Clinical, provider and sociodemographic predictors of late initiation of antenatal care in England and Wales. Emil Kupek a. , Stavros Petrou b,*, Sarah Vausec.
BJOG: an International Journal of Obstetrics and Gynaecology March 2002, Vol. 109, pp. 265 –273
Clinical, provider and sociodemographic predictors of late initiation of antenatal care in England and Wales Emil Kupeka, Stavros Petroub,*, Sarah Vausec, Michael Mareshc Objective To identify factors that are predictive of late initiation of antenatal care in England and Wales. Design A multivariate binomial regression model was constructed to examine the association between clinical, provider and sociodemographic characteristics and late initiation of antenatal care. Setting Nine maternity units in Northern England and North Wales. Population A total of 20,771 women with a singleton pregnancy who delivered a liveborn or stillborn baby between 1 August 1994 and 31 July 1995. All analyses were based on the 17,765 (85.5%) women for whom information on gestational age at initial presentation for antenatal care and other variables incorporated into the regression model was retrievable from the case records. Results Primiparous women of high obstetric risk were 13.4% more likely to initiate antenatal care after 10 weeks of gestation than a low risk reference group (adjusted OR 1.134, 95% CI 1.011, 1.272; P ¼ 0.0312), and 34.3% more likely to initiate antenatal care after 18 weeks of gestation (adjusted OR 1.343, 95% CI 1.046, 1.724; P ¼ 0.0208). This association between high obstetric risk status and late initiation of antenatal care was not replicated among multiparous women. When the effects of other independent variables on gestational age at booking were examined, the following characteristics were associated with failure to initiate antenatal care by 10 weeks of gestation ( P 0.05): maternal age at booking, smoking status, ethnicity, type of hospital at booking, the planned pattern of antenatal care and the planned place of delivery. Adopting a criterion of 18 weeks of gestation exacerbated the association between clinical and sociodemographic characteristics and late initiation of antenatal care, but appeared to dilute the association between provider characteristics and late initiation of antenatal care. Conclusions There is a pressing need for further research to identify the specific concerns of late bookers, to identify areas where new interventions might encourage the uptake of services and to gauge the likely impact of increased dissemination of information about the availability of antenatal care services.
INTRODUCTION Antenatal care is generally recognised as an effective method of preventing adverse outcomes in pregnant women and their children1. The combination of the imparting of information, facilitation of education, screening for abnormalities and complications, ongoing assessment and care, and preparation for delivery and motherhood are considered to be an effective means of detecting and treating ailments, providing timely intervention, promoting health and facilitating informed choice.
a
Department of Public Health, Centro de Ciencias de Saude, Santa Catarina Federal University, Trinidad, Brazil b National Perinatal Epidemiology Unit, Institute of Health Sciences, University of Oxford, UK c Royal College of Obstetricians and Gynaecologists Audit Unit, St Mary’s Hospital for Women and Children, Manchester, UK * Correspondence: Dr S. Petrou, National Perinatal Epidemiology Unit, Institute of Health Sciences, University of Oxford, Old Road, Headington, Oxford OX3 7LF, UK. D RCOG 2002 BJOG: an International Journal of Obstetrics and Gynaecology PII: S 1 4 7 0 - 0 3 2 8 ( 0 2 ) 0 0 5 2 4 - 4
Although many antenatal care practices have been introduced without proper scientific evaluation1, and disagreements remain about the appropriate number and timing of antenatal visits2, the benefits of initiating antenatal care during early pregnancy are not disputed. Eight national clinical practice guidelines for the content of antenatal care, developed to promote consistency in practice and to reduce inappropriate interventions, highlight the value of initiating antenatal care during early pregnancy3 – 10. Interventions generally recommended during the first trimester include blood pressure measurement; a full blood count that will give information about the haemoglobin level, red blood cell indices, the white cell count and the platelet count; screening for rubella immunity, syphilis infection, hepatitis B virus, human immunodeficiency virus and asymptomatic bacteriuria; anti-smoking and dietary advice; and a full assessment of the woman’s medical history and obstetric risk. By the early second trimester, further interventions are recommended, such as routine ultrasonography for the detection of fetal anomalies. The benefits of initiating antenatal care during the first and early second trimesters appear to be supported by epidemiological studies. These studies have demonstrated an association between gestational age at the initiation of antenatal care and maternal www.bjog-elsevier.com
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and infant outcomes, after controlling for confounding factors, such as the overall duration of pregnancy11 – 13. To ensure that adequate antenatal care is delivered during early pregnancy, a clear understanding is required of the factors that currently influence initiation of the care process. Documented external or organisational barriers to early initiation of antenatal care include financial barriers, such as the lack of health insurance14 – 26, difficulties in obtaining an appointment17,20,25,27,28, long distances from care settings17,19, problems with child care17,25 and lack of transportation25,29. Documented sociodemographic barriers to early initiation of antenatal care include non-caucasian ethnic origin 15,18 – 20,22 – 24,26,27,30 – 33 , young maternal age20,22 – 26,30,31,34, few educational achievements on the part of the mother 20,23,24,26,30,31, low social class17,31,34,35, low parental income 19,24,25, unmarried status of the mother 20,23,31,36 and high parity 20,23,25,27 – 31,34,37. Furthermore, a number of intrinsic psychosocial or cultural barriers to early initiation of antenatal care have been reported. These include an unwanted pregnancy23,25,33,38,39, failure to recognise pregnancy symptoms17 – 19,24,25,35, fear of parental response35 and fear of drug use being detected40. The majority of the studies published to date have been conducted in the United States. Consequently, they are limited in their generalisability to the British context by differences in the coverage of the health care system, as well as the greater availability of public transportation and shorter distances than would characterise much of the USA. The study reported in this paper uses a recently collected data set to determine, for the first time, the relative associations between clinical, provider and sociodemographic variables and late initiation of antenatal care in England and Wales. Moreover, the study is unique in that it is, to our knowledge, the first to consider the independent association between women’s obstetric risk and the late initiation of antenatal care. This represents an important methodological advance in that it permits an assessment of whether the clinical needs of women are being met in a context within which antenatal care services are free at the point of service delivery and most external or organisational barriers to antenatal care seeking appear to be absent.
METHODS Source of data This study uses data from a retrospective survey of the antenatal experiences of women conducted by two of the authors41. The sampling frame for the survey included all women with a singleton pregnancy that delivered a liveborn or stillborn baby between 1 August 1994 and 31 July 1995 at nine maternity units in Northern England and North Wales. These units were selected within areas that reflect geographical variations, as well as variations in the size and teaching status of the institution. Furthermore, care was
taken to ensure that the selected maternity units offered the complete spectrum of antenatal care management models currently available within the British National Health Service (NHS). This included consultant based care, shared care, team midwifery, general practitioner and community midwife care. The sampling frame for the survey included women with a singleton pregnancy regardless of method of conception. However, women with multiple pregnancies and women who had received part of their antenatal care in a different hospital setting or in a private health care setting were excluded. This ensured that, as far as possible, the population studied reflected users of antenatal care resources in the British NHS. A research assistant based at each of the maternity units extracted all data required for the study from women’s case records. In eight of the nine maternity units, data were entered directly from the case records into a purpose built data entry programme with on line validation. Data entry was performed at each unit by the research assistant who received training and supervision by a research fellow (S.V.) to ensure consistency. At the ninth and smallest maternity unit, data were entered onto forms by midwives and then entered electronically by the research fellow. The complete data set was then verified by dual coding and cross-checking study records against separately held hospital records of key variables. It was thought that missing records for eligible women who were delivered during the period of the survey might relate to increased obstetric risk. To ensure that a biased sample had not been obtained, basic obstetric data on each of these women was also obtained directly from the maternity units.
Study design The basic analytic problem was the identification of factors that are predictive of late initiation of antenatal care. In order to address this problem, the gestational age at which women first presented for antenatal care was converted into a binary variable, representing either early or late initiation, and then modelled as a function of obstetric risk factors identified at booking, provider characteristics and sociodemographic characteristics. Late initiation of antenatal care was defined by two time points: 1. later than 10 weeks of gestation and 2. later than 18 weeks of gestation. The former time point fell towards the upper limit of the range recommended by eight national clinical practice guidelines for the content of antenatal care3 – 10, while the latter time point fell beyond the recommended range and was considered by the authors to represent the final time point at which antenatal care can safely be initiated. Obstetric risk factors identified at booking were defined a priori by the study working group using information gathered from seven seminal pieces of empirical work within obstetrics42 – 48. These risk factors included a history D RCOG 2002 Br J Obstet Gynaecol 109, pp. 265 – 273
PREDICTORS OF LATE INITIATION OF ANTENATAL CARE
of diabetes mellitus, cardiac disease, essential hypertension, renal disease, thrombosis, substance abuse and a range of less prevalent disorders (including anorexia, asthma, depression, epilepsy and schizophrenia). Furthermore, they included diminutive stature (18 weeks
n
11 – 18 weeks
>18 weeks
37.6 37.8 34.4 40.9 35.5 36.7 39.7 37.1 35.3 38.8 28.8 40.1 24.6 38.9 40.9 30.5 34.6 38.1 27.8 42.1 25.3 36.0 34.3 38.7 55.0 41.6
7.3 7.7 5.7 16.3 9.9 4.6 7.3 6.6 8.1 4.9 12.4 19.0 6.1 17.5 8.4 5.2 5.9 7.4 5.5 6.0 15.2 7.3 8.6 5.2 4.6 4.5
2802 2658 1795 609 2944 3438 264 5606 1649 5350 76 489 1107 233 3740 2233 1282 4807 1280 1048 120 6000 302 744 193 16
36.9 37.7 29.5 40.9 34.0 35.3 38.6 35.8 34.0 37.9 27.6 35.2 23.9 34.3 40.1 29.9 31.0 37.0 25.9 40.9 24.2 34.8 32.1 36.8 50.8 0.1
6.1 6.9 5.7 15.8 9.0 2.4 5.7 6.3 6.4 4.8 10.5 20.4 5.1 15.4 7.3 5.0 5.6 6.7 5.0 5.1 15.0 6.7 5.6 4.2 3.6 0.0
2527 4251 3732 58 2811 6506 1135 7870 2640 7218 101 1293 1542 356 5680 3112 1718 6595 1846 1853 216 8325 482 1385 245 73
38.3 37.9 36.8 41.4 37.1 37.4 39.9 38.1 36.1 39.5 29.7 42.0 25.0 41.8 41.4 31.0 37.3 38.9 29.2 42.8 25.9 36.8 35.7 39.7 58.4 39.7
8.7 8.3 5.8 22.4 10.9 5.8 7.7 6.9 9.2 5.0 13.9 18.5 6.9 18.8 9.1 5.3 6.2 7.9 5.9 6.6 15.3 7.7 10.4 5.8 5.7 5.3
* Combines results for GP/midwife care without team midwifery, GP/midwife care with team midwifery and midwife only care.
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Table 2. Binomial regression showing adjusted odds of initiating antenatal care after 10 weeks and 18 weeks gestation: all women for whom information was available (n ¼ 17,765). OR ¼ odds ratio; TM ¼ team midwifery. Independent variables
Levels
n
Booked after 10 weeks gestation Adjusted OR*
Risk category
Maternal age Smoking status Ethnicity
Hospital type
Planned pattern of antenatal care
Planned place of delivery
Low risk multiparous High risk multiparous Unknown risk multiparous Low risk primiparous High risk primiparous Unknown risk primiparous Per year change Non-smoker Smoker White British Indian Pakistani No information All others Urban non-teaching Urban teaching Rural district general Shared care without TM Shared care with TM GP/midwife/TM care** Hospital consultant care Hospital consultant unit Satellite consultant unit GP unit within hospital Isolated GP unit Home
2527 4251 3732 2802 2658 1795 17765 13476 4289 12568 177 1782 2649 589 9420 5345 3000 11402 3126 2901 336 14325 784 2129 438 89
(95% CI)
P
y
1.000 0.987 0.873 0.854 0.925 0.599 0.983 1.000y 1.123 1.000y 0.731 1.588 0.409 1.591 1.000y 0.546 0.589 1.000y 0.586 1.393 0.913 1.000y 0.709 0.654 1.420 1.076
Booked after 18 weeks gestation Adjusted OR*
(95% CI)
P
(0.954,1.441) (0.728,1.147) (0.534,0.861) (0.736,1.169) (0.505,0.876) (0.915,0.941)
0.1294 0.4374 0.0014 0.5266 0.4374
