Antenatal bleeding & Isoimmunization
31-year-old, G1P0, 14+3 weeks, presents with vaginal bleeding.
Vitals: 73 bpm, BP 118/76, RR 16, temp 36.5℃
DDx for Antepartum bleeding*
<20 weeks
>20 weeks
*this list is not exhaustive, and lists only the most common causes of antepartum bleeding.
What do you want to know on history?
What do you want to know on history?
Make sure to remember…
…we should be asking questions to screen for life-threatening causes like ectopic pregnancy!
Recall the risk factors of an ectopic pregnancy and let this guide your history
History findings
The patient has had continuous spotting for the past 2 days. The blood is bright red, she has not noticed any clots or tissue being passed, and the last time she had intercourse was over a week ago. She is not having any abdominal pain or abnormal discharge other than the bleeding. All other symptoms on ROS were negative.
This is her first pregnancy, conceived by IVF. EDD is March 27th. She is very concerned about a potential miscarriage. She has a history of chronic migraines that she manages with sumatriptan. She has had a tonsillectomy as a child, and no other surgeries. She has no allergies. Gynecological and family history are unremarkable.
She lives in Edmonton with her partner. She use to smoke ½ pack a day since she was 18, but she quit 1 year ago when she was struggling with fertility. She used to have 1-2 drinks per week but has not had any since she found out she was pregnant. She does not use any other substances.
What to look for on physical exam?
Abdomen
Pelvis
General
Physical exam findings
Abdomen
Pelvis
General
What investigations do you want to order?
Labs: CBC-diff, serum hCG, type + screen
Imaging: transabdominal US
US report
Estimated GA: 14 weeks 3 days
EDD: 03-26-2024
Placenta: posterior
Hyperechoic subchorionic hematoma present, approximately 17% of the size of the gestational sac.
CBC
WBC 7.3
RBC 3.9
HGB 102 (L)
HCT 0.40
MCV 84
RDW 14.1
PLT 216
serum hCG
28,774 IU/L
Investigations
US report
Estimated GA: 14 weeks 3 days
EDD: 03-26-2024
Placenta: posterior
Hyperechoic subchorionic hematoma present, approximately 17% of the size of the gestational sac.
You remember from pre-clerkship that a subchorionic hematoma is when blood accumulates between the uterine wall and the chorion membrane that encloses the amniotic sac.
You also remember that this is a common cause of bleeding in early pregnancy and often resolves spontaneously!
Since the patient is stable and not symptomatic, you propose that the patient be discharged.
But wait…
Your senior resident reminds you to check the patient’s Type and Screen!
You pull up the report on Netcare and read the following:
ABO Group:
O
Rh:
Negative
How does this change your management?
Isoimmunization
Recall that Rh incompatibility between mom and baby can result in Rh isoimmunization!
Causes
Isoimmunization
Clinical outcomes range from mild anemia to hydrops fetalis, including:
This can lead to Hemolytic Disease of the Fetus & Newborn
Note: Hemolytic anemia can also occur with incompatibility between ABO and other antigens (anti-kell, duffy, kidd…). See here for more info.
Management
Management of Antepartum Bleeding
Management
Run a Kleihauer-Betke test (after 20w) and administer Rhogam
*round to the nearest whole number and add 1
# of vials* = (% fetal cells present) x (maternal blood volume)
30 mL per vial
For example, if KB test shows 0.9% fetal cells
Maternal blood volume is ~4500 mL
# vials = (0.9% x 4500 mL) / 30 mL = 1.35 (round to 1 and add 1)
Administer 2 vials of Rhogam
Management
Management of Antepartum Bleeding
Practice
CASE 2: A 30-year old G1P0 patient presents to the ER with sudden onset moderate back pain and bright red vaginal bleeding that began 1 hour ago.
Pertinent History:
Patient has had no prenatal care, but estimates their LMP was around 8 months ago. Endorses methamphetamine and cannabis use in pregnancy. Previous history of GERD, depression and psoriasis. Had an appendectomy at 14 years old. Takes sertraline 100 mg and prenatal vitamins daily.
Physical Exam:
BP 100/72 mmHg, HR 105 bpm, RR 18/min, temp 36.5℃, SpO2 97%
GCS 15, pale and mildly diaphoretic
SFH is 36 cm
Abdomen: No palpable uterine contractions, tenderness along the lower abdomen.
Vaginal: Bright red blood present in vaginal vault, active bleeding from the
cervical os. Cervix is 1cm dilated, 30% effaced, station -4
Practice
CASE 2: A 30-year old G1P0 patient presents to the ER with sudden onset moderate back pain and bright red vaginal bleeding that began 1 hour ago.
Investigations:
Labs: Hb 108, INR 1.2
Type & Screen: AB, Rh-
NST: FHR 142 bpm, moderate variability, no accelerations or decelerations present
Transabdominal US: Cephalic presentation, retroplacental hemorrhage
How do you manage this patient?
Practice
CASE 2: A 30-year old G1P0 patient presents to the ER with sudden onset moderate back pain and bright red vaginal bleeding that began 1 hour ago.
How do you manage this patient?
US confirmed placental abruption. Patient is mildly hypotensive and tachycardic, pale and still actively bleeding. No signs of imminent delivery.
Practice
CASE 2: A 30-year old G1P0 patient presents to the ER with sudden onset moderate back pain and bright red vaginal bleeding that began 1 hour ago.
C-section was performed.
Mom required transfusion of 2 units packed RBCs.
Baby required resuscitation and was transferred to NICU.
A Kleihauer-Betke test is ordered 24h after the procedure and shows 4.6% fetal cells present in maternal blood. How much Rhogam should be administered? (note: patient’s height is 155 cm and weight is 61 kg)
Estimated maternal blood volume: 3.5L
# vials = (4.6% x 3500 mL) / 30 mL = 5.36 → administer 6 vials Rhogam
Resources
Interested in learning more? Check out these articles!
SOGC Prevention of Rh Alloimmunization Guidelines: https://www.jogc.com/article/S1701-2163(17)31111-8/abstract
�Placental Abruption - StatPearls
https://www.ncbi.nlm.nih.gov/books/NBK482335/
Battula SP, Mohammed N, & Datta S (2021). Antepartum haemorrhage. Obstetrics, Gynaecology & Reproductive Medicine, 31(4), 117-123.
Authors
Claudia Turco
Rahim Janmohamed