Risk factors for preeclampsia-eclampsia among Zimbabwean women: recurrence risk and familial tendency towards hypertension

We sought to estimate the risk of recurrence of preeclampsia-eclampsia among Zimbabwean women. Additionally, we sought to assess the extent to which family history of pregnancy-induced or chronic hypertension was predicative of the risk of developing preeclampsia-eclampsia. This hospital based case-control study was conducted at Harare Maternity Hospital, Harare Zimbabwe during the period June 1995 to April 1996. Study participants were 200 women with preeclampsia or eclampsia and 200 normotensive pregnant women serving as controls. Logistic regression procedures were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Among multiparous women, a history of any pregnancy-induced hypertension was associated with a 10.5-fold increase in risk of preeclampsia-eclampsia in a subsequent pregnancy (95% CI 4.7-23.5). Women who reported that their mother or sisters experienced pregnancy-induced hypertension were found to be at an increased risk of preeclampsia-eclampsia (OR = 2.3 and 2.6, respectively). A 2.3-fold excess risk of preeclampsia-eclampsia was associated with paturients' maternal history of chronic hypertension (95% CI 1.3-3.6). The corresponding relative risk of preeclampsia-eclampsia for women reporting to have a sister with chronic hypertension was 2.6 (95% CI 1.2-5.3). Zimbabwean women, like North American and European women, are at increased risk for the recurrence of preeclampsia-eclampsia. Findings from our study and those of others suggest a possible genetic component involved in the multifactorial aetiology of preeclampsia-eclampsia. The information provided here should be useful to clinicians involved in the management of patients with a prior history or family history of hypertension.

Erythrocyte omega-3, omega-6 and trans fatty acids in relation to risk of preeclampsia among women delivering at Harare Maternity Hospital, Zimbabwe

We sought to examine the association between maternal erythrocyte omega-3, omega-6 and trans fatty acids and risk of preeclampsia. We conducted a case-control study of 170 women with proteinuric, pregnancy-induced hypertension and 185 normotensive pregnant women who delivered at Harare Maternity Hospital, Harare, Zimbabwe. We measured erythrocyte omega-3, omega-6 and trans fatty acid as the percentage of total fatty acids using gas chromatography. After multivariate adjustment for confounding factors, women in the highest quartile group for total omega-3 fatty acids compared with women in the lowest quartile experienced a 14% reduction in risk of preeclampsia (odds ratio 0.86, 95% confidence interval 0.45 to 1.63). For total omega-6 fatty acids the odds ratio was 0.46 (95% confidence interval 0.23 to 0.92), although there was suggestion of a slight increase in risk of preeclampsia associated with high levels of arachidonic acid. Among women in the highest quartile for arachidonic acid the odds ratio was 1.29 (95% confidence interval 0.66 to 2.54). A strong statistically significant positive association of diunsaturated fatty acids with a trans double bond with risk of preeclampsia was observed. Women in the upper quartile of 9-cis 12-trans octadecanoic acid (C(18:2n6ct)) compared with those in the lowest quartile experienced a 3-fold higher risk of preeclampsia (odds ratio = 3.02, 95% confidence interval 1.41 to 6.45). Among women in the highest quartile for 9-trans 12-cis octadecanoic acid (C(18:2n6tc)) the odds ratio was 3.32 (95% confidence interval 1.55 to 7.13). Monounsaturated trans fatty acids were also positively associated with the risk of preeclampsia, although of much reduced magnitude. We observed a strong positive association of trans fatty acids, particularly diunsaturated trans fatty acids, with the risk of preeclampsia. We found little support for the hypothesized inverse association between omega-3 fatty acids and preeclampsia risk in this population. Polyunsaturated fatty acids, particularly omega-3 fatty acids, were comparatively lower in Zimbabwean than among US pregnant women. Given the limited inter-person variation in omega-3 fatty acids among Zimbabwean women, our sample size may be too small to adequately assess the relation in this population.

Seroprevalence and risk factors of syphilis infection in pregnant women delivering at Harare Maternity Hospital, Zimbabwe

OBJECTIVE

To evaluate risk factors and outcomes of syphilis during pregnancy.

DESIGN

Hospital based, cross sectional study.

SETTING

Harare Maternity Hospital, Harare, Zimbabwe.

SUBJECTS

A random sample of 2 969 pregnant women.

MAIN OUTCOME MEASURES

Syphilis seroprevalence.

RESULTS

Of the 2 969 women who provided blood samples, 4.8% were RPR positive. Approximately 2.2% of study subjects were RPR positive and TPHA negative. Notably, 2.5% of the population was RPR and TPHA positive at the time of giving birth. Older women had a higher risk of having positive syphilis status (p = 0.057). Increases in parity and gravidity were significantly associated with increased risk of syphilis infection. Prior stillbirths were associated with an increased risk of syphilis infection (odds ratio [OR], 3.4; 95% CI, 1.61 to 7.37; p = 0.001). Syphilis positive mothers were significantly more likely to give birth to syphilis positive newborns (p < 0.0001).

CONCLUSIONS

Our results suggest that there should be more effective antenatal screening and treatment of syphilis in Harare. Syphilis affects many sub-Saharan countries where effective educational outreach, screening, and treatment should take place to prevent the transmission of this venereal disease, especially among reproductive age and pregnant women.

Prenatal care utilization and foetal outcomes at Harare Maternity Hospital, Zimbabwe

OBJECTIVES

To examine the association between adverse infant outcomes and maternal under utilization of prenatal care, among women delivering at Harare Maternity Hospital.

DESIGN

Hospital based, cross sectional study.

SETTING

Harare Maternity Hospital, Harare, Zimbabwe.

SUBJECTS

A random sample of 3,864 pregnant women.

MAIN OUTCOME MEASURES

Prenatal care utilization, maternal socio-demographic information, as well as birth weight and other neonatal outcome characteristics.

RESULTS

Of the total number of women who participated in this study 3,491 (90%) had at least one prenatal care visit. Women receiving no prenatal care, were more likely to be younger, unmarried and to have been transferred for delivery as compared with women receiving prenatal care. Women receiving no prenatal care were seven times more likely to deliver an infant weighing less than 1,500 grams, adjusted odd ratio (OR) = 7.22; 95% confidence interval (CI) 4.58 to 11.39 as compared with those who booked for care. Newborns of unbooked mothers were more likely to have a low apgar score at birth, adjusted OR = 1.71; to have been admitted to the neonatal intensive care unit, adjusted OR = 2.14, and to require intubation, adjusted OR = 3.35. A large proportion of women (31.4%) initiated prenatal care after 30 weeks gestation.

CONCLUSIONS

There were significant differences between maternal characteristics and foetal outcomes in relation to booking status. Under utilization of prenatal care was associated with sub-optimal foetal outcomes. Improving the socio-economic status of women, their education and access to health care, and family planning methods are all strategies that should contribute to the reduction of adverse foetal outcomes.

Seroprevalence of hepatitis C virus infection among indigent urban pregnant women in Zimbabwe

OBJECTIVE

To estimate the seroprevalence of hepatitis C virus (HCV) infection among indigent pregnant women.

DESIGN

A serological survey study of indigent pregnant women admitted for labour and delivery.

SETTING

Harare Maternity Hospital, Harare, Zimbabwe.

SUBJECTS

A random sample of 1,607 women, delivering at the hospital during the study period agreed to participate in the research. Serum samples were available for 1,591 women.

MAIN OUTCOME MEASURES

Serum samples were tested for the presence of antibodies to HCV using a second generation agglutination assay and a third generation enzyme immuno-assay (EIA).

RESULTS

Of the 1,591 women tested 25 (1.6%) were anti-HCV positive (95% confidence interval 1.0% to 2.2%). The frequency of anti-HCV positives was associated with maternal age (p = 0.0202) and maternal syphilis status (p = 0.020). Gravidas aged 25 to 29 years had the highest anti-HCV seroprevalence (3.4%) as compared with gravidas of other age categories (1.0% to 1.5%). Women with serologic evidence of syphilis infection during the index pregnancy had an increased prevalence of anti-HCV as compared with those women without evidence of syphilis infection (7.9% versus 1.4%, p = 0.020). There was some evidence (p = 0.094) that a positive prior history of delivering a stillborn infant was also associated with an increased prevalence of anti-HCV (4.1% vs 1.4%). Other maternal characteristics, including hepatitis B virus carriage status, parity, and whether she had received prenatal care during the index pregnancy were not determinants of maternal anti-HCV status.

CONCLUSIONS

Overall, hepatitis C antibody was detected in 1.6% of indigent women delivering at Harare Maternity Hospital. This proportion of anti-HCV positive pregnant women is similar to estimates published for North American and European women. Factors positively associated with maternal seropositivity in our population included maternal age (between 25 to 29 years), prior history of delivering a stillborn infant, and seropositivity for syphilis during the index pregnancy. Given the relatively low seroprevalence of HCV and the fact that risk factors for HCV infection remain largely unknown, more studies are needed to identify high risk populations likely to benefit from HCV screening and treatment programmes.

Leukocyte selenium, zinc, and copper concentrations in preeclamptic and normotensive pregnant women

Preeclampsia is an important cause of maternal and perinatal mortality worldwide. The etiology of this relatively common medical complication of pregnancy, however, remains unknown. We studied the relationship between maternal leukocyte selenium, zinc, and copper concentrations and the risk of preeclampsia in a large hospital-based case-control study. One hundred seventy-one women with proteinuric pregnancy-induced hypertension (with or without seizures) comprised the case group. Controls were 184 normotensive pregnant women. Leukocytes were separated from blood samples collected during the patients' postpartum labor and delivery admission. Leukocyte concentrations for the three cations were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Concentrations for each cation were reported as micrograms per gram of total protein. Women with preeclampsia had significantly higher median leukocyte selenium concentrations than normotensive controls (3.23 vs 2.80 microg/g total protein, p < 0.0001). Median leukocyte zinc concentrations were 31% higher in preeclamptics as compared with controls (179.15 vs 136.44 microg/g total protein, p < 0.0001). Although median leukocyte copper concentrations were slightly higher for cases than controls, this difference did not reach statistical significance (17.72 vs 17.00 microg/g total protein, p = 0.468). There was evidence of a linear increase in risk of preeclampsia with increasing concentrations of selenium and zinc. The relative risk for preeclampsia was 3.38 (adjusted odds ratio [OR] = 3.38, 95% confidence interval [CI] = 1.53-7.54) among women in the highest quartile of the control selenium distribution compared with women in the lowest quartile. The corresponding relative risk and 95% CI for preeclampsia was 5.30 (2.45-11.44) for women in the highest quartile of the control zinc distribution compared with women in the lowest quartile. There was no clear pattern of a linear trend in risk with increasing concentration of leukocyte copper concentrations (adjusted for linear trend in risk = 0.299). Our results are consistent with some previous reports. Prospective studies are needed to determine whether observed alterations in selenium and zinc concentrations precede preeclampsia or whether the differences may be attributed to preeclampsia-related alterations in maternal and fetal-placental trace metal metabolism.

Hepatitis B virus infection among pregnant women delivering at Harare Maternity Hospital, Harare Zimbabwe, 1996 to 1997

OBJECTIVE

To determine the prevalence of hepatitis B virus (HBV) carrier and infectivity status among pregnant women delivering at Harare Maternity Hospital.

DESIGN

A serological survey study of pregnant women admitted for labour and delivery.

SETTING

Harare Maternity Hospital, Harare, Zimbabwe between June 1996 and June 1997.

SUBJECTS

A random sample of 1,000 women, delivering at the hospital during the study period agreed to participate in the study. Serum samples were available for 984 women.

MAIN OUTCOME MEASURES

HBV carriage status was determined by the presence of hepatitis B surface antigen (HBsAg) by enzyme immunoassay (EIA). Maternal HBV infectivity status was determined by testing all HBsAg positive women for the presence of hepatitis e surface antigen (HBeAg) using EIA.

RESULTS

Overall 246 (25%) women were identified as carriers of HBV (95% confidence interval 22 to 28%). The frequency of HBV carriers did not vary with maternal age, parity or marital status. Only a positive prior history of spontaneous abortion was associated with an increased prevalence of HBV carriage status. Eight of the 246 (3.3%) women identified as HBV carriers tested positive for HBeAg. Hence, 0.8% of the entire study population was found to be at high risk of transmitting HBV to their newborns.

CONCLUSIONS

Our results demonstrate a high prevalence of HBV carriage among women giving birth at Harare Maternity Hospital. None of the demographic variables studied were important predictors of HBV carriage status. The high carriage rate and low infectivity rates suggest that HBV infection is likely to be acquired by horizontal, rather than by vertical means of transmission. Given the scarcity of financial resources, routine testing of mothers for HBsAg may not be feasible. Our results suggest, however, that mass vaccination of all infants, irrespective of maternal HBV carriage status, may be the most effective approach to HBV prevention and control in Zimbabwe.

Plasma tumor necrosis factor-alpha soluble receptor p55 (sTNFp55) concentrations in eclamptic, preeclamptic and normotensive pregnant Zimbabwean women

We sought to examine the relationship between excessive tumor necrosis factor-alpha (TNF-alpha) release (as measured by sTNFp55 plasma concentrations) and risk of eclampsia and preeclampsia, respectively, among sub-Saharan African women delivering at Harare Maternity Hospital, Zimbabwe. In total, 33 pregnant women with eclampsia, 138 women with preeclampsia and 185 normotensive women were included in a case-control study conducted during the period, June 1995 through April 1996. Postpartum plasma sTNFp55 was measured by enzyme linked immunosorbent assay. Women with eclampsia had significantly higher sTNFp55 than normotensive controls (1.87 vs 1.35 ng/ml, P<0.001). Similarly, women with preeclampsia had sTNFp55 concentrations higher than normotensive controls (1.69 vs 1.35 ng/ml, P < 0.001). The odds ratio for eclampsia was 5.00 (adjusted odds ratio (OR) 5.00, 95% confidence interval (CI) 1.20-20.92) among women in the highest quartile of the control sTNFp55 distribution compared with women in the lowest quartile. The corresponding odds ratio and 95% CI for preeclampsia was 2.37 (1.11-5.06). Postpartum plasma sTNFp55 concentrations are increased among Zimbabwean women with eclampsia and preeclampsia as compared with their normotensive counterparts. These findings are consistent with the hypothesized role of cytokines in mediating endothelial dysfunction and the pathogenesis of preeclampsia/eclampsia. Additional work is needed to identify modifiable risk factors for the excessive synthesis and release of TNF-alpha in pregnancy; and to assess whether measurements of sTNFp55 early in pregnancy may be used to identify women likely to benefit from anti-inflammatory therapy.

Risk factors for pre-eclampsia among Zimbabwean women: maternal arm circumference and other anthropometric measures of obesity

Maternal pre-pregnancy obesity is a risk factor for pre-eclampsia (proteinuric hypertension in pregnancy) among North American and European women. We studied the relationship between maternal obesity and risk of pre-eclampsia among Zimbabwean women. A case-control study was conducted at Harare Maternity Hospital, Harare, Zimbabwe, between June 1995 and April 1996. Study participants were 144 women with pre-eclampsia and 194 normotensive women serving as controls. Maternal weight, height and mid-arm circumference were measured and recorded during study participants' postpartum hospital admission. Maternal mid-arm circumference, considered to be relatively stable during pregnancy among women of developing countries, was used as the primary indicator of maternal pre-pregnancy obesity. Logistic regression procedures were used to estimate odds ratios and 95% confidence intervals. There were linear trends in risk of pre-eclampsia with increasing mid-arm circumference, increasing weight and increasing body mass index. After adjusting for potential confounding factors, women in the highest quintile for mid-arm circumference (28-39 cm) were 4.4 times more likely to have had their pregnancy complicated by pre-eclampsia than women in the lowest quintile (21-23 cm). Odds ratios of similar magnitude were observed for the other anthropometric measures. To our knowledge, this is the first study to demonstrate a positive association between maternal obesity and pre-eclampsia risk in a black African population. Biological mechanisms thought to explain this relatively consistent epidemiological finding include endothelial cell injury, possibly resulting from hyperlipidaemia.

Dietary risk factors for pre-eclampsia among women attending Harare Maternity Hospital, Zimbabwe

OBJECTIVE

To identify specific foods that predispose Zimbabwean women to a higher or lower risk of pre-eclampsia and/or eclampsia.

DESIGN

A case control study was implemented. Participants were asked by questionnaire to recall the specific amounts of meats, poultry, fruits, fish, vegetables and dairy products they had consumed in the month prior to giving birth.

SETTING

Harare Maternity Hospital, Harare, Zimbabwe between June of 1995 and April of 1996.

SUBJECTS

180 women clinically diagnosed with pre-eclampsia (144) or eclampsia (36), and 194 normotensive women without these conditions.

MAIN OUTCOME MEASURES

Pre-eclampsia/eclampsia.

RESULTS

There were few associations between consumption of specific food items and the occurrence of pre-eclampsia/eclampsia. Meat and fruit were the only foods found to be significantly associated with pre-eclampsia. Women who consumed 12 or more servings of meat per month were more likely to have pre-eclampsia/eclampsia when compared to women eating 11 servings of meat or less per month. While intake of bananas and mangos was unrelated to risk, women who consumed other fruits (i.e. apples, oranges, grapes, peaches, apricots, paw paw, and plums), were 1.7 (95% CI = 1.0 to 3.1) times more likely to develop pre-eclampsia/eclampsia as women who ate none of these fruits. However, women who consumed relatively large quantities of these fruits were not at a particularly high risk. Increased consumption of kapenta was modestly associated with a decrease in disease risk, but this finding was well within the limits of chance and no association was present with intake of other types of fish.

CONCLUSIONS

Our findings suggest that variation in consumption of specific foods do not have a strong effect on the incidence of pre-eclampsia in this population. However, further research involving the use of a more comprehensive dietary measure, biochemical measurements of nutrients, pre-pregnancy assessment and ascertainment of dietary intake prior to the development of pre-eclampsia are needed.

Hypertension in pregnancy--a major hospital cause for concern

OBJECTIVE

To document the contribution made by hypertensive disease of pregnancy on maternal and foetal outcome in order to suggest possible changes in management.

DESIGN

A descriptive study.

SETTING

Harare Hospital-a tertiary referral hospital in Zimbabwe.

SUBJECTS

Records of all women seen in the Unit were reviewed on a daily basis by one research fellow.

MAIN OUTCOME MEASURES

Predefined events related to maternal and foetal outcome.

RESULTS

A total of 354 women out of 4,846 cases reviewed were admitted for hypertensive related problems. Seven hundred and thirteen women were admitted to the antenatal ward, 39.8% because of hypertension; 55.6% were multiparous. Hypertensive women stayed in the antenatal ward for a mean of 7.9 days and gestation on admission was over 32 weeks in 64.4% of cases. Low birthweight, preterm labour, perinatal and maternal mortality and all measures of short term perinatal morbidity were significantly increased in the hypertensive group.

CONCLUSION

The results clearly demonstrate the reproductive health issues associated with hypertension in pregnancy. The discussion focuses on methods to improve the management of these women.