Please select the eligibility criteria that correspond to the clinical trial below.
Title: Nifedipine Alone or Nifedipine Plus Indomethacin for Treatment of Acute Preterm Labor: An Open Label, Randomized Comparative Effectiveness Controlled Trial
Brief Summary: Tocolytic agents are used for the treatment of preterm labor. It is unclear whether combination treatments of two tocolytic agents are more effective in stopping preterm labor compared to one. Therefore, the investigators propose a comparative effective trial of nifedipine plus indomethacin vs. nifedipine alone for the treatment of preterm labor


Options:
A: Inclusion Criteria:

* pregnant women with preterm labor admitted to hospital and treated with tocolysis
* pregnant women less than 28.0 and those women from 28.0 to 32.0 with a sonographic cervical length \< 15 mm
* single pregnancy
* normal amniotic fluid
* normal arterial ductus

Exclusion Criteria:

* Age below 18 years
* previous use of indomethacin in the index pregnancy
* chorioamnionitis, preterm prelabour rupture of membranes or those fetal or maternal pathologies which could be responsible of an iatrogenic preterm delivery.
* oligohydramnios
* allergy to NSAID
* previous history of gastrointestinal bleeding
* use of NSAID contraindicated
* not adherence to the study
B: Inclusion Criteria:

* Singe fetus
* Gestational age between 24+0/7 and 31+6/7
* At least one uterine contraction in ten minutes for at least 20 minutes upon tocography admission
* Cervical parameters: 1 cm dilation or more or 80% cervical effacement or cervical length 20mm or less

Exclusion Criteria:

* Rupture of membranes
* Vaginal bleeding
* Cervical dilation ≥5cm
* Known fetal malformations
* Fetal heart rate abnormalities
* Suspected placental abruption of adherent placental syndrome
* Known sensitivity to one of the drugs used in the study (Indometacin and nifedipine)
* Maternal hypotension and known aortic or mitral stenosis
* Presence of cervical cerclage
* Previous administration of tocolytic drugs in current pregnancy
C: Inclusion Criteria:

* We will include pregnant women between 22 0/7 to 31 6/7 weeks gestation who present with regular uterine contractions defined as at least one contraction every 10 minutes for 30 minutes with at least one of the following:
* cervical change of at least 1 cm or
* cervical dilation of 2 cm at the time of initial exam or
* positive fetal fibronectin and transvaginal cervical length \<2.5 cm

Exclusion Criteria:

* We will exclude pregnant women with any contraindication to tocolysis:
* clinical chorioamnionitis (defined as a temperature of \>100.4 F and any of the following: fundal tenderness, maternal tachycardia, fetal tachycardia or purulent vaginal discharge)
* non reassuring fetal heart tones
* suspected placental abruption
* preterm premature rupture of membranes
* prior tocolytic treatment during the past 48 hours
* known adverse effect to indomethacin or nifedipine
* already receiving nifedipine for chronic hypertension
D: Inclusion Criteria:

* Patients between 240/7-320/7 weeks gestation with findings consistent with preterm labor defined by at least one of the following criteria in accordance with regular uterine contractions (\>4 uterine contractions in 20 minutes):

  1. Cervix \> 2 cm in dilation or 80% effaced
  2. Positive fetal fibronectin (if performed).
  3. Demonstrated cervical change between two exams within 90 minutes.

Exclusion Criteria:

* Negative fetal fibronectin
* \> 5cm dilatation
* Multiple gestations
* Known fetal anomalies or chromosomal abnormalities
* Ruptured membranes
* Significant vaginal bleeding
* Suspected chorioamnionitis
* Preeclampsia or uncontrolled hypertension
* Non-reassuring fetal heart tracing
* Placenta previa and/or accreta
* Placenta abruption
* Intrauterine growth restriction
* Maternal renal disease
* Underlying maternal cardiac condition
* Symptomatic hyperthyroidism
* Significant maternal disease
* Contraindication to nifedipine or magnesium
* Cerclage presence
* Tocolytic use within the last 12 hours
* Hypotension (defined as average blood pressure of \<70/40's unresponsive to 1000 cc fluid bolus

Answer: C