synÂ·theÂ·size (sÄ­nâ²thÄ­-sÄ«zâ²) v. synÂ·theÂ·sized, synÂ·theÂ·sizÂ·ing, synÂ·theÂ·sizÂ·es v.tr. 1. To combine so as to form a new, complex product: His works synthesize photography, painting and linguistic devices (Paul Taylor). 2. To form or produce by chemical synthesis. 3. To produce (sound or music) by means of a synthesizer. v.intr. To form a synthesis.
The cause of preterm birth is often not known. Risk factors include diabetes, high blood pressure, being pregnant with more than one baby, being either obese or underweight, a number of vaginal infections, tobacco smoking, and psychological stress, among others.
1 Placenta previa can cause severe vaginal bleeding before or during delivery. 2  A C-section delivery usually is required if the placenta previa is present at the time of delivery. 3  Placenta accreta. 4  This condition occurs when the blood vessels of the placenta grow too deeply into the uterine wall.