Prior preterm birth management US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Prior preterm birth management. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Prior preterm birth management US Medical PG Question 1: A 25-year-old G1P0000 presents to her obstetrician’s office for her first prenatal visit. She had a positive pregnancy test 6 weeks ago, and her last period was about two months ago, though at baseline her periods are irregular. Aside from some slight nausea in the mornings, she feels well. Which of the following measurements would provide the most accurate dating of this patient’s pregnancy?
- A. Crown-rump length (Correct Answer)
- B. Femur length
- C. Abdominal circumference
- D. Biparietal diameter
- E. Serum beta-hCG
Prior preterm birth management Explanation: ***Crown-rump length***
- This measurement, typically obtained via **transvaginal ultrasound** in the first trimester (up to 13 weeks 6 days), provides the **most accurate gestational age dating**.
- It's highly precise because fetal growth is very consistent during this early period, minimizing variability.
*Femur length*
- This is a biometric measurement typically used for dating in the **second and third trimesters**.
- Its accuracy for dating is lower than CRL in the first trimester and becomes more variable in later pregnancy due to individual fetal growth differences.
*Abdominal circumference*
- This measurement is primarily used in the **late second and third trimetes**r to assess fetal growth and weight, rather than for accurate dating.
- It is highly susceptible to variations based on fetal nutrition and health, making it a poor choice for initial dating.
*Biparietal diameter*
- This is a reliable measurement for dating from the **late first trimester through the second trimester**, but it is less accurate than CRL in the very early first trimester.
- After the first trimester, its accuracy declines compared to earlier measurements as individual variations in head size become more prominent.
*Serum beta-hCG*
- While a **positive beta-hCG test** confirms pregnancy and quantitative levels can suggest gestational age ranges, it's not a precise dating tool.
- Levels vary widely among individuals and with different types of pregnancies (e.g., multiples), making it unsuitable for accurate dating.
Prior preterm birth management US Medical PG Question 2: A 26-year-old Caucasian G1 presents at 35 weeks gestation with mild vaginal bleeding. She reports no abdominal pain or uterine contractions. She received no prenatal care after 20 weeks gestation because she was traveling. Prior to the current pregnancy, she used oral contraception. At 22 years of age she underwent a cervical polypectomy. She has a 5 pack-year smoking history. The blood pressure is 115/70 mmHg, the heart rate is 88/min, the respiratory rate is 14/min, and the temperature is 36.7℃ (98℉). Abdominal palpation reveals no uterine tenderness or contractions. The fundus is palpable between the umbilicus and the xiphoid process. An ultrasound exam shows placental extension over the internal cervical os. Which of the following factors present in this patient is the risk factor for her condition?
- A. White race
- B. Smoking (Correct Answer)
- C. History of cervical polyp
- D. Intake of oral contraceptives
- E. Nulliparity
Prior preterm birth management Explanation: **Smoking**
- **Smoking** is a well-established risk factor for **placenta previa**, as it impairs placental development and increases the likelihood of abnormal implantation.
- Nicotine and other toxins in cigarette smoke can cause **vasoconstriction** and **ischemia**, leading to placental abnormalities, including a lower implantation site.
*White race*
- While certain ethnicities may have varying rates of obstetrical complications, **white race** is generally not considered an independent or significant risk factor for placenta previa.
- Risk factors for placenta previa are primarily related to uterine health, placental development, and obstetric history.
*History of cervical polyp*
- A history of **cervical polyps** is not a known or significant risk factor for **placenta previa**.
- Cervical polyps are benign growths of the cervix and do not inherently affect the site of placental implantation.
*Intake of oral contraceptives*
- The use of **oral contraceptives** prior to pregnancy is not a risk factor for **placenta previa**.
- Oral contraceptives primarily affect ovarian function and have no direct impact on the subsequent placental implantation site.
*Nulliparity*
- **Nulliparity** (never having given birth) is actually associated with a *lower* risk of placenta previa compared to multiparity.
- The risk of placenta previa generally **increases with the number of previous pregnancies** and deliveries due to changes in the uterine lining.
Prior preterm birth management US Medical PG Question 3: 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
Prior preterm birth management 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.
Prior preterm birth management US Medical PG Question 4: A 24-year-old woman comes to the physician for preconceptional advice. She has been married for 2 years and would like to conceive within the next year. Menses occur at regular 30-day intervals and last 4 days with normal flow. She does not smoke or drink alcohol and follows a balanced diet. She takes no medications. She is 160 cm (5 ft 3 in) tall and weighs 55 kg (121 lb); BMI is 21.5 kg/m2. Physical examination, including pelvic examination, shows no abnormalities. She has adequate knowledge of the fertile days of her menstrual cycle. Which of the following is most appropriate recommendation for this patient at this time?
- A. Begin high-dose vitamin A supplementation
- B. Begin vitamin B12 supplementation
- C. Begin folate supplementation (Correct Answer)
- D. Begin iron supplementation
- E. Gain 2 kg prior to conception
Prior preterm birth management Explanation: ***Begin folate supplementation***
- **Folate supplementation** of 400 mcg daily is recommended for all women of childbearing age to reduce the risk of **neural tube defects** (NTDs) in the fetus. This should ideally begin at least one month before conception and continue through the first trimester.
- The patient is planning to conceive, making preemptive folate supplementation critical for preventing serious birth defects.
*Begin high-dose vitamin A supplementation*
- **High-dose vitamin A** (more than 10,000 IU/day) can be **teratogenic** and is therefore contraindicated during preconception and pregnancy.
- While vitamin A is essential for fetal development, excessive amounts can lead to fetal abnormalities.
*Begin vitamin B12 supplementation*
- **Vitamin B12 supplementation** is generally not necessary unless the patient has a diagnosed deficiency, such as in strict vegetarians or those with malabsorption issues.
- There is no indication of B12 deficiency in this patient's history or presentation.
*Begin iron supplementation*
- Routine **iron supplementation** is not recommended preconception unless the patient is diagnosed with **iron deficiency anemia**.
- Excessive iron intake without a clear indication can cause gastrointestinal upset and has not been shown to improve pregnancy outcomes in non-anemic women.
*Gain 2 kg prior to conception*
- The patient has a **healthy BMI of 21.5 kg/m2**, which is within the normal range (18.5-24.9 kg/m2).
- There is no medical indication for her to gain weight prior to conception.
Prior preterm birth management US Medical PG Question 5: A 24-year-old primigravida presents at 36 weeks gestation with vaginal bleeding, mild abdominal pain, and uterine contractions that appeared after bumping into a handrail. The vital signs are as follows: blood pressure 130/80 mm Hg, heart rate 79/min, respiratory rate 12/min, and temperature 36.5℃ (97.7℉). The fetal heart rate was 145/min. Uterine fundus is at the level of the xiphoid process. Slight uterine tenderness and contractions are noted on palpation. The perineum is bloody. The gynecologic examination shows no vaginal or cervical lesions. The cervix is long and closed. Streaks of bright red blood are passing through the cervix. A transabdominal ultrasound shows the placenta to be attached to the lateral uterine wall with a marginal retroplacental hematoma (an approximate volume of 150 ml). The maternal hematocrit is 36%. What is the next best step in the management of this patient?
- A. Manage as an outpatient with modified rest
- B. Induction of vaginal labor
- C. Corticosteroid administration and schedule a cesarean section after
- D. Admit for maternal and fetal monitoring and observation (Correct Answer)
- E. Urgent cesarean delivery
Prior preterm birth management Explanation: ***Admit for maternal and fetal monitoring and observation***
- This patient presents with signs of a **mild placental abruption** (vaginal bleeding, contractions, mild abdominal pain, retroplacental hematoma) after trauma, but her **vital signs are stable**, fetal heart rate is reassuring, and the abruption volume is relatively small.
- Expectant management with **close monitoring** for signs of worsening abruption (increasing pain, vital sign changes, fetal distress) is appropriate for a patient at 36 weeks with a non-catastrophic abruption.
*Manage as an outpatient with modified rest*
- Given the presence of **vaginal bleeding, contractions**, and a **retroplacental hematoma** suggesting placental abruption, outpatient management is not safe.
- There is a risk of the abruption progressing, requiring immediate medical intervention, making **hospital admission for close monitoring** essential.
*Induction of vaginal labor*
- While vaginal delivery might be considered for a stable abruption in some cases, **active induction is not the immediate next step** given the patient's stable status and the need for continuous monitoring.
- The **cervix is long and closed**, indicating that she is not in active labor and immediate induction might not be successful or necessary.
*Corticosteroid administration and schedule a cesarean section after*
- **Corticosteroids** are typically administered for fetal lung maturity when delivery is anticipated before **34 weeks of gestation**; at 36 weeks, this is generally not indicated.
- A scheduled cesarean section is premature as the patient is **stable**, and the immediate goal is to monitor for progression or resolution of the abruption, not immediate delivery.
*Urgent cesarean delivery*
- There are no signs of **maternal or fetal distress** (stable vitals, reassuring fetal heart rate) that would necessitate an urgent cesarean delivery.
- An urgent cesarean is reserved for cases of **severe abruption** with significant bleeding, hemodynamic instability, or fetal compromise.
Prior preterm birth management US Medical PG Question 6: A 24-year-old woman, gravida 1, at 35 weeks gestation is admitted to the hospital with regular contractions and pelvic pressure for the last 5 hours. Her pregnancy has been uncomplicated and she has attended many prenatal appointments and followed the physician's advice about screening for diseases, laboratory testing, diet, and exercise. She has had no history of fluid leakage or bleeding. At the hospital, her temperature is 37.2°C (99.0°F), blood pressure is 108/60 mm Hg, pulse is 88/min, and respirations are 16/min. Cervical examination shows 60% effacement and 5 cm dilation with intact membranes. Cardiotocography shows a contraction amplitude of 220 MVU in 10 minutes. Which of the following is the most appropriate pharmacotherapy at this time?
- A. Magnesium sulfate
- B. No pharmacotherapy at this time (Correct Answer)
- C. Dexamethasone
- D. Oxytocin
- E. Terbutaline
Prior preterm birth management Explanation: ***No pharmacotherapy at this time***
- The patient is at **35 weeks gestation** and in **active labor** (5 cm dilated, 60% effacement, regular contractions with adequate Montevideo units). At this gestational age, labor is typically allowed to progress without intervention unless there are complications.
- Pharmacotherapy to stop labor (tocolysis) or induce fetal lung maturity (corticosteroids) is generally not indicated at or beyond 34 weeks gestation in uncomplicated cases.
*Magnesium sulfate*
- This is primarily used for **fetal neuroprotection** in anticipated preterm birth before 32 weeks gestation, or as a **tocolytic** to inhibit contractions, neither of which is indicated here.
- The patient is 35 weeks, beyond the typical window for neuroprotection, and stopping labor is not appropriate given her advanced dilation and gestational age.
*Dexamethasone*
- **Corticosteroids** like dexamethasone are administered to accelerate **fetal lung maturity** in cases of anticipated preterm birth, typically between 24 and 34 weeks gestation.
- At 35 weeks, the benefits of corticosteroids for lung maturity are minimal and generally not recommended.
*Oxytocin*
- **Oxytocin** is used to **induce or augment labor** if contractions are inadequate or to prevent **postpartum hemorrhage**.
- This patient is already in active, effective labor with adequate contractions (220 MVU in 10 minutes), so oxytocin for augmentation is not needed.
*Terbutaline*
- **Terbutaline** is a **beta-agonist tocolytic** used to relax the uterus and stop preterm labor.
- Given the patient's gestational age of 35 weeks and the progression of her labor (5 cm dilated), stopping contractions is not the appropriate management.
Prior preterm birth management US Medical PG Question 7: A 27-year-old G0P0 female presents to her OB/GYN for a preconception visit to seek advice before becoming pregnant. A detailed history reveals no prior medical or surgical history, and she appears to be in good health currently. Her vaccination history is up-to-date. She denies tobacco or recreational drug use and admits to drinking 2 glasses of wine per week. She states that she is looking to start trying to become pregnant within the next month, hopefully by the end of January. Which of the following is NOT recommended as a next step for this patient's preconception care?
- A. Begin 400 mcg folic acid supplementation
- B. Administer measles, mumps, rubella (MMR) vaccination (Correct Answer)
- C. Obtain rubella titer
- D. Obtain varicella zoster titer
- E. Recommend inactivated influenza vaccination
Prior preterm birth management Explanation: ***Administer measles, mumps, rubella (MMR) vaccination***
- Live-attenuated vaccines like **MMR** are contraindicated during pregnancy and should ideally be given **at least one month prior to conception**.
- If her vaccination history is up-to-date and she plans to conceive within the month, administering MMR is not recommended at this time without confirming immunity first.
*Begin 400 mcg folic acid supplementation*
- **Folic acid supplementation** at 400 mcg daily is recommended for all women of childbearing age to prevent **neural tube defects**, ideally starting at least one month before conception and continuing through the first trimester.
- This is a crucial step in preconception care to ensure adequate levels when the neural tube is forming.
*Obtain rubella titer*
- Checking a **rubella titer** is standard preconception care to determine immunity, as rubella infection during pregnancy can lead to serious congenital anomalies.
- If she is not immune, the MMR vaccine can be offered, but with a **one-month contraception period** before attempting conception.
*Obtain varicella zoster titer*
- Determining **varicella immunity** is important because congenital varicella syndrome can occur if a non-immune mother contracts chickenpox during pregnancy.
- If she is not immune, the **varicella vaccine** can be administered, followed by a **one-month waiting period** before conception.
*Recommend inactivated influenza vaccination*
- **Inactivated influenza vaccination** is safe and recommended during any stage of pregnancy, including the preconception period, to protect both the mother and newborn from severe influenza outcomes.
- It can be given even if she plans to conceive within the month, as it is not a live vaccine.
Prior preterm birth management US Medical PG Question 8: A 26-year-old gravida 1 at 36 weeks gestation is brought to the emergency department by her husband complaining of contractions lasting up to 2 minutes. The contractions are mostly in the front of her abdomen and do not radiate. The frequency and intensity of contractions have not changed since the onset. The patient worries that she is in labor. The blood pressure is 125/80 mm Hg, the heart rate is 96/min, the respiratory rate is 15/min, and the temperature 36.8°C (98.2℉). The physical examination is unremarkable. The estimated fetal weight is 3200 g (6.6 lb). The fetal heart rate is 146/min. The cervix is not dilated. The vertex is at the -4 station. Which of the following would be proper short-term management of this woman?
- A. Reassurance, hydration, and ambulation (Correct Answer)
- B. Admit to the Obstetrics Department for observation
- C. Manage with terbutaline
- D. Admit to the Obstetrics Department in preparation for labor induction
- E. Perform an ultrasound examination
Prior preterm birth management Explanation: ***Reassurance, hydration, and ambulation***
- This patient is experiencing **Braxton-Hicks contractions**, which are irregular, do not cause cervical change, and often resolve with hydration and rest or light activity.
- Given her stable vital signs, normal fetal heart rate, and undilated cervix, these interventions are appropriate to differentiate from true labor and provide comfort.
*Admit to the Obstetrics Department for observation*
- Admission for observation is unnecessary as there are no signs of **true labor** (cervical dilation or effacement) or fetal distress.
- The contractions are described as not changing in frequency or intensity and are localized to the anterior abdomen, consistent with **false labor**.
*Manage with terbutaline*
- **Terbutaline** is a tocolytic used to stop or prevent premature labor, but this patient is at 36 weeks gestation, which is near term, and not in true labor.
- Using a tocolytic for **Braxton-Hicks contractions** is not indicated and can have adverse effects.
*Admit to the Obstetrics Department in preparation for labor induction*
- There is no indication for **labor induction** as the patient is not in active labor and has not reached her due date.
- Labor induction is reserved for medical or obstetric indications, which are not present here.
*Perform an ultrasound examination*
- An ultrasound has already provided an estimated fetal weight and the fetal heart rate is normal, suggesting no immediate need for further **ultrasound evaluation**.
- There are no clinical signs to suggest fetal distress or other complications that would warrant an **urgent ultrasound**.
Prior preterm birth management US Medical PG Question 9: A 9-month-old boy is brought to the physician because of abnormal crawling and inability to sit without support. A 2nd-trimester urinary tract infection that required antibiotic use and a spontaneous preterm birth via vaginal delivery at 36 weeks’ gestation both complicated the mother’s pregnancy. Physical examination shows a scissoring posture of the legs when the child is suspended by the axillae. Examination of the lower extremities shows brisk tendon reflexes, ankle clonus, and upward plantar reflexes bilaterally. When encouraged by his mother, the infant crawls forward by using normal reciprocal movements of his arms, while his legs drag behind. A brain MRI shows scarring and atrophy in the white matter around the ventricles with ventricular enlargement. Which of the following is most likely associated with the findings in this child?
- A. Antenatal injury
- B. Genetic defect
- C. Postnatal head trauma
- D. Intrapartum asphyxia
- E. Preterm birth (Correct Answer)
Prior preterm birth management Explanation: ***Preterm birth***
- The combination of **abnormal crawling**, **inability to sit without support**, **scissoring posture**, **spasticity**, and **periventricular white matter scarring** (periventricular leukomalacia, PVL) are classic signs of **spastic cerebral palsy**.
- **Preterm birth** is the most significant risk factor for **PVL** and the subsequent development of spastic cerebral palsy, particularly spastic diplegia.
- The **periventricular white matter** in preterm infants (especially <34 weeks, but also late preterm at 34-37 weeks) is highly vulnerable to ischemic injury due to immature vascular development and susceptibility to hypoxic-ischemic insults during the perinatal period.
- This infant was born at **36 weeks (late preterm)**, which is a known risk factor for PVL and cerebral palsy.
*Antenatal injury*
- While brain injury can occur in the antenatal period, the specific finding of **periventricular leukomalacia** is most characteristically associated with **prematurity** and perinatal/early postnatal events rather than purely antenatal injury.
- The term "antenatal injury" is too vague and doesn't capture the specific pathophysiology of PVL, which occurs around the time of birth in vulnerable preterm infants.
*Genetic defect*
- While some forms of cerebral palsy can have a genetic component, the clinical picture here, especially the MRI findings of **periventricular leukomalacia**, strongly points to an acquired brain injury rather than a primary genetic defect.
- Genetic conditions typically present with more widespread or specific neurodevelopmental abnormalities, often without the focal periventricular white matter scarring seen in PVL.
*Postnatal head trauma*
- **Postnatal head trauma** would typically present with a history of injury and more acute neurological deficits or focal lesions on imaging (e.g., subdural hematoma, contusions), rather than the characteristic **periventricular white matter scarring** observed here.
- The presentation is consistent with a developmental disorder from perinatal brain injury, not an acute traumatic event from infancy.
*Intrapartum asphyxia*
- **Intrapartum asphyxia** (hypoxic-ischemic encephalopathy) in term infants characteristically leads to damage in the **deep grey matter** (e.g., basal ganglia, thalamus) and cortex, not primarily **periventricular white matter** as seen here.
- The MRI findings of **periventricular leukomalacia** are pathognomonic for **prematurity-related injury**, not term asphyxia.
Prior preterm birth management US Medical PG Question 10: A 21-year-old G2P1 woman presents to the clinic and is curious about contraception immediately after her baby is born. She is anxious about taking care of one child and does not believe that she can handle the responsibility of caring for another. She has no other questions or complaints today. Her past medical history consists of generalized anxiety disorder, antithrombin deficiency, and chronic deep vein thrombosis. She has been hospitalized for acute on chronic deep vein thrombosis. Her only medication is buspirone. Her blood pressure is 119/78 mm Hg and the heart rate is 78/min. BMI of the patient is 32 kg/m2. On physical examination, her fundal height is 21 cm from pubic symphysis. No ovarian masses are palpated during the bimanual examination. Ultrasound exhibits a monoamniotic, monochorionic fetus. Which of the following forms of contraception would be the most detrimental given her risk factors?
- A. Copper IUD
- B. Transdermal contraceptive patch (Correct Answer)
- C. Norethindrone
- D. Depot medroxyprogesterone acetate
- E. Levonorgestrel IUD
Prior preterm birth management Explanation: ***Transdermal contraceptive patch***
- The transdermal contraceptive patch contains **estrogen**, which significantly increases the risk of **thromboembolism**. With a history of **antithrombin deficiency** and **recurrent deep vein thrombosis (DVT)**, estrogen-containing contraception is absolutely contraindicated due to the high risk of fatal clotting events.
- The patient's underlying **antithrombin deficiency** makes her particularly susceptible to prothrombotic effects, and combined hormonal contraceptives like the patch further exacerbate this risk.
*Copper IUD*
- The **copper IUD** is a **non-hormonal** contraceptive option, making it safe for individuals with a history of thromboembolism.
- Its mechanism of action involves creating a local inflammatory reaction in the uterus to prevent fertilization and implantation, thus posing no systemic clotting risk.
*Norethindrone*
- **Norethindrone** is a **progestin-only pill**, which does not contain estrogen and is generally considered safe for individuals with a history of thromboembolism.
- Progestin-only contraceptives avoid the estrogen-induced increase in clotting factors, making them a suitable option in this high-risk patient.
*Depot medroxyprogesterone acetate*
- **Depot medroxyprogesterone acetate (DMPA)** is an injectable **progestin-only contraceptive** that is safe for patients with a history of **thromboembolism**.
- It works by suppressing ovulation and thickening cervical mucus and does not carry the same clotting risks as estrogen-containing methods.
*Levonorgestrel IUD*
- The **levonorgestrel IUD** is a **progestin-only** contraceptive that releases hormones locally within the uterus, with minimal systemic absorption.
- It is a safe and highly effective option for patients with a history of thromboembolism due to the absence of estrogen and limited systemic hormonal effects.
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