A drug delivery system provides for controlled mixing of drugs, using flow controllers to guide drugs into single or multiple catheters, enabling a single lumen catheter to dispense multiple drugs, diluting a concentrated drug to provide varying drug concentration, using a buffer fluid to deliver precise amounts of drug or to separate drugs within a catheter, and using a patient's bodily fluid as a diluent or buffer fluid. A drug testing/filler apparatus may be used prior to system use to facilitate filling of multiple reservoirs and may also be used for refilling. The system can provide bolus or continuous delivery and enable the measured delivery of drug to selected distal locations at independent rates. New types of catheter systems, catheter hub assemblies, and uses therefore are also described. New methods for promotion of healthy pregnancy and treatment of a developing fetus are disclosed.
