Incidence,Risk Factors,Surgical Options,and Maternal and Perinatal Outcomes of Ruptured Uterus in Nnewi: A 10-Year Review

Introduction

Uterine rupture is an obstetric disaster that may complicate pregnancy, labor, and delivery, with attendant fetal and maternal complications. ¹ There are variations in occurrence of ruptured uterus in different parts of the world. In the developed world, the incidence has decreased significantly because of the availability of good and accessible obstetric care services, but in the developing countries, especially in Africa, it is still a major public health problem, because of illiteracy, poverty, ignorance, and poor use of existing health facilities. ²

Maternal case fatality as high as 10.3%–16.0% and fetal mortality rate between 70.0% and 90.0% have been reported.^2–4

Maternal morbidities such as anemia, wound and genital tract sepsis, septicemia, and burst abdomen are common.^3,4 Some women with these conditions lose their uterus and therefore, their chance of future fertility. ³

This study aims at determining the incidence of uterine rupture, associated risk factors, clinical presentations, associated maternal and perinatal mortalities, and various ways of reducing prevalence.

Materials and Methods

This is a retrospective study of patients who had uterine rupture at Nnamdi Azikiwe University Teaching Hospital Nnewi over a 10-year period between January 1999 and December 2008.

The folder numbers were extracted from the delivery and obstetric theater registers and the retrieved from Medical Records Department of the hospital. Out of the 8042 deliveries, 54 cases of uterine rupture were recorded and only 48 folders were retrieved; this formed the basis for the analysis.

Information on risk factors, surgical procedures performed, associated maternal morbidity and mortality, fetal outcome, and blood transfusion were extracted. This was analyzed using Epi Info version 5.1.

In this study, a patient was considered “booked” if she attended the antenatal clinic at least once. An “unbooked” patient was a patient who was not evaluated in the antenatal period before presentation with complications in labor.

Results

Out of the total 8042 deliveries within the study period, 54 cases of uterine rupture were managed. The incidence of the rupture was 6.7/1000 or 1 in 149 deliveries. Twenty people (41.7%) had parity between 0 and 1, 25(52%) had parity between 2 and 3, whereas 3(6.3%) had parity up to 4. Modal parity group was 2–3.

Six (12.3%) of the patients were booked whereas 42 (87.5%) were unbooked (χ²=24.5, p value 0.000 which was statically significant). Table 1 shows the parity distribution.

Table 2 shows the etiologic risk factors. One patient (2.1%) who had had a previous classic cesarean section had a ruptured uterus before the onset of labor. Three (6.3%) had had two previous cesarean sections and had a ruptured uterus without augmentation or induction of labor. Twenty-four (50.1%) of the patients, who had one previous lower-segment cesarean uterine scar, received oxytocin induction/augmentation of labor. Six (12.5%) had oxytocin induction without a previous uterine scar. Table 3 shows that the most common surgical procedure performed was repair and bilateral tubal ligation (62.5%), whereas the least common was subtotal hysterectomy (12.5%).

Table 4 shows the complications following the uterine rupture. Twelve patients had associated cervical injury (25.0%) whereas 3 had associated bladder injury (6.3%).

Thirty patients were transfused with blood (62.5%). Twenty-seven patients had anemia postoperatively (56.3%). The anemia was secondary to hemorrhage following the uterine rupture. Nine had wound sepsis (18.6%) whereas 3 had deep vein thrombosis (6.3%). Some patients had more than one complication. There was no history of puerperal sepsis in previous deliveries of those women who had had a previous cesarean section.

The fetal heart sound was absent in 42 patients (87.5%). The perinatal mortality was 87.5%. Nine (18.6%) of the patients died: 3 died within ∼1 hour of presentation, 3 died during the intraoperative period and the 3 died within 6 hours postoperatively.

Discussion

The incidence of ruptured uterus was 1 in 149 deliveries. This is lower than the 1 in 129 deliveries recorded in Ibadan, ³ or the 1 in 75 reported in Sokoto. ⁴ It is also lower than the 1 in 110 recorded in an Ethopian ² study and the 1 in 40 reported in the Ivory Coast. ⁵ It is also higher than values at Enugu: 1 in 188 deliveries. ⁶ Ebeigbe et al. ⁷ recorded a significant low value of 1 in 426 deliveries in Benin.

Lower values were recorded in Yemen and Nepal, two countries that are categorized as developing countries: 0.63% (1 in 159) ⁸ and 0.33%(1 in 303), ⁹ respectively.

The abovementioned incidence is in sharp contrast to values from Western countries (developed countries and other countries with good and accessible maternity care services). ¹⁰ In Qarter the incidence was 0.01 % (1 in 4968) and in Israel ¹¹ it was 0.035% (1 in 2857). There is a variable incidence in different parts of the same country. This supports the pattern observed by Danso. ¹²

The difference between incidences in developing countries as compared to those in developed countries is also very great. The variations were attributable on a number of variables such as obstetric risk factors, availability of skilled obstetric personnel, maternity services, the socioeconomic status of the patient, and harmful cultural practices. These factors continue to increase the incidence of ruptured uterus in developing countries.^2–6,12

It was also found that the majority of the patients in this study were unbooked 42 (87.5%), which is comparable to the figure from other parts of the country and in other countries in sub-Saharan Africa.^2–4,6,13

The parity distribution was similar to that in studies in Ibadan ³ and Enugu. ⁶ Twenty people (41.7%) had parity between 0 and 1, 25(52%) had parity between 2 and 3, whereas 3(6.3%) had parity up to 4. Modal parity group was 2–3. This shows that primigravidas are not immune to rupture although uterine rupture is usually associated with grand multiparity. This is in correspondence to similar findings in Ibadan ³ and Enugu ⁶ , Ethopia. ² This also calls for caution in the use of oxytoxics in induction of labor in nulliparous women.

There exist some variations in the etiologic classification of ruptured uterus by different authors. ¹² The most common risk factor for ruptured uterus in this study was the use of oxytoxics in previous cesarean section 24(50.1%). It was difficult to obtain the history of the concentration and protocol for oxytocin in these patients. This is because majority were referred orally from traditional birth attendants, faith-based homes, and maternity homes. Previous cesarean section alone contributed 12 (24.08%) of the ruptured uterus cases. Studies performed at Ibadan and Enugu showed that scarred uterus contributed to 57.1% and 56.5% respectively.^3,6 Also, oxytoxics were used in 30 of the ruptured uterus cases (24 had previous scar, 6 had no previous scar). This compares favorably to the studies in Enugu ⁶ and Ibadan. ³

The predominance of previous scar and use of oxytoxics is in sharp contrast to the study in Benin in which the major risk factors were grand multiparity and prolonged obstructed labor. Previous scar and oxytoxic use contributed minimally in the study. Other risk factors in this study included fundal pressure and obstructed labor, which are well-documented risk factors.^1,12

No consensus has been reached as to the best surgical option that should be used.^3,6,12. The surgical option chosen should be individualized.^3,6,12 The procedure chosen should depend upon the anatomy of the rupture, the condition of the patient, and the skill of the surgeon. It must be safe, short, and feasible. ¹² The need for reproductive function should also be taken into consideration. ¹⁴

In this study, repair with bilateral tubal ligation was the most common surgical operation. This compares with studies in Ibadan ² and Enugu. ⁶ This was followed by subtotal hysterectomy. The maternal mortality ratio was 18,600/100,000. This compares with 17,900/100,000 in Ibadan, 13,000/100,000 in Enugu, 11,000/100,000 in Sokoto, and 24,000/100,000 in Ethopia.

The fetal mortality was high (87.5%) which compares with 91.3% in Enugu, ⁶ 100.0% in Sokoto, ⁴ and 92.9% in Ibadan. ³ This is in sharp contrast to figures in developed countries where the maternal mortality and fetal mortality were < 1.0%.^15–17

The postoperative complications included anemia, wound sepsis, genital sepsis, and deep vein thrombosis. These are all documented complications from rupture.^3,6,8,9,12

Conclusions

In conclusion, uterine rupture constitutes a major obstetric problem at Nnamdi Azikiwe University Teaching Hospital Nnewi. The incidence of ruptured uterus can be reduced drastically by health education, careful selection of patients for vaginal birth after cesarean section, and uptake of antenatal care and provision of emergency obstetric care services that are accessible and affordable. The use of a partogram by midwives in maternity homes, and referral to secondary or tertiary centers once labor passes the alert line are very essential for reduction of the incidence of uterine rupture and its attendant complications. There should be a system for prompt referral of patients. In addition, traditional birth attendants should be integrated into the health system or abolished, because of their poor knowledge of emergency obstetric care. Antenatal care and maternity care services should be made affordable for the general population.