In a fetus insulin secretion begins by?

SCTIMST Staff Nurse - 2016

Obstetrics and Midwifery Nursing

Easy

Appeared in: SCTIMST Staff Nurse - 2016

Explanation

The fetal pancreas develops from the endoderm of the foregut and becomes functional early in pregnancy.
According to embryological timelines, insulin-containing granules can be identified in the fetal pancreas by 9 to 10 weeks of gestation.
Insulin becomes detectable in the fetal plasma by 12 weeks, which falls within the 3rd month of pregnancy, marking the onset of secretion.
This early insulin production is vital for regulating fetal glucose metabolism and growth throughout the remainder of the pregnancy.

Option B: This is incorrect. By the 5th month, the fetal pancreas is already actively secreting insulin in response to fetal glucose levels. The onset is much earlier.
Option C: This is incorrect. The 7th month is in the third trimester, by which time the fetal endocrine system, including insulin secretion, is well-established and plays a significant role in fetal growth.
Option D: This is incorrect. The 9th month is at the end of gestation. Insulin secretion has been active for the majority of the pregnancy by this point.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The concept tested is the timeline of fetal endocrine development, specifically the onset of insulin secretion during gestation as background academic context rather than a clinical decision trigger.
Understanding the onset of fetal insulin secretion is critical for managing pregnancies in diabetic mothers.
Because maternal insulin does not cross the placenta, the fetus is solely responsible for its own insulin production. Maternal hyperglycemia directly causes fetal hyperglycemia, leading to fetal hyperinsulinism, which can result in macrosomia (large baby) and increase the risk of birth complications.
After delivery, the newborn of a diabetic mother is at high risk for neonatal hypoglycemia because the constant glucose supply from the mother is cut, but the infant's pancreas continues to overproduce insulin.

How to Approach the Question

Identify the core of the question: it asks for the starting point ('begins by') of a specific fetal physiological function ('insulin secretion').
This is a factual recall question based on knowledge of fetal development (embryology and physiology).
Recall the general timeline of organogenesis. Most major organ systems are formed and begin to function during the first trimester.
Consider the options provided: 3rd, 5th, 7th, and 9th months.
Eliminate the later months (5th, 7th, 9th) as they are well past the initial phase of organ development. The pancreas is a vital organ that would be expected to function relatively early.
Select the earliest plausible option, the 3rd month, which corresponds to the end of the first trimester when many foundational physiological processes begin.

Concept Tested & Keywords

Concept Tested: The concept tested is the timeline of fetal endocrine development, specifically the onset of insulin secretion during gestation.
Stem keywords: fetus, insulin secretion, begins by
Lead-in keywords: BEST, MOST RELEVANT CLUE
Negative lead-in flag: false

QOzBs4ySfqtJEnSkzMXpod

E6 Obstetrics Williams p. 27-46