Abortions and sexually transmitted infections among women in St. Petersburg in the early 2000s. Comparison by population based surveys in Estonia and Finland

Background
Abortions and sexually transmitted infections have been very common in Russia while in neighbouring Finland the rates of both abortions and STIs have been stable and relatively low. Estonia, one of the former states of the Soviet Union, has a common history with Russia but different development in reproductive health care in recent decades. Knowing what kind of women are at risk of abortion and STIs helps to organize better health care services.

Objectives
The study aims to describe the main characteristics (socio-demographic and sexual behaviour) of women with abortion or with self-reported sexually transmitted infections in the three areas comparing the characteristics within each area and between the areas, with the main emphasis on women in St. Petersburg.

Materials and methods
Data from four population-based questionnaire surveys were used. In St. Petersburg a questionnaire was sent to a random sample of reproductive aged women residing in two districts of the city. Response rate was 67%. In Estonia a random sample stratified by age was taken for women aged 16–25, 26–35 and 36–44 years. The response rate was 54%. In Finland two surveys were used. The 1991 study was an interview survey and the 1999 study was a postal survey, the response rates being 78% and 52% respectively. The questionnaires used were very similar. The Russian and Estonian questionnaires were made at the same time using the questions from the Finnish surveys as models. Logistic regressions within each area were used to examine the association between women’s characteristics and the use of specific contraceptive methods at last intercourse, women’s abortion history and STIs. The regression models were adjusted for age, marital status and parity, or age only, and for estimation of odds ratios (OR) and 95% confidence intervals (95% CI).

Results
In St. Petersburg an increase in the mean age of first intercourse from those aged 18-24 to those aged 35-44 was found (Paper I). A notable change was found in condom use at first intercourse which was more common among younger respondents than among older ones (I, III). In St. Petersburg reliable contraception (OC, IUD or condom) at last intercourse was used by only half of the women. The highest proportion of OC users was found in the youngest age group and among wealthier women. Condom was the most frequently used contraceptive method, especially among the youngest women. Those with a history of no condom use at first intercourse were less likely to report current condom use. Those who lived in poor conditions or had 1-2 children had a higher probability of using unreliable methods (spermicides, rhythm method, syringing, withdrawal, emergency contraception) at last intercourse. Wealthy women were more likely to have had multiple sexual partners in the previous year and concurrent (parallel) sexual relationships. Most women in St Petersburg had at least one risky sexual behaviour (age at first intercourse <18 years, no using condom at first intercourse, unreliable contraception at last intercourse, multiple sexual partners or concurrent sexual relationships). In Finland most women in all age groups had had their first intercourse at age younger than 18 years and this was more common than in St Petersburg and Estonia. But the proportion of those using a condom at first intercourse was also higher in Finland than among those in St. Petersburg or Estonia. The highest proportion of women who had ever had an abortion or repeat abortions was found in St. Petersburg (II, III). Socio-demographic and behavioural risk-factors for abortion were mostly similar in the three areas (III). In all areas women with an abortion history were more likely to have low education, to have children, to start sexual life at an age younger than 18 years and to have a history of multiple partners. However, in St. Petersburg and Estonia the factor most strongly associated with abortion was number of children while in Finland the strongest factor was multiple sexual partners. Contraception use was related to abortion in all areas. The highest rate of unreliable contraceptive use - both at first and most recent intercourse -was found among women in St. Petersburg and Estonia. The highest prevalence of reporting sexually transmitted infections was found in St. Petersburg and the lowest in Finland. In all study areas women mostly shared similar sexual behaviour risk factors for having three STIs (chlamydia, gonorrhoea, syphilis). Those who had had STIs were more likely to have first intercourse under the age of 18 years, have not used condoms at first intercourse, had a large number of lifetime sexual partners and sexual partners in the past year. In Finland cohabiting and well-educated women were more likely to have had sexually transmitted infections than other Finnish women but no significant association was found in St. Petersburg and Estonia. In Estonia, the characteristics of women having had sexually transmitted infections were mostly similar to those in St. Petersburg. No major differences were found among Russian-speaking and Estonian-speaking women. The women with both abortions and STIs were partly the same women in St. Petersburg but largerly different in Estonia and Finland.

Conclusions
Common use of unreliable contraceptive method or no use in St. Petersburg demonstrate a need to improve reproductive health services, including sexual education and contraceptive provision to a wide range of women of all ages. Even though the sexual behaviour of women in St. Petersburg was more conservative than those in Estonia and Finland the high prevalence of sexually transmitted infections in St. Petersburg suggests a need to take special precautions against STIs, probably due to the epidemic situation. Additionally, the high proportion of those with both abortion and STIs in St. Petersburg should be taken into account in prevention.

• http://urn.fi/urn:isbn:978-951-44-7826-0