Please select the eligibility criteria that correspond to the clinical trial below.
Title: Maintenance Oral Nifedipine for Management of Symptomatic Placenta Previa : A Randomized Clinical Trial
Brief Summary: The objective of our study is to determine the clinical utility related to the maintenance oral nifedipine therapy in patients with symptomatic placenta previa. This study is a prospective, randomized controlled trial with the inclusion, after 24 weeks gestation, of hospitalized patients with symptomatic placenta praevia. All patients may initially receive oral nifedipine therapy with steroid prophylaxis for 48 hours. After then, patients are randomly assigned to receive either oral nifedipine (20 mg every 8 hours) or placebo (one every 8 hours) until 37 weeks of gestation.

The primary outcome for the trial is the length of pregnancy in days after the enrollment. A sample size calculation is designed to detect at least a 14 -day difference in time gained in patients with maintenance oral nifedipine therapy. A sample size of about 52 patients per group would have a 80 % chance of detecting this difference at the 5 % level of significance.


Options:
A: Inclusion Criteria:

* Placenta previa is diagnosed when the lowest placental edge is located within 5 cm of the internal os at ultrasonography
* Placenta previa may be symptomatic with at least one episode of bleeding
* Estimated gestational age within 24 to 34 weeks
* Maternal age \> 18 years
* Informed consent after received an explanation of the study and an information sheet
* Social affiliation

Exclusion Criteria:

* Premature rupture of membranes
* Severe bleeding requiring an immediate termination of pregnancy
* Abnormal fetal heart rates requiring an immediate termination of pregnancy
* Intrauterine fetal death
* Pre-eclampsia, chorioamnionitis, liver disease, severe chronic renal disease, heart disease
* Abruptio placentae
* Nifedipine sensibility
* Drugs interaction with nifedipine
B: Inclusion Criteria:

* GA between 24 to 34 weeks
* early-onset signs of delivery (≥4 uterine contractions during 20 minutes, ≥1 centimeters (cm) of dilation and effacement over 80%).

Exclusion Criteria:

* maternal or fetal life-threatening conditions which require emergency termination
* multiple pregnancy
* premature rupture of membrane
* fatal anomaly or intra-uterine fetal death
* cervical dilation ≥4 cm
* any tocolytic treatment in previous days and positive allergy to GTN
C: Inclusion Criteria:

* Singleton and twin gestations
* Intact amniotic membranes
* No contra-indications to tocolysis
* 24-34 weeks gestation by last menstrual period and/or ultrasound
* Documented cervical change, and regular painful uterine contractions at least every 5 minutes, or at least 2 cm cervical dilation and 80% effacement

Exclusion Criteria:

* Ruptured amniotic membranes
* Signs/symptoms of chorioamnionitis (maternal temperature greater than 100.4 F/38.0 C, fetal tachycardia, uterine tenderness)
* Non-reassuring fetal heart rate tracings
* Contra-indications to indomethacin or nifedipine
* Contra-indications to tocolysis
D: Inclusion Criteria:

* Gestational age between 24 0/7 - 31 5/7 weeks by LMP or ultrasound
* Documentation of rupture by demonstrating pooling or 2/3 diagnostic tests (pooling, ferning and nitrazine positivity)

Exclusion Criteria:

* Membrane rupture greater than 72 hours
* Persistent labor characterized by regular painful contractions with cervical change and/or cervix visually greater than 5 cm
* Chorioamnionitis defined by having 2 or more of the following: maternal temperature \> 100.4, persistent fetal tachycardia (\>170bpm), maternal tachycardia (\>110bpm) in the absence of other likely cause, uterine tenderness.
* Non-reassuring fetal heart rate tracing or biophysical testing
* Vaginal hemorrhage
* Lethal fetal anomalies
* Intrauterine fetal demise
* Maternal conditions which precludes expectant management
* Fetal condition which precludes expectant management
* Maternal allergy to indomethacin
* Maternal active gastritis
* Multiple gestations
* HIV with viral load \>1000
* HSV with active herpetic lesions
* Cervical cerclage

Answer: A