In one year, we recorded 142 cases of placenta previa out of a total of 15,888 deliveries, i.e. a frequency of 0.89%.

The average age of the patients was 28.51 years with extremes of 16 and 44 years, the age group 25 to 29 years represented 27.46% (Table 1).

The metrorrhagia of the third trimester of pregnancy represented 57.74% of the reasons for admission (Table 2). The general condition of the patients was good, fair and poor in 24.65%, 71.83% and 3.52% respectively. Concerning obstetrical history, the average parity was 2.60 with extremes of 1 and 9, pauciparous patients represented 36.62%, those who had at least one abortion were 23.94%, patients with at least one uterine scar represented 15.5% (Table 3). On admission, 104 patients were in labor, of whom 56.34% had a covering placenta previa and 16.90% had a non-covering placenta previa.

The blood count was performed in all patients and showed severe anaemia in 41

patients (28.87%), moderate anaemia in 41 patients (28.87%) and mild anaemia in 38 patients (26.76%). Obstetrical ultrasound was performedin 38 patients (26.76%) and revealed a central placenta previa in 17 patients (11.97%), marginal in 13 cases (9.15%) and lateral in 8 cases (5.63%).

Blood transfusion was performed in 81 patients (57.04%). The blood products transfused were red blood cells, iso group and iso rhesus. The delivery route was caesarean section for 133 patients (93.66%) and vaginal delivery for 9 women (6.34%).

In 125 cases (88.02%) we recorded complications. There were five (05) cases of postoperative infectious complications (3.52%) including 3 cases (2.11%) of parietal suppurations and 2 cases (1.41%) of endometritis, and 120 cases of anaemia, i.e. 84.50%. We noted 4 maternal deaths, i.e. a case fatality rate of 2.81%.

With regard to foetal prognosis, out of a total of 148 births, we recorded 108 live births (72.97%), with 21.62% very premature; 29.73% moderately premature and 48.65% full term. We recorded 30 stillbirths and 4 newborns who died before 7 days of life, i.e. a perinatal mortality rate of 23.94%.

Placenta previa remains a formidable obstetric pathology. Its actual frequency is poorly defined in the literature and is approximately 1/200 pregnancies [4]. This frequency depends on the clinical criteria used, the methods of diagnosis, the time of diagnosis (during pregnancy, during labor or after delivery) and the anatomical varieties selected. In our study we found a frequency of 0.89% higher than those of Ciemensti [5], Sheiner [6], and Ghazli [7] who reported rates of 0.2%, 0.38%, and 0.4% respectively. The referral nature of our service, which allows it to receive serious or complicated cases from peripheral maternity hospitals, partly explains our results.

Advanced maternal age is a factor favouring the occurrence of placenta previa. Foote [8] reported that the risk of placenta previa is multiplied by 2 beyond 29 years of age and by 3 beyond 35 years of age according to Nelson [8]; this was the case in our series where we found 42.96% of the patients who were 30 years of age or older.

Housewives represented 57.04% in our study. The probable financial dependence of these women, often associated with the lack of income-generating activity, could make access to obstetrical ultrasound difficult, which allows for early diagnosis of this pathology, which could explain the low rate of ultrasound diagnosis of placenta previa in our study (29.76%).

The typical profile of the placenta previa candidate is that of a multigester and multiparous woman with a history of abortions and uterine scarring, and with several miscarriages due to preferential implantation of the egg on the damaged endometrium [9]. In our study, multigestation women represented 50.70%, multiparous women 42.25%, those with at least one previous abortion 23.94% and those with at least one uterine scar 15.40%. Placenta previa (PP) is the main cause of metrorrhagia in the third trimester of pregnancy and this metrorrhagia may worsen during labor due to uterine contractions. In our series, metrorrhagia represented 77.46% of the reasons for admission; this rate could be explained by the high number of patients in labor at admission (73.23%).

Anaemia was severe in 28.87% of patients, moderate in 28.87% and 26.76% of patients had mild anaemia. All these cases of anaemia could be due to bleeding related to the placenta previa; this bleeding, even if minimal, can aggravate anaemia already existing during the pregnancy, explaining the cases of severe anaemia.

Anaemia remains a major public health problem in Burkina because of peripartum hemorrhages that very often occur in women who are already anaemic. Blood transfusion in our context is generally done according to blood loss and the clinical condition of the patient. In our study, blood transfusion was given to 81 patients (57.45%).

The caesarean section rate was 93.66% in our study. It varies from 28.83% to 87% in the literature [10] [11]. Our rate reflects the attitude to reduce the risk of neonatal death in the peri-natal period, because caesarean section saves 2 to 7 times more foetuses than vaginal delivery [12]. For Bhide [13], caesarean section should be systematic in cases of haemorrhagic PP.

Maternal morbidity was marked by severe anaemia and parietal suppurations which represented 28.87% and 3.52% respectively. Several authors agree that morbidity is important in PP and even more so after caesarean section [6] [12]. Buambo Bamanga noted a maternal anaemia rate of 8.6% and parietal suppurations of 5.5% [1]. This high rate of anaemia in our study can be explained by the early onset of the first hemorrhages, the recurrence of hemorrhages, and the importance of the quantity of blood lost prepartum in patients who were already anaemic. This anaemia, which is often poorly corrected either by insufficient transfusion or by a lack of blood in our blood banks, predisposes to infectious complications.

In our study, 4 cases of death were recorded, representing a case fatality rate of 2.81%. This rate is higher than those found by Douysset [10] and Ley [11] in France as well as Ibtissam in Algeria [14] who had not recorded any deaths. This difference can be explained by the fact that developed countries have increasingly sophisticated means of survival.

Prematurity, due to its numerous complications, is the main cause of perinatal mortality associated with placenta previa, but also foetal deaths in utero secondary to hemorrhagic shock [15]. In our series, perinatal mortality was 23.94%, which is higher than that reported by Traoré [3], which was 12.70%. This high rate in our study could be due to the proportions of very premature births (21.62%) and still births (21.12%) recorded.