Abstract

Placenta Previa is a rare form of impaired placentation where the placenta lies low in the uterine cavity, covering completely or partially the internal cervical ostium. It is one of the main causes of vaginal bleeding in third trimester. The prevalence of Placenta Previa is about 0.2% -1.5% ’.The pregnancies complicated by Placenta Previa are prone for bleeding during ante-partum period which accrue the risk of adverse maternal and perinatal outcome as compared to general population. These patients are particularly at an increased risk of peri-partum hysterectomy², usually performed due to uncontrolled bleeding whose obvious result is loss of future fertility.

Objectives: Main primary objectives were

1. To study the trends of Placenta Previa and its determinants during the last five years

2.To compare the risk factors for major and minor degree of placenta previa.

Secondary Objectives were to study the maternal morbidity in pregnancies complicated by Placenta Previa and the foetal outcome in pregnancies complicated by Placenta Previa

Materials and Methods: This study is a descriptive study conducted in Department of Obstetrics and Gynaecology Sri Avittom Thirunal Hospital, Thiruvananthapuram. Study population included data of patients with a diagnosis of placenta previa during the five year period from 2006 to 2010. The details of the cases were collected from the medical records using structured proforma. The diagnosis of placenta previa was confirmed either using last ultrasonographic examination before delivery or from intraoperative findings. Trend was analyzed for cases for last five years.

Results: The data of all the patients with diagnosis of placenta previa during the 5 year period from 2006 to 2010 were included in the study. There were 876 patients with placenta previa during this period. The patients were diagnosed with placenta previa either by last antenatal ultrasound or confirmed intra-operatively. Results showed that the incidence of placenta, ranged from 1.35- 1.67. The rate increased by 23% from 2006 to 2010. Majority of patients belonged to age group 21-30 yrs.18.7% of patients included in the study were above the age of 30 years. In our patients 20.2% of the patients had history of abortions. There were 106 spontaneous abortions (12.1%) and 91 induced abortions (10.4%).In our study 25.4% of the patients with placenta previa had previous vaginal delivery while 26.5 % had previous Cesarean section. There was a slight increase of 1.1% in the number of patients with prior cesarean section as compared to those with previous vaginal delivery.. In our study 5% of patients had history of treatment for infertility while 95% did not have any history of infertility treatment Majority of patients with placenta previa did not have a history of placenta previa in previous pregnancies. Though a recurrence rate of 4-8% in placenta previa was shown in studies, our patients with placenta previa did not have a significant past history of placenta previa (0.9%).Uterine myoma was present in 3% of patients with placenta previa. The average age of incidence of placenta previa was 27.7+/- 4.68 during 2006 and was 26.64+/- 3.6 in 2010 showing a decrease in mean age by 0.83 years over the last 5 years but this was not statistically significant. Our analysis showed an increase in the number of patients having previous cesarean between 2006(44%) and 2010(55.3%) . The increase in the number of patients with previous cesarean was not found to be statistically significant, but could be a reflection of the general increase in the incidence of cesarean section and could have contributed to the increasing incidence of placenta previa. There is an increase in the proportion of patients having history of prior abortion, an increase from 21% in 2006 to26.6 % in 2010, probably contributing to the increase in incidence of placenta previa. Major degree of placenta previa (Type3+4) constituted 53% as compared to minor degree of previa. (Typel+2) which was 47%.In our study outcome analysis showed, 15.5% of our patients with placenta previa having malpresentations. 80.5% of the patients had history of antepartum hemorrhage (2^nd or 3^rd trimester). 9 patients had adherent placenta(0.01%) and all these patients had previous cesarean section. 51.3% of the patients had their pregnancy terminated before 37 weeks. 94.6% of patients with placenta previa were delivered by Cesarean section which included 57.9% of patients who needed emergency Cesarean section. Major intraoperative complications were excessive bleeding and blood transfusion. Hysterectomy was done for 14 patients constituting 1.6% .Post partum complications like postpartum hemorrhage was present in 5.02% of our patients and 3.19% had postpartum sepsis.51.1% of the babies were delivered preterm while 48.9% of the babies were delivered term. 11.8 % of babies born to patients with placenta previa had respiratory distress soon after birth, 7.7% of babies had low 1 min APGAR score (<7) and 12.2% of babies required admission to inborn nursery. 40.5% of the babies had birth weight less than 2.5 kg.57.5% of babies bom as preterm had pregnancy complicated by major previa as compared to 43.8% in minor which was statistically significant. 36.8% of patients with major previa had birth weight < 2.5 kg against 29.4% among minor previa which was statistically significant. Low Apgar scores at birth, respiratory distress soon after birth and admission to inborn nursery were high among patients with major placenta previa as compared to minor previa.

Conclusion: The rate of incidence of Placenta Previa showed an increasing trend from 2006 – 2010 and the rate increased from 1.35-1.67% indicating a 23% increase in incidence over 5 year. Our hospital being a tertiary centre, 35.6% of patients were referred patients with Placenta Previa. Majority of patients (91.7%) belong to low income group, probably because our hospital services are mainly utilized by the people from low socio economic strata. Risk factors of Placenta Previa like history of prior spontaneous or induced abortions, previous cesarean section, short inter pregnancy interval were prevalent in our patients. Risk factors like multiparity, multiple gestation, prior history of Placenta Previa, presence of uterine myoma, previous myomectomy, treatment for infertility, smoking and illicit drug abuse were not prevalent in our subjects. Determinants like history of abortions, previous cesarean section, short inter pregnancy interval and infertility treatment have shown increase in trend from 2006 to 2010.Attributes like advanced maternal age, presence of uterine myoma, previous myomectomy, history of prior Placenta Previa have not exhibited significant trend deviation.53% of the patients had major degree of placenta previa and 47% had minor degree of placenta previa. Risk factors like history of abortion including spontaneous and induced abortions, history of treatment for infertility were significantly related with major degree of placenta previa. No significant association was observed between type of placenta previa with risk factors like Previous cesarean section, short inter pregnancy interval, multiparity, presence of uterine myoma and previous myomectomy. Placenta previa was associated with malpresentation in 15.5% of subjects.80.5% of the pregnancies with placenta previa were complicated by antepartum hemorrhage. Placenta accreta was present in 9 patients and all of them had history of previous cesarean section. The number of patients with placenta accreta did not show any increase in trend during 2006 and 2010.More than half of patients i.e. 50.3% had pregnancy terminated before 37 weeks. Cesarean section was the mode of delivery in 94.6% of the patients and significant number of patients required emergency cesarean section. Major intra-operative complication were excessive bleeding, blood transfusion and hysterectomy. Peripartum hysterectomy was done for 14 patients with placenta previa (1.6%)Intra-operative complications were significantly high in major degree of placenta previa. Peripartum Hysterectomy was done for 14 patients with placenta previa.51 % of the babies were born preterm. In our study neonatal complications like respiratory distress, low 1 minute APGAR scores, low birth weight and admission to neonatal care unit were more with major degree of placenta previa.