BMC Public Health 2007, 7:268 http://www.biomedcentral.com/1471-2458/7/268 hand, the results of a recent systematic review suggested that women with low-risk pregnancies can safely have fewer antenatal care visits [2]. Child-bearing women's own expectations are diverse, some wishing for more and some, specifically women over 35 years of age or with an unfortunate timing of pregnancy, wanting fewer antenatal care visits [7]. Most pertinent studies in this field concentrating on the risk profile of women booking late or not booking at all to antenatal care have shown that the most common bar- riers to attendance at antenatal care in modern Western society are lack of insurance, low income, low educational level, low social class, unmarried status, ethnic origin of the woman, difficulties in obtaining appointments and long distances [8,9]. In Finland, almost the entire (99.8%) pregnant popula- tion attends antenatal care [10] since it is provided by the state free of charge and is easily accessible. Furthermore, the attendance is encouraged by linking the opportunity to receive maternity benefits to the first visit to maternity care units before the 16th week of pregnancy. The average number of 17 antenatal care visits is high [11]. This number exceeds both international standards [2] and national recommendations of 13–17 visits in first preg- nancy and 9–13 visits in others, two of the visits sched- uled after birth [12]. Currently, maternal and perinatal mortality rates [13] and the incidence of suboptimal care are very low [14]. Although the content and frequency of antenatal care are thorough considered, a small minority of women do not attend. The purpose of this study was to assess the outcome of pregnancies when antenatal care has been inadequate – either totally lacking or low in number of visits. Methods We investigated an existing clinical database of the total population of 27776 births at Kuopio University Hospital between 1989 and 2001. Information on maternal char- acteristics was based on data from self-administered ques- tionnaires at approximately 20 weeks of pregnancy, returned to the hospital by 22 weeks of pregnancy. When any data were missing, they were complemented by inter- views with a nurse at the delivery ward. The questionnaire consisted of 75 items, concerning marital status, employ- ment, previous operations, illnesses, obstetric history, contraceptive use, smoking, alcohol consumption and paternal characteristics. Information on pregnancy com- plications, pregnancy outcome and the neonatal period was collected real timely as part of clinical work to the database by the nurses and midwives who took care of delivery and neonatal care. The Institutional Review Board accepted the study and childbearing women gave informed consent at the time of data collection. The ethi- cal committee has accepted the database and given per- mission for using it for research purposes. The data were processed anonymously. Exclusion criteria were: 1) multiple pregnancies (n = 548) and 2) major fetal structural anomalies (n = 275), because such pregnancies carry an unusually high risk of adverse outcome. Information of the number of antenatal care visits was missing from 77 women. Women who had an extensive number of 19 visits or over to antenatal care units, were considered a clinically different group, with high morbidity, and were not included in this study. We analyzed 23 614 births, of which 270 were among women who did not attend antenatal care (non-attenders) and 207 were among women with few antenatal care visits (1– 5, under-attenders). Women with an average number (6– 18) of antenatal care visits, totaling 23137, were used as reference group. Kuopio University Hospital is a tertiary level obstetric referral centre, but it also serves as the only hospital in our district dealing with deliveries. The antenatal care model was general practitioner- and nurse- or midwife-led for women with uncomplicated pregnancies. The appoint- ments were structured and involved clear referral path- ways to university hospital obstetricians when complications arose. Antenatal care was readily and easily accessible to all women. Intrapartum care was obstetri- cian-led and planned home deliveries were exceptional. The women carried their own maternity case notes, and structured, national maternity records were collected. The following definitions were used: Young maternal age was defined as age under 18 years at birth. Women aged over 35 years at birth were considered old parturients. Unmarried status was defined as any civilian status other than marriage (including cohabiting, single, widowed and divorced women). Unemployment status was asked in the questionnaire yes/no. Educational attainment was divided into three categories: high, average and low, according to the women's own evaluation. Grand multi- parity was defined as more than 7 previous deliveries. Prior induced abortion of a viable fetus was separated from miscarriage. An overweight condition was consid- ered when pre-pregnancy body mass index (BMI) was over 25 kg/m2. The woman was considered a smoker if she smoked 5 cigarettes or more per day during pregnancy. Alcohol use was recorded as yes/no. Chronic illnesses were defined as conditions requiring regular medication that has possible effect on pregnancy, specifically, thyroid dis- ease, arthritis, epilepsy, cardio-vascular and kidney dis- eases. Maternal diabetes was defined as insulin-treatment during pregnancy. Chronic hypertension was self reported as a multiple choice concerning maternal illnesses in the questionnaire. Illness data were complemented by infor- Page 2 of 8 (page number not for citation purposes)