Please select the eligibility criteria that correspond to the clinical trial below.
Title: Up-down Determination of the ED90 of Oxytocin Infusions for the Prevention of Postpartum Uterine Atony in Parturients Undergoing Cesarean Delivery
Brief Summary: This study is designed to determine the minimum effective dose (ED90) of infusions of oxytocin for the prevention of uterine atony / postpartum hemorrhage and the need for additional uterotonics, in low risk parturients presenting for an elective CD.

The primary outcome measure is the response of effective uterine contraction as either satisfactory or unsatisfactory as determined by the obstetrician blinded to the oxytocin infusion dose. Secondary outcomes will include need for additional uterotonics, calculated intra-operative blood loss and presence of oxytocin related adverse effects.


Options:
A: Inclusion Criteria:

* gestational age between 37 and 42 weeks
* singleton pregnancy
* live fetus
* cephalic presentation
* neonatal birth weight of 2500-4500 g
* parity between one and five
* maternal age \< 35 years
* vaginal birth

Exclusion Criteria:

* blood pressure ≥ 140/90mmHg
* placenta previa
* placental abruption
* a history of any bleeding during pregnancy
* a history of curettage
* cesarean section or any uterine scar
* a history of postpartum hemorrhage
* polyhydramnios
* signs or symptoms of maternal infection
* known uterine anomalies
* history of any drug use during labor
* abnormal placentation)
* coagulation defects
* instrumental deliveries
* hemoglobin concentration \< 8 g/dL
* history of anticoagulant drugs
* beta-mimetic medications during pregnancy
* prolongation of the first stage of labor \> 15 hours.
B: Inclusion Criteria:

1. Non-emergent cesarean delivery with planned spinal anesthesia (i.e. elective planned cesarean delivery for malposition, patient choice, cervical pelvic disproportion, previous cesarean delivery and other diagnosis that require a predetermined cesarean delivery)
2. American Society of Anesthesia physical status class I \& II (ASA I - Healthy, ASA II - mild and controlled systemic disease, eg. controlled essential hypertension)
3. Age ≥ 18 years
4. Term gestational age (≥ 37 weeks)
5. English-speaking

Exclusion Criteria:

1. Morbid Obesity (Body Mass Index ≥ 45 kg/m2) (Morbidly obese parturients require a dose of local anesthetic less than the standardized dose in this study and the blood pressure cuff occasionally needs to be replaced by an intraarterial catheter due to limitations in size)
2. Laboring women
3. Urgent or emergency cesarean delivery
4. Severe hypertensive disease of pregnancy defined as systolic blood pressure (SBP) \> 160mmHg, diastolic blood pressure (DBP) \> 110mmHg and/or requiring antihypertensive treatment or associated with significant proteinuria
5. Severe maternal cardiac disease
6. Subjects predisposed to uterine atony and postpartum hemorrhage (i.e. placenta previa, multiple gestation, macrosomia, polyhydramnios, uterine abnormalities, or bleeding diathesis, \> 2 previous CD)
7. Fetal anomalies /Intrauterine Fetal Demise
8. Failed spinal anesthesia
9. Patient enrollment in another study involving a study medication within 30 days of CD
10. Any other physical or psychiatric condition which may impair their ability to cooperate with study data collection
C: Inclusion Criteria:

* Gestational age equal to or greater than 28 weeks pregnant
* Planning to deliver at home or at a sub-center in the Belgaum District, Karnataka India
* Anticipating a spontaneous vaginal delivery
* Ability and willingness to provide informed consent

Exclusion Criteria:

* Previous caesarian section
* Scheduled for caesarian section
* Hemoglobin level less than 8 Gms%
* Episodes of antepartum bleeding during the current pregnancy
* Blood pressure more than 140 mm of Hg systolic and 90 mm of Hg diastolic
* In active labor and not previously screened, recruited, and consented
* Absence of fetal heart sounds
* Multiple pregnancy
* Known history of bronchial asthma
* Prior enrollment in this study during a previous pregnancy
* History of complications (ante/postpartum hemorrhage/retained placenta/ acute inversion of uterus) during a previous pregnancy
* High risk conditions including: diabetes, cardiac ailments, seizures, placenta previa or anticipated breech delivery.
* Receiving injectable medicine at time of delivery
D: Inclusion Criteria:

* Study subjects will be women delivering via an elective cesarean section at term
* All study subjects will have singleton gestation with no obstetric or medical complication.

Exclusion Criteria:

* Laboring women
* Multifetal gestation
* Prolonged oxytocin use (\>12 hours)
* Hypertensive disorders
* Chorioamnionitis
* Suspected macrosomia
* Polyhydramnios
* History of postpartum Hemorrhage
* Clotting disorder
* Intake of magnesium sulfate
* Uterine fibroids
* Placenta previa
* Placental abruption
* Anticoagulation

Answer: B