Parturition — MCQs
Which drug is associated with decreased fetal heart rate during labor?
A patient presents with infraumbilical flattening and the fetal heart rate is heard laterally. What is the most likely fetal position?
A primigravida presents to the labor room at 40 weeks of gestation with lower abdominal pain. She has been in labor for 3 hours. Which of the following will determine if she is in active labor?
True about oxytocin are all except
Female with 41 wk gestation confirmed by radiological investigation, very sure of her LMP, no uterine contractions, no effacement and no dilatation. What should be done to induce labor?
Serum prolactin levels are highest
All are examples of negative feedback except
Milk production in pregnancy is inhibited by :
At the time point indicated by the arrow, the hormone levels are:
The structure marked $A$ begins to close by what time frame and due to what cause?
Parturition Indian Medical PG Practice Questions and MCQs
Question 1: Which drug is associated with decreased fetal heart rate during labor?
- A. Oxytocin (Correct Answer)
- B. Sodium bicarbonate
- C. IV fluids
- D. Iron
Explanation: ***Oxytocin*** - **Oxytocin** stimulates uterine contractions, which can reduce blood flow to the placenta and temporarily decrease **fetal oxygenation**, leading to **fetal heart rate decelerations**. - Overstimulation of the uterus by oxytocin can result in **tachysystole** (>5 contractions in 10 minutes), potentially causing **fetal hypoxia** and associated changes in fetal heart rate patterns such as late decelerations or bradycardia. *Sodium bicarbonate* - **Sodium bicarbonate** is used to correct metabolic acidosis, but it does not directly affect **fetal heart rate** or uterine activity in a way that causes decelerations. - Its administration is unlikely to impact fetal heart rate unless the underlying condition causing acidosis also affects fetal well-being, which is not a direct drug effect. *IV fluids* - **Intravenous fluids** are often administered during labor to maintain hydration and support maternal circulation, which generally helps improve **fetal well-being** and maintain normal fetal heart rate patterns. - They can help optimize **uterine perfusion**, thereby improving oxygen delivery to the fetus and reducing the risk of fetal distress. *Iron* - **Iron** is essential for red blood cell production and preventing maternal anemia; it has no direct or acute effect on **fetal heart rate** during labor. - Administered as a supplement, iron is not a medication used during labor to impact **uterine contractility** or fetal heart rate in the way oxytocin does.
Question 2: A patient presents with infraumbilical flattening and the fetal heart rate is heard laterally. What is the most likely fetal position?
- A. Occipitoposterior (Correct Answer)
- B. Right occipitoanterior
- C. Right dorsoanterior
- D. Left occipitoanterior
Explanation: ***Occipitoposterior*** - **Infraumbilical flattening** of the abdomen is a classic sign of an occipitoposterior position due to the fetal spine lying against the maternal spine. - The **heart sounds are heard laterally** because the fetal back, where the heart sounds are best transmitted, is positioned towards the maternal flanks. *Right occipitoanterior* - In a right occipitoanterior position, the fetal spine is anterior and slightly to the right, leading to a more **convex abdomen** and **heart sounds audible anteriorly** and to the right of the midline. - This position does not typically cause infraumbilical flattening. *Right dorsoanterior* - This term is more commonly associated with a **breech presentation** where the fetal back (dorsum) is anterior. - In a cephalic presentation, "dorsoanterior" is not a standard term for fetal position relative to the occiput. *Left occipitoanterior* - In a left occipitoanterior position, the fetal spine is anterior and slightly to the left, resulting in a **convex abdomen** and **heart sounds audible anteriorly** and to the left of the midline. - Infraumbilical flattening is not a characteristic finding for this position.
Question 3: A primigravida presents to the labor room at 40 weeks of gestation with lower abdominal pain. She has been in labor for 3 hours. Which of the following will determine if she is in active labor?
- A. Fetal head 5/5 palpable on abdominal examination
- B. Two contractions lasting for 10 seconds in 10 minutes
- C. Rupture of membranes
- D. Cervical dilatation of 6 cm or more with regular contractions (Correct Answer)
Explanation: ***Cervical dilatation of 6 cm or more with regular contractions*** - Active labor is officially defined by **cervical dilatation of 6 cm or more** according to the ACOG and SMFM 2014 consensus guidelines, which redefined the labor curve based on the Consortium on Safe Labor study. - This represents a shift from the traditional Friedman curve definition of 4 cm, recognizing that **significant progressive cervical change** with regular uterine contractions is the hallmark of active labor. - Complete effacement typically occurs during the latent phase, and while regular contractions accompany active labor, **cervical dilatation ≥6 cm is the primary diagnostic criterion**. *Fetal head 5/5 palpable on abdominal examination* - This finding indicates a **high fetal head** that is not engaged (0/5 of the head has entered the pelvis), which does not determine whether active labor has begun. - **Fetal station and engagement** are important for assessing labor progression and potential for cephalopelvic disproportion, but are not the primary criteria for diagnosing active labor. *Two contractions lasting for 10 seconds in 10 minutes* - These contractions are **infrequent and very short**, more characteristic of latent labor or Braxton Hicks contractions. - Active labor typically involves **3-5 contractions in 10 minutes, each lasting 45-60 seconds**, with sufficient intensity to cause progressive cervical change. *Rupture of membranes* - **Rupture of membranes (ROM)**, whether spontaneous or artificial, is an important event but does not by itself indicate active labor. - A woman can have ROM in the **latent phase** or even before labor begins (prelabor ROM or PROM), and **cervical dilatation remains the primary determinant** of active labor.
Question 4: True about oxytocin are all except
- A. Causes contraction of upper segment
- B. Causes uterine contraction of body
- C. Secreted by posterior pituitary
- D. Synthesized by anterior pituitary (Correct Answer)
Explanation: ***Synthesized by anterior pituitary*** - Oxytocin is **synthesized in the hypothalamus** (specifically in the paraventricular and supraoptic nuclei), not in the anterior pituitary. - The **anterior pituitary** produces different hormones like **FSH, LH, ACTH, TSH, prolactin, and growth hormone**, but does not synthesize oxytocin. *Causes contraction of upper segment* - Oxytocin does cause **contractions of the upper uterine segment** as part of coordinated uterine activity during labor. - This contributes to **fundal dominance** where contractions are strongest at the fundus and weaken toward the cervix. *Causes uterine contraction of body* - Oxytocin stimulates **rhythmic contractions of the myometrium** throughout the uterine body during labor. - These **coordinated contractions** are essential for effective cervical dilation and fetal expulsion. *Secreted by posterior pituitary* - Oxytocin is indeed **stored and released by the posterior pituitary** after being transported from the hypothalamus. - The posterior pituitary acts as a **storage and release site** for both oxytocin and **antidiuretic hormone (ADH)**.
Question 5: Female with 41 wk gestation confirmed by radiological investigation, very sure of her LMP, no uterine contractions, no effacement and no dilatation. What should be done to induce labor?
- A. PGE1 tab (Correct Answer)
- B. PGE2 gel
- C. PGF2alpha
- D. Intracervical foley’s
Explanation: ***PGE1 tab*** - **Misoprostol (PGE1)** is an effective agent for **cervical ripening** and labor induction in cases of an unfavorable cervix (no effacement, no dilatation). - It is cost-effective, stable at room temperature, and widely used in resource-limited settings. - Can be administered orally or vaginally with good efficacy for cervical ripening at term. - In this post-term pregnancy with unfavorable cervix, pharmacological ripening is appropriate. *PGE2 gel* - **PGE2 (dinoprostone)** gel or cervical insert is also an effective option for cervical ripening. - Both PGE1 and PGE2 are acceptable first-line agents; the choice may depend on availability, cost, and institutional protocols. - PGE2 formulations are FDA-approved and widely used, though may be more expensive than misoprostol. *PGF2alpha* - **PGF2alpha (carboprost)** is primarily used for the **management of postpartum hemorrhage** due to its potent myometrial contracting effect. - It is **not indicated** for induction of labor at term as its strong uterine contractions can cause excessive uterine stimulation and fetal distress. *Intracervical foley's* - An **intracervical Foley catheter** is a mechanical method that causes cervical ripening through direct pressure and stimulation of local prostaglandin release. - It is an evidence-based alternative with lower risk of uterine hyperstimulation compared to pharmacological methods. - Both mechanical and pharmacological methods are acceptable first-line options for cervical ripening in post-term pregnancy with unfavorable cervix.
Question 6: Serum prolactin levels are highest
- A. 24 hrs after parturition
- B. REM sleep
- C. In actively lactating mothers
- D. During third trimester of pregnancy (Correct Answer)
Explanation: ***Correct: During third trimester of pregnancy*** - **Serum prolactin levels reach their absolute highest** during the **third trimester of pregnancy**, rising progressively from normal levels (5-25 ng/mL) to peak values of **200-400 ng/mL** near term. - This represents the **highest physiological prolactin levels** observed in humans. - Despite these high levels, **lactation does not occur** during pregnancy because **estrogen and progesterone** block prolactin's action on mammary tissue. - The high prolactin prepares the breast for lactation but milk secretion is inhibited until delivery. *Incorrect: 24 hrs after parturition* - After delivery, prolactin levels actually begin to **decline** from their pregnancy peak, though they remain elevated (around 200 ng/mL). - While **lactogenesis II** (copious milk production) begins 24-72 hours postpartum, this is due to the **removal of estrogen/progesterone inhibition**, not because prolactin levels peak at this time. - The confusion arises from conflating **functional milk production** with **peak hormone levels**. *Incorrect: REM sleep* - Prolactin exhibits **circadian variation** with nocturnal rise during sleep, peaking in early morning hours. - However, these sleep-related peaks (typically 25-40 ng/mL) are **much lower** than pregnancy levels. - This physiological variation is unrelated to reproductive function. *Incorrect: In actively lactating mothers* - During established lactation, basal prolactin levels gradually decline over weeks to months. - Each **suckling episode** causes transient prolactin surges (2-10 fold increase), but these peaks are still **lower than third trimester levels**. - By 6 months postpartum, basal prolactin may return near pre-pregnancy levels despite continued lactation.
Question 7: All are examples of negative feedback except
- A. Regulation of blood CO2 level
- B. Regulation of pituitary hormones
- C. Regulation of blood pressure
- D. Coagulation of the blood (Correct Answer)
Explanation: ***Coagulation of the blood*** - **Blood coagulation** is a classic example of **positive feedback**, where the initial clotting process amplifies itself until bleeding stops - Platelets aggregate and release factors that promote further platelet aggregation and activation of the clotting cascade, thereby **accelerating the response** rather than diminishing it - This is the exception among the options, as it represents positive feedback while all others are negative feedback *Regulation of blood CO2 level* - The regulation of **blood CO2 levels** is a vital example of **negative feedback**, where an increase in CO2 stimulates breathing to expel excess CO2 - This mechanism works to return the blood CO2 concentration to its homeostatic set point, thus **counteracting the initial stimulus** - Central and peripheral chemoreceptors detect elevated CO2 and trigger increased ventilation *Regulation of pituitary hormones* - The regulation of **pituitary hormones** involves **negative feedback loops**, where high levels of target gland hormones inhibit the release of stimulating hormones from the pituitary and hypothalamus - For example, high thyroid hormone levels inhibit TSH release from the pituitary and TRH from the hypothalamus - This effectively **reduces the initial stimulus** and maintains hormonal balance *Regulation of blood pressure* - The regulation of **blood pressure** is primarily controlled by **negative feedback mechanisms** involving baroreceptors, which detect changes in pressure - If blood pressure rises, baroreceptors in the carotid sinus and aortic arch signal the medulla to reduce heart rate and dilate blood vessels - This response **lowers the pressure back to the set point**, maintaining cardiovascular homeostasis
Question 8: Milk production in pregnancy is inhibited by :
- A. Low luteinizing hormone
- B. Low thyroid-stimulating hormone
- C. High estrogen (Correct Answer)
- D. Human somatomammotropin
Explanation: ***High estrogen*** - High levels of **estrogen** and progesterone during pregnancy inhibit milk production by blocking the action of **prolactin** on the mammary glands. - After delivery, the sudden drop in these hormones removes the inhibition, allowing prolactin to stimulate **lactogenesis**. *Low luteinizing hormone* - **Luteinizing hormone (LH)** is primarily involved in ovulation and corpus luteum formation, not directly in the inhibition of milk production. - Low LH levels would impact fertility but not have a direct inhibitory effect on lactation. *Low thyroid-stimulating hormone* - **Thyroid-stimulating hormone (TSH)** regulates thyroid function, which can indirectly affect metabolism and overall well-being. - While **hypothyroidism** can impact milk supply, low TSH itself is not a direct inhibitor of milk production. *Human somatomammotropin* - **Human placental lactogen (HPL)**, also known as human chorion somatomammotropin, is produced by the placenta. - It promotes mammary gland development and has weak lactogenic properties but does not inhibit milk production.
Question 9: At the time point indicated by the arrow, the hormone levels are:
- A. Decreased estrogen, increased progesterone
- B. Increased estrogen, increased progesterone
- C. Decreased estrogen, decreased progesterone
- D. Increased estrogen, decreased progesterone (Correct Answer)
Explanation: ***Increased estrogen, decreased progesterone*** - The arrow (red circle) points to Day 14, marking the approximate time of **ovulation**. At this point, the graph shows that **estrogen levels peak** just before ovulation and begin to decrease during ovulation. - Progesterone levels are relatively **low** during the follicular phase and only start to significantly increase **after ovulation** as the corpus luteum forms. *Decreased estrogen, increased progesterone* - This hormonal profile is characteristic of the **mid to late luteal phase**, not ovulation. - During the luteal phase, post-ovulation, the **corpus luteum** predominantly produces **progesterone**, leading to its increase, while estrogen levels decline from their pre-ovulatory peak. *Increased estrogen, increased progesterone* - While estrogen is high just before ovulation, **progesterone remains low** until after ovulation. - An increase in both significant progesterone and estrogen would be more indicative of the middle of the **luteal phase** when the corpus luteum is fully functional and producing both hormones in higher amounts. *Decreased estrogen, decreased progesterone* - This hormone profile typically occurs at the **very end of the luteal phase** if pregnancy does not occur, leading to the breakdown of the corpus luteum and subsequent menstruation. - It also characterizes the early follicular phase, not the time around ovulation.
Question 10: The structure marked $A$ begins to close by what time frame and due to what cause?
- A. Begins to close at 10-15 hours after birth, due to expression of prostaglandins
- B. Begins to close 4 weeks after birth, due to fall in oxygen concentration
- C. Begins to close 4 weeks after birth, due to rise in oxygen tension
- D. Begins to close at 10-15 hours after birth, due to withdrawal of prostaglandins (Correct Answer)
Explanation: ***Begins to close at 10-15 hours after birth, due to withdrawal of prostaglandins*** - The structure marked 'A' is the **ductus arteriosus**, which begins **functional closure** at **10-15 hours** after birth when **prostaglandin E2 (PGE2)** levels drop. - **Withdrawal of prostaglandins** is the primary mechanism that initiates closure, along with increased **oxygen tension**, causing smooth muscle constriction in the ductal wall. *Begins to close at 10-15 hours after birth, due to expression of prostaglandins* - **Prostaglandin E2 (PGE2)** actually **maintains patency** of the ductus arteriosus during fetal life, so increased expression would keep it open. - Closure occurs due to **withdrawal** (not expression) of prostaglandins after birth when placental PGE2 production ceases. *Begins to close 4 weeks after birth, due to fall in oxygen concentration* - A **fall in oxygen concentration** would actually **promote ductal patency**, as seen in fetal circulation where low oxygen helps maintain the shunt. - Additionally, **4 weeks** refers to **complete anatomical closure** (fibrosis), not when closure initially begins. *Begins to close 4 weeks after birth, due to rise in oxygen tension* - While **rise in oxygen tension** does contribute to ductal closure, the timing is incorrect for when closure "begins." - **4 weeks** represents **anatomical closure** (complete fibrosis), whereas **functional closure begins** at **10-15 hours** after birth.
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