by David F. Toro, Diana V. Yepes, Ryan H. Holzhauer
As you begin the morning of your next weekend day shift in a small community hospital, the triage nurse comes in running and asks you to evaluate a patient that is being registered in the Emergency Department. You find a visibly pregnant 29-year-old female patient complaining of having regular uterine contractions for the last 10 hours and passed a significant amount of clear liquid per vagina on the way to the hospital, as well as a sensation of pelvic fullness and an increasing urge to use the bathroom with every uterine contraction.
On your evaluation, you find the patient is having uterine contractions at regular intervals, 4 times on a 10-minute period, lasting around 3 minutes each. You are able to detect a normal fetal heart rate and fetal movements. On the pelvic exam, you find a fully effaced and dilated cervix and palpate the fetal head at the level of the ischial spines. Only at this moment, you remember your hospital does not have a gynecologist in-house, and your nearest transfer center is 1 hour away. What would you do next?
Every year around 4 million babies are born in the US; unfortunately, there is no information on how many of these are born outside the regular delivery units, including the Emergency Department. Fortunately, however, it is an uncommon occurrence in Emergency Medicine. Just as it applies to many other emergency procedures, the Emergency Medicine provider needs to be familiar with the normal vaginal delivery. The provider must know preparations for it as well as how to identify and treat immediate complications for those cases where immediate access to an obstetrician is not readily available or if delivery is imminent before arrival to a birthing unit, such as in a patient arriving late to the hospital or a precipitous delivery.
This chapter describes the evaluation of the patient in possible active labor, the normal delivery technique, and immediate post-delivery care.
Identifying True Labor
Labor is the process by which the fetus is expelled from the uterus and can be a lengthy process on nulliparous women but becomes a shorter process on subsequent pregnancies. It begins when an organized uterine activity starts, causing gradual effacement or thinning of the cervix and dilatation in order to allow passage of the fetus during the final stages.
The labor process can be divided into latent and active phases. The latent phase begins when there is organized and regular uterine activity causing a cervical dilatation and effacement; it is considered active phase when it causes 3 or more cm dilatation and/or effacement of 80%.
The active labor is normally divided into 4 stages. The first stage concludes when dilatation and effacement are complete. The second stage ends when the fetus is delivered, the third stage ends when the placenta is delivered, and the 4th stage is the approximate period of 1 hour after the third stage concludes.
Contractions occur since the 2nd trimester as Braxton-Hicks contractions, but they become more common as the 3rd trimester goes by, transforming gradually into active labor. Braxton-Hicks contractions tend to be limited to the suprapubic area and thighs, are short and irregular in duration, have a low strength and are sporadic in timing.
True labor contractions, in contrast, are progressively longer in duration, radiated to the back and pelvic area, occur at regular intervals that become more frequent, are progressively stronger and cause effacement and dilatation of the cervix.
Other signs that indicate true labor are rupture of membranes and “bloody show.” The spontaneous rupture of membranes manifests by a sudden gush of clear fluid or by continuous leakage of vaginal fluid, with bleach or semen smell, but may not occur until the moment of delivery.
Although Vaginal pH changes during pregnancy, normal vaginal fluid tends to have an acidic pH (4.5-6.0) where as amniotic fluid is alkaline (pH 7.0-7.5). Therefore, another way of identifying amniotic fluid is using nitrazine or pH paper. Under acidic environment, this paper changes color from yellow to orange, and when amniotic fluid is present, it changes from orange to yellow, green or blue (Figure 1).
Figure 1. Under the presence of amniotic fluid, nitrazine paper turns from orange to yellow, green or blue.
“Bloody show” is the common name given to the expulsion of the blood-tinged cervical mucus plug as effacement and dilatation occur. Although by definition it is always present, in practice, it may not be noticed as it can occur gradually instead of all at once. When noticed, it can precede the initiation of active labor by several days.
In order to plan ahead for the imminent delivery, it is important to perform a vaginal and abdominal exam to determine the fetal well-being, lie, position, presentation, dilatation, effacement, and station.
- The Leopold maneuvers are part of the abdominal exam.
- First, palpate the uterine fundus to determine if the fetus is in a vertical or transverse lie by feeling if the fetal pole represents the head, breech (buttocks) or back.
- Second, apply pressure to the sides of the uterus with the entire hand, being sure to utilize both hands, to determine where the spine and extremities are.
- Third, with your dominant hand index and thumb, palpate just above pubic symphysis to locate the presenting part and determine if it is engaged on the pelvis. If the presenting part is movable, it is not yet engaged. If it is not movable, it is engaged.
- Forth, while facing the maternal legs from the abdomen palpate, enter the presenting part with both hands moving towards the birth canal while applying deep pressure. When the head is the presenting part, you will feel a round prominence in one of your hands. If this cephalic prominence is on the same side as the back and spine, the fetus is in face presentation. If the prominence is on the same side as the small parts, the fetus is on vertex presentation.
- In the situation of imminent delivery, there is little use for advanced fetal monitoring in the ED. Nevertheless, an initial assessment of the fetal well-being is appropriate if time allows. The most basic way to assess the fetal wellbeing is by listening to the fetal heart rate (FHR). This can be done by auscultating with a stethoscope, Doppler US or bedside ultrasound, placed on the mother’s abdomen and in the area where the fetal thorax is located.
- The normal fetal heart rate is 110-160 BPM and should be measured over 2 minutes, as it is normally variable. Higher rates represent fetal distress. Decelerations on FHR can be normal or abnormal.
- Decelerations occurring during the uterine contractions are called early decelerations and are due to the vagal response to the compression of the fetal head on the mother’s pelvis.
- Decelerations occurring towards the end of the contractions and peaking after the contraction are called late decelerations and constitute a sign of fetal distress or placental insufficiency.
- Decelerations occurring at any moment without relation to the contractions are called variable decelerations and represent an indication of umbilical cord compression or umbilical cord prolapse.
- In the case of late or variable decelerations, the patient should be given oxygen, IV fluid bolus, placed on lateral decubitus and immediate OB consultation should be obtained as immediate emergency delivery may be indicated.
The effacement, dilatation, station, and position should be determined. On vaginal exam, while using lubricated sterile gloves, locate the cervix and the presenting part. Palpate the cervix to determine effacement and dilatation, palpate the presenting part to locate anterior and posterior fontanel, chin or sacrum and locate the ischial spines and determine the station.
- The position is the relation of the occiput or posterior fontanel in relation to the maternal pelvis. If the fetus is presenting breech, the sacrum is used as fetal reference, and if it is presenting face, the chin is the point of reference. The most common presentation and what is considered normal is left/right occiput anterior.
- Effacement is the progressive thinning and shortening of the cervix that occurs slowly during early labor and progressively faster during active labor. It may occur simultaneously with dilatation, especially on multiparous women. It is measured qualitatively from 0% (long and rubbery) to 100% (very thin and soft) by palpation of the cervix. (Figure 2)
Figure 2. a. Normal long and thick cervix, b. Shorter and slightly thinner cervix at around 50% effacement, c. Fully effaced cervix
- Cervical dilatation is the measurement of the cervical os diameter, expressed in centimeters. 10cm is considered full dilatation. A cervix permeable to 1 finger is considered dilated to 1cm and if it’s permeable to 2 fingers is considered dilated to 3cm, which is considered active labor.
- Station is the level of the presenting part in relation to the ischial spines. This measurement is done by palpation, where the ischial spines are at 8- and 4-o’clock on the vaginal canal. It is also described in centimeters where 0 is at the level of the ischial spines, negative numbers (-1, -2, -3, -4, -5) are above and positive numbers (+1, +2, +3, +4, +5) are below the spines. (Figure 3).
Fetal Movements During Labor
As the fetus descends on the birth canal, several movements occur as a mechanical process where the fetus follows the path of least resistance, adapting the position of the presenting part to the dimensions of the birth canal and producing the following movements: (Figure 4)
Figure 4. Fetal positions for delivery. 1. Cephalic fetal presentation before labor, 2. Engagement, 3. Flexion, 4. Internal Rotation, 5. Extension, 6. External rotation, 7. Expulsion of anterior shoulder, 8. Expulsion of posterior shoulder.
- Engagement: During this stage, the bi-parietal diameter passes through the pelvic inlet and is considered engaged when the head reaches station 0. On primigravid patient, this movement occurs in the last 2 weeks of pregnancy, but on multiparous patients, it may occur when labor begins.
- Flexion: During this stage, the fetus neck is flexed to present a shorter diameter on the pelvis.
- Internal Rotation: This occurs as the presenting part crosses the ischial spines. At this point, the relative transverse position on the head moves back to the original occiput anterior position.
- Extension: The occiput reaches the vaginal introitus and passes under the symphysis pubis. During this stage, the head is born from the occipital area, the bregma, forehead, nose and finally chin, at the perineal area of the vaginal introitus.
- External rotation: The head returns to an anatomic position in relation to the rest of the fetal torso. The head returns now to a transverse position, just as during engagement, while the fetal shoulders are passing between the ischial spines.
- Expulsion: During this stage, the rest of the fetal body is born. The shoulders continue descending on an oblique position as they finalize their descent on the pelvis and are delivered – first the anterior shoulder and then the posterior one at the level of the perineum. The fetal pelvis is the smallest of the large fetal diameters and descends on the maternal pelvis following the same path and is delivered all at once, in contrast to the fetal head and the shoulders.
The Delivery Procedure
The following materials are typically used for a normal vaginal delivery procedure (does not include equipment for neonatal resuscitation):
- 0-0 absorbable (Chromic catgut or undyed Vicryl) suture material
- Kelly clamps
- Light source
- Long needle driver
- Mask with face shield
- Material scissors
- Povidone-Iodine solution
- Shoe covers
- Sterile drapes and towels
- Sterile gauze
- Sterile gloves
- Sterile lubricant gel
- Sterile waterproof gown
- Suction device or bulb syringe
- Syringes (10-20mL), and needles (22-24 gauge)
- Tissue Forceps
- Tissue scissors
- Umbilical cord clamp
Before you begin the procedure, as there is a high risk of exposure to body fluids, remember to wear sterile gloves, mask with eye protection, waterproof sterile gown, and shoe covers.
Apply iodine solution to the perineal area and clean with sterile water, then apply sterile drapes to the patient’s thighs and abdomen. It is likely that stool is expelled during the birthing process; so, additional sterile drapes should be available to prevent fecal contamination of the baby or the perineal area.
The ideal position of the patient is on a birthing table with stirrups and lithotomy position. If this is not available, additional personnel may help the patient maintain the knees flexed and the hips abducted. If a regular stretcher is used, it is helpful to place folded sheets or an inverted bedpan to elevate the patient’s pelvis and provide additional space for the delivery maneuvers.
The following videos describe and illustrate a step by step guide to the normal vaginal delivery procedure.
This video demonstrates the hand technique for spontaneous vaginal delivery on a simulated environment.
This video shows the baby’s process on a virtual simulation.
Once the fetus has been delivered, carefully place him/her on the sterile drape on the mother’s abdomen and stimulate while drying with sterile towels or gauze.
After drying and stimulating, clamp the umbilical cord about 1 in or 3 cm from the newborn’s abdominal skin using an umbilical clamp, Kelly clamp with rubber ligature or fabric ligature. Then place a Kelly clamp about 1 in from the umbilical clamp and use the scissors to cut the umbilical cord between the two clamps.
Obtain a blood sample from the placental end of the cord for neonatal testing.
At this moment, follow the neonatal resuscitation guidelines, calculate the initial APGAR scale and wrap the newborn to prevent hypothermia. Then, place the newborn under radiated heat.
Immediate Post-Delivery Care
Delivery of the placenta occurs up to 30 to 40 minutes after fetal delivery, and it is, for the most part, a passive process. Once you see a slight increase in vaginal bleeding and the remaining umbilical cord protrudes slightly, ask the mother to bear down and apply very gentle traction on the umbilical cord to gently advance the placenta through the vaginal canal, while applying cephalad suprapubic massage to the contracted uterus to prevent uterine inversion.
Never force the expulsion of the placenta or apply more than gentle traction as umbilical cord separation and uterine inversion can cause major bleeding.
Once the placenta is delivered, inspect it to ensure it was delivered completely, and there are no remaining parts in the uterus.
After delivering the placenta, inspect the cervix, vaginal mucosa and the perineum for tears that may need to be repaired.
The main mechanism for hemostasis after the placenta has detached is uterine muscle contraction over the blood vessels, so an infusion of oxytocin, ergonovine or methylergonovine may be given to aid in the process. Oxytocin (Pitocin) is the most commonly used agent. Add 20 units to a 1 Liter Normal Saline bag and infuse at 10 mL/min until bleeding is controlled. Once bleeding is controlled, finish the infusion at 1-2 mL/min.
Key Additional Points
A controlled and gentle delivery of every fetal part is preferred to an explosive delivery and decreases, to some extent, the probability of vaginal tears.
During delivery of the head, gentle upward pressure with a sterile towel or drape to prevent anal contamination on the perineal area helps elevate the presenting part and decrease the pressure the fetal chin exerts on the perineal skin.
Immediately following delivery of the head, palpate the fetal neck to inspect for umbilical cord encircling the neck. This cord needs to be reduced over the fetal head before delivery can continue.
As with any other procedure, don’t stand too close to the patient as fluids may be suddenly expelled risking contamination.
Be very careful when holding the newborn, as he/she will be very slippery. It is advisable to hold him/her close to your body.
References and Further Reading
- Hamilton BE, Martin JA, Osterman MJK, Curtin SC. Births: Preliminary data for 2014, National Vital Statistics report. National Center for Health Statistics, 2015, Vol 64, no 6.
- VanRooyen, Michael J, and Jennifer A Scott. “Emergency Delivery.” In Tintinalli’s Emergency Medicine A Comprehensive Study Guide, by Tintinalli JE, Stapczynski JS, Ma OJ, Cline DM, Cytulka RK and Meckler GD, edited by Judith E. Tintinalli, 703-711. McGraw Hill Medical, 2011.
- Lew GH, Pulia MS. “Emergency Childbrith.” In Clinical Procedures in Emergency Medicine, by Custalow, Thomsen Roberts, edited by Roberts & Hedges, 1155-1179. Philadelphia, PA: Elsevier Saunders, 2014.
- Cunningham FG, Leveno KJ, Bloom SL. Williams Obstetrics, 23rd ed. New York: McGraw-Hill, 2010.
- Perinatology.com. Leopold’s Maneuvers. http://perinatology.com/Reference/glossary/L/Leopolds.htm (accessed 09 29, 2015).
- American College of Obstetricians and Gynecologists. “Management of intrapartum fetal heart rate tracings.” American College of Obstetricians and Gynecologists Practice Bulletin, 2010: 1232-1240.
- I, Delke. “Delivery in the emergency department.” In Handbook of Obstetric and Gynecologic Emergencies, by Benrubi GI (eds), 160. Philadelphia, PA: Lippincott, Williams & Wilkins, 2010.
- Aasheim V, Nilsen AB, Lukasse M, Reinar LM. “Perineal techniques during the second stage of labour for reducing perineal trauma.” Cochrane Database Syst Rev (Th Cochrane Collaboration), no. 12 (12 2011): 1-47.
- Pergialiotis V, Vlachos D, Protopapas A, Pappa K, Vlachos G. “Risk factors for severe perineal lacerations during childbirth.” International Journal of Gynecology & Obstetrics (Elsevier) 125, no. 1 (04 2014): 6-14