Augmentation of labor — MCQs

10 questions

A 36-year-old primigravid woman at 26 weeks' gestation comes to the physician complaining of absent fetal movements for the last 2 days. Pregnancy was confirmed by ultrasonography 14 weeks earlier. She has no vaginal bleeding or discharge. She has a history of type 1 diabetes mellitus controlled with insulin. Vital signs are all within the normal limits. Pelvic examination shows a soft, 2-cm long cervix in the midline with a cervical os measuring 3 cm and a uterus consistent in size with 24 weeks' gestation. Transvaginal ultrasonography shows a fetus with no cardiac activity. Which of the following is the most appropriate next step in management?

A 39-year-old woman, gravida 5, para 4, at 41 weeks' gestation is brought to the hospital because of regular uterine contractions that started 2 hours ago. Pregnancy has been complicated by iron deficiency anemia treated with iron supplements. Pelvic examination shows the cervix is 90% effaced and 7-cm dilated; the vertex is at -1 station. Fetal heart tracing is shown. The patient is repositioned, O2 therapy is initiated, and amnioinfusion is done. A repeat assessment after 20 minutes shows a similar cervical status, and no changes in the fetal heart tracing, and less than 5 contractions in a period of 10 minutes.What is the most appropriate next step in management?

A 22-year-old G4P2 at 35 weeks gestation presents to the hospital after she noticed that "her water broke." Her prenatal course is unremarkable, but her obstetric history includes postpartum hemorrhage after her third pregnancy, attributed to a retained placenta. The patient undergoes augmentation of labor with oxytocin and within four hours delivers a male infant with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. Three minutes later, the placenta passes the vagina, but a smooth mass attached to the placenta continues to follow. Her temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 90/min, and respirations are 20/min. What is the most likely complication in the absence of intervention?

A 27-year old primigravid woman at 37 weeks' gestation comes to the emergency department because of frequent contractions for 4 hours. Her pregnancy has been complicated by hyperemesis gravidarum which subsided in the second trimester. The contractions occur every 10–15 minutes and have been increasing in intensity and duration since onset. Her temperature is 37.1°C (98.8°F), pulse is 110/min, and blood pressure is 140/85 mm Hg. Uterine contractions are felt on palpation. Pelvic examination shows clear fluid in the vagina. The cervix is 50% effaced and 3 cm dilated. After 4 hours the cervix is 80% effaced and 6 cm dilated. Pelvic examination is inconclusive for the position of the fetal head. The fetal heart rate is reassuring. Which of the following is the most appropriate next step?

You are a resident in the surgical ICU. One of the patients you are covering is a 35-year-old pregnant G1P0 in her first trimester admitted for complicated appendicitis and awaiting appendectomy. Your attending surgeon would like you to start the patient on moxifloxacin IV preoperatively. You remember from your obstetrics clerkship, however, that moxifloxacin is Pregnancy Category C, and animal studies have shown that immature animals exposed to fluoroquinolones like moxifloxacin may experience cartilage damage. You know that there are potentially safer antibiotics, such as piperacillin/tazobactam, which is in Pregnancy Category B. What should you do?

A 44-year-old woman with high blood pressure and diabetes presents to the outpatient clinic and informs you that she is trying to get pregnant. Her current medications include lisinopril, metformin, and sitagliptin. Her blood pressure is 136/92 mm Hg and heart rate is 79/min. Her physical examination is unremarkable. What should you do regarding her medication for high blood pressure?

A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

A 30-year-old woman, gravida 2, para 1, at 38 weeks' gestation comes to the hospital for regular, painful contractions that have been increasing in frequency. Her pregnancy has been complicated by gestational diabetes treated with insulin. Pelvic examination shows the cervix is 50% effaced and 4 cm dilated; the vertex is at -1 station. Ultrasonography shows no abnormalities. A tocometer and Doppler fetal heart monitor are placed on the patient's abdomen. The fetal heart rate monitoring strip shows a baseline heart rate of 145/min with a variability of ≥ 15/min. Within a 20-minute recording, there are 7 uterine contractions, 4 accelerations, and 3 decelerations that have a nadir occurring within half a minute. The decelerations occur at differing intervals relative to the contractions. Which of the following is the most appropriate next step in the management of this patient?

A 22-year-old primigravid woman at 41 weeks' gestation is admitted to the hospital in active labor. Pregnancy has been uncomplicated. She has asthma treated with theophylline and inhaled corticosteroids. She has had 2 surgeries in the past to repair multiple lower limb and pelvis fractures that were the result of a car accident. She is otherwise healthy. Her temperature is 37.2°C (99°F) and blood pressure is 108/70 mm Hg. Examination shows the cervix is 100% effaced and 10 cm dilated; the vertex is at -4 station, with the occiput in the anterior position. Uterine activity is measured at 275 MVUs. Maternal pushing occurs during the contractions. Fetal heart tracing is 166/min and reactive with no decelerations. Epidural anesthesia is initiated for pain relief. After 4 hours of pushing, the vertex is found to be at -4 station, with increasing strength and rate of uterine contractions; fetal heart tracing shows late decelerations. Which of the following is the most likely cause of this patient's prolonged labor?

Q10

A 28-year-old woman, gravida 2, para 1, at 40 weeks of gestation is admitted to the hospital in active labor. The patient has attended many prenatal appointments and followed her physician's advice about screening for diseases, laboratory testing, diet, and exercise. Her pregnancy has been uncomplicated. She has no history of a serious illness. Her first child was delivered via normal vaginal delivery. Her vital signs are within normal limits. Cervical examination shows 80% effacement, 5 cm dilation and softening without visible fetal parts or prolapsed umbilical cord. A cardiotocograph is shown. Which of the following options is the most appropriate initial step in management?

Augmentation of labor US Medical PG Practice Questions and MCQs

Question 1: A 36-year-old primigravid woman at 26 weeks' gestation comes to the physician complaining of absent fetal movements for the last 2 days. Pregnancy was confirmed by ultrasonography 14 weeks earlier. She has no vaginal bleeding or discharge. She has a history of type 1 diabetes mellitus controlled with insulin. Vital signs are all within the normal limits. Pelvic examination shows a soft, 2-cm long cervix in the midline with a cervical os measuring 3 cm and a uterus consistent in size with 24 weeks' gestation. Transvaginal ultrasonography shows a fetus with no cardiac activity. Which of the following is the most appropriate next step in management?

A. Plan for oxytocin administration (Correct Answer)
B. Perform weekly pelvic ultrasound
C. Perform dilation and curettage
D. Perform cesarean delivery
E. Administer magnesium sulfate

Explanation: ***Plan for oxytocin administration*** - The patient is at 26 weeks' gestation with confirmed fetal demise and an effaced, dilated cervix (2 cm long, 3 cm dilated). This indicates the cervix is already preparing for delivery. - **Oxytocin** is the most appropriate next step to induce labor and facilitate vaginal delivery in cases of **intrauterine fetal demise** (IUFD) after the first trimester, especially when cervical changes have begun. *Perform weekly pelvic ultrasound* - The ultrasound has already confirmed **absent fetal cardiac activity**, making repeated ultrasounds unnecessary as the diagnosis of IUFD is already established. - This option would delay necessary management and exposure to the deceased fetus in utero could increase risks such as **coagulopathy** if prolonged. *Perform dilation and curettage* - **Dilation and curettage (D&C)** is generally reserved for termination of pregnancy or management of miscarriage up to **16-18 weeks' gestation**. - At **26 weeks' gestation**, the size of the fetus and uterus makes D&C a less safe and less effective procedure compared to labor induction. *Perform cesarean delivery* - **Cesarean delivery** for IUFD is typically reserved for cases with maternal indications (e.g., prior classical C-section scar, placenta previa obstructing the birth canal) or when labor induction fails. - There are no maternal or fetal contraindications to vaginal delivery in this scenario, and a C-section would primarily increase maternal morbidity without fetal benefit. *Administer magnesium sulfate* - **Magnesium sulfate** is used for **neuroprotection** in preterm deliveries (usually before 32 weeks) and seizure prophylaxis in **preeclampsia/eclampsia**. - As the fetus is deceased, neuroprotection is not applicable, and there are no signs of preeclampsia, making this intervention inappropriate.

Question 2: A 39-year-old woman, gravida 5, para 4, at 41 weeks' gestation is brought to the hospital because of regular uterine contractions that started 2 hours ago. Pregnancy has been complicated by iron deficiency anemia treated with iron supplements. Pelvic examination shows the cervix is 90% effaced and 7-cm dilated; the vertex is at -1 station. Fetal heart tracing is shown. The patient is repositioned, O2 therapy is initiated, and amnioinfusion is done. A repeat assessment after 20 minutes shows a similar cervical status, and no changes in the fetal heart tracing, and less than 5 contractions in a period of 10 minutes.What is the most appropriate next step in management?

A. Emergent cesarean delivery (Correct Answer)
B. Monitor without intervention
C. Begin active pushing
D. Retry maternal repositioning
E. Administer tocolytics

Explanation: ***Emergent cesarean delivery*** - The fetal heart tracing shows **recurrent late decelerations** unresponsive to **intrauterine resuscitation** (repositioning, O2, amnioinfusion), indicating fetal distress and uteroplacental insufficiency. - Given the fetal distress and persistent late decelerations despite interventions, **expedited delivery** via cesarean section is indicated to prevent further fetal compromise. *Monitor without intervention* - This approach is inappropriate as the fetal heart tracing indicates **fetal distress** with recurrent **late decelerations** that have not resolved with initial interventions. - Continued monitoring without action would place the fetus at risk for **hypoxia** and acidosis. *Begin active pushing* - The cervix is 7-cm dilated, meaning the patient is still in the **active phase of labor** and has not reached **complete cervical dilation** (10 cm) necessary for effective pushing. - Pushing at this stage is unlikely to resolve the fetal distress and can potentially worsen **fetal acidosis** and maternal exhaustion. *Retry maternal repositioning* - The patient has already been repositioned and received other intrauterine resuscitation measures (O2 therapy, amnioinfusion) without improvement in the fetal heart tracing. - Repeated repositioning alone is unlikely to resolve the underlying cause of the **late decelerations** in this context. *Administer tocolytics* - Tocolytics are used to **reduce uterine contractions** and manage conditions like **uterine tachysystole** or arrested labor, which are not explicitly present as the primary problem here (less than 5 contractions in 10 minutes). - While they can temporarily improve uterine blood flow, they do not address the persistent **fetal distress** indicated by the recurrent late decelerations unresponsive to other interventions.

Question 3: A 22-year-old G4P2 at 35 weeks gestation presents to the hospital after she noticed that "her water broke." Her prenatal course is unremarkable, but her obstetric history includes postpartum hemorrhage after her third pregnancy, attributed to a retained placenta. The patient undergoes augmentation of labor with oxytocin and within four hours delivers a male infant with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. Three minutes later, the placenta passes the vagina, but a smooth mass attached to the placenta continues to follow. Her temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 90/min, and respirations are 20/min. What is the most likely complication in the absence of intervention?

A. Hypertension
B. Hemorrhagic shock (Correct Answer)
C. Tachypnea
D. Heart failure
E. Hyperthermia

Explanation: ***Hemorrhagic shock*** - The presenting symptoms suggest **uterine inversion**, a rare but serious obstetrical emergency where the uterus turns inside out, which is usually accompanied by a **sudden gush of blood** or **postpartum hemorrhage**. - Without immediate intervention to correct the uterine inversion and manage bleeding, the rapid and significant blood loss will lead to **hemorrhagic shock**, characterized by inadequate tissue perfusion and oxygen delivery. *Hypertension* - **Uterine inversion** and associated significant blood loss would typically lead to **hypotension** and shock, not hypertension. - Hypertension in the postpartum period is usually linked to conditions like **preeclampsia** or **essential hypertension**, which are not indicated here. *Tachypnea* - While tachypnea can be a symptom of **hemorrhagic shock** due to metabolic acidosis and compensatory mechanisms, it is a *symptom* of the underlying problem, not the most likely primary complication itself. - The immediate life-threatening complication from uterine inversion is **massive blood loss**, leading to shock. *Heart failure* - **Acute heart failure** due to uterine inversion or postpartum hemorrhage is unlikely unless the patient has pre-existing cardiac conditions or develops severe, prolonged shock leading to multi-organ dysfunction. - The immediate concern is the **circulatory collapse** from blood loss, not primary cardiac failure. *Hyperthermia* - **Hyperthermia** (fever) is typically associated with **infection**, such as endometritis or chorioamnionitis, and not a direct consequence of uterine inversion or immediate postpartum hemorrhage. - The patient's temperature is normal, indicating no infection at presentation.

Question 4: A 27-year old primigravid woman at 37 weeks' gestation comes to the emergency department because of frequent contractions for 4 hours. Her pregnancy has been complicated by hyperemesis gravidarum which subsided in the second trimester. The contractions occur every 10–15 minutes and have been increasing in intensity and duration since onset. Her temperature is 37.1°C (98.8°F), pulse is 110/min, and blood pressure is 140/85 mm Hg. Uterine contractions are felt on palpation. Pelvic examination shows clear fluid in the vagina. The cervix is 50% effaced and 3 cm dilated. After 4 hours the cervix is 80% effaced and 6 cm dilated. Pelvic examination is inconclusive for the position of the fetal head. The fetal heart rate is reassuring. Which of the following is the most appropriate next step?

A. Administer oxytocin
B. Perform external cephalic version
C. Administer misoprostol
D. Perform Mauriceau-Smellie-Veit maneuver
E. Perform ultrasonography (Correct Answer)

Explanation: ***Perform ultrasonography*** - The examination notes that the **pelvic examination is inconclusive for the position of the fetal head**, which is a critical piece of information needed for safe delivery. **Ultrasonography** is the most appropriate next step to ascertain the fetal presentation and position, especially given the dilated cervix. - Determining fetal position is essential to rule out **malpresentation**, such as **breech** or **transverse lie**, which would significantly impact the delivery plan and potentially necessitate a **cesarean section**. *Administer oxytocin* - **Oxytocin** is used to induce or augment labor when contractions are insufficient or labor is prolonged, but in this case, the cervix is progressing well (from 3 cm to 6 cm dilation in 4 hours), indicating **active labor**. - Without knowing the fetal presentation, administering oxytocin could exacerbate issues if there's a **malpresentation**, potentially leading to **fetal distress** or **uterine rupture**. *Perform external cephalic version* - **External cephalic version (ECV)** is performed to change a **breech presentation** to a **cephalic presentation** by external manipulation, typically done before labor onset or early in labor at term. - This patient is already in **active labor** with significant cervical dilation (6 cm), making ECV less likely to be successful and potentially increasing risks like **placental abruption** or **umbilical cord compression**. *Administer misoprostol* - **Misoprostol** is a prostaglandin analog used for **cervical ripening** and **labor induction** in cases where the cervix is unfavorable or labor needs to be initiated. - This patient is already in **active labor** with progressive cervical dilation, making misoprostol unnecessary and potentially harmful due to the risk of **uterine hyperstimulation**. *Perform Mauriceau-Smellie-Veit maneuver* - The **Mauriceau-Smellie-Veit maneuver** is a technique used during a **vaginal breech delivery** to deliver the fetal head, specifically in cases of **frank or complete breech** that are being delivered vaginally. - This maneuver is only performed *during* delivery of a breech baby, and the fetal position is currently unknown. It would be premature and inappropriate to consider this maneuver without first confirming a **breech presentation** and the decision for vaginal delivery.

Question 5: You are a resident in the surgical ICU. One of the patients you are covering is a 35-year-old pregnant G1P0 in her first trimester admitted for complicated appendicitis and awaiting appendectomy. Your attending surgeon would like you to start the patient on moxifloxacin IV preoperatively. You remember from your obstetrics clerkship, however, that moxifloxacin is Pregnancy Category C, and animal studies have shown that immature animals exposed to fluoroquinolones like moxifloxacin may experience cartilage damage. You know that there are potentially safer antibiotics, such as piperacillin/tazobactam, which is in Pregnancy Category B. What should you do?

A. Administer moxifloxacin since it is only Pregnancy Category C and, although studies may have revealed adverse effects in animals, there is no definite evidence that it causes risk in humans.
B. Administer piperacillin/tazobactam instead of moxifloxacin without discussing with the attending since your obligation is to "first, do no harm" and both are acceptable antibiotics for complicated appendicitis.
C. Discuss the adverse effects of each antibiotic with the patient, and then let the patient decide which antibiotic she would prefer.
D. Wait to administer any antibiotics until you discuss your safety concerns with your attending. (Correct Answer)
E. Administer moxifloxacin since the attending is the executive decision maker and had to know the patient was pregnant when deciding on an antibiotic.

Explanation: **Wait to administer any antibiotics until you discuss your safety concerns with your attending.** - As a resident, you have a **professional and ethical obligation** to voice concerns about patient safety, especially regarding medication choices in vulnerable populations like pregnant women. - Discussing your concerns with the attending physician allows for a **re-evaluation of the treatment plan** based on current evidence and patient-specific factors, ensuring the safest care. *Administer moxifloxacin since it is only Pregnancy Category C and, although studies may have revealed adverse effects in animals, there is no definite evidence that it causes risk in humans.* - While Category C means risk cannot be ruled out and benefits *may* outweigh risks, the presence of **known adverse effects in animal studies** and the availability of a safer alternative warrant reconsideration. - Administering a drug with known potential harm without discussing alternatives or concerns goes against the principle of **prudence and patient safety**. *Administer piperacillin/tazobactam instead of moxifloxacin without discussing with the attending since your obligation is to "first, do no harm" and both are acceptable antibiotics for complicated appendicitis.* - While "first, do no harm" is paramount, **unilaterally changing a treatment plan** ordered by an attending physician is inappropriate and breaches professional hierarchy and communication protocols. - The correct approach is to **communicate concerns** to the attending, allowing for a collaborative decision, rather than making independent substitutions. *Discuss the adverse effects of each antibiotic with the patient, and then let the patient decide which antibiotic she would prefer.* - While patient autonomy and informed consent are crucial, decisions about specific antibiotic choices, especially for a complicated condition like appendicitis, require **medical expertise**. - As a resident, it is your role to present information but not to delegate such complex medical decisions to a patient, particularly when you yourself have **unresolved concerns** with the attending's order. *Administer moxifloxacin since the attending is the executive decision maker and had to know the patient was pregnant when deciding on an antibiotic.* - While the attending is the senior decision-maker, it is possible for **oversights or errors to occur**, even with experienced physicians. - Assuming the attending "had to know" and therefore dismissing your own clinical judgment and knowledge of potential harm is **irresponsible** and compromises patient safety.

Question 6: A 44-year-old woman with high blood pressure and diabetes presents to the outpatient clinic and informs you that she is trying to get pregnant. Her current medications include lisinopril, metformin, and sitagliptin. Her blood pressure is 136/92 mm Hg and heart rate is 79/min. Her physical examination is unremarkable. What should you do regarding her medication for high blood pressure?

A. Discontinue lisinopril and initiate aliskiren
B. Discontinue lisinopril and initiate labetalol (Correct Answer)
C. Continue her current regimen
D. Continue her current regimen and add a beta-blocker for increased control
E. Discontinue lisinopril and initiate candesartan

Explanation: ***Discontinue lisinopril and initiate labetalol*** - **Lisinopril**, an ACE inhibitor, is **teratogenic** and is contraindicated in pregnancy due to the risk of fetal renal dysfunction, oligohydramnios, and neonatal death. - **Labetalol** is a **beta-blocker** commonly used in pregnancy for hypertension as it is considered safe and effective in this population. *Discontinue lisinopril and initiate aliskiren* - **Aliskiren**, a direct renin inhibitor, is also **teratogenic** and contraindicated in pregnancy due to similar risks as ACE inhibitors and ARBs. - Replacing one teratogenic drug with another does not solve the primary concern of fetal safety. *Continue her current regimen* - **Continuing lisinopril** would expose the fetus to significant risks, as it is a known teratogen. - The patient is actively trying to conceive, making it imperative to switch medications immediately. *Continue her current regimen and add a beta-blocker for increased control* - Adding a beta-blocker while continuing lisinopril is still inappropriate because **lisinopril itself is harmful during pregnancy**. - The primary goal is to **discontinue teratogenic medications**, not simply to improve blood pressure control with an additional drug. *Discontinue lisinopril and initiate candesartan* - **Candesartan**, an **angiotensin receptor blocker (ARB)**, shares the same **teratogenic risks** as ACE inhibitors and is contraindicated in pregnancy. - Replacing an ACE inhibitor with an ARB provides no benefit in terms of fetal safety.

Question 7: A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

A. "Does the diarrhea typically precede the constipation, or vice-versa?"
B. "Is the diarrhea foul-smelling?"
C. "Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"
D. "Are the symptoms worse in the morning or at night?"
E. "Can you tell me more about the symptoms you have been experiencing?" (Correct Answer)

Explanation: ***Can you tell me more about the symptoms you have been experiencing?*** - This **open-ended question** encourages the patient to provide a **comprehensive narrative** of their symptoms, including details about onset, frequency, duration, alleviating/aggravating factors, and associated symptoms, which is crucial for diagnosis. - In a patient presenting with vague, intermittent symptoms like alternating constipation and diarrhea, allowing them to elaborate freely can reveal important clues that might not be captured by more targeted questions. *Does the diarrhea typically precede the constipation, or vice-versa?* - While knowing the sequence of symptoms can be helpful in understanding the **pattern of bowel dysfunction**, it is a very specific question that might overlook other important aspects of the patient's experience. - It prematurely narrows the focus without first obtaining a broad understanding of the patient's overall symptomatic picture. *Is the diarrhea foul-smelling?* - Foul-smelling diarrhea can indicate **malabsorption** or **bacterial overgrowth**, which are important to consider in some gastrointestinal conditions. - However, this is a **specific symptom inquiry** that should follow a more general exploration of the patient's symptoms, as it may not be relevant if other crucial details are missed. *Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life* - Quantifying pain intensity is useful for assessing the **severity of discomfort** and monitoring changes over time. - However, for a patient with intermittent rather than acute, severe pain, understanding the **character, location, and triggers** of the pain is often more diagnostically valuable than just a numerical rating initially. *Are the symptoms worse in the morning or at night?* - Diurnal variation can be relevant in certain conditions, such as inflammatory bowel diseases where nocturnal symptoms might be more concerning, or functional disorders whose symptoms might be stress-related. - This is another **specific question** that should come after gathering a more complete initial picture of the patient's symptoms to ensure no key information is overlooked.

Question 8: A 30-year-old woman, gravida 2, para 1, at 38 weeks' gestation comes to the hospital for regular, painful contractions that have been increasing in frequency. Her pregnancy has been complicated by gestational diabetes treated with insulin. Pelvic examination shows the cervix is 50% effaced and 4 cm dilated; the vertex is at -1 station. Ultrasonography shows no abnormalities. A tocometer and Doppler fetal heart monitor are placed on the patient's abdomen. The fetal heart rate monitoring strip shows a baseline heart rate of 145/min with a variability of ≥ 15/min. Within a 20-minute recording, there are 7 uterine contractions, 4 accelerations, and 3 decelerations that have a nadir occurring within half a minute. The decelerations occur at differing intervals relative to the contractions. Which of the following is the most appropriate next step in the management of this patient?

A. Vibroacoustic stimulation
B. Routine monitoring (Correct Answer)
C. Administer tocolytics
D. Emergent cesarean delivery
E. Placement of fetal scalp electrode

Explanation: ***Routine monitoring*** - The presented FHR tracing exhibits a **normal baseline rate** (145/min), **moderate variability** (≥15/min), and the presence of **accelerations**, indicating a reassuring fetal status. - The described decelerations are **variable decelerations** due to their sudden onset, nadir within 30 seconds, and variable relationship to contractions, which are generally benign unless prolonged, deep, or repetitive. Given the otherwise reassuring status, continued routine monitoring is appropriate. *Vibroacoustic stimulation* - This intervention is used to elicit **fetal accelerations** or movement during non-stress tests (NSTs) when the fetus is quiet or shows a non-reactive pattern. - In this case, the fetus is already showing **accelerations** and moderate variability, so stimulation is not needed to assess fetal well-being. *Administer tocolytics* - **Tocolytics** are used to stop or slow down labor, typically in cases of preterm labor or uterine tachysystole causing fetal distress. - This patient is at **38 weeks' gestation** and in active labor, and there are no signs of fetal distress warranting the cessation of contractions. *Emergent cesarean delivery* - **Emergent cesarean delivery** is indicated for acute fetal distress, such as prolonged decelerations, significant bradycardia, or absent variability in conjunction with other concerning FHR patterns. - The FHR tracing described is largely reassuring with moderate variability and accelerations, and the variable decelerations are not indicative of immediate threat, making emergent delivery unnecessary. *Placement of fetal scalp electrode* - A **fetal scalp electrode** provides a more accurate and continuous measure of the FHR, often used when external monitoring is difficult or when there are concerns about the reliability of the tracing. - While it can be useful in some situations, the current tracing is **interpretable as reassuring**, making invasive monitoring currently unnecessary.

Question 9: A 22-year-old primigravid woman at 41 weeks' gestation is admitted to the hospital in active labor. Pregnancy has been uncomplicated. She has asthma treated with theophylline and inhaled corticosteroids. She has had 2 surgeries in the past to repair multiple lower limb and pelvis fractures that were the result of a car accident. She is otherwise healthy. Her temperature is 37.2°C (99°F) and blood pressure is 108/70 mm Hg. Examination shows the cervix is 100% effaced and 10 cm dilated; the vertex is at -4 station, with the occiput in the anterior position. Uterine activity is measured at 275 MVUs. Maternal pushing occurs during the contractions. Fetal heart tracing is 166/min and reactive with no decelerations. Epidural anesthesia is initiated for pain relief. After 4 hours of pushing, the vertex is found to be at -4 station, with increasing strength and rate of uterine contractions; fetal heart tracing shows late decelerations. Which of the following is the most likely cause of this patient's prolonged labor?

A. Deep transverse arrest
B. Insufficient uterine contraction
C. Epidural anesthesia
D. Cephalopelvic disproportion (Correct Answer)
E. Inefficient maternal pushing

Explanation: ***Cephalopelvic disproportion*** - The history of **multiple lower limb and pelvis fractures** from a car accident suggests a high likelihood of a **contracted or abnormally shaped pelvis**. This can lead to **cephalopelvic disproportion (CPD)**, where the fetal head cannot fit through the maternal pelvis despite adequate uterine contractions (275 MVUs). - The combination of **prolonged labor** (4 hours of pushing with no descent), **vertex at -4 station** even after full dilation, increasing contraction strength, and new **late decelerations** (indicating fetal distress due to impaired oxygenation from prolonged compression) points towards an obstruction. *Deep transverse arrest* - This occurs when the fetal head rotates into the transverse diameter of the pelvis and fails to rotate anteriorly. While it causes **arrest of descent and dilation**, the primary issue is **malposition**, not a fundamental size mismatch. - The occiput is described as in the **anterior position**, which does not immediately suggest deep transverse arrest. *Insufficient uterine contraction* - The uterine activity is measured at **275 MVUs**, which indicates **adequate contraction strength**. Insufficient contractions would typically be below 200 MVUs. - While weak contractions can cause prolonged labor, the current uterine activity suggests this is not the primary problem. *Epidural anesthesia* - Epidural anesthesia can sometimes prolong the second stage of labor by reducing the urge to push or temporarily decreasing the effectiveness of pushing efforts. However, the patient's **strong uterine activity (275 MVUs)** and previous **pelvic fractures** make a mechanical obstruction (CPD) a more specific and likely cause of arrest in this scenario. - Furthermore, the vertex remaining at -4 station for 4 hours despite strong contractions points to a physical barrier rather than just altered pushing dynamics. *Inefficient maternal pushing* - While inefficient maternal pushing can contribute to prolonged labor, the fetus remaining at -4 station for 4 hours with **strong uterine contractions (275 MVUs)** indicates that the issue is likely beyond just inadequate pushing efforts. - The historical detail of **pelvic fractures** points more strongly to an anatomical obstruction rather than simply ineffective maternal exertion.

Question 10: A 28-year-old woman, gravida 2, para 1, at 40 weeks of gestation is admitted to the hospital in active labor. The patient has attended many prenatal appointments and followed her physician's advice about screening for diseases, laboratory testing, diet, and exercise. Her pregnancy has been uncomplicated. She has no history of a serious illness. Her first child was delivered via normal vaginal delivery. Her vital signs are within normal limits. Cervical examination shows 80% effacement, 5 cm dilation and softening without visible fetal parts or prolapsed umbilical cord. A cardiotocograph is shown. Which of the following options is the most appropriate initial step in management?

A. Operative vaginal delivery
B. Repositioning (Correct Answer)
C. Administration of beta-agonists
D. Amnioinfusion
E. Urgent Cesarean delivery

Explanation: ***Repositioning*** - The cardiotocograph likely shows **variable decelerations**, which are often caused by **umbilical cord compression**. - **Maternal repositioning** (e.g., to the left lateral side) can relieve cord compression and improve fetal oxygenation, making it the most appropriate initial, non-invasive step. *Operative vaginal delivery* - This is a more invasive procedure and should not be the initial step for a potentially correctable issue like cord compression, especially with a cervix that is only 5 cm dilated and no visible fetal parts. - It's typically considered for **prolonged second stage of labor** or **fetal distress** with a fully dilated cervix when less invasive measures have failed. *Administration of beta-agonists* - Beta-agonists (like terbutaline) can relax the uterus, potentially reducing uterine contractions and improving uterine blood flow, which might be considered in cases of **uterine hyperstimulation** or persistent decelerations, but generally not as the first line for variable decelerations. - This intervention is more appropriate when there is evidence of excessive uterine activity rather than simply cord compression. *Amnioinfusion* - **Amnioinfusion** involves introducing saline into the uterine cavity and is considered for **recurrent severe variable decelerations** due to **oligohydramnios** or cord compression that doesn't respond to repositioning. - It is a more invasive procedure than repositioning and should not be the initial step. *Urgent Cesarean delivery* - **Cesarean delivery** is reserved for situations where there is persistent fetal distress despite conservative management or when there is an obstetric indication that precludes vaginal delivery. - It is a major surgical procedure and premature for a situation that might be resolved with a simple maternal position change.

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