Hydration and Rate of Cesarean Delivery Among Nulliparous

Inclusion Criteria:• Non-anomalous singleton * Nulliparous (no prior delivery after 20 weeks) * Presenting at ≥37 weeks of gestation * Presenting for anticipated induction of labor or spontaneous labor (regular contractions for more than 2 hours), but cervical dilation less than 4 cm * Rupture of membranes * Expected to deliver at one of the participating hospitals Exclusion Criteria:• Not in the inclusion criteria * Autoimmune disorders (antiphospholipid antibody, lupus, rheumatoid arthritis, scleroderma) * Diabetes mellitus-gestational or pre-gestational * Enrollment in another randomized clinical trial * Hematologic disorders (coagulation defects, sickle cell disease, thrombocytopenia, thrombophilia) * Hypertension (chronic or pregnancy induced) before randomization * HIV (human immunodeficiency virus) * Placenta previa / 3rd trimester bleeding * Renal insufficiency (serum creatinine \> 1.5 mg/dL) * Restrictive lung disease * Seizure disorder on medication * Thyroid disease on medication * Any contraindications to vaginal delivery (breech, active herpes, schedule cesarean, abnormal fetal heart tracing)