Fetal outcome of antepartum and intrapartum eclampsia in Aba,southeastern Nigeria

Introduction

Eclampsia is an emergency obstetric condition that defies ethnic and racial barriers affecting women all over the world. It results in high maternal and perinatal morbidity and mortality, especially in developing countries. ^1–8 Apart from the well-documented complication of intrauterine growth restriction observed in newborns delivered of eclamptic mothers with early-onset preeclampsia, ^9,10 other common perinatal complications related to the eclamptic process in antepartum and intrapartum eclampsia include stillbirth, birth asphyxia and prematurity with their attendant high morbidity and mortality. ¹¹

Though studies on eclampsia are generally rife, there is a scarcity of published works on fetal outcome of eclampsia in Nigeria and Africa as a whole. This study was therefore undertaken to evaluate the fetal outcome of antepartum and intrapartum eclampsia in Abia State University Teaching Hospital, Aba, Southeast Nigeria. It is hoped that the findings would help in formulating policy measures towards reducing the incidence of eclampsia and improving its fetal outcome.

Materials and methods

All cases of newborns delivered by mothers who developed antepartum and intrapartum eclampsia in the Department of Obstetrics and Gynaecology at Abia State University from 1 January 2002 to 31 December 2007 were retrospectively studied.

The hospital was formerly a state government general hospital and was converted into the teaching hospital of the then newly established state university in 1994. It is located in Aba, the densely populated commercial nerve centre of Abia State about 45 km south of Umuahia, the state capital. It serves both as a secondary health-care centre and a referral centre for peripheral hospitals in Aba and the neighbouring states of Rivers and Akwaibom in the Niger Delta (south-south) and Imo (southeast of Nigeria). It has an annual delivery rate of approximately 1100.

Relevant information was obtained by reference to the delivery registers of the Central Delivery Unit and Obstetrics and Gynaecology theatre and mothers' case folders. This included the gestational age, birthweight, five-minute Apgar score of the fetus and the mothers' age, booking status, parity, number of fits before presentation as well as mode of delivery. Diagnosis of antepartum and intrapartum eclampsia was made based on the occurrence of generalised tonic-clonic seizure during pregnancy or delivery after excluding other neurological causes of convulsion. ¹² Booked patients were those who registered for and attended antenatal care in the hospital or other referring hospitals (primary, secondary or tertiary facilities), whereas the unbooked comprised unregistered cases referred or brought to the hospital after the onset of convulsion. The total number of deliveries over the study period was also derived. The fetuses delivered by the eclamptic mothers constituted the subjects of the study. Newborns of eclamptics delivered outside the hospital as well as those of mothers with postpartum eclampsia were excluded from the study.

Data obtained was analysed using simple arithmetic mean, frequency distribution and presented in tables. Ethical approval for the study was obtained from the chief medical director of the hospital.

Results

There were 6598 deliveries in our institution during the study period including 53 cases of antepartum and intrapartum eclampsia (i.e. a hospital incidence of 0.80%). Five of the 53 were excluded from further analysis due to inadequate data.

Ninety-nine (1.5%) of all deliveries in the study period were unbooked. Thirty-three (68.8%) and 15 (31.2%) of the fetuses were delivered following antepartum and intrapartum eclampsia, respectively. All of the fetuses were delivered in the last trimester of pregnancy with a majority (62.5%) occurring from 35 weeks upwards. The mean gestational age of the subjects was 36.8 weeks (range, 28–42 weeks), with a great majority (68.8%) being preterm (Table 1).

The mean birth weight of the babies was 2261 g (range 900–4200 g; Table 2); 87.5% had a five-minute Apgar score of less than seven; 60.4% were stillborn; and 8.3% being severely asphyxiated (Table 3). All of the severely asphyxiated and 45% of the stillbirths were full-sized babies (birth weight 2500 g or more).

One (2.1%) of the patients was over 40 years old; most were aged 20–29 years (54%); four were teenagers aged 16–19 years. The median age of the mothers was 27 years (range, 16–42 years). A large number of eclamptics (33%) had suffered two seizures before presentation. The range of the number of seizures was 1–6 with a mean of 2.3 (Table 4). The median parity of the mothers was 0 (range, 0–7) with nulliparous mothers constituting the highest incidence (62.5%) (Table 5). Forty-three (89.6%) were married. Four of the five unmarried mothers were teenagers.

Forty-one (85.4%) of the eclamptics were unbooked; seven (14.6%) were booked; 34 (70.9%) of the babies were delivered vaginally by induction or augmentation of labour; 14 (29.1%) were delivered abdominally because of an unfavourable cervix. There were 11 maternal deaths, a case fatality of 20.8% and an overall maternal mortality rate attributable to eclampsia of 166.7 per 100,000 hospital deliveries.

Discussion

Eclampsia has remained an obstetric catastrophe associated with significant fetal and maternal morbidity and mortality worldwide, particularly in developing countries. ^13–15

The 0.80% incidence of eclampsia obtained in this study is an in-hospital value and is comparable to 0.91% reported recently from Obafemi Awolowo University Teaching Hospital in Ile-Ife, ¹⁵ southwestern Nigeria, and results obtained from teaching hospitals in Ekpoma ¹⁶ and Nnewi ¹⁷ southern and southeast Nigeria, and much higher than figures from the developed nations. ^18,19

The high numbers of unbooked eclamptics were a result of early interventions in booked pre-eclamptic cases. Also, our study populations are mostly poor, illiterate traders and rural farmers who would rather patronize the traditional birth attendants, churches or, at best, the primary health facilities. They come to us as a last resort if they survive the traditional crude oil pushed into their mouths and eyes in order to cure the fits. In addition, the doors of our tertiary hospital's unbooked delivery suites are not always open. When overwhelmed by work or returning from one of the numerous industrial actions, the unbooked delivery suites may be closed for some time until conditions normalize. Also, our tertiary facility sees more unbooked eclamptics than any other unbooked complications because our average citizen is only motivated to seek tertiary help when confronted by fits that are more frightening to them than any other complication. The result shows that 68.8% and 31.2% of the subjects delivered following ante- and intrapartum eclampsia, respectively. The high proportion of antepartum eclampsia observed in this study is similar to observations in Ile-Ife ¹⁵ and Nnewi ¹⁷ teaching hospitals. However, intrapartum eclampsia was more common in a 2004 study from Benin City (Niger Delta Area). ¹³

The result of the study also indicates that all of the subjects were delivered in the last trimester – 62.5% delivered near term at 35 weeks or above. The HELLP syndrome (haemolysis, elevated liver enzymes, low platelet count) was diagnosed in only three mothers. HELLP can only be diagnosed with a high index of suspicion as the clinical features overlap with those of pregnancy-induced hypertension, pre-eclampsia and eclampsia. ²⁰ Early detection with prompt termination of the pregnancy offers the only hope of a cure. Educating the gravid about sudden weight gain, poor urine production, headaches, light-headedness, visual disturbances, tightness of the upper abdomen and on the need to visit and report promptly to antenatal care staff when such are observed, as well as teaching the staff to reacting quickly and appropriately, improves the detection and management of pre-eclampsia and thereby reduce its high morbidity and mortality.

A larger proportion (58.4%) of the babies weighed less than 2500 g at birth, which is similar to reports from previous studies. ^15,16 Low birth weight may have resulted from prematurity and intrauterine growth restriction (IUGR) due to placental insufficiency caused by prolonged pre-eclampsia. ^15,18 Prematurity and IUGR, among other problems, predispose the fetus to suffer: stillbirth; perinatal morbidity including birth asphyxia; sepsis; hypoglycaemia; seizures; and, possibly, neonatal mortality. ^12,13,15 A majority of the babies (60.4%) were stillborne (Apgar score, 0) and 8.3% were severely asphyxiated.

This could be explained partly by the fact that they were products of antepartum and intrapartum eclampsia and may have suffered anoxia and its asphyxiogenic effect in utero during maternal convulsions. ¹⁵ Also, 62.5% and 85.4% of the mothers in this study were nulliparous and unbooked, respectively. Non-booked status and nulliparity are independently significant risk factors for severe birth asphyxia and even stillbirth. ^19,21 Lack of supervision during pregnancy denies an expectant woman of the possibility of the early detection of complications such as pre-eclampsia, impending eclampsia and HELLP, which may result in maternal and fetal morbidity such as birth asphyxia and stillbirth.

A majority of the eclampsia cases (54%) occurring in the younger age group (less than 30 years old) observed in this study has also been reported in previous studies. ^13,15 Most of the eclamptics in our study had at least two convulsions before presentation, which is consistent with previous findings. ^11,15 The number of convulsions before presentation is related to the extent of delay before arrival at the hospital. Delay in bringing eclamptics to hospital by bystanders or relatives is probably a result of their ignorance of the seriousness of the mother's condition. Seizures also affect the management outcome as fetal and maternal morbidity and mortality are directly proportional to the number of seizures suffered. ¹⁵

A majority of the eclamptics (62.5%) in this study were nulliparous, which is comparable to results reported in previous studies. ^11,15,18 The results of this study indicate that an overwhelming majority of eclamptics (85.40%) had not been booked. Again, this is similar to observations reported in several previous studies. ^11,15,18

A large proportion of the subjects in this study (70.9%) were delivered vaginally because most of the deliveries involved still births. The maternal case fatality rate of 20.8% is definitely quite high when compared to figures seen in developed countries, ²² but is in similar to those reported from tertiary centres in Nigeria. ^13,23

Conclusion

Stillbirths and severe birth asphyxia were the predominant fetal outcomes observed in this study. Non-booking and nulliparity of the mothers were particularly associated with antepartum and intrapartum eclampsia. Sustained and effective education of the general public about the need for early booking, regular attendance to antenatal care and delivery in appropriate healthcare facility by all pregnant women, particularly the nulliparous, are necessary in order to avoid this unacceptable situation. Pregnancy-related issues should also be incorporated in the health education curriculum for adolescents in school health programmes.