[OB2] LE 1 Flashcards

Question

Q: A pregnant patient at 38 weeks gestation desires vaginal delivery. Which factor increases the likelihood of a successful vaginal delivery? A. Previous preterm labor B. Short interpregnancy interval C. Adequate pelvic dimensions D. Fetal macrosomia

Answer 1

C. Adequate pelvic dimensions Rationale: Adequate pelvic dimensions improve the likelihood of a successful vaginal delivery by ensuring sufficient space for the fetus to descend and pass through the birth canal.

Answer 2

D. Uterine rupture Rationale: Uterine rupture is a life-threatening complication, especially in VBAC candidates. Sudden abdominal pain, fetal distress, and loss of station are hallmark signs, particularly after membrane rupture during labor.

Answer 3

A. Fetal urinary tract obstruction Rationale: In early to mid-pregnancy, amniotic fluid is primarily produced by fetal kidneys. A urinary tract obstruction, such as posterior urethral valves, can severely reduce fluid production, leading to oligohydramnios and growth restriction.

Answer 4

A. Macrosomic Rationale: Obesity (BMI ≥30) is associated with fetal macrosomia due to increased insulin resistance and maternal glucose levels, leading to enhanced fetal growth. While prematurity is possible, macrosomia is more consistently linked.

Answer 5

C. 2 weeks before the gestational age of prior neonatal death Rationale: High-risk patients, especially those with previous neonatal demise, should start antepartum surveillance 2 weeks earlier than the gestational age at which the complication occurred to improve fetal outcomes.

Answer 6

B. Preeclampsia may ensue sooner or later Rationale: Persistent notching in the uterine artery waveform, especially in the third trimester, suggests impaired placental perfusion, which is a strong predictor for preeclampsia or IUGR.

Answer 7

C. Did you undergo infertility workup with an OB-GYN? Rationale: Multifetal pregnancies in older women, especially primigravidas over 35, often result from assisted reproductive technologies (ART), so this history is highly relevant.

Answer 8

C. Biparietal diameter Rationale: In the second trimester, Biparietal Diameter (BPD) on ultrasound is the most accurate tool for dating pregnancy, especially when the last menstrual period is unknown.

Answer 9

B. March 2, 2024 Rationale: Quickening in multiparas typically occurs around 16 weeks, so counting back 16 weeks from June 15 gives an LMP around March 2, 2024. This is a helpful method for dating pregnancy when LMP is uncertain.

Answer 10

B. Incorrect gestational age assessment Rationale: At 4–5 weeks of amenorrhea, it's often too early to detect a fetal heartbeat. The most likely cause of a non-visualized heartbeat this early is incorrect dating, not necessarily fetal demise.

Answer 11

B. Sudden cord accident or undiagnosed anomaly Rationale: A previously reassuring BPS (8/8) followed by sudden fetal demise suggests an acute catastrophic event, such as cord accident, placental abruption, or undetected congenital anomaly. These can occur even in low-risk pregnancies.

Answer 12

B. OGTT Rationale: The patient has multiple risk factors for gestational diabetes (prior GDM/macrosomia, age >30, obesity likely). OGTT is the most appropriate early screening test for glucose intolerance in high-risk pregnancies.

Answer 13

C. Close antenatal surveillance with ultrasound Rationale: Placenta previa diagnosed at 20 weeks often resolves as the uterus grows. Management is expectant, involving serial ultrasounds to monitor placental position unless bleeding occurs or persists into the third trimester.

Answer 14

C. Tocolytic therapy and corticosteroids Rationale: This patient is in preterm labor. Management includes tocolytics to delay labor and corticosteroids to promote fetal lung maturity, especially between 24–34 weeks gestation.

Answer 15

C. Immediate cesarean delivery Rationale: This is HELLP syndrome, a severe form of preeclampsia. The definitive treatment is delivery, especially after viability is reached. Delay increases maternal and fetal risk.

Answer 16

C. Detailed fetal ultrasound Rationale: In high-risk pregnancies with advanced maternal age and comorbidities, an early detailed fetal anatomic scan is essential to assess for anomalies and growth issues.

Answer 17

D. Fetal surveillance and biophysical profile Rationale: Poorly controlled gestational diabetes increases risk of macrosomia, stillbirth, and placental insufficiency. Fetal BPP helps monitor well-being and guide timing of delivery.

Answer 18

B. Immediate cesarean delivery Rationale: At 36 weeks with active bleeding and placenta previa, cesarean delivery is indicated to prevent maternal hemorrhage and fetal compromise. Advanced maternal age increases risks, warranting timely intervention.

Answer 19

C. Moderate-intensity exercise Rationale: In obese pregnant patients, moderate-intensity exercise (e.g., brisk walking) is safe and helps reduce risk of GDM, hypertension, and macrosomia. Dieting or weight loss meds are not advised during pregnancy.

Answer 20

C. Early lactation support and education Rationale: Obese mothers are at higher risk of delayed lactogenesis and early cessation of breastfeeding. Early support and education greatly improve breastfeeding initiation and continuation.

Answer 21

C. Close cardiac monitoring throughout pregnancy Rationale: Most asymptomatic MVP cases are benign in pregnancy, but due to potential for arrhythmias or regurgitation, regular monitoring is recommended. No routine antibiotic prophylaxis is needed unless complicated.

Answer 22

C. Risk for uterine rupture during labor Rationale: The most crucial counseling point when discussing a repeat cesarean (especially if the patient considered TOLAC) is the risk of uterine rupture. This risk shapes decisions on trial of labor vs. planned C-section.

Answer 23

C. Close fetal monitoring with biophysical profile Rationale: An AFI ≤5 cm is considered oligohydramnios. If the patient is stable and preterm, management includes close surveillance with serial BPPs to monitor fetal well-being and delay delivery when possible.

Answer 24

C. Subject patient to contraction stress test Rationale: In post-term pregnancies with decreased fetal movement, a contraction stress test is appropriate to assess placental function and fetal tolerance to stress, helping guide whether immediate delivery is necessary.

Answer 25

B. 7 weeks and 6 days Rationale: From June 20 to August 15 is 7 weeks and 6 days. Gestational age is calculated from the first day of the LMP, not from the date of conception.

Answer 26

C. Repeat BPP in 24 hours Rationale: A BPP of 4/10 is equivocal. In preterm patients, if non-reassuring but not critical, the preferred management is to repeat the test in 24 hours to monitor trends before deciding on early delivery.

Answer 27

D. Continue close antenatal surveillance Rationale: A BPP score of 8/10 is considered reassuring, especially if fetal heart tracing is reactive. The loss of 1 parameter does not immediately necessitate delivery. Close follow-up is sufficient.

Answer 28

D. Perform contraction stress test (CST) Rationale: A non-reactive NST is inconclusive. At term, next step is to perform CST to assess placental reserve and how the fetus tolerates contractions. This helps determine need for delivery or expectant management.

Answer 29

B. Induce labor Rationale: At 41 weeks with GDM, pregnancy is post-term and high risk. A non-reactive NST suggests possible compromise, but negative CST indicates fetal tolerance. Induction is appropriate to avoid complications of prolonged pregnancy.

Answer 30

C. Repeat NST in one week Rationale: In chronic hypertensive pregnancies, antepartum fetal surveillance typically starts in the third trimester. If an NST is reactive, there’s no immediate concern. Weekly testing is appropriate at this stage.

Answer 31

C. Schedule cesarean delivery Rationale: In a patient with preeclampsia, non-reactive NST plus variable decelerations indicates fetal compromise. At 34 weeks, the risk of intrauterine demise outweighs prematurity. Immediate delivery is indicated.

Answer 32

C. Further assessment based on history and symptoms Rationale: In patients with PCOS and irregular cycles, gestational dating and risk factors must be evaluated carefully. Individualized assessment is key before proceeding to further interventions.

Answer 33

C. Request for Biophysical Profile (BPP) Rationale: Decreased fetal movement at term can indicate fetal compromise. A BPP is a comprehensive test to evaluate fetal well-being and determine the need for immediate intervention or delivery.

Answer 34

C. Obstetric history Rationale: A prior obstetric history of pregnancy loss or preterm birth is the strongest risk factor for future preterm labor, even in the absence of lifestyle or medical risk factors.

Answer 35

C. Admit and augment labor Rationale: A patient in early active labor (≥3 cm) with regular contractions should be admitted. If labor is slow to progress, augmentation with oxytocin may be initiated depending on clinical assessment.

Answer 36

C. Ultrasound for placental status Rationale: In patients with multiple prior cesareans, there’s an increased risk of placenta previa or accreta. An ultrasound to evaluate placental location is critical before considering trial of labor or planning delivery.

Answer 37

C. Continue to monitor fetal heart rate Rationale: Early decelerations with moderate variability and normal baseline are benign and usually due to head compression. No intervention is required; continued monitoring is appropriate.

Answer 38

B. Consider a biophysical profile Rationale: A reactive NST with isolated variable deceleration warrants further assessment of fetal well-being, especially with OED. A BPP offers a more comprehensive evaluation.

Answer 39

C. Request a biophysical profile Rationale: A non-reactive NST requires confirmation of fetal status. A BPP provides a broader picture, assessing both acute and chronic markers of fetal well-being before deciding on delivery.

Answer 40

C. Repeat NST in one week Rationale: In well-controlled gestational diabetes with reassuring fetal testing, management includes weekly NSTs starting around 32–36 weeks. There is no indication for early delivery or more frequent testing if stable.

Answer 41

C. Perform backup tests like contraction stress test (CST) Rationale: A BPP score of 8/10 with low AFI (oligohydramnios) suggests chronic uteroplacental insufficiency. A CST or further fetal surveillance helps determine if the fetus can tolerate labor or if immediate delivery is needed.

Answer 42

C. Expectant management Rationale: In cases of mild oligohydramnios and a stable pregnancy, especially at preterm gestation, the best approach is close monitoring with serial ultrasounds and fetal testing.

Answer 43

C. Give corticosteroids to accelerate fetal lung maturity Rationale: At 32 weeks with signs of preterm labor, antenatal corticosteroids should be given to enhance fetal lung development, reducing neonatal morbidity if preterm birth occurs.

Answer 44

C. It always occurs after 37 weeks Rationale: Preterm labor is defined as labor that occurs before 37 weeks gestation. Any reference to it occurring after 37 weeks is incorrect and refers to term or post-term labor.

Answer 45

D. Obesity Rationale: While smoking, low BMI, and substance abuse increase risk for spontaneous preterm labor, obesity is more commonly associated with post-term pregnancy, macrosomia, and preeclampsia, not spontaneous preterm labor.

Answer 46

D. Respiratory droplets Rationale: The main infectious routes that lead to spontaneous preterm labor are ascending infections (from the vagina), transplacental, and retrograde from the peritoneum. Respiratory droplets do not cause intrauterine infection directly and are not implicated in spontaneous preterm labor.

Answer 47

D. Fever Rationale: Maternal fever is the most reliable and consistent clinical sign of chorioamnionitis, particularly when associated with maternal or fetal tachycardia, uterine tenderness, or foul-smelling amniotic fluid.

Answer 48

C. 24 hours Rationale: For antenatal corticosteroids (e.g., betamethasone) to significantly reduce the risk of RDS, delivery should ideally be delayed by at least 24 hours to allow time for fetal lung maturation.

Answer 49

C. Expedite delivery Rationale: Once the fetus reaches 34 weeks, the risks of infection (e.g., chorioamnionitis) outweigh the risks of prematurity. The recommendation is to expedite delivery, particularly if there are no contraindications.

Answer 50

D. You will not identify Kerning pattern Rationale: The statement “You will not identify Kerning pattern” is irrelevant to fetal fibronectin. The fFN assay is used to predict preterm birth risk and has high negative predictive value. Kerning’s sign is associated with meningitis, not OB.

Answer 51

D. Cesarean section Rationale: C-section is not a preventive measure for preterm labor. Prevention strategies include cerclage (in cervical insufficiency), progestins (in high-risk patients), and addressing modifiable health issues like infections.

Answer 52

D. Contraction Stress Test Rationale: At term, a Contraction Stress Test (CST) is a reliable way to assess placental reserve and fetal tolerance to labor. It's especially useful when the non-stress test is non-reactive, and the fetus is mature enough for delivery if needed.

Answer 53

B. Abruptio placenta Rationale: Polyhydramnios causes uterine overdistension, which increases the risk for placental abruption, preterm labor, and malpresentation. Sudden uterine decompression may trigger placental separation.

Answer 54

B. Subject the patient to contraction stress test Rationale: At 41 weeks, placental aging increases the risk of fetal compromise. With decreased fetal movement, a CST is appropriate to evaluate fetal tolerance to stress and decide if delivery is needed.

Answer 55

B. Cardio-renal disease Rationale: Obesity in pregnancy (BMI ≥30) is associated with cardiovascular and renal complications, as well as gestational diabetes, preeclampsia, and macrosomia. The risk increases with higher BMI levels.

Answer 56

C. Multiparous Rationale: Placenta previa is more common in multiparous women, especially those with prior uterine surgeries or cesarean deliveries. The risk increases with parity and endometrial damage.

Answer 57

C. Immature delivery Rationale: Cervical insufficiency often leads to painless cervical dilation in the second trimester, resulting in immature or mid-trimester delivery — a hallmark presentation of this condition.

Answer 58

D. Fetal tone Rationale: Among BPP parameters, fetal tone is the most resistant to hypoxia and is the last to be affected. It reflects chronic hypoxia only after other signs have already deteriorated.

Answer 59

C. Monitor closely for abnormal fetal heart tracing Rationale: Thick meconium may indicate fetal stress, but intervention depends on fetal heart tracing. If reassuring, observe. If non-reassuring, expedited delivery may be warranted.

Answer 60

B. 2 or more accelerations in 20 minutes, each lasting ≥15 sec and rising ≥15 bpm Rationale: A reactive NST indicates reassuring fetal well-being, with 2 or more accelerations in 20 minutes. Less than 2 is considered non-reactive.

Answer 61

C. Perform a contraction stress test Rationale: A BPP of 8/10 with low AFI (oligohydramnios) suggests potential placental insufficiency. A contraction stress test (CST) is used as a backup test to evaluate fetal tolerance to stress and determine if delivery is needed.

Answer 62

C. Umbilical artery Rationale: The umbilical artery Doppler is the standard for evaluating placental resistance and blood flow. Abnormal flow patterns (e.g., absent or reversed end-diastolic flow) indicate uteroplacental insufficiency.

Answer 63

C. Premature rupture of membranes (PROM) Rationale: PROM leads to loss of amniotic fluid cushioning, increasing the likelihood of variable descent of the fetal head and umbilical cord compression, which may cause variable decelerations.

Answer 64

B. 2 gross body movements Rationale: A score of 2 for gross body movement requires at least 3 distinct movements within 30 minutes. Only 2 movements does not meet the criteria and scores 0.

Answer 65

C. Late deceleration Rationale: Late decelerations are a sign of uteroplacental insufficiency and fetal hypoxia, especially when recurrent. They warrant immediate evaluation, often requiring delivery if persistent.

Answer 66

B. Count the number of minutes it takes for 10 fetal movements to occur Rationale: The “Count to 10” method involves recording how long it takes for a pregnant patient to perceive 10 fetal movements. Typically, 10 movements within 2 hours is considered reassuring.

Answer 67

B. Very limited use in case of fetal tachycardia Rationale: Fetal scalp stimulation is used to assess fetal well-being during labor. However, its use is limited when fetal tachycardia is present, as it may further increase heart rate and is not reliable in that setting.

Answer 68

D. Tachysystole Rationale: Tachysystole refers to more than 5 uterine contractions in 10 minutes, averaged over 30 minutes. If contractions are too frequent, even at 5-minute intervals or less, they may compromise fetal oxygenation.

Answer 69

D. Biophysical profile (BPP) Rationale: The BPP evaluates fetal tone, movement, breathing, and amniotic fluid, providing a comprehensive functional assessment of the fetus — essentially mimicking a fetal physical exam.

Answer 70

C. Expectant management and complete bed rest Rationale: For IUGR at 32 weeks with abnormal Doppler findings but no signs of fetal distress, expectant management with close monitoring, bed rest, and possibly corticosteroids is appropriate to prolong pregnancy safely.

Answer 71

B. Fetal heart rate is auscultated for a whole minute Rationale: For auscultation to be reliable and comparable to continuous monitoring, the fetal heart rate must be counted for a full minute, especially after a contraction, to detect baseline and variability changes.

Answer 72

D. Non-Stress Test (NST) Rationale: A reactive NST reflects normal autonomic regulation, indirectly suggesting adequate oxygenation and neurologic activity — including fetal breathing movements. It's a key tool for assessing fetal well-being.

Answer 73

B. Meconium aspiration Rationale: Post-term pregnancies are at higher risk for meconium-stained amniotic fluid, which may lead to meconium aspiration syndrome (MAS) — a potentially serious neonatal respiratory condition.

Answer 74

B. Admit patient for steroid administration Rationale: Early diastolic notching in the uterine artery Doppler, especially in the second or early third trimester, suggests impaired uteroplacental perfusion. Steroids are indicated to promote fetal lung maturity in anticipation of preterm delivery.

Answer 75

C. Middle cerebral artery Rationale: In fetal hypoxia, the fetus compensates by redistributing blood flow to vital organs like the brain. This "brain-sparing" effect is best observed by a decrease in pulsatility index in the middle cerebral artery (MCA) on Doppler.

Answer 76

B. Baseline 110–160 bpm, moderate variability, no late/variable decels

Answer 77

C. Fetal breathing Rationale: Fetal breathing is one of the first BPP parameters to be affected by hypoxia or infection, making it highly sensitive for early fetal compromise.

Answer 78

D. Amniotic fluid volume Rationale: Amniotic fluid volume reflects chronic placental function, whereas other BPP parameters (tone, movement, breathing, NST) are acute markers of fetal well-being.

Answer 79

C. Contraction Stress Test (CST) Rationale: The CST assesses fetal response to uterine contractions, simulating the stress of labor. It evaluates uteroplacental sufficiency, making it highly relevant to predicting intrapartum tolerance.

Answer 80

C. 24–38 weeks Rationale: The congenital anomaly scan is best performed in the mid to late second trimester, commonly between 18–24 weeks, but can still be useful up to 38 weeks in some high-risk pregnancies or late referrals.

Answer 81

D. Indirect electronic fetal monitoring (CTG) Rationale: CTG (Cardiotocography) uses external sensors and does not require cervical dilation or ruptured membranes, unlike internal methods such as fetal scalp electrodes or pH sampling.

Answer 82

C. When pH is <7.2, immediate abdominal delivery is warranted Rationale: A fetal scalp pH <7.2 suggests fetal acidemia, which is an indication for urgent delivery, often via cesarean section, to prevent hypoxic injury.

Answer 83

C. Three Rationale: In missed abortion, three infusions of oxytocin have been shown to be effective in stimulating uterine contractions to complete the evacuation process.

Answer 84

C. Adequate uterine contraction Rationale: Based on progressive cervical dilation with 70% effacement and a supportive tracing, the patient is showing signs of effective labor contractions leading to cervical changes.

Answer 85

C. 140–150 bpm Rationale: A normal baseline FHR ranges from 110–160 bpm. A rate of 140–150 bpm is considered normal and reassuring, indicating a well-oxygenated fetus.

Answer 86

B. Presence of accelerations Rationale: Accelerations are a strong indicator of fetal well-being and intact autonomic function. Their presence implies adequate oxygenation and no significant acidosis, making them the most reassuring feature.

Answer 87

B. Discontinue uterine stimulants Rationale: In fetal distress, reducing uterine activity is a key resuscitative step. Stopping oxytocin and giving maternal oxygen, IV fluids, or changing position helps improve fetal oxygenation.

Answer 88

C. Provide better view of ultrasound resolution Rationale: Optimizing maternal position or using ultrasound gel can enhance resolution and improve visualization of fetal anatomy, especially when views are suboptimal due to maternal habitus or fetal position.

Answer 89

C. Macrosomic deliveries Rationale: Taller women often have larger pelvic capacity, which correlates with larger fetal growth potential. This makes macrosomia a more common concern, increasing the risk of labor complications.

Answer 90

C. Previous post-term pregnancy is a risk factor Rationale: A prior history of post-term pregnancy significantly increases the risk of recurrence due to possible genetic or hormonal predisposition.

Answer 91

C. 36 weeks Rationale: Amniotic fluid volume increases throughout pregnancy and reaches its peak at around 36 weeks of gestation, averaging about 800 to 1000 mL. After this peak, the volume gradually decreases as term approaches due to decreased fetal urine production and increased fetal swallowing. • At 28 weeks, fluid volume is still increasing. • By 32 weeks, it’s nearing its peak but not yet at the maximum. • 36 weeks is when the peak typically occurs. • By 38 weeks, the volume usually begins to decline.

Answer 92

B. Amniotic fluid volume is 2–7.9 cm Rationale: In modified BPP, a score of 8/8 is acceptable only if the amniotic fluid index (AFI) falls within 2–7.9 cm, as this reflects chronic placental sufficiency.

Answer 93

B. Contraction Rationale: The Bishop Score includes dilation, effacement, station, consistency, and position of the cervix. Contractions are not part of the scoring but may influence labor decisions.

Answer 94

A. Give cervical ripening agent Rationale: A closed, firm cervix in a post-term pregnancy results in a low Bishop score (<6). The cervix is unfavorable, so the appropriate management is to begin cervical ripening before initiating labor induction.

Answer 95

A. Oligohydramnios Rationale: Post-term pregnancy is commonly associated with oligohydramnios due to declining placental function, leading to decreased fetal urine output and lower amniotic fluid levels.

Answer 96

D. Long, wide soft tissue mass Rationale: Postmature infants are thin with decreased subcutaneous fat, wrinkled dry skin, and long nails. They appear alert, but do not have large or wide soft tissue mass, which is not characteristic of postmaturity.

Answer 97

B. Loss of protective vernix Rationale: In post-term infants, the vernix caseosa (protective coating) is absent, leading to dry, cracked, peeling skin — a hallmark of postmaturity.

Answer 98

D. A patient with a previous post-term pregnancy Rationale: A history of post-term pregnancy is the strongest risk factor for recurrence due to genetic and hormonal influences.

Answer 99

C. Healthy and large Rationale: In post-term pregnancies with intact placental function and normal AFI, the fetus continues to grow and is often macrosomic (large for gestational age), representing a healthy and well-nourished baby.

Answer 100

C. Oligohydramnios Rationale: Dysmaturity syndrome is associated with placental insufficiency, leading to oligohydramnios, fetal wasting, and features such as peeling skin, long nails, and meconium staining.

Answer 101

A. Fundic height Rationale: In late pregnancy, if LMP is unknown, the fundic height provides a quick and reasonable estimate of gestational age, especially when ultrasound dating is unavailable or uncertain.

Answer 102

D. Biparietal diameter (BPD) via ultrasound Rationale: In the second trimester, ultrasound measurement of biparietal diameter (BPD) is the most accurate and reliable way to determine gestational age when dating by LMP is not possible.

Answer 103

B. Prostaglandin and membrane stripping Rationale: Cervical ripening is commonly achieved using prostaglandins (e.g., misoprostol or dinoprostone) and mechanical methods like membrane stripping, which promote cervical effacement and dilation.

Answer 104

C. Meconium aspiration Rationale: Post-term infants are at high risk of meconium-stained amniotic fluid, which may lead to meconium aspiration syndrome (MAS) — a serious respiratory complication in newborns.

Answer 105

C. 20 weeks Rationale: The fundus reaches the level of the umbilicus at approximately 20 weeks gestation, which is a common clinical method for estimating gestational age during prenatal checkups.

Answer 106

C. Preterm Rationale: Neural tube defects are associated with preterm delivery, either spontaneous or medically indicated due to fetal anomalies. They are not linked to post-term pregnancies.

Answer 107

C. Preeclampsia Rationale: Post-term pregnancy increases maternal risk for preeclampsia, postpartum hemorrhage, and cesarean delivery. Stillbirth and meconium aspiration are fetal complications.

Answer 108

A. Associated with decreased kisspeptin levels Rationale: Kisspeptin, a placental hormone, plays a role in trophoblast invasion and placental development. Low kisspeptin levels are linked with placental insufficiency, especially in IUGR and post-term pregnancies.

Answer 109

A. Pulmonary hypoplasia Rationale: Oligohydramnios restricts fetal movement and lung development, especially when prolonged, and is associated with pulmonary hypoplasia, limb contractures, and cord compression.

Answer 110

C. It is associated with cervical change Rationale: Preterm labor is defined as regular uterine contractions with progressive cervical changes (dilation or effacement) before 37 weeks gestation.

Answer 111

A. Those delivered after 37 weeks Rationale: Preterm infants are born before 37 weeks. Infants born after 37 weeks are considered term. The rest of the options correctly describe preterm neonatal risks.

Answer 112

D. Absence of regular uterine contraction Rationale: Uterine distension (from multiples or polyhydramnios) is a known cause of spontaneous preterm labor due to increased myometrial stretch, leading to regular contractions — not their absence.

Answer 113

C. Ascending infection Rationale: The most common route of infection leading to preterm labor is ascending infection from the vagina/cervix, often involving bacteria like GBS or anaerobes ascending into the amniotic cavity.

Answer 114

D. Cervical incompetence Rationale: Cervical incompetence is defined as painless cervical dilatation typically occurring in the second trimester, leading to recurrent pregnancy loss or preterm birth without contractions.

Answer 115

D. Fever Rationale: The most reliable clinical sign of chorioamnionitis is maternal fever. While fetal tachycardia and leukocytosis may be present, fever is the most indicative and diagnostic sign.

Answer 116

D. All of the above Rationale: Cerclage is indicated in patients with: Recurrent second-trimester losses Ultrasound-diagnosed short cervix Cervical changes with threatened preterm labor All three scenarios justify cerclage to prevent pregnancy loss or preterm delivery.

Answer 117

C. Risk of additive neuromuscular blockade, which may depress cardiac and respiratory function High-Yield Rationale: Nifedipine (a calcium channel blocker) and magnesium sulfate (a neuromuscular blocker) both reduce calcium influx in muscle tissue. Co-administration can result in exaggerated neuromuscular blockade, leading to hypotension, respiratory depression, and cardiac compromise — especially dangerous in preterm labor and preeclampsia cases.

Answer 118

B. It is used for neuroprotection in term infants with normal birth weight High-Yield Rationale: MgSO₄ provides neuroprotection primarily for very low birth weight preterm infants (<32 weeks), reducing the risk of cerebral palsy. It is not indicated for neuroprotection in term or normal birth weight infants. All other statements regarding mechanism, monitoring, and toxicity management are correct.