Maternal Care: Skills workshop Vaginal examination in labour

Maternal Care: Skills workshop Vaginal examination in labour

• 1.
  8B Skills workshop: Vaginal examination in labour 4. A suitable instrument for rupturing the Objectives membranes. 5. An antiseptic vaginal cream or sterile lubricant. When you have completed this skills An ordinary surgical glove can be used and workshop you should be able to: the patient does not need to be swabbed if the • Perform a complete vaginal examination membranes have not ruptured yet and are not during labour. going to be ruptured during the examination. • Assess the state of the cervix. • Assess the presenting part. B. Preparation of the patient for • Assess the size of the pelvis. a sterile vaginal examination 1. Explain to the patient what examination is to be done, and why it is going to be done. PREPARATION FOR 2. The woman needs to know that it will be an uncomfortable examination, and A VAGINAL EXAMINATION sometimes even a little painful. IN LABOUR 3. The patient should lie on her back, with her legs flexed and knees apart. Do not expose the patient until you are ready to examine A. Equipment that should be available her. It is sometimes necessary to examine for a sterile vaginal examination the patient in the lithotomy position. 4. The patient’s vulva and perineum are A vaginal examination in labour is a sterile swabbed with tap water. This is done by procedure if the membranes have ruptured first swabbing the labia majora and groin or are going to be ruptured during the on both sides and then swabbing the examination. Therefore, a sterile tray is introitus while keeping the labia majora needed. The basic necessities are: apart with your thumb and forefinger. 1. Swabs. 2. Tap water for swabbing. 3. Sterile gloves.
• 2.
  SK ILLS WORKSHOP: VAGINAL EXAMINATION IN LABOUR 171 C. Preparation needed by the examiner • Presentation or prolapse of the umbilical cord. 1. The person to do the vaginal examination 3. A speculum examination, not a digital must have either scrubbed or thoroughly examination, must be done if it is thought washed his/her hands. that the patient has preterm or prelabour 2. Sterile gloves must be worn. rupture of the membranes. 3. The examiner must think about the findings, and their significance for the patient and the management of her labour. THE CERVIX PROCEDURE OF When you examine the cervix you should observe: EXAMINATION 1. Length. 2. Dilatation. A vaginal examination in labour is a systematic examination, and the following should be assessed: E. Measuring cervical length 1. Vulva and vagina. The cervix becomes progressively shorter 2. Cervix. in early labour. The length of the cervix is 3. Membranes. measured by assessing the length of the 4. Liquor. endocervical canal. This is the distance 5. Presenting part. between the internal os and the external os 6. Pelvis. on digital examination. The endocervical canal of an uneffaced cervix is approximately Always examine the abdomen before 3 cm long, but when the cervix is fully effaced performing a vaginal examination in labour. there will be no endocervical canal, only a ring of thin cervix. The length of the cervix is An abdominal examination should always be measured in centimetres. In the past the term ‘cervical effacement’ was used and this was done before a vaginal examination. measured as a percentage. F. Dilatation THE VULVA AND VAGINA Dilatation must be assessed in centimetres, and is best measured by comparing the D. Important aspects of the degree of separation of the fingers on vaginal examination of the vulva and vagina examination, with the set of circles in the labour ward. In assessing the dilatation of the This examination is particularly important cervix, it is easy to make two mistakes: when the patient is first admitted: 1. If the cervix is very thin, it may be difficult 1. When you examine the vulva you should to feel, and the patient may be said to be look for ulceration, condylomata, varices fully dilated, when in fact she is not. and any perineal scarring or rigidity. 2. When feeling the rim of the cervix, it 2. When you examine the vagina, the is easy to stretch it, or pass the fingers presence or absence of the following through the cervix and feel the rim with features should be noted: the side of the fingers. Both of these • A vaginal discharge. methods cause the recording of dilatation • A full rectum. to be more than it really is. The correct • A vaginal stricture or septum.
• 3.
  172 MATERNAL CARE Correct Incorrect Figure 8B-1: The correct method of measuring cervical dilatation method is to place the tips of the fingers on for the cord to prolapse while the the edges of the cervix. hand of the examiner is in the vagina, when it can be detected immediately, than to have the cord prolapse with THE MEMBRANES spontaneous rupture of the membranes AND LIQUOR while the patient is unattended. • HIV-positive patients should not have their membranes ruptured unless there G. Assessment of the membranes is poor progress of labour. 2. What is the condition of the liquor when Rupture of the membranes may be obvious if the membranes rupture? there is liquor draining. However, one should • The presence of meconium may change always feel for the presence of membranes the management of the patient as it overlying the presenting part. If the presenting indicates that fetal distress has been part is high, it is usually quite easy to feel and may still be present. intact membranes. It may be difficult to feel them if the presenting part is well applied to the cervix. In this case, one should wait for a THE PRESENTING PART contraction, when some liquor often comes in front of the presenting part, allowing the An abdominal examination must have membranes to be felt. Sometimes the umbilical been done before the vaginal examination cord can be felt in front of the presenting part to determine the lie of the fetus and the (a cord presentation). presenting part. If the presenting part is the If the membranes are intact, the following two fetal head, the number of fifths palpable above questions should be asked: the pelvic brim must first be determined. 1. Should the membranes be ruptured? When palpating the presenting part on • In most instances, if the patient is in the vaginal examination, there are four important active phase of labour, the membranes questions that you must ask yourself: should be ruptured. 1. What is the presenting part, e.g. head, • When the presenting part is high, there breech or shoulder? is always the danger that the umbilical cord may prolapse. However, it is better
• 4.
  SK ILLS WORKSHOP: VAGINAL EXAMINATION IN LABOUR 173 2. If the head is presenting, what is the part is the head. However, on vaginal presentation, e.g. vertex, brow or face examination: presentation? • Instead of a firm skull, something soft 3. What is the position of the presenting part is felt. in relation to the mother’s pelvis? • The gum margins distinguish the 4. If the presentation is occiput, vault or brow mouth from the anus. brow, is moulding present? • The cheek bones and the mouth form a triangle. H. Assessing the presenting part • The orbital ridges above the eyes can be felt. The presenting part is usually the head but • The ears may be felt. may be the breech, the arm, or the shoulder. 3. Features of a brow presentation. The 1. Features of an occiput presentation. The presenting part is high. The anterior posterior fontanelle is normally felt. It is fontanelle is felt on one side of the pelvis, a small triangular space. In contrast, the the root of the nose on the other side, and anterior fontanelle is diamond shaped. the orbital ridges may be felt laterally. Figure 8B-2: Features of an occiput presentation Figure 8B-4: Features of a brow presentation If the head is well flexed, the anterior 4. Features of a breech presentation. On fontanelle will not be felt. If the anterior abdominal examination the presenting fontanelle can be easily felt, the head is part is the breech (soft and triangular). On deflexed and the presenting part the vault. vaginal examination: 2. Features of a face presentation. On • Instead of a firm skull, something soft abdominal examination the presenting is felt. • The anus does not have gum margins. Figure 8B-3: Features of a face presentation Figure 8B-5: Features of a breech presentation
• 5.
  174 MATERNAL CARE Left occipito-anterior (LOA) Right occipito-posterior (ROP) Left mento-anterior (LMA) Left sacro-posterior (LSP) Figure 8B-6: Examples of the position of the presenting part with the patient lying on her back • The anus and the ischial tuberosities pelvis. The position is determined on vaginal form a straight line. examination. 5. Features of a shoulder presentation. On 1. In a vertex presentation the point of abdominal examination the lie will reference is the posterior fontanelle (i.e. the be transverse or oblique. Features of occiput). a shoulder presentation on vaginal 2. In a face presentation the point of reference examination will be quite easy if the arm is the chin (i.e. the mentum). has prolapsed. The shoulder is not always 3. In a breech presentation the point of that easy to identify, unless the arm can be reference is the sacrum of the fetus. felt. The presenting part is usually high. J. Determining the descent and I. Determining the position engagement of the head of the presenting part The descent and engagement of the head is Position means the relationship of a fixed assessed on abdominal and not on vaginal point on the presenting part (i.e. the point of examination. reference or the denominator) to the mother’s
• 6.
  SK ILLS WORKSHOP: VAGINAL EXAMINATION IN LABOUR 175 MOULDING 1. To assess the size of the pelvic inlet, the sacral promontory and the retropubic area are palpated. Moulding is the overlapping of the fetal skull 2. To assess the size of the mid-pelvis, the bones at a suture which may occur during curve of the sacrum, the sacrospinous labour due to the head being compressed as it ligaments and the ischial spines are passes through the pelvis of the mother. palpated. 3. To assess the size of the pelvic outlet, the K. The diagnosis of moulding subpubic angle, intertuberous diameter In a cephalic (head) presentation, moulding and mobility of the coccyx are determined. is diagnosed by feeling the overlap of the It is important to use a step-by-step method to sutures of the skull on vaginal examination, assess the pelvis. and assessing whether or not the overlap can be reduced (corrected) by pressing gently with Step 1. The sacrum the examining finger. Start with the sacral promontory and follow The presence of caput succedaneum can also the curve of the sacrum down the midline. be felt as a soft, boggy swelling, which may 1. An adequate pelvis: The promontory make it difficult to identify the presenting part cannot be easily palpated, the sacrum is of the fetal head clearly. With severe caput the well curved and the coccyx cannot be felt. sutures may be impossible to feel. 2. A small pelvis: The promontory is easily palpated and prominent, the sacrum is L. Grading the degree of moulding straight, and the coccyx is prominent and/ The occipito-parietal and the sagittal or fixed. sutures are palpated and the relationship or Step 2. The ischial spines and sacrospinous closeness of the two adjacent bones assessed. ligaments The amount of moulding recorded on the partogram should be the most severe degree Lateral to the midsacrum, the sacrospinous found in any of the sutures palpated. ligaments can be felt. If these ligaments are followed laterally, the ischial spines can be The degree of moulding is assessed according palpated. to the following scale: 1. An adequate pelvis: Two fingers can be 0 = Normal separation of the bones with open placed on the sacrospinous ligaments (i.e. sutures. they are 3 cm or longer) and the spines are 1+ = Bones touching each other. small and round. 2. A small pelvis: The ligaments allow 2+ = Bones overlapping, but can be separated less than two fingers and the spines are with gentle digital pressure. prominent and sharp. 3+ = Bones overlapping, but cannot be Step 3. Retropubic area separated with gentle digital pressure. (3+ is regarded as severe moulding.) Put two examining fingers, with the palm of the hand facing upwards, behind the symphysis pubis and then move them laterally M. Assessing the pelvis to both sides: When assessing the pelvis, the size and shape 1. An adequate pelvis: The retropubic area of the pelvic inlet, the mid-pelvis, and the is flat. pelvic outlet must be determined. 2. A small pelvis: The retropubic area is angulated.
• 7.
  176 MATERNAL CARE Figure 8B-7: Lateral view of the pelvis, showing the examining fingers just reaching the sacral promontory Normal pelvis Abnormal pelvis Figure 8B-8: The brim of the pelvis Step 4. The subpubic angle and intertuberous 1. An adequate pelvis: The subpubic angle diameter allows three fingers (i.e. an angle of about 90 degrees) and the intertuberous diameter To measure the subpubic angle, the examining allows four knuckles. fingers are turned so that the palm of the 2. A small pelvis: The subpubic angle allows hand faces upward, a third finger is held at the only two fingers (i.e. an angle of about entrance of the vagina (introitus) and the angle 60 degrees) and the intertuberous diameter under the pubis felt. The intertuberous diameter allows only three knuckles. is measured with the knuckles of a closed fist placed between the ischial tuberosities.
• 8.
  SK ILLS WORKSHOP: VAGINAL EXAMINATION IN LABOUR 177 Symphysis pubis Sacrum Ischeal tuberosity Coccyx – not palpable Figure 8B-9: The pelvic outlet