Fertilization of 2 ova released in two different cycles is called?

ISRO 2024

Obstetrics & Gynaecology

Easy

Appeared in: ISRO 2024

Explanation

Superfetation is the correct term for the fertilization of an oocyte released in a menstrual cycle that occurs after a previous cycle's oocyte has already been fertilized and implanted.
This process results in two fetuses of distinctly different gestational ages co-existing within the uterus.
The key differentiator from other terms is that the two fertilization events are separated by at least one full ovulatory cycle.
It is an extremely rare occurrence in humans because the hormonal environment of an established pregnancy typically prevents further ovulation.

Option A: Superfecundation involves the fertilization of two or more ova released during the same ovulatory cycle, not different cycles. The acts of intercourse may be separate but occur within a short time frame.
Option C: Foetus papyraceous is not a method of conception but rather a complication of a multiple pregnancy. It describes the outcome when one fetus dies in utero and becomes flattened and mummified.
Option D: This option is incorrect because a specific term for the described phenomenon, Superfetation, is provided as one of the choices.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Atypical fertilization events in multiple pregnancies as background academic context rather than a clinical decision trigger.
Understanding these rare terms is important for nurses, especially in obstetrics and neonatology, to correctly interpret clinical findings and communicate with the healthcare team, even if they are unlikely to encounter a case.
With the increasing use of Assisted Reproductive Technologies (ART), unusual reproductive phenomena may be seen more often, and nurses should be aware of the possibilities.
A finding of two fetuses with a significant size discrepancy on an ultrasound would prompt investigation. While superfetation is a remote possibility, more common causes like intrauterine growth restriction (IUGR) or twin-to-twin transfusion syndrome (TTTS) must be ruled out first.

How to Approach the Question

First, analyze the keywords in the question stem: 'fertilization', '2 ova', and 'two different cycles'. The most critical phrase is 'different cycles'.
Recognize this is a definition-based question testing knowledge of specific obstetric terminology.
Evaluate each option. The prefixes 'super-' (meaning 'over' or 'in addition') and the roots 'fetation' (development of a fetus) and 'fecundation' (fertilization) are clues.
Superfetation literally means 'fetus on top of fetus', implying one is already established when the other begins. This aligns with 'different cycles'.
Superfecundation means 'extra fertilization', which aligns with multiple fertilizations happening around the same time (same cycle).
Eliminate 'Foetus papyraceous' as it describes a complication (fetal demise) rather than a type of conception.

Concept Tested & Keywords

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 1048-1050