Immediate Cesarean Section is Indicated
For a 33-week pregnant woman with 2 cm cervical dilation and fetal head palpable in the vagina, cesarean section (CS) is the correct answer (A). This clinical scenario describes preterm labor with an extremely high-risk situation where the fetal head has descended prematurely into the vagina at only 2 cm dilation, creating a dangerous setup for impacted fetal head during any attempted delivery.
Critical Clinical Context
At 33 weeks gestation, this fetus is significantly preterm and requires immediate delivery via CS to optimize neonatal outcomes while avoiding the catastrophic complications of attempting vaginal delivery or operative vaginal delivery at this gestational age 1.
The fetal head being palpable in the vagina at only 2 cm dilation is highly abnormal and indicates either precipitous descent or an anatomical mismatch that will result in severe impaction if labor progresses 2.
Forceps (B) and vacuum extraction (C) are absolutely contraindicated at 33 weeks gestation due to the extreme prematurity of the fetus and the minimal cervical dilation (2 cm versus the required full dilation of 10 cm for operative vaginal delivery) 3.
Fetal scalp sampling (D) is irrelevant to this clinical scenario as it addresses fetal acid-base status during labor, not the fundamental problem of preterm labor with abnormal fetal descent 3.
Why Cesarean Section is Mandatory
The combination of prematurity (33 weeks) and abnormal fetal head position creates multiple life-threatening risks:
Impacted fetal head is highly likely given the premature descent with minimal cervical dilation, which would result in difficulty delivering the head, increased risk of uterine incision extension, hemorrhage, and bladder/ureteric injuries 1.
Nulliparous women with floating or abnormally positioned fetal heads have substantially increased cesarean rates (17.1% vs 4.2% for engaged heads), and those with persistently abnormal head position at 7 cm dilation rarely deliver vaginally 2.
At 33 weeks, the fetus requires neonatal intensive care and any traumatic delivery method would significantly worsen neonatal morbidity and mortality 4.
Management Algorithm
Immediate preparation for cesarean delivery should include:
Antenatal corticosteroid administration if not already given, as delivery before 33 6/7 weeks is anticipated 5.
Magnesium sulfate for neonatal neuroprotection given the gestational age less than 32 weeks (if exactly 33 weeks 0 days) or consideration if close to this threshold 5.
Preparation for potential impacted fetal head during the cesarean, with readiness for manual vaginal disimpaction (vaginal push method) or use of a Fetal Pillow device to elevate the head from the pelvis before making the uterine incision 1.
Neonatal resuscitation team must be present given the high likelihood of delivering a depressed preterm neonate requiring advanced resuscitation 1.
Critical Pitfalls to Avoid
Do not attempt vaginal delivery or operative vaginal delivery:
Operative vaginal delivery requires full cervical dilation (10 cm), and this patient has only 2 cm dilation, making forceps or vacuum physically impossible and extremely dangerous 3, 6.
Preterm infants are at higher risk of intracranial hemorrhage with operative vaginal delivery, making this approach unacceptable at 33 weeks 4.
Do not delay delivery waiting for further cervical change:
The abnormal fetal head position at minimal dilation indicates high risk for obstructed labor and fetal compromise if labor continues 2, 6.
Fetal head malposition is associated with 89.1% of full dilatation cesarean sections versus 9.5% of successful operative deliveries, indicating that abnormal positioning predicts cesarean necessity 6.