Placenta previa: obstetric risk factors and pregnancy outcome

Abstract

Objective:To determine the incidence, obstetric risk factors and perinatal outcome of placenta previa. Study design: All singleton deliveries at our institution between 1990 and 1998 complicated with placenta previa were compared with those without placenta previa. Results: Placenta previa complicated 0.38% (n = 298) of all singleton deliveries (n = 78 524). A back-step multiple logistic regression model found the following factors to be independently correlated with the occurrence of placenta previa: maternal age above 40 years (OR 3.1, 95% CI 2.0-4.9), infertility treatments (OR 3.1, 95% CI 1.8-5.6), a previous Cesarean section (OR 1.8, 95% CI 1.4-2.4), a history of habitual abortions (OR 1.3, 95% CI 1.3-2.7) and Jewish ethnicity (OR 1.3, 95% CI 1.1-1.8). Pregnancies complicated with placenta previa had significantly higher rates of second-trimester bleeding (OR 156.0, 95% CI 87.2-277.5), pathological presentations (OR 7.6, 95% CI 5.7-10.1), abruptio placentae (OR 13.1, 95% CI 8.2-20.7), congenital malformations (OR 2.6, 95% CI 1.5-4.2), perinatal mortality (OR 2.6, 95% CI 1.1-5.6), Cesarean delivery (OR 57.4, 95% CI 40.7-81.4), Apgar scores at 5 min lower than 7 (OR 4.4, 95% CI 2.3-8.3), placenta accreta (OR 3.6, 95% CI 1.1-9.9) postpartum hemorrhage (OR 3.8, 95% CI 1.2-10.5), postpartum anemia (OR 5.5, 95% CI 4.4-6.9) and delayed maternal and infant discharge from the hospital (OR 10.9, 95% CI 7.3-16.1) as compared to pregnancies without placenta previa. In a multivariable analysis investigating risk factors for perinatal mortality, the following were found to be independent significant factors: congenital malformations, placental abruption, pathological presentations and preterm delivery. In contrast, placenta previa and Cesarean section were found to be protective factors against the occurrence of perinatal mortality while controlling for confounders. C onclusion: Although an abnormal implantation per se was not an independent risk factor for perinatal mortality, placenta previa should be considered as a marker for possible obstetric complications. Hence, the detection of placenta previa should encourage a careful evaluation with timely delivery in order to reduce the associated maternal and perinatal complications.It is accepted that placenta previa poses severe hazards to both mother and fetus 1-4 . Several studies have attempted to discover various epidemiological factors associated with this condition. Major risk factors found to be associated with placenta previa were previous Cesarean

Study of antepartum haemorrhage and its maternal and perinatal outcome

“…10,11 History of previous LSCS was present in 27% of APH cases and history of D and C present in 16%. Previous LSCS scar was present in 33.75% of PP cases and 6.25 % had history of D and C emphasizing the increased incidence of PP in these patient groups as was also seen in studies by Sheiner et al Rasmussen et al 6,8 Incidence of placenta accrete syndrome in patients with placenta previa and scarred uterus in our study was 6.25% while the study by Nasreen et al showed the incidence of placenta accreta to be 14.2% in scarred uterus with placenta praevia. 5 25% cases of PP had associated malpresentation which is the same (25%) as seen in study by Maurya et al, Pandey et al 10,11 Around 39% cases of PP had malpresentation in study by Nasreen et al 5 This high incidence of malpresentation also accounts for increased caesarean rate even in minor degrees of PP.…”

Risk factors of placenta previa: a population based study and the review of the literature

“…In literature, the prevalence of placenta previa has been reported as 0.3%-0.8% [5][6][7]. In recent years, several studies have reported an increase in the prevalence of placenta previa.…”

“…The incidence of placenta previa and complicated pregnancy varies according to the population and has been reported as approximately 0.3%-0.8% [5][6][7]. While the etiology of placenta previa has not been fully clarified, related risk factors are known to be a history of caesarean section, advanced maternal age, multiparity, history of abortion, cigarette smoking and male gender fetus [5,6].…”

“…While the etiology of placenta previa has not been fully clarified, related risk factors are known to be a history of caesarean section, advanced maternal age, multiparity, history of abortion, cigarette smoking and male gender fetus [5,6].…”

Author reply: No immediate increase in morbidity of infants delivered by term cesarean section for placenta previa: some concerns

“…On the other hand, there is no doubt with regard to increased maternal hemorrhagic morbidity surrounding placenta previa pregnancies, during the pregnancy course and, dramatically so, during the cesarean delivery itself [4,5]. We could not agree more with regard to the need of a specialized and experienced obstetrical team to insure maximal maternal safety.…”