Abnormalities of the third stage of labor
BY:DR.ISHRAQ MOHAMMED1- post-partum hemorrhage
2- retained placenta3- uterine inversion
4- ruptured uterus
5- obstetric shock (collapse)
PRIMARY PPH:
Postpartum hemorrhage, defined as the loss of more than 500 mL of blood from the genital tract following, but within the first 24 hours of, the delivery of the baby., occurs in up to 5 percent of all deliveries.1,2 Blood loss exceeding 1,000 mL is considered physiologically significant and can result in hemodynamic instability.3 Even with appropriate management, approximately 0,7percent of vaginal deliveries will result in severe post-partum hemorrhage.4 It is the most common maternal morbidity in developed countries and a major cause of death worldwide
Secondary pph:
Is more of a subjective diagnosis, as its definition is blood loss from the genital tract of a volume greater than expected after the first 24 hours, but within the first 6 weeks of delivery.The major etiological factors associated with secondary pph are retained placental fragments & endometritis.
Complications:
Complications from postpartum hemorrhage include :1- maternal death
2- acute renal failure
3- embolism
4- anemia
5- sheehan,s syndrome
6- sepsis
7- failure of lactation
Aetiology:
Causes of postpartum hemorrhage are uterine atony, trauma, retained placenta, and coagulopathy, commonly referred to as the "four Ts":[1]
Tone: uterine atony is the inability of the uterus to contract and may lead to continuous bleeding. Retained placental tissue and infection may contribute to uterine atony.
Trauma: trauma from the delivery may tear tissue and vessels leading to significant postpartum bleeding.
Tissue: retention of tissue from the placenta or fetus may lead to bleeding.
Thrombin: a bleeding disorder occurs when there is a failure of clotting, such as with diseases known as coagulopathies.
Causes of postpartum hemorrhage and their incidence[1]CauseIncidenceUterine atony70%Trauma20%Retained tissue10%Coagulopathy1%
Risk factors
Factors relating to the pregnancy:Antepartum haemorrhage in this pregnancy
Placenta praevia (15 x risk)
Multiple pregnancy (5 x risk)
Pre-eclampsia or pregnancy-induced hypertension (4 x risk)
multiparity (3 x risk)
Previous PPH (3 x risk)
Asian ethnic origin (2 x risk)
Maternal obesity (2 x risk)
Factors relating to delivery:
Emergency Caesarean section (CS) (9 x risk)[5]Elective CS (4 x risk) - especially if >3 repeat procedures[6]
Retained placenta (5 x risk)
Mediolateral episiotomy (5 x risk)
Operative vaginal delivery (2x risk)
Labour of >12 hours (2 x risk)
>4 kg baby (2 x risk)
Maternal pyrexia in labour (2 x risk)
Pre-existing maternal haemorrhagic conditions:
Factor 8 deficiency - Haemophilia A carrier
Factor 9 deficiency - Haemophilia B carrier
Von Willebrand's disease
Management:prevention:
The best preventive strategy is active management of the third stage of labor .8 Hospital guidelines encouraging this practice have resulted in significant reductions in the incidence of massive hemorrhage.19 Active management, which involves administering a uterotonic drug with or soon after the delivery of the anterior shoulder, controlled cord traction, and, usually, early cord clamping and cutting, decreases the risk of postpartum hemorrhage and shortens the third stage of labor with no significant increase in the risk of retained placenta.17,18 Compared with expectant management, in which the placenta is allowed to separate spontaneously aided only by gravity or nipple stimulation, active management decreases the incidence of postpartum hemorrhage by 68 percent.17
Prophylactic administration of oxytocin (Pitocin) reduces rates of postpartum hemorrhage by 40 percent24; this reduction also occurs if oxytocin is given after placental delivery.2,18 Oxytocin is the drug of choice for preventing postpartum hemorrhage because it is at least as effective as ergot alkaloids or prostaglandins and has fewer side effects.2,25,26 Misoprostol (Cytotec) has a role in the prevention of postpartum hemorrhage (NNT = 18)16; this agent has more side effects but is inexpensive, heat- and light-stable, and requires no syringes.27
Diagnosis and Management
The diagnosis of postpartum hemorrhage begins with recognition of excessive bleeding and methodic examination to determine its cause (Figure 1). The “Four Ts” mnemonic (Tone, Trauma, Tissue, and Thrombin) can be used to detect specific causes (Table 1).
Resuscitation:
Two large-bore intravenous cannulae(16G).Fluid administration(studies failed to show any benefit of colloids over crystalloids).
Application of facial oxygen.
Examination to determine the etiology of the hemorrhage, often performing uterine massage.
Obtain blood for a full blood count, clotting studies&group&cross-matching.
Disseminated intravascular coagulation:
Is a life threatening complication of massive PPH.Regardless the etiology, the management should aim to follow four basic principles:
1-to maintain the intravascular volume.
2-to administer fresh frozen plasma at a rate to keep the APTT:control ratio less than 1,5.
3-to administer platelets to maintain their count more than 75000.
4-to administer cryoprecipitate to keep fibrinogen level more than 1 gm/dl.
TONE
TONE
Uterine atony is the most common cause of postpartum hemorrhage.28 Because hemostasis associated with placental separation depends on myometrial contraction, atony is treated initially by pharmcological or a combination of pharmacological & surgical intervention( ergometrine administeration followed by a syntocinon infustion).
Should these efforts fail to control bleeding, examination of the genital tract need to be performed in an operating theatre . This include examination of vagina, cervix &, in case of continued bleeding, exploration of the uterine cavity digitally to identify & removed any retained fragments of placenta.
At this time, if no other cause for the hemorrhage , administration of prostaglandin analogues .
Syntocinone i.v bolus dose of 5 i.u followed if necessary by an infusion of 40 i.u .
Ergometrine i.v/i.m 250-500 ug
Misoprostol p.r 800-1000 ug
Bimanual compression of the uterus , put the uterine arteries under tension .
In addition to uterotonics, drugs that promote coagulation can be administered, such as tranexamic acid & recombinant active factor 7.
Figure 2.
Technique of bimanual massage for uterine atony. Bimanual uterine compression massage is performed by placing one hand in the vagina and pushing against the body of the uterus while the other hand compresses the fundus from above through the abdominal wall. The posterior aspect of the uterus is massaged with the abdominal hand and the anterior aspect with the vaginal hand.Redrawn with permission from Anderson J, Etches D, Smith D. Postpartum hemorrhage. In: Baxley E. Advanced Life Support in Obstetrics course syllabus. 4th ed. Leawood, Kan.: American Academy of Family Physicians, 2001.
If these measures failed, the uterus can be packed (gauze, balloon insufflation).
Laparotomy: unilateral or bilateral uterine artery ligation with success rate of more than 90 percent.Five steps: unilateral ligation of the uterine artery at the level of the lower uterine segment .
Bilateral ligation.
Low ligation of the uterine artery after mobilization of the bladder.
Unilateral ovarian vessel ligation.
Bilateral ovarian vessel ligation.
Internal iliac arteries ligation.
Compression sutures: B-lynch sutures.
Arterial embolization.
Hysterectomy with ovarian conservation may be required as a life saving procedure.
Post operative management:
ICU, CVP, professional counseling.
Prostaglandins enhance uterine contractility and cause vasoconstriction.34 The prostaglandin most commonly used is 15-methyl prostaglandin F2a, or carboprost (Hemabate). Carboprost can be administered intramyometrially or intramuscularly in a dose of 0.25 mg; this dose can be repeated every 15 minutes for a total dose of 2 mg. Carboprost has been proven to control hemorrhage in up to 87 percent of patients.35 In cases where it is not effective, chorioamnionitis or other risk factors for hemorrhage often are present.35 Hypersensitivity is the only absolute contraindication, but carboprost should be used with caution in patients with asthma or hypertension. Side effects include nausea, vomiting, diarrhea, hypertension, headache, flushing, and pyrexia.34
Misoprostol is another prostaglandin that increases uterine tone and decreases postpartum bleeding.36Misoprostol is effective in the treatment of postpartum hemorrhage, but side effects may limit its use.28,37It can be administered sublingually, orally, vaginally, and rectally. Doses range from 200 to 1,000 mcg; the dose recommended by FIGO is 1,000 mcg administered rectally.28,37,38 Higher peak levels and larger doses are associated with more side effects, including shivering, pyrexia, and diarrhea.28,39 Although misoprostol is widely used in the treatment of postpartum hemorrhage, it is not approved by the U.S. Food and Drug Administration for this indication.
TRAUMA
TRAUMALacerations and hematomas resulting from birth trauma can cause significant blood loss that can be lessened by hemostasis and timely repair. Sutures should be placed if direct pressure does not stop the bleeding. Episiotomy increases blood loss and the risk of anal sphincter tears,11,12,40 and this procedure should be avoided unless urgent delivery is necessary and the perineum is thought to be a limiting factor.14
Hematomas can present as pain or as a change in vital signs disproportionate to the amount of blood loss. Small hematomas can be managed with close observation.41 Patients with persistent signs of volume loss despite fluid replacement, as well as those with large or enlarging hematomas, require incision and evacuation of the clot.41 The involved area should be irrigated and the bleeding vessels ligated. In patients with diffuse oozing, a layered closure will help to secure hemostasis and eliminate dead space.
Uterine Inversion
Uterine inversion is rare, occurring in 0.05 percent of deliveries.10 Active management of the third stage of labor may reduce the incidence of uterine inversion.42 Fundal implantation of the placenta may lead to inversion; the roles of fundal pressure and undue cord traction are uncertain.10 The inverted uterus usually appears as a bluish-gray mass protruding from the vagina. Vasovagal effects producing vital sign changes disproportionate to the amount of bleeding may be an additional clue. The placenta often is still attached, and it should be left in place until after reduction.42 Every attempt should be made to replace the uterus quickly. The Johnson method of reduction begins with grasping the protruding fundus Figure 3A29) with the palm of the hand and fingers directed toward the posterior fornix (Figure 3B29). The uterus is returned to position by lifting it up through the pelvis and into the abdomen (Figure 3C29).43 Once the uterus is reverted, uterotonic agents should be given to promote uterine tone and to prevent recurrence. If initial attempts to replace the uterus fail or a cervical contraction ring develops, administration of magnesium sulfate, terbutaline (Brethine), nitroglycerin, or general anesthesia may allow sufficient uterine relaxation for manipulation. If these methods fail, the uterus will need to be replaced surgically.42
Figure 3.
Reduction of uterine inversion (Johnson method). (A) The protruding fundus is grasped with fingers directed toward the posterior fornix. (B, C) The uterus is returned to position by pushing it through the pelvis and into the abdomen with steady pressure towards the umbilicus.Redrawn with permission from Anderson J, Etches D, Smith D. Postpartum hemorrhage. In: Baxley E. Advanced Life Support in Obstetrics course syllabus. 4th ed. Leawood, Kan.: American Academy of Family Physicians, 2001.
Uterine Rupture
Although rare in an unscarred uterus, clinically significant uterine rupture occurs in 0.6 to 0.7 percent of vaginal births after cesarean delivery in women with a low transverse or unknown uterine scar.44–46 The risk increases significantly with previous classical incisions or uterine surgeries, and to a lesser extent with shorter intervals between pregnancies or a history of multiple cesarean deliveries, particularly in women with no previous vaginal deliveries.44–48 Compared with spontaneous labor, induction or augmentation increases the rate of uterine rupture, more so if prostaglandins and oxytocin are used sequentially. However, the incidence of rupture is still low (i.e., 1 to 2.4 percent).46,48 Misoprostol should not be used for cervical ripening or induction when attempting vaginal birth after previous cesarean delivery.48Before delivery, the primary sign of uterine rupture is fetal bradycardia.45 Tachycardia or late decelerations can also herald a uterine rupture, as can vaginal bleeding, abdominal tenderness, maternal tachycardia, circulatory collapse, or increasing abdominal girth.47 Symptomatic uterine rupture requires surgical repair of the defect or hysterectomy. When detected in the postpartum period, a small asymptomatic lower uterine segment defect or bloodless dehiscence can be followed expectantly.47
TISSUE
TISSUEClassic signs of placental separation include a small gush of blood with lengthening of the umbilical cord and a slight rise of the uterus in the pelvis. Placental delivery can be achieved by use of the Brandt-Andrews maneuver, which involves applying firm traction on the umbilical cord with one hand while the other applies suprapubic counterpressure (Figure 429).49 The mean time from delivery until placental expulsion is eight to nine minutes.4 Longer intervals are associated with an increased risk of postpartum hemorrhage, with rates doubling after 10 minutes.4 Retained placenta (i.e., failure of the placenta to deliver within 30 minutes after birth) occurs in less than 3 percent of vaginal deliveries.50 One management option is to inject the umbilical vein with 20 mL of a solution of 0.9 percent saline and 20 units of oxytocin. This significantly reduces the need for manual removal of the placenta compared with injecting saline alone.51 Alternatively, physicians may proceed directly to manual removal of the placenta, using appropriate analgesia. If the tissue plane between the uterine wall and placenta cannot be developed through blunt dissection with the edge of the gloved hand, invasive placenta should be considered.
Figure 4.
Brandt-Andrews maneuver for cord traction. Firm traction is applied to the umbilical cord with one hand while the other applies suprapubic counterpressure.Redrawn with permission from Anderson J, Etches D, Smith D. Postpartum hemorrhage. In: Baxley E. Advanced Life Support in Obstetrics course syllabus. 4th ed. Leawood, Kan.: American Academy of Family Physicians, 200
Invasive placenta can be life threatening.50 The incidence has increased from 0.003 percent to 0.04 percent of deliveries since 1950s; this increase is likely a result of the increase in cesarean section rates.49 Classification is based on the depth of invasion and can be easily remembered through alliteration: placenta accreta adheres to the myometrium, placenta increta invades the myometrium, and placentapercreta penetrates the myometrium to or beyond the serosa.10 Risk factors include advanced maternal age, high parity, previous invasive placenta or cesarean delivery, and placenta previa (especially in combination with previous cesarean delivery, increasing to 67 percent with four or more).49 The most common treatment for invasive placenta is hysterectomy.49 However, conservative management (i.e., leaving the placenta in place or giving weekly oral methotrexate52 until ⊠ human chorionic gonadotropin levels are 0) is sometimes successful.53 Women treated for a retained placenta must be observed for late sequelae, including infection and late postpartum bleeding.52,53
THROMBIN
THROMBINCoagulation disorders, a rare cause of post-partum hemorrhage, are unlikely to respond to the measures described above.10 Most coagulopathies are identified before delivery, allowing for advance planning to prevent postpartum hemorrhage. These disorders include idiopathic thrombocytopenic purpura, thrombotic thrombocytopenic purpura, von Willebrand's disease, and hemophilia. Patients also can develop HELLP (hemolysis, elevated liver enzyme levels, and low platelet levels) syndrome or disseminated intravascular coagulation. Risk factors for disseminated intravascular coagulation include severe pre-eclampsia, amniotic fluid embolism, sepsis, placental abruption, and prolonged retention of fetal demise.54,55Abruption is associated with cocaine use and hypertensive disorders.54 Excessive bleeding can deplete coagulation factors and lead to consumptive coagulation, which promotes further bleeding. Coagulation defects should be suspected in patients who have not responded to the usual measures to treat post-partum hemorrhage, and in those who are not forming blood clots or are oozing from puncture sites
Evaluation should include a platelet count and measurement of prothrombin time, partial thromboplastin time, fibrinogen level, and fibrin split products (i.e., d-dimer). Management consists of treating the underlying disease process, supporting intravascular volume, serially evaluating coagulation status, and replacing appropriate blood components. Administration of recombinant factor VIIa or clot-promoting medications (e.g., tranexamic acid [Cyklokapron]) may be considered.33,5