Obstetrics Pg No 413 -407

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Questions and Answers

Which condition is typically associated with immune hydrops fetalis?

Maternal diabetes

Multiple pregnancies

Rh-negative pregnancies (correct)

High fetal hemoglobin

Immune hydrops fetalis can occur in Rh-positive pregnancies.

False

What is a common consequence of immune hydrops fetalis?

Low fetal hemoglobin

Immune hydrops fetalis is characterized by _____ hemoglobin.

low fetal Signup and view all the answers

Match the type of hydrops fetalis with its characteristics:

Immune Hydrops = Occurs in Rh-negative pregnancies Non-immune Hydrops = Generally related to structural or chromosomal abnormalities Signup and view all the answers

What is the appropriate dose of anti-D given for Rh negative pregnancy prophylaxis?

300 mcg Signup and view all the answers

Postpartum prophylaxis is not required if the newborn is Rh negative.

True Signup and view all the answers

When should the Indirect Coombs test (ICT) be repeated during pregnancy?

At 28 weeks Signup and view all the answers

The aim of postpartum prophylaxis is to protect the __________ pregnancy.

next Signup and view all the answers

Match the following procedures with their appropriate indications:

Indirect Coombs Test = Assess if Rh negative woman is sensitized Postpartum prophylaxis = Protect future pregnancies Direct Coombs Test = Determine Rh status of newborn Early cord clamping = Prevent sensitization during delivery Signup and view all the answers

What is considered a critical titre for anti-D antibodies in Rh-ve sensitized pregnancy?

1:16 Signup and view all the answers

A maternal antibody titre of less than 1:16 is considered significant.

False Signup and view all the answers

What is the purpose of checking antibody titre in an Rh-ve sensitized pregnancy?

To determine the presence and significance of anti-D antibodies that may cross the placenta. Signup and view all the answers

A critical titre of antibodies is designated at __________ or greater for it to be considered significant.

1:16 Signup and view all the answers

Match the following antibody titres with their significance:

1:4 = Not significant 1:8 = Not significant 1:16 = Significant 1:32 = Potentially severe risk Signup and view all the answers

What is the recommended action for a fetus with anemia (Hb < 2 SD or Hematocrit < 30%)?

Delivery at 37-38 weeks with fetal surveillance from 32 weeks Signup and view all the answers

Delayed cord clamping is recommended for all Rh negative mothers regardless of ICT status.

False Signup and view all the answers

What is the action taken when a fetus has severe anemia with Hb ≥ 2 SD or Hematocrit ≥ 30%?

Delivery if ≥ 35 weeks or intra-uterine blood transfusion if < 35 weeks Signup and view all the answers

A fetus exhibiting signs of _____ requires fetal surveillance from 32 weeks and delivery at 37-38 weeks if anemia is mild.

anemia Signup and view all the answers

Match the following conditions with their corresponding management:

Mild Anemia = Repeat Hb and hematocrit weekly Severe Anemia & < 35 weeks = Intra-uterine blood transfusion Severe Anemia & ≥ 35 weeks = Delivery Rh-ve, ICT+ve = Delayed cord clamping Signup and view all the answers

What is the purpose of the Kleihauer Betke test?

To estimate the volume of fetal maternal hemorrhage Signup and view all the answers

Anti-D immunoglobulin is indicated after an abortion in the first trimester.

True Signup and view all the answers

What is the recommended dosage of Anti-D immunoglobulin for a patient less than 12 weeks pregnant according to ACOG?

50 µg intramuscular Signup and view all the answers

The Singer alkali denaturation test is used to distinguish between _____ and placenta previa.

vasa previa Signup and view all the answers

Match the following indications for Anti-D immunoglobulin with their respective trimesters:

After amniocentesis = Second/Third Trimester After ectopic pregnancy = First Trimester Unexplained bleeding = Second/Third Trimester After chorionic villi sampling = First Trimester Signup and view all the answers

Study Notes

Immune Hydrops Fetalis

Occurs in Rh-negative pregnancies, often associated with low fetal hemoglobin.

Rh Negative Pregnancy

Dose: 300 mcg of anti-D (Low dose).
Neutralizes 30 mL of FMH/15 mL of fetal RBC.
Does not cause hemolysis even on crossing placenta.

### Indirect Coombs Test (ICT)

Used to determine if an Rh-negative pregnant woman is sensitized.
Performed during the first antenatal care visit and repeated at 28 weeks.
Blood sample taken from the mother.

Rh Unsensitized

Antepartum prophylaxis: 300 µg/1500 IU of anti-D given.
Remains negative.

Unsensitized Rh-negative Females

Anti-D: To protect the current pregnancy.
Delivery:
- Time: 39-40 weeks.
- Mode: Vaginal delivery.
- Early cord clamping: To prevent sensitization during delivery.

Post Delivery

If the newborn is Rh-positive, a direct Coombs test (DCT) is performed on the newborn's blood.
- If negative, the mother receives 300 µg anti-D (postpartum prophylaxis).
If the newborn is Rh-negative, postpartum prophylaxis is not required.

Postpartum Prophylaxis

Indication: Rh-positive newborn + DCT-negative.
Aim: To protect the next pregnancy.
Ideal time: Within 72 hours of vaginal delivery/C-section (can be given up to 28 days).
Anti-D: Given even if postpartum sterilization is to be done.

Management of Rh-negative Sensitized Pregnancy

Check Antibody Titre: To determine if anti-D antibodies are present in sufficient amounts to cross the placenta and cause hemolysis.
- Critical Titre: 1:16 (mother's blood is serially diluted). If antibodies are present at ≥ 1:16, it is considered significant.
- Maternal Antibody Titre is used to guide management.

Cordocentesis (Blood from umbilical cord)

Hb of fetus < 2 SD or Hematocrit < 30%:
- Mild anemia: Repeat Hb and hematocrit weekly, fetal surveillance from 32 weeks, delivery at 37-38 weeks.
Hb of fetus ≥ 2 SD or Hematocrit ≥30%:
- Severe anemia: If ≥ 35 weeks, delivery. If < 35 weeks: Intra-uterine blood transfusion.

Intrapartum Mx

Mode of delivery: Vaginal delivery + delayed cord clamping if the mother is already sensitized.
Cord clamping:
- ICT status not measured:
  - Rh-negative, ICT-negative: Early cord clamping.
  - Rh-negative, ICT-positive: Delayed cord clamping.

Fetomaternal Hemorrhage & Other Indications of Anti-D

FETOMATERNAL HEMORRHAGE (FMH)
- Normal FMH: 30 mL (15 mL fetal RBC)
- Kleihauer Betke test: Used to quantify FMH.

Anti-D Immunoglobulin

Dose: 300 µg per 30 mL of FMH.

Tests

Rosette test: A screening test for FMH.
Kleihauer Betke test: A quantitative test to estimate the exact volume of FMH.
Singer Alkali Denaturation test: A qualitative test to distinguish between vasa previa and placenta previa, and also helps detect FMH.

Other Indications for Anti-D

First Trimester:
- After abortion, ectopic pregnancy, molar pregnancy, chorionic villi sampling.
Dosage (less than 12 weeks):
- ACOG: 50 µg intramuscular.
- RCOG: 300 µg intramuscular.
Second/Third Trimester:
- After amniocentesis, external cephalic/Internal podalic version, unexplained bleeding, antepartum hemorrhage, fetal death, abdominal trauma.
Dosage (more than 12 weeks): 300 µg intramuscular.

Important Note

Anti-D immunoglobulin has no role in cordocentesis when sensitization has already occurred (ICT+ve).
Delivery should occur within 28 days of Anti-D administration.

Miscellaneous Topics

Minor Antigens
- High Risk of Sensitization: Kell, Kidd, Duffy-A.
- No Risk of Sensitization: Lewis, 1-antigen, Duffy-B.

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Description

This quiz covers essential topics related to Rh-negative pregnancies, including immune hydrops fetalis, prophylaxis measures, and the roles of anti-D antibodies. Test your knowledge on the indirect and direct Coombs tests, and understand the management protocols for unsensitized Rh-negative females. Ensure you are well-informed on maternal-fetal Rh incompatibility issues.