Results : Labour augmentation and Caesarean rates were higher and labour was longer among the cases than controls. (50.5 vs 36.4%: P=0.0001, 27.3 vs 7.0%: P=0001 and 7.6 vs 6.2 hrs: P=0.0028 respectively). Blood loss at delivery was more and neonatal hospital admission was more frequent among the cases than controls. Conclusion : Prolonged latent phase of labour is a predictor of labour dystocia and neonatal morbidity. Keywords : outcome, maternal, fetal, prolonged latent phase of labour Tropical Journal of Obstetrics and Gynaecology Vol. 22(2) 2005: 171-176

Labour management: An appraisal of the role of false labour and latent phase on the delivery mode

SummaryAchieving normal vaginal delivery requires an orderly transition from early labour to an established active labour. We analysed retrospectively the outcome of labour and the delivery mode based on the diagnosis of labour from the first examination of 3,130 parturients. A total of 1,847 (59.1%) delivered mothers had the first vaginal examination performed by the senior house officer (SHO). The majority (74.4%) of the mothers presented in established labour (cervical dilatation ≥4 cm), 25.6% in early labour, while 11.3% in latent phase. Patients who presented in established labour had a statistically significant higher spontaneous vertex delivery (SVD) rate (Pearson χ2 = 29.74, p = 0.000). A total of 62 parturients (17.5%) who presented in the latent phase and 204 (29.1%) in early labour had an unfavourable delivery mode; 46 had a caesarean section. There was a significant correlation between delivery mode and prolonged latent phase (Pearson correlation coefficient R = −0.066, p = 0.000). Linear regression analysis showed that the total number of VEs was the most significant predictor of the delivery mode of SVD (Regression ß-coefficient = 0.278, t = 10.37, p = 0.000). Early admissions in labour and a prolonged (abnormal) latent phase are significant predictors of difficult mode of delivery (poor labour outcome). We suggest that the first vaginal examination should be undertaken by the most experienced medical personal present at admission.

Kvinnors upplevelser av taktil massage under forlossningens latensfas

Massage during childbirth has a potential to decrease pain and anxiety. A special vulnerable group are women with prolonged latent phase (cervix dilation not more than 3 cm), since a prolonged labour is connected to several delivery complications. The aim of the study reported here was to describe women's experiences of tactile massage during the latent phase of labour. 10 primiparous women, who had received tactile massage for 30 minutes after admission to the delivery unit, were interviewed one day after childbirth. The interviews were tape-recorded and analysed using a phenomenological method. The setting was Södra Älvsborgs Hospital, Borås, Sweden. The essential structure indicates that the massage was a turning point that put them ‘back on track’. A turning point means that that the process of childbirth was changed. Being ‘back on track’ implies for the woman to get further in the process by releasing her thoughts and follow the process of childbirth. Thereby the woman could relax and recover her strength. The essential structure can be further described by its three themes: to relax and recover one's strength, to put the thoughts out of mind, to have somebody present for the woman.

Sonographic Assessment of the Cervix Before, During, and After a Uterine Contraction Is Effective in Predicting the Course of Labor

Using the traditional means of assessing the progress of labor, by vaginal examination at 2- to 3-hour intervals, an abnormal pattern of labor such as uterine dysfunction might not be detected before considerable time haspassed. The authors measured cervical length by transvaginal ultrasonography before, during, and after a contraction in the first stage of labor. The question was whether the degree of cervical change during contractions distinguishes between latent and active labor, and between a normal and abnormal labor pattern. The study group included 73 women at term after an uncomplicated pregnancy, 39 of whom were nulliparous. The entire cervix was imaged as uterine contractions were monitored by cardiotocography. Cervical length was measured as the distance between the internal os and external os along the inner surface of the posterior cervical lip. The degree of shortening was expressed as the decrease in cervical length at the peak of a contraction as a percentage of the precontraction length. Five labor patterns were distinguished: normal latent phase (n-latent), prolonged latent phase (p-latent), normal active phase (n-active), protracted active phase (p-active), and false labor. In women in the n-active and p-active groups, the cervix was more dilated and effaced than in the other 3 groups. On average, cervical length was diminished by approximately half during a contraction in normal labor. Assessing the station of the fetal head yielded similar findings, but p-latent women had a significantly higher station than the n-latent group. When cervical length was measured just before a contraction began, there were significant differences between the n-active and false labor groups, and between the p-active and the n-latent, p-latent, and false labor groups. Measurements made just after a contraction did not differ significantly from the precontraction length except in the n-active phase. Only in the n-latent and n-active groups did cervical length decrease to a significant degree. There were no significant differences in degree of cervical shortening between the parous and nulliparous women in the n-latent and n-active phases. Real-time ultrasound study of the cervix during uterine contractions could help to distinguish between normal and inefficient contractions, and in this way predict the subsequent course of labor.

Sonographic assessment of the cervix before, during and after a uterine contraction is effective in predicting the course of labor.

To investigate whether the degree of change in cervical length during a uterine contraction is predictive of subsequent progression of labor. The subjects were 73 uncomplicated parturient women at term. We observed the cervix before, during and after a uterine contraction by transvaginal ultrasound in the first stage of labor and determined the degree of cervical shortening during the contraction relative to the cervical length before contraction. We related the degree of cervical shortening to labor patterns at the time of the ultrasound examination, which were retrospectively determined by reviewing the partogram. The cervix was shortened in length by about 50% on average during a uterine contraction in the normal course of labor. The degree of cervical shortening was significantly greater in the normal latent and active phases than it was in the prolonged latent phase, protracted active phase and false labor, whereas there were no differences between the former two phases nor between the latter three phases. Nulliparous and parous women exhibited almost the same degree of shortening in the normal latent and active phases. Real-time ultrasound observation of the cervix during uterine contraction could help differentiate inefficient uterine contractions from normal ones and thus predict the subsequent course of labor.

Differences in women presenting in latent and active phase of labor

Women presenting in latent phase are at increased risk for Cesarean (CD) than those presenting in active phase. We sought to evaluate patient, labor, management and outcome differences between those presenting in latent phase and active phase. We evaluated all low-risk singleton, term women with vertex presentations, presenting in active phase (AP: contractions with or without ROM > = 4 cm) or latent phase (LP: contractions with or without ROM <4 cm or ROM only) delivering at MetroHealth Medical Center between January 1993 and June 2001. Women with a prior CD, or contraindication to labor or vaginal delivery were excluded, as were those with medical/obstetric complications or substance abuse. AP and LP gravidas were compared for baseline characteristics. Labor outcomes were assessed by logistic regression, controlling for parity. P<0.01 considered significant. OR = Odds ratio. 11,176 of 25,998 singleton gestations (43%) met our strict inclusion criteria: 6,744 AP and 4,432 LP gravidas. LP women were more likely nulliparous (57 vs. 33%), had smaller infants (3316 vs 3365 g), had more private insurance (26 vs 23%), p<0.0001 for each. Maternal race, age, weight, gestation at delivery were not different. LP women were at increased risk for CD (nulliparas: 15.7 vs 7.8%, multiparas; 3.7 vs 1.7, p<0.0001 for each). LP women had more prolonged latent phase (OR = 5.6), active phase arrest (OR = 2.2), and had more oxytocin use (OR = 3.1) scalp pH (OR = 2.0), IUPC (OR = 2.5) and ECG (OR = 1.8) monitoring performed, p < 0.001 for each, but not more CDs for arrest of descent. LP women had more amnionitis (OR 2.6) and postpartum infection (OR = 2.0) but not operative vaginal delivery, postpartum hemorrhage or need for neonatal intubation. Arriving in latent phase may be a marker for labor abnormalities in active phase unrelated to maternal or fetal characteristics. Whether these labor abnormalities cause or result from early presentation or subsequent physician intervention remains unresolved.

Maternal and fetal risks associated with prolonged latent phase of labour

A pregnancy cohort study was undertaken to assess the fetal, maternal and obstetric risks associated with the prolonged latent phase of labour. One hundred and fifty cases (latent phase >8 hours) were compared with 100 controls (latent phase <8 hours). Data were collected from hospital records. There were more nulliparas in the case group (73% vs. 39%; P <0·0001). Cases required oxytocin augmentation (62% vs. 17%; P <0·0001) and caesarean section (29% vs. 6%; P <0·0001) more frequently than controls. Thick meconium staining of the liquor was more frequent in cases (15% vs. 5%; P <0·05), as were 5-minute Apgar scores less than 7 (17% vs. 3%; P <0·001) and admission to the neonatal unit (22% vs. 1%; P <0·0001). Prolonged latent phase is associated with increased risks for obstetric intervention and poor fetal outcome. The optimal management of prolonged latent phase is still unknown and requires further study by means of randomised controlled trials.

Management of prolonged latent phase labor

Prolonged latent phase labor can be a physical, emotional, and mental challenge for both the woman in labor, her support system, and nurse-midwife. In this article, four nurse-midwives offer suggestions for coping with this common clinical dilemma.

Zinc status, pregnancy complications, and labor abnormalities

Maternal plasma zinc levels, red blood cell levels, and serum alkaline phosphatase activity were used as indices of zinc status in 279 pregnant women at delivery and were compared with the incidence of complications during the antenatal period and major dysfunctional labor patterns. The median values for plasma zinc, red blood cell zinc, and alkaline phosphatase were used as cutoff points to subdivide the patient population into “low” and “high” groups. Low levels of maternal plasma zinc were associated with more complications in the antenatal or intrapartum periods than maternal levels of either alkaline phosphatase or red blood cell zinc. Plasma zinc levels less than the median value were more commonly associated with mild toxemia (p = 0.02), vaginitis (p = 0.01), and postdates (p = 0.01) in the antenatal period. During the intrapartum period, low plasma zinc levels were associated with a prolonged latent phase (p = 0.05), a protracted active phase (p = 0.04), labor >20 hours (p = 0.03), second stage >2.5 hours (p = 0.01), and cervical and vaginal lacerations (p = 0.02). Low levels of maternal alkaline phosphatase were strongly associated with a history of previous stillbirth (p = 0.0005). A low maternal red blood cell zinc level was not associated with complications during either period. Since a low plasma zinc level is a valid predictor of pregnancy complications and abnormal labor, the results suggest that plasma zinc screening, as part of the patient's antenatal workup should be evaluated.

Simplified cervicograph for rural maternity practice.

The cervicograph is a graphical representation of cervical dilatation recorded at regular intervals. It is based on a series of laboring women who showed labor to consist of a prolonged latent phase and a shorter but more consistent acceleration phase. The cervicograph utilizes the acceleration phase. By drawing the cervicograph in centimeter intervals a series of circles for comparing finger measurements can be incorporated. It can also be colored to give an indication of the level of risk. A pilot study was conducted in which nurses used the vertical baseline of the original cervicograph. It was found that only 5 to 10 minutes of instruction were required for the cervicograph to be understood. Once instructed nurses were easily able to teach their junior staff. The antenatal check can discover many of the risk factors in the pregnant woman especially if she has had previous experience of delivery. With the primiparous a carefully monitored labor is required to indicate if and when referral is necessary. Ideally the slope of the baseline should be constructed from the records of a large number of normal deliveries. It may be useful to have separate cervicographs for primiparous and for multiparous women.

Obstetric characteristics in different racial groups.

A detailed analysis of 2632 consecutive pregnancies in white, black and Asian women, who were delivered during the period 1978 to 1980, found significant differences between the three ethnic groups. Asian primiparae had the longest first and second stages of labour, with the highest incidence of prolonged latent phase (14%) and primary dysfunctional labour (30%). Black primiparae and multiparae had the highest incidence of secondary arrest in the first stage of labour (10% and 4% respectively) and of primary dysfunctional labour, with the greatest recourse to emergency caesarean section (13% and 4% respectively). The mean birthweight for singletons born between 37 and 42 weeks was 3.37 kg for white babies, 3.25 kg for black babies and 3.14 kg for Asian babies. There was no racial difference in perinatal mortality or morbidity in this survey.

Abnormal Labor

A prolonged latent phase should be treated with rest; a protracted disorder with expectant management; and an arrest of labor with oxytocin therapy once CPD has been excluded.

Management of the latent phase of labor.

1. Iatrogenic causes of prolonged latent phase such as sedation, narcotic analgesia, and epidural anesthesia should be avoided during the latent phase. 2. Cesarean delivery is not appropriate management solely for failure to progress in latent phase. 3. Multiparas in latent phase with favorable cervices should be treated with oxytocin stimulation. 4. Multiparas with unfavorable cervices and most nulliparas should be treated with therapeutic rest when they become exhausted during a long latent phase, without regard to an arbitrary time table. 5. Characteristics of latent phase in induced labors are undefined. 6. Management of latent phase in the presence of ruptured membranes should take into consideration the total clinical picture, including gestational age, presentation, and risk of infection and other pertinent factors.

Predictive value of cervimetric labour patterns in primigravidae.

From a study of 2000 consecutive labours the outcome of the 684 primigravid patients admitted in spontaneous labour has been examined according to their cervimetric progress during the first stage of labour. A partogram and labour stencil were used to identify dysfunctional labour which was treated with a standard protocol of augmentation by oxytocin. This policy achieved labours with a mean 'observed first stage' of 6.3 h and a caesarean section rate of 8.7%. There was one stillbirth due to multiple congenital abnormalities and no increase in perinatal morbidity. Our data show that the type of first stage cervimetric pattern is helpful in predicting the outcome of labour. A normal cervimetric pattern resulted in a vaginal delivery rate of 98.4%; primary dysfunctional labour, which could be improved by oxytocin, had a 93.8% incidence of vaginal delivery, but if there was no improvement in the rate of cervical dilatation when this was administered the vaginal delivery rate was only 22.7% . A prolonged latent phase was associated with a caesarean section rate of 16.7% and the incidence of neonatal intubation was nearly as high as that found in uncorrected primary dysfunctional labour. The neonatal asphyxia in secondary arrest was minimal with an overall caesarean section rate of 28.4%; there was no increased incidence of neonatal morbidity with this cervimetric type.

The Labor Curve

The labor curve is useful as a means for following labors in progress and for identifying labor disorders as they arise. A specific problem, once it is identified, requires a specific remedy. Management of prolonged latent phase, protraction disorders, and arrest disorders with or without cephalopelvic disproportion is discussed.

Early detection of abnormal labor using the Friedman labor graph.

Early recognition and appropriate management of abnormal labor can reduce perinatal mortality and morbidity and lower the cesarean section rate. A simple labor graph devised over 25 years ago and later modified makes labor abnormalities easy to detect; the two main divisions of labor, the latent and active phases, are easily recognized. A prolonged latent phase has no serious effects on mother or fetus, but protraction and arrest disorders of the active phase--eg, protracted cervical dilatation, arrest or failure of descent of the presenting part--may have a deleterious effect. Common causes of a prolonged latent phase include false labor and inappropriate use of analgesia and anesthesia. Fetopelvic disproportion and fetal malposition are common causes of disorders of the active phase.