Factors associated with inadequacy of prenatal care utilization
Liberata C CoimbraI; Antônio AM SilvaII; Elba G MochelI; Maria TSSB AlvesI; Valdinar S RibeiroIII; Vânia MF AragãoIII; Heloisa BettiolIV
IDepartamento de Enfermagem da Universidade Federal do Maranhão. São Luís, MA, Brasil
IIDepartamento de Saúde Pública da Universidade Federal do Maranhão. São Luís, MA, Brasil
IIIDepartamento de Medicina III da Universidade Federal do Maranhão. São Luís, MA, Brasil
IVDepartamento de Puericultura e Pediatria da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo. Ribeirão Preto, SP, Brasil
OBJECTIVE: To identify factors associated with inadequacy of prenatal care utilization in urban community.
METHODS: A cross-sectional study of a systematic sample stratified by maternity hospital, consisting of hospital births in the municipality of São Luís, Brazil, was carried out from March 1997 to February 1998. Socioeconomic and demographic factors, reproductive health, morbidity during pregnancy, and utilization of prenatal care services were studied. Mothers answered a standardized questionnaire before hospital discharge. The adequacy of prenatal care utilization was analyzed by means of two indexes: APNCU (Adequacy of Prenatal Care Utilization) and a new index based on the recommendations of the Brazilian Ministry of Health.
RESULTS: There were interviewed 2,831 women who delivered at 10 public and private maternity hospitals. The inadequacy of prenatal care utilization was 49.2% according to the APNCU index and 24.5% when determined by the Brazilian index. Prenatal care at public services, low maternal schooling, low income, having no partner, and absence of maternal diseases during pregnancy were associated with inadequacy of prenatal care use according to both indexes. High parity and maternal age of 35 years or more were also associated with inadequacy, whereas primiparity, morbidity, and young maternal age (<20 years) seemed to protect from inadequacy when the Brazilian index was used.
CONCLUSIONS: Prenatal care showed low coverage in the municipality of São Luís. The inadequacy of prenatal care utilization was associated with several factors linked to social inequality.
Keywords: Prenatal care, statistics. Maternal health services. Health services coverage. Quality of health care. Socioeconomic factors. Risk factors. Cross-sectional studies. Equity.
Maternal and child mortality coefficients are influenced by the conditions of prenatal and delivery care, as well as by the biological aspects of human reproduction and the presence of diseases provoked by the gravidic-puerperal cycle. About 98% of womens deaths due to maternal causes would be avoidable by the adoption of relatively simple measures involving the improvement of quality of prenatal care and guaranteed access to health services.2
The coverage of prenatal care is still low in Brazil, although it has been increasing over the last decades. Inequalities in the utilization of care still persist. The percentage of women residing in the rural zone who do not receive prenatal care is high. There is also a wide difference in coverage according to geographic region. In the Northeast region, Maranhão is one of the states where the percentage of women receiving no prenatal care is higher.2
According to official health agencies recommendations, prenatal control should start early in pregnancy, have universal coverage, be carried out in a periodic manner, be integrated with the remaining preventive and curative actions, and involve the minimum recommended number of visits.3 Its success depends largely on its starting time and the number of visits. This number varies according to the pregnancy month when prenatal care is started and intervening events during pregnancy.8,12
Several indexes have been proposed to assess the adequacy of prenatal care utilization. Among them are the Kessner,1 GINDEX and APNCU (Adequacy of Prenatal Care Utilization), proposed by Kotelchuck,6 in 1994) indexes. All of them take into account the number of prenatal visits, the starting pregnancy month, and gestational age at delivery. Since mothers of premature infants have a smaller number of prenatal visits, there is a tendency to overestimate or to identify a non-existing association between higher percentages of inadequacy of prenatal care and preterm births.1 Thus, it is important to adjust any measurement of adequacy of prenatal care according to the duration of gestation in order to reduce this bias, as proposed by the indexes mentioned before.
All these indexes use as a parameter the minimum number of visits recommended by the American College of Obstetrics and Gynecology (ACOG), which ranges from 11 to 14. However, the World Health Organization has recently questioned whether the number of visits recommended by the ACOG is inflated, since some studies have demonstrated there is no significant difference in perinatal outcomes when the number of prenatal visits is reduced.6,10,13
The Brazilian Health Ministry recommends at least six prenatal visits for a term pregnancy involving pregnant women with no detectable risk factors, starting early, i.e., up to the fourth month of pregnancy. The interval between two visits should not exceed eight weeks.8 This number of visits is much smaller than that recommended by the ACOG, which serves as a parameter for the evaluation by means of most of the indexes available.
The objective of the present study is to identified some factors associated with inadequacy of utilization of prenatal care in the municipality of São Luís, Brazil.
A cross-sectional study was conducted in a systematic sample of all hospital births in municipality of São Luís, and stratified according to maternity hospital, from March 1997 to February 1998. The following factors were assessed for 2,831 puerperal women: socioeconomic and demographic indicators, reproductive health, morbidity during pregnancy, and the utilization of prenatal services. Regarding utilization of prenatal care, women were asked whether they had attended prenatal visits and to report the number of visits and pregnancy month when the visits were started. A standardized questionnaire was applied to puerperal women before discharge from the hospital. Details concerning the methodology have been published elsewhere.14
In the analysis of inadequate prenatal care utilization, two indexes were used: the APNCU,6 and a new index formulated by the authors based on the minimum schedule of visits recommended by the Brazilian Health Ministry.8 The latter index took into consideration the number of visits, starting pregnancy month and gestational age at the first visit. This index includes five categories of adequacy: adequate, intermediate, inadequate, no prenatal care, plus a category consisting of subjects with unknown data. Table 1 shows the index categories, as well as a description of each one.
Data were analyzed by descriptive analysis with point estimate and confidence intervals. Logistic regression analysis was also applied using the Stata statistical package in order to determine the association between different independent variables and inadequate utilization of prenatal care.
Socioeconomic and demographic variables (family income, age, maternal schooling, marital status, head of the familys occupation, residence area, mothers occupation, and category of health care), and variables concerning womens reproductive life (previous stillborn, parity, previous low-birth weight infants) and maternal morbidity were included in the logistic regression model.
The risk for all variables included in the analysis was always calculated in relation to the baseline category, which was considered to be the category of lowest risk for the dependent variable under analysis.
The dependent variable inadequate utilization of prenatal care was categorized into three different manners and three different logistic regression models were applied. In the first model the dependent variable was coded zero when the utilization of care was classified as adequate or intensive and coded one in the other cases. In the second model, the dependent variable was coded zero when the utilization of prenatal care was classified as adequate, intensive and intermediate, and coded one when it was classified as inadequate. And in the third model, corresponding to regression with the proposed index, the dependent variable was coded zero when the utilization of care was classified as adequate and intermediate, and was coded one when the utilization of care was classified as inadequate.
In the initial step, all variables associated with the dependent event at a level of significance of 0.20 in non-adjusted analysis were included, whereas only those that continued to be associated at a level of significance of at least 0.10 were included in the final model. The significance of each variable in the model was determined by the likelihood ratio tests by comparing the previous step to the current step, also including the variable in question.
The crude and adjusted odds ratios with their respective 95% confidence intervals were calculated using logistic regression analysis in models with 2,798 observations, after the exclusion of missing values of some variables.
Prenatal care coverage in the municipality of São Luís, considering women who had at least one visit, was 89.5%. However, only 62.9% of puerperal women had five or more prenatal visits, 60.2% started the visits in the first trimester of pregnancy, and 9.3% had no care. The mean number of visits was 6.6.
The National Unified Health System accounted for 84.2% of the visits. Only 3.8% of the visits were private, and 12.0% occurred through a health contract or health insurance.
The inadequacy of utilization of prenatal care according to the APNCU was 49.9% and the adequacy was only 10.0%. The percentage of women receiving an intermediate level of prenatal care was 37.8%. When the adequate level was summed to the intensive one, only 13.0% of pregnant women were found to have received adequate prenatal care.
According to the proposed index, only 49.6% of the puerperal women received adequate prenatal care, i.e., starting by the fourth month of pregnancy and involving a minimum of six visits for a term pregnancy, or a smaller number according to gestational age. The utilization of prenatal care was considered intermediate for 15.2% of mothers, and prenatal care started after the sixth month of pregnancy or women had a number of visits below the minimum recommended for gestational age (being considered inadequate) in 24.5% of cases. The category no prenatal care included 9.3% of the puerperal women and the missing category included 1.4%, who were unable to inform about the month when care was started or number of visits.
Tables 2 and 3 present the estimates of the logistic regression model and the effects of the variables on inadequate utilization of prenatal care according to the APNCU.
The socioeconomic characteristics were those mostly associated with inadequate utilization of prenatal care in the two models. When it was analyzed the association between inadequate utilization of prenatal care and the effect of independent variables, with the intermediate category included as inadequate prenatal care, it was observed that only low maternal schooling (less than nine years) and public health care were associated with inadequate utilization of prenatal care (Table 2).
However, when the intermediate category was also considered to represent adequate utilization of prenatal care, a larger number of variables was associated with the utilization of care. Inadequate utilization was associated with low maternal schooling, low family income, unskilled manual occupation of the head of the family, having no partner, public health care, and absence of maternal morbidity (Table 3).
According to the proposed index, inadequacy was associated with low maternal schooling, low family income, having no partner, care at public health services, high parity, and maternal age of 35 years or more. The occurrence of some morbid maternal episodes, maternal age of less than 18 years and having only one child were protecting factors against inadequate utilization of prenatal care (Table 4).
Although studies that use the starting time of visits and the number of visits to assess inadequate utilization of prenatal care do not provide information about the content, continuity and quality of care received, they provide important information on the extent of care.
According to the APNCU, by summing up adequate and intensive prenatal care level, it can be concluded that, in São Luís, only 13% of women received adequate prenatal care, whereas it was 49.6% when the proposed index was used.
In Pelotas, in the state of Rio Grande do Sul, data from medical records of public health services showed that 37% of mothers received adequate prenatal care based on Kessner index, had six or more visits and prenatal care started before week 20 of pregnancy.15
The adequate and intensive utilization of prenatal care in the municipality of São Luís is intimately related to socioeconomic characteristics such as high level of maternal schooling and care outside the public health services network. When adequate, intensive and intermediate categories were considered to represent adequate utilization of prenatal care, other socioeconomic and demographic factors and factors related to medical care were also found to be associated with inadequate utilization of prenatal care, such as low family income, unskilled manual occupation, having no partner, and care at public services. Several studies have demonstrated the association between schooling level and prenatal care.10,13 In the present study, the lowest levels of maternal schooling were associated with inadequate utilization of prenatal care in all models used.
According to the developed index, it was observed that, except for the variable head of the familys occupation, all the remaining variables were associated with inadequate utilization of prenatal care. In contrast to other studies,5,9 maternal age of less than 18 years seemed to yield a protective effect against inadequate utilization of prenatal care. Other protective factors were having only one child and occurrence of disease during pregnancy. On the other hand, high parity seemed to be a risk factor for inadequacy. Several studies have shown that high parity (four or more children) is frequently related to the risk of inadequate utilization of prenatal care.5 This risk of inadequacy has also been reported to be higher for single multiparous women and low schooling and income women.5,11 It is possible that multiparous mothers, who have greater experience, feel more confident during pregnancy and consider prenatal care less important. Similarly, younger and primiparous women may look for prenatal care at a higher frequency due to their lower experience.
The inadequacy of prenatal care utilization was also higher for women attending public hospitals and with lower schooling and family income. These data agree with those reported in other studies.4,9
The inadequacy of prenatal care utilization was associated with several factors indicative of social inequality, showing that the groups most socially vulnerable receive unsatisfactory prenatal care and clearly demonstrating the inverse care law, whereby resources for health care are distributed inversely to the need.4 It is suggested the use of intervention strategies aimed at groups that require greater attention in order to increase not only the number of pregnant women at risk followed up in the health service network, but also the frequency of visits with an earlier starting time for prenatal care.
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Liberata Campos Coimbra
Rua 13, Quadra 24, Casa 05 COHATRAC IV
65052-040 São Luís, MA, Brasil
Received on 31/1/2002.
Reviewed on 11/2/2003.
Approved on 12/2/2003.
Research supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - Process n. 523474/96-2).
Part of a masters dissertation presented in the Universidade Federal do Maranhão, in 1999.