div class=”ChapterContextInformation”>
19. Vaginal Bleeding in Late Trimester
Keywords
Vaginal bleedingPlacenta previaAbruption placentaeVasa previaMaternal mortality19.1 Introduction
Causes of vaginal bleeding in late trimester
There are no consistent definitions of the severity of APH. It is recognized that the amount of blood lost is often underestimated and that the amount of blood coming from the introitus may not represent the total blood lost (e.g., in a concealed placental abruption). It is important, therefore, when estimating the blood loss, to assess for signs of clinical shock. The presence of fetal compromise or fetal demise is an important indicator of volume depletion.
According to RCOG guidelines 2011, the hemorrhage is considered to be:
Minor hemorrhage—blood loss less than 50 mL that has settled.
Major hemorrhage—blood loss of 50–1000 mL, with no signs of clinical shock.
Massive hemorrhage—blood loss greater than 1000 mL and/or signs of clinical shock.
Those with a major hemorrhage.
Those with an APH where immediate resuscitative measures are not required.
19.2 Major APH: Emergency Management
Observation—General maternal condition, pulse, BP, respiration, and oxygen saturation.
History—LMP, pregnancy history, recent trauma, amount of blood loss, and pain.
Call for help—Additional staff.
Basic life support—Airway, breathing, and circulation.
IV access and fluid replacement—Via large bore cannula. Crystalloid (up to 2 L of ringer lactate/Hartmann’s solution) or colloid (up to 1 L) depending upon the severity of bleeding.
Blood and blood products—RCC to be transfused according to the patient’s condition. Four units of FFP and ten units of cryoprecipitate (two packs) can be transfused if coagulopathy is suspected even before blood investigations arrive.
Investigations—CBC, coagulation profile, KFT, electrolytes, Kleihauer-Betke test, ABG in severe cases.
Obstetric examination—Uterine size, fetal presentation, and lie. Assess uterine activity, pain, and tenderness.
CTG and USG—To assess fetal Well-being and placental localization.
Speculum examination—To observe for amount and source of bleeding.
Consider delivery—To improve maternal hemodynamics.
Medication—If time permits corticosteroids for fetal lung maturation, consider MgSO4 for fetal neuroprotection if <30 weeks of gestation and imminent delivery is likely. Anti-D if she is Rh−ve.
Documentation.
Communication—With the woman and her family should be clear and unambiguous.
19.3 APH Where Immediate Resuscitative Measures Are Not Required
History
Timing and amount of blood loss.
Associated features—e.g., trauma or sexual intercourse.
Fetal movements since the bleeding has started.
Previous episodes of bleeding in current pregnancy.
Review of any USG performed earlier in the pregnancy, particularly for placental site.
Past obstetric, gynecological, medical, and surgical history.
Examination
General condition—PR, BP, RR, temp, pallor, edema.
Obstetric examination—Fundal height, fetal size and presentation, uterine tenderness.
Vaginal examination—With speculum only, to assess the site of bleeding.
Blood investigations
CBC.
Blood group and cross match (at least two units).
Coagulation profile.
Kleihauer-Betke test.
KFT, electrolytes.
Fetal well-being assessment
CTG.
USG.
Ultrasound scan
For placental location.
An ultrasound scan is not the investigation of choice to diagnose a placental abruption.
Medication
Corticosteroids if <34 weeks.
Anti-D if Rh-ve.
If birth is imminent at a gestation less than 30 weeks, consider MgSO4 infusion for fetal neuroprotection.
Analgesia if required.
Documentation and communication
While it has been a common clinical practice to routinely admit women who have experienced an APH, there is no high level evidence to support this practice.
19.4 Placenta Previa
19.4.1 Definition
Placenta previa is defined as implantation of placenta in lower segment of uterus (LUS) overlying or within 2 cm of internal os [2]. It is classified ultrasonographically as major when the placenta either partly or completely covers the internal os and minor degree when the leading edge of the placenta is within 2 cm of internal os but not covering it [3].
19.4.2 Incidence and Epidemiology
Placenta previa occurs in approximately 0.5% of pregnancies reaching third trimester. The diagnosis of low-lying placenta is often identified at 16–20 week ultrasound; however, 90% will not have abnormal placentation after 30 weeks of gestation. Therefore, a transvaginal scan (TVS) at 20 weeks can reclassify 26–60% of cases where transabdominal scan (TAS) showed a diagnosis of low-lying placenta.
19.4.3 Risk Factors
Multiple pregnancy.
Advanced age > 35 years.
High parity >6 pregnancies.
Smoking.
Deficient endometrium as in scarred uterus due to previous cesarean section or myomectomy or any uterine surgery.
Manual removal of placenta.
Endometritis.
Uterine curettage.
19.4.4 Pathophysiology
The pathophysiology of placenta previa is not fully understood. Preferentially placenta grows in fundal region of the uterus as it has more blood supply than LUS. Abnormal placentation can be due to the above mentioned risk factors or failed placental apparent migration that occurs due to differential growth of LUS.
Relationship between previous cesarean section (CS) and risk of placenta previa and accreta
No. of CS | Placenta previa incidence (%) | Placenta accrete incidence (%) |
|---|---|---|
0 | 0.26 | 3 |
1 | 0.65 | 11 |
2 | 1.5 | 40 |
3 | 2.2 | 61 |
4 | 10 | 67 |
5 | 10 | 67 |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
