Vaginal Examination Although not all nurses perform vaginal examinations on laboring women in all practice settings, most

nurses working in community hospitals do so because physicians are not routinely present in labor and birth suites. Vaginal examinations are also performed by midwives and physicians. It is an assessment skill that takes time and experience to develop; only by doing it frequently in clinical practice can the practitioner s skill level improve. The purpose of performing a vaginal examination is to assess the amount of cervical dilation, percentage of cervical effacement, and fetal membrane status and gather information on presentation, position, station, degree of fetal head flexion, and presence of fetal skull swelling or molding. Prepare the woman by informing her about the procedure, what information will be obtained from it, how can she assist with the procedure, how it will be performed, and who will be performing it. The woman is typically on her back during the vaginal examinations. The vaginal examinations is performed gently, with concern of the woman s comfort. If it is the initial vaginal examination to check for membrane status, water is used as a lubricant. If membranes have already ruptured, an antiseptic solution is used to prevent an ascending infection. After donning sterile gloves, the examiner inserts his or her index and middle fingers into the vaginal introitus, next, the cervix is palpated to assess dilation, effacement, and position (e.g., posterior or anterior). If the cervix is open to any degree, the presenting fetal part, fetal position, station, and presence of molding can be assessed. In addition, the membranes can be evaluated and described as intact, bulging, or ruptured. At the conclusion of the vaginal examination, the findings are discussed with the woman and her partner to bring them up to date about labor progress. In addition, the findings are documented either electronically or in writing and reported to the primary healthcare professional in charge of the case.

Cervical Dilation and Effacement The amount of cervical dilation and the degree of cervical effacement are key areas assessed during the vaginal examination as the cervix is palpated with the gloved index finger. Although this finding is somewhat subjective, experienced examiners typically come up with similar findings. The width of cervical opening determines dilation, and the length of the cervix assess effacement. The information yielded by this examination serves as a basis for determining which stage of labor the woman is in and what her ongoing care should be.

Fetal Descent and Presenting Part In addition to cervical dilation and effacement findings, the vaginal examination can also determine fetal descent (station) and presenting part. During the vaginal examination, the gloved index finger is used to palpate the fetal skull (if vertex presentation) through the opened cervix or the buttocks

in the case of a breech presentation. Station is assessed in relation to the material ischial spines and the presenting fetal part. These spines are not sharp protrusions but rather blunted prominences at the mid pelvis. The iscial spines serve as landmarks and have been designated as zero station. If the presenting part is palpated higher than the material ischial spines, a negative number is assigned; is the presenting fetal part is below the maternal ischial spines, a plus number is assigned, denoting how many centimeters below zero station. Rupture of Membranes The integrity of the membranes can be determined during the vaginal examination. Typically, if intact, the membranes will be felt as a soft bulge that is more prominent during a contraction. If the membranes have ruptured, the woman may have reported as sudden gush of fluid. Membrane rupture also may occur as a slow trickle of fluid. To confirm that membranes have ruptured, a sample of fluid is taken from the vagina and tested with nitrazine paper to determine the fluid s pH. Vaginal fluid is acidic, whereas amniotic fluid is alkaline and turns nitrazine paper blue. Sometimes, however, false-positive results may occur, especially in women experiencing in a large amount of bloody show, because blood is alkaline. The membranes are most likely intact if the nitrazine test tape remains yellow to olive green, with pH between 5 and 6. The membranes are probably ruptured if the nitrazine test tape turns a bluegreen to deep blue, with pH ranging from 6.5 to 7.5. if the nitrazine test is inconclusive, an additional test, called the fern test, can be used to confirm rupture of the membranes. With these test, a sample of fluid is obtained, applied to a microscope slide and allowed to dry. Using a microscope, the slide is examined for a characteristic fern pattern that indicates the presence of amniotic fluid. Uterine Contractions The primary power of labor is uterine contractions, which are involuntary. Uterine contractions increase intrauterine pressure, causing a tension on the cervix. This tension leads to cervical dilation and thinning, which in turn eventually forces the fetus through the birth canal. Normal uterine contractions have a contraction (systole) and relaxation (diastole) phase. The contraction resembles a wave, moving downward to the cervix and upward to the fundus of the uterus. Each contraction starts with a building up (increment), gradually reaching an acme (peak intensity), and then letting down (decrement). Each contraction is followed by an interval of rest, which ends when the next contraction begins. At the acme (peak) of the contraction, the entire uterus is contracting, with the greatest intensity in the fundal area. The relaxation phase follows and occurs simultaneously throughout the uterus uterine contractions with an intensity of30mmHg or greater initiative cervical dilation. During active labor, the intensity usually reaches 50 to 80mmHg. Resting tone is normally between 5 and 10mmHg in early labor and between 12 and 18mmHg inactive labor