[Placenta praevia. Maternal and perinatal repercussions. Analysis of 170 cases].

One hundred and seventy cases with placenta previa, at Instituto Nacional de Perinatología, from 1989 to 1993, were reviewed. Incidence in our population was 0.62%; average maternal age was 31 years; the greater amount of cases was among nulliparae; in 72% of them there was the antecedent of uterine scar. Ultrasound diagnosis was done in 81% of the patients, and most frequent placental insertion type was the low one in 49%, and in 31%, total, central placenta. The first hemorrhagic episode occurred at a gestational age of 34 weeks. Most frequent complication was threatening pre-term delivery, and ethinyl adrianol was used as uterine inhibitor. All pregnancies were interrupted, via abdominal. Placental accretion was a frequent complication. Hemorrhage during the second half of gestation is one of the main causes of perinatal morbidity-mortality. Frequency of this complication is from 3% to 5%, of all pregnancies in an open population; and when it appears, is one of the most serious urgencies; so its early diagnosis and opportune treatment will diminish maternal and perinatal morbidity-mortality. Etiology is unknown, but diminished endometrial vascularization, at fundus and body, may be the causal factor. There are other predisposing causes as age, advanced maternal age, multiparity, tumours, scars and smoking. The objective of this study, was to analyze maternal and perinatal repercussions, of placenta previa, based on the experience at Instituto Nacional de Perinatología.