Please select the eligibility criteria that correspond to the clinical trial below.
Title: Extended Release Nifedipine Treatment as Maintenance Tocolysis to Prevent Preterm Delivery:A Prospective Interventional Study
Brief Summary: To evaluate the treatment efficacy and safety usig extended release nifedipine, as maintenance therapy to pregnant women who were hospitalized and treated for preterm labor until 34 weeks' gestation. After the PTL will stop, we will randomize these women for the treatment group and the control (no treatment) group.

The main outcome will be preterm delivery before 34 weeks' gestation. the secondary outcome will be the side effects of the medication and the newborn/mother health variables.


Options:
A: Inclusion Criteria:

* pregnancy week 24-33
* Singleton pregnancy
* After successful treatment to stop PTL

Exclusion Criteria:

* Contraindications for Nifedipine extended release treatment.
B: Inclusion Criteria:

* Women in preterm labor between 24 to 32 6/7 weeks' gestation with intact membranes with an age range of 15 to 50 years old.

Exclusion Criteria:

* Cervical dilatation of ≥ 6 cm
* Maternal contraindication to tocolysis
* Known fetal anomalies
* Suspected chorioamnionitis
* Nonreassuring fetal heart tracing
* Vaginal bleeding due to placenta previa or abruptio placenta
* Preterm premature rupture of membranes
* Prolapsed membranes
* Human immunodeficiency virus positive
* Multiple gestation
* Patients on procardia within 24 hours of po intake
* Magnesium sulfate tocolysis prior to randomization
* Patient refusal
C: Inclusion Criteria:

* BMI between (20 - 30 kg /m²).
* pregnant female with single viable fetus who presented to the outpatient clinic or Emergency room with the criteria of diagnosis of preterm labor between 28 and before completing 34 weeks pregnancy

Exclusion Criteria:

* - Any condition in which continuation of pregnancy will jeopardize maternal or fetal welfare.
* Cervix dilatation greater than 4 cm.
* Polyhydramnios \[amniotic fluid index (AFI) greater than 24 cm or deep vertical pocket more than 8 cm.\]
* Oligohydramnios (AFI less than 5 cm).
* Suspected intrauterine infection if Maternal fever is present as a constant feature plus one or more of the following:-

  * Maternal leucocytosis (more than 15,000)
  * purulent vaginal discharge
  * Fetal tachycardia more than 180 bpm.
* Growth restriction.
* Major antepartum hemorrhage
* Major maternal medical disorders such as diabetes, hypertension, systemic lupus,liver and kidney dysfunction .
* Multiple gestation pregnancy.
* Signs of fetal non reassuring CTG
* Signs of fetal abnormal CTG
* Lethal fetal anomaly incompatible with life.
* Premature Rupture of membrane.

  --Contraindication for the use of Nifedipine and/or Nicorandil such as drug allergy, cardiac disease, liver disease and kidney disease
* previous caesarean section
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: A