A 25 year old pregnant woman with Rh incompatibility has delivered a baby. What would be the likely complications in the neonate?

Appeared in: RML Lucknow - 2021

Explanation

In Rh incompatibility, the Rh-negative mother produces IgG antibodies against the Rh-positive fetus's red blood cells (RBCs).
These maternal antibodies cross the placenta and cause destruction (haemolysis) of the fetal RBCs.
This widespread destruction of RBCs leads directly to haemolytic anaemia in the neonate, which is the hallmark of Haemolytic Disease of the Fetus and Newborn (HDFN).

Option A: A delayed cry is a sign of birth asphyxia or central nervous system depression, which can have many causes but is not a direct or specific result of the haemolytic process in Rh disease.
Option B: While hypoglycaemia can occur in severe HDFN due to hyperinsulinism, it is not the primary or most likely complication. The defining issue is RBC destruction.
Option C: This is a secondary complication that occurs only in severe cases of HDFN that progress to hydrops fetalis (severe anaemia causing heart failure and fluid overload). The primary problem that leads to this is haemolytic anaemia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Neonatal complications of Rh incompatibility as background academic context rather than a clinical decision trigger.
Nurses must monitor newborns of Rh-negative mothers for early signs of jaundice (within 24 hours), pallor, and tachycardia, which indicate haemolytic anaemia.
A key nursing role is the administration of Rho(D) immune globulin to Rh-negative mothers around 28 weeks of gestation and within 72 hours after delivering an Rh-positive baby to prevent sensitization for future pregnancies.
What if? If this was the mother's first pregnancy and she had not been previously sensitized, the risk of severe HDFN would be much lower. Sensitization typically occurs during the first delivery, so the first baby is usually unaffected, but subsequent Rh-positive babies are at high risk.

How to Approach the Question

First, identify the core clinical condition presented in the question: a newborn delivered to a mother with Rh incompatibility.
Next, recall the fundamental pathophysiology of this condition, which is an immune reaction where maternal antibodies attack fetal red blood cells.
Analyze the term 'haemolysis' (destruction of blood cells) and 'anaemia' (low red blood cell count).
Connect the pathophysiology directly to the options. The destruction of red blood cells is haemolysis, which by definition causes haemolytic anaemia. This makes it the most direct and likely complication.
Evaluate the other options to confirm they are less likely. Recognize respiratory distress and hypoglycaemia as potential but secondary or less common complications, and delayed cry as unrelated.

Concept Tested & Keywords

Concept Tested: Neonatal complications of Rh incompatibility
Stem keywords: Rh incompatibility, pregnant woman, neonate, complications
Lead-in keywords: likely complications
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.
Negative lead-in flag: false

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 1133-1135, 1134-1136, 1135-1137

Practise the full RML Lucknow - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.