Which of the following tends to initiate Braxton Hicks contractions, or 'false labor'?

• A. Increased estrogen levels
• B. Stretching of the uterine muscles
• C. Decreased progesterone secretion
• D. Release of oxytocin from the posterior pituitary

Answer: (B)

Verified step by step guidance

1. Understand the concept of Braxton Hicks contractions: These are irregular, non-labor contractions of the uterus that occur during pregnancy. They are often referred to as 'false labor' because they do not lead to childbirth.
2. Review the physiological triggers for uterine contractions: Uterine contractions can be influenced by hormonal changes, mechanical stretching, and other factors. Braxton Hicks contractions are typically associated with the stretching of uterine muscles as the pregnancy progresses.
3. Analyze the role of estrogen and progesterone: Increased estrogen levels can prepare the uterus for labor by promoting uterine sensitivity to oxytocin, while decreased progesterone levels reduce the inhibitory effect on uterine contractions. However, these hormonal changes are more closely associated with true labor rather than Braxton Hicks contractions.
4. Examine the role of oxytocin: Oxytocin is a hormone released by the posterior pituitary that stimulates uterine contractions during true labor. While oxytocin can influence uterine activity, it is not the primary cause of Braxton Hicks contractions.
5. Conclude that the stretching of uterine muscles is the most likely trigger for Braxton Hicks contractions: As the uterus expands to accommodate the growing fetus, the mechanical stretching of the uterine muscles can initiate these irregular contractions.