Venous thromboembolism and subsequent permanent work-related disability

Essentials The burden of venous thromboembolism (VTE) related to permanent work-related disability is unknown. In a cohort of 66 005 individuals, the risk of work-related disability after a VTE was assessed. Unprovoked VTE was associated with 52% increased risk of work-related disability. This suggests that indirect costs due to loss of work time may add to the economic burden of VTE.

SUMMARY

Background The burden of venous thromboembolism (VTE) related to permanent work-related disability has never been assessed among a general population. Therefore, we aimed to estimate the risk of work-related disability in subjects with incident VTE compared with those without VTE in a population-based cohort. Methods From the Tromsø Study and the Nord-Trøndelag Health Study (HUNT), Norway, 66 005 individuals aged 20-65 years were enrolled in 1994-1997 and followed to 31 December 2008. Incident VTE events among the study participants were identified and validated, and information on work-related disability was obtained from the Norwegian National Insurance Administration database. Cox-regression models using age as time-scale and VTE as time-varying exposure were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for sex, body mass index, smoking, education level, marital status, history of cancer, diabetes, cardiovascular disease and self-rated general health. Results During follow-up, 384 subjects had a first VTE and 9862 participants were granted disability pension. The crude incidence rate of work-related disability after VTE was 37.5 (95% CI, 29.7-47.3) per 1000 person-years, vs. 13.5 (13.2-13.7) per 1000 person-years among those without VTE. Subjects with unprovoked VTE had a 52% higher risk of work-related disability than those without VTE (HR, 1.52; 95% CI, 1.09-2.14) after multivariable adjustment, and the association appeared to be driven by deep vein thrombosis. Conclusion VTE was associated with subsequent work-related disability in a cohort recruited from the general working-age population. Our findings suggest that indirect costs because of loss of work time may add to the economic burden of VTE.

Ante- and postnatal risk factors of venous thrombosis: a hospital-based case-control study

OBJECTIVE

To study ante- and postnatal risk factors of venous thrombosis (VT) in pregnancy.

METHODS

A hospital-based case-control study. Cases were women with objectively verified VT during pregnancy or postpartum. Two controls were selected for each case. Validated risk factors were analyzed using chi-square test and logistic regression.

RESULTS

In total 559 cases with no prior VT, 268 ante- and 291 postnatal cases were identified together with 1229 controls. Risk factors for antenatal VT were assisted reproduction technique (ART), antepartum immobilization, cigarette smoking, and slight weight gain (<7 kg). Conception after ART and multiple pregnancy had an additive effect, whereas antepartum immobilization and high body mass index (BMI) had a multiplicative effect on the risk for antepartum VT. No other interaction was found between risk factors for antepartum VT. Risk factors for postnatal VT were antepartum immobilization, cigarette smoking, intrauterine fetal growth restriction (IUGR), preeclampsia, emergency cesarean section, postpartum hemorrhage, infection, surgery, and age and parity. Antepartum immobilization, high BMI and reoperation on the indication of bleeding showed multiplicative effects on the risk of postnatal VT.

CONCLUSIONS

Ante- and postpartum risk factors differed markedly. More attention should be paid to pregnant women of high BMI who are immobilized.

Time trends in ectopic pregnancies in a Norwegian county 1970–2004—a population-based study

BACKGROUND

The study objective was to estimate temporal trends in ectopic pregnancy in a well-defined population.

METHODS

We identified patients with ectopic pregnancy in hospital discharge registries in Sør-Trøndelag County, Norway, 1970-2004, and retrieved data from medical records. We calculated age-specific ectopic pregnancy incidence, proportions of patients with first ectopic pregnancy/prior infertility treatment, incidence of ectopic pregnancy by birth cohort and age and ratio of ectopic pregnancy to live births (extrauterine ratio) by age and parity.

RESULTS

Age-adjusted ectopic pregnancy incidence rates increased from 4.3 to 16.0 per 10 000 women-years over the period 1970-1974 to 1990-1994 and declined to 8.4 per 10 000 women-years in 2000-2004. Incidences were highest among women aged 25-34 years throughout the study period. We observed decreases in proportions of women with previous ectopic pregnancy and with prior infertility treatment after 1990-1994. Incidence rates were the highest for women born between 1960 and 1964 in all age groups. Extrauterine ratio increased with age and was higher for women with two or more previous births compared with women with none or one prior birth.

CONCLUSIONS

The epidemic increase in ectopic pregnancy towards 1990-1994 was followed by a marked decrease.

[Can human papillomavirus testing and vaccination prevent cervical cancer?]

BACKGROUND

Cervical cancer is the third most frequent cancer among women worldwide. Human papillomavirus (HPV) infection is a necessary risk factor and the first step in cervical carcinogenesis.

MATERIAL AND METHODS

This article reviews the current literature concerning the possibility of preventing cervical cancer by HPV testing and vaccination.

RESULTS

HPV testing cannot replace cytology, but will reduce false negative cytology and may improve the screening programme for cervical neoplasia. It has not yet been incorporated in any national cervical cancer screening program, but trials are ongoing in Scandinavia and in the Netherlands. The cost-effectiveness of HPV testing in screening has to be proven and whether it can affect the recommended screening-intervals. Therapeutic and prophylactic vaccines for HPV associated disease are in progress. Evaluating the clinical trials that are ongoing will take several years. Several anti-HPV vaccines are now in clinical trials; Norway will also participate. Therapeutic vaccines against cervical cancer have so far not been successful, but anogenital dysplasias and condylomas may be more susceptible. Prophylactic vaccines against HPV 6, 11, 16 and 18 have been evaluated in clinical phase I and II trials, and phase III trials are in progress.

INTERPRETATION

HPV testing improves the specificity and sensitivity of cervical cytology and it can be used to clarify cases with atypical cells of undetermined significance (ASCUS) and low-grade intraepithelial neoplasia. In the near future it may also be included in the cervical cancer screening programme for women above the age of 30. The first results in clinical vaccine trials are encouraging, and final conclusions about the effectiveness of these vaccines may be achieved in five years' time.

Primary treatment of cervical carcinoma. Ten years experience from one Norwegian health region

OBJECTIVE

To study the primary care of cervical carcinoma with regard to clinical and pathological factors, treatment decisions, complications and survival.

DESIGN

A historical cohort comprising all women hospitalized with invasive cervical carcinoma (n=293) during the period 1987-1996.

RESULTS

Median age was 52 years (range 23-90). FIGO stage distribution was 62%, 15%, 18% and 5% in stages I, II, III and IV, respectively. Early stage disease correlated with young age. Histologic types were: squamous cell carcinoma 84%, adenocarcinoma 11%, adenosquamous carcinoma 4% and small cell/anaplastic carcinoma 1%. Primary therapies were: surgery 188 women (64%), radiotherapy 99 women (34%), chemotherapy two women (0.7%); four women not treated (1.3%). Complications after surgery in 25 women (13%), none were fatal. Acute or late complications after primary or postoperative radiotherapy in 39 women (25%), seven (4.6%) were late serious complications. Three women died from complications related to radiotherapy. Mean follow-up of surviving patients was 58 months. Overall disease specific five-year survival was 70%. Five-year survival in stages IA, IB, II and III was 100%, 88%, 58% and 20%, respectively. One-year survival in stage IV was 31%. Median survival in stages III and IV according to curative or palliative aim of treatment was 20 and 6 months, respectively (p<0.005).

CONCLUSION

Satisfactory quality of diagnosis and therapy have been maintained through regional care for cervical cancer patients.

Retesting and follow-up of first-catch urines from men yield variable results with three Chlamydia trachomatis nucleic acid amplification tests

First-catch urines from 276 asymptomatic male military recruits were screened by polymerase chain reaction for the detection of Chlamydia trachomatis. Eight initially positive specimens were retested by polymerase chain reaction, ligase chain reaction and transcription-mediated amplification. Urine specimens from six (2.2%) subjects were considered to contain C. trachomatis. However, retesting of serially collected urines from five of these six subjects using different nucleic acid amplification methods showed some discrepancy. This may have a major impact on the efficacy of screening programs for C. trachomatis in low prevalence populations.

Oral contraceptive failures among women terminating their pregnancy

BACKGROUND

There are several methodological problems when studying contraceptive efficacy. The present study focuses on efficacy issues from the use of oral contraceptives (OC).

METHODS

Through a computerized system of medical records kept at the Department of Gynecology, Regional Hospital of Trondheim, Norway, 800 OC-failure pregnancies were identified among 8192 women having pregnancy termination from January 1, 1987 to December 31, 1996. Ascertainment of cases was done by validating hospital data on OC failures by data collected by the referring practitioner. Inconsistencies in failure data were found among 257 of the 800 (32%) women who claimed at the hospital that an OC was in use at time for conception. The medical record kept by their practitioners stated that 158 women had stopped using OC before last menstrual period, of the remaining 99 women neither data on actual use nor data on prescription could be confirmed.

RESULTS

Over the 10-year study period the proportion of failures by brand of OC was remarkably constant from year to year and reflected the user pattern of OCs in Norway. One-third of the total number of failures (n=523) were claimed to be method failures. The annual overall OC-failure rate was estimated to be 1% during the 10-year study.

CONCLUSION

Case-control studies focusing on efficacy of OCs must be carefully designed and comprise both women carrying a pregnancy to term as well as women terminating their pregnancies. Our study focused on only one segment of the population of women experiencing an OC failure: women having pregnancy termination. The present study has shown that exposure data collected from interviews have to be validated against prescription data.

Prevalence of GB virus C (also called hepatitis G virus) markers in Norwegian blood donors

GB virus C (GBV-C), also called hepatitis G virus (HGV), occurs worldwide, but the clinical significance of this virus is still unclear. Plasma samples from 1,001 blood donors were tested by reverse transcription PCR using primers from the NS5 region and by a commercial enzyme-linked immunosorbent assay (ELISA) for the detection of immunoglobulin G antibodies against the putative envelope of HGV (anti-HGV E2). GBV-C/HGV RNA was present in the plasma from 2.5% of the blood donors, and anti-HGV E2 antibodies could be detected in 10.5% of the samples. Only one of the blood donors with viremia had elevated levels of alanine aminotransferase. Among ELISA-positive donors, there was a significantly higher percentage (16.5%) of individuals who had been treated by acupuncture than individuals who had not been given this treatment (9.4%). No other variables showed significant differences. Screening of medical records from 401 recipients of blood from PCR-positive donors revealed no association with liver disease. Four of 12 partners (33%) were HGV RNA positive, and sequence analyses of the strains showed that four of the couples probably were infected with the same strains, while strains from different couples were not identical. Anti-HGV E2 antibodies were detected in serum samples from four other partners. The prevalence of GBV-C/HGV among blood donors in our region is dramatically higher than the prevalence of hepatitis C virus (0.03%).

[Reporting of adverse drug reactions to the Norwegian Drug Control Agency]

This article reports on a retrospective study in two major Norwegian hospitals of spontaneous reporting to the Adverse Drug Reaction Committee of the Norwegian Medicines Control Agency of adverse reactions from the use of oral contraceptives (OCs) among patients with a diagnosis of venous thromboembolism. In these two hospitals, 168 women between 15 and 44 were diagnosed with a first event of venous thromboembolism during the ten-year period up to the end og 1997; 69 of them were OC users at the time of diagnosis. Three medical records (4%) kept at the hospital contained information on a report of adverse drug reaction to the Norwegian Medicines Control Agency. The Agency's database of all spontaneous reports on adverse drug reactions contains 112 reports of venous thromboembolism in the context of OC use. These reports came from all over Norway during the ten-year period of our study; four of the reports came from the study hospitals. We conclude that venous thromboembolism during the use of OCs was underreported by more than 90%. This corresponds to estimates of underreporting of other adverse drug reactions from the use of various compounds, in Norway as well as in other countries.

[Pulmonary embolism among young non-pregnant women]

This study focuses on the incidence and risk profile among young women with a diagnosis of pulmonary embolism over the 10-year period 1988-97. A total of 66 non-pregnant women aged 15-44, treated for the first event of pulmonary embolism, were identified by discharge diagnosis at two main Norwegian hospitals (The Regional Hospital of Trondheim and Ullevål Hospital, Oslo). The estimated overall incidence of pulmonary embolism was 6.8 per 100,000 women-years. The crude incidence decreased from 7.5 per 100,000 women-years in 1988-90 to 4.1 per 100,000 women-years in 1996-97 (p < 0.1). 25 (38%) of the 66 patients were identified with at least one medical risk factor, four patients (6%) with a family history of thrombophilia and 30 patients (45%) used oral contraceptives (OC) at the time of diagnosis. 25 (68%) of the 37 patients without registered risk factors used OC. The incidence of pulmonary embolism decreased during the 10-year period, with unchanged risk profile. Two women (3%) died from pulmonary emboli shorter than three weeks after onset of symptoms.

[Deep venous thrombosis in young women in Norway]

The incidence and distribution of risk factors in non-pregnant women diagnosed with deep vein thrombosis is not well known and was the target of the present study. The medical records of 102 non-pregnant women aged 15-44 hospitalized with deep vein thrombosis at two major Norwegian hospitals were examined retrospectively. The overall incidence of first event of deep vein thrombosis remained fairly constant over the 10-year study period and was estimated at 10.5 per 100,000 women-years. The incidence increased with age and was found twice as high for women 35-44 years of age when compared with the 15-34 age group. Forty-three (42%) of the patients had no identifiable risk factors. Surgery or trauma was found in 37 (36%) of the patients, eight (8%) had a diagnosis of associated cancer, and five (5%) were drug addicts. Five of eight patients registered with immobilization had immobilizing chronic neurological diseases. Thirty-nine (38%) of the patients used oral contraceptives at the time of diagnosis, and 14 of the 39 users of oral contraceptives were identified with medical risk factors. Over the 10-year study period there was no change in the incidence of venous thromboembolism and the risk profile among cases remained constant.

[Sale of oral contraceptives, births and abortions prior to and after the "Marvelon issue"]

This study focuses on the situation in Norway after the UK Committee on Safety of Medicines issued an alert on an increased risk of venous thromboembolism with third-generation OCs on 18 October 1995. The Norwegian Medicine Control. Agency immediately issued a press release warning Norwegian women about the health risk associated with third-generation OCs (in Norway, the drug Marvelon only). In this study the effects of the Norwegian warning are evaluated by the use of data on the sale of OCs, number of induced abortions, and births by quarter for the 1992 to 1998 period. From third quarter 1995 to first quarter 1996, sales of Marvelon to pharmacies dropped by 75%, while total sales of OCs were reduced by 5%. From late October 1995 thorough January 1996, approximately 50,000 women stopped taking Marvelon. A maximum increase of 200 induced abortions could be attributed to the negative news on OCs in October and November 1995. There was no subsequent change in the birth pattern. These data confirm that Norwegian women who shifted to another type or stopped taking OCs during the 1995 media crisis avoided unplanned pregnancies.

[Induction of abortion in the second trimester by prostaglandin vagitories]

Medical termination of pregnancy in the second trimester is a painful and a time-consuming procedure. This study comprises 110 consecutive second trimester terminations of pregnancy performed 1994-96. In 76 women (69%) the procedure was a legal abortion due to foetal malformations, 25 women (23%) had an intrauterine foetal death, and in 9 (8%) cases pregnancy was terminated because of persisting drainage of amniotic fluid. All cases with intrauterine foetal death and early drainage of amniotic fluid were successfully treated after application of up to five vagitories of gemeprost (mean 2.8 vagitories; mean induction-abortion interval 8.9 hours). In patients undergoing abortion due to foetal malformations, the mean induction-abortion time was longer (mean 22.7 hours, mean 5.2 vagitories) and 20% did not respond adequately to prostaglandin. Our results show that gemeprost is an efficient means of terminating a pregnancy in cases of foetal death or pre-term amniorrhea, but that it is less efficient in inducing abortion.

Association between the HLA DQB1*0301 gene and human papillomavirus infection in high-grade cervical intraepithelial neoplasia

This study describes the distribution of DQB1genes in Norwegian women treated for high-grade cervical intraepithelial neoplasia (CIN). Formalin-fixed, paraffin-embedded tissue sections from 170 biopsy specimens with diagnoses of CIN II (n = 54) or CIN III (n = 116) were DQB1-typed using allele-specific polymerase chain reaction. The follow-up period for cases was 13 to 15 years. The control material comprised blood samples and endocervical brushes from 213 women without CIN. Both cases and controls had previously been human papillomavirus (HPV)-typed. The DQB1*0301 allele was overrepresented among cases compared with controls (odds ratio [OR] = 1.8). Presence of CIN was related to HPV infection, and HPV 16 positivity was significantly associated with the presence of DQB1*0301 (OR 1.8). The DQBI*0301 allele was significantly more prevalent in CIN III than in CIN II cases. The lesions in two women recurred in the follow-up period, one of whom was carrying the DQB1*0301 allele. Women carrying the HLA-DQB1*0301 allele have an increased risk of developing CIN when infected by HPV 16, although there was not an increased frequency of recurrent disease among women carrying this allele.

[The salpingitis diagnosis under scrutiny]

The rationale for the diagnosis of Pelvic Inflammatory Disease (PID) was studied among hospitalized patients at the Department of Gynaecology, Regional Hospital of Trondheim, Trondheim. From 1 January 1991 to 31 December 1993, 153 patients were discharged with a diagnosis of Pelvic Inflammatory Disease. In retrospect, the diagnoses were reconsidered applying strict criteria. All 26 patients (17%) who had a diagnosis verified by laparoscopy were classified as suffering from a "true" diagnosis, 83 (54%) patients were reconsidered as suffering from a "more likely" and 44 (29% as suffering from a "less likely" diagnosis of Pelvic Inflammatory Disease. Women who had a laparoscopy verified diagnosis of Pelvic Inflammatory Disease, had higher ESR (erythrocyte sedimentation rate), C-reactive protein and temperature when compared with women reclassified as "less likely" suffering from Pelvic Inflammatory Disease. Only 72% of the patients had microbiological sampling from the cervix. In order to increase diagnostic precision we argue for minimum criteria and a systematic clinical examination, including vaginal ultrasound, when diagnosing Pelvic Inflammatory Disease. We recommend more diagnostic use of laparoscopy especially among women with mild symptoms and few objective signs.

The risk-of-malignancy index to evaluate potential ovarian cancers in local hospitals

OBJECTIVE

To assess the risk-of-malignancy index (a scoring system based on menopausal status, ultrasound features, and serum CA 125) at district hospitals for referral of women with suspected malignant pelvic masses for primary surgery at a central gynecologic oncology unit.

METHODS

All seven hospitals in Health Region IV, Norway, agreed to refer women with pelvic masses and risk-of-malignancy indices of 200 or more for centralized primary surgery. In total, 365 women 30 years of age or older, admitted consecutively at the local hospitals, were enrolled in the study from February 1, 1995, to January 31, 1997.

RESULTS

Compliance with the study was satisfactory; 84% (65 of 77) of women with risk-of-malignancy indices of at least 200 were referred for centralized primary surgery. Sensitivity and specificity to malignancy were 71% and 92%, respectively, which is in agreement with previous validation of the risk-of-malignancy index in teaching hospital settings. False negatives were due mainly to stage Ia (18 of 24) ovarian cancer, whereas 27 of 28 stage II-IV ovarian cancer cases were identified correctly.

CONCLUSION

The risk-of-malignancy index identified women with malignant pelvic masses efficiently. Our study showed the risk-of-malignancy index strategy in a practical setting to be able to centralize primary surgery for advanced ovarian cancer from local hospitals to a subspecialty unit. We recommend the risk-of-malignancy index for detection of patients with advanced ovarian cancer for centralized primary surgery.

Oral contraceptives and thrombosis. From risk estimates to health impact

OBJECTIVE

The scientific debate on oral contraceptives (OCs) and thrombotic diseases continues unabated. The aim of this survey was to evaluate available scientific data on OCs and thrombotic diseases and to make tentative prescription recommendations of OCs to women with and without various thrombotic risk factors.

CONSENSUS

In women 15-29 years old, venous thromboembolism is about twice as common as arterial complications. In women between 30 and 44 years, the number of arterial complications exceeds venous diseases by about 50%. The mortality from arterial diseases is 3.5 times higher than the number of deaths from venous diseases in women below 30 years, and 8.5 times higher in women 30-44 years old. A significant disability is more frequent in women suffering and surviving an arterial complication than in women with venous thromboembolism. Although many important scientific issues still have to be addressed, the available scientific data suggests a differential influence of OCs with second and third generation progestagens on the risk of venous and arterial diseases. OCs with second generation progestagens seem to confer a smaller increase in the risk of venous diseases and a higher increase in risk of arterial complications, compared with OCs containing third generation progestagens. The possible difference on the venous side seems to be smaller than primarily anticipated.

RESULTS

Young women without any known risk factor for thrombotic diseases may use any low-dose OC. If OCs are prescribed to women with known risk factors for arterial thrombotic disease; e.g. smoking, diabetes, controlled hypertension, migraine without aura, family disposition of acute myocardial infarction (AMI) or thrombotic stroke, a low-dose pill with a third generation progestagen may have an advantage. If OCs are considered for women with risk factors for venous disease such as severe obesity, varicose veins, family history of VTE or with factor V Leiden mutation, a low-dose combined pill with a second generation progestagen may be preferable. In women above 30 years, OCs with third generation progestagens generally seem to confer less overall thrombotic morbidity, mortality and disability than OCs with second generation progestagens. These women should reconsider, however, the indication of combined OCs in the presence of significant risk factors of thrombotic diseases.

CO2 laser conization for cervical intraepithelial neoplasia grade II-III: complications and efficacy

AIMS

To examine per- and postoperative complication rates and efficacy of laser conization in the treatment of cervical intraepithelial neoplasia (CIN) grade II-III.

MATERIAL AND METHODS

Eligible for analyses were all women treated with their first laser conization because of CIN II-III during the time-period January 1, 1983 to December 31, 1992. The study population comprises 1081 women who were permanent residents of one Norwegian county (Sør-Trøndelag). All analyses were performed in SPSS applying chi-square for trend, Mann-Whitney test, survival analyses and logistic regression.

RESULTS

In total 86 women (8.0%) were observed with one or two (4:86) complications. Bleeding was most frequent (n = 66) followed by symptomatic cervical stenosis (n = 18). Most bleeding complications (74.2%) occurred one to two weeks postoperatively. Both bleeding complications and the occurrence of cervical stenosis were associated with cone height. Three emergency hysterectomies, two for bleeding and one for bladder perforation, were performed. Persistent disease was diagnosed in 1.9% (20:1053) of the women. All women with persistent disease were diagnosed among those with CIN III. Persistent disease was more than 20 times more common among women with disease-involved resection margins compared to those with free resection margins.

CONCLUSIONS

Our evaluation of ten years' consistent use of conization by CO2 laser in the treatment of CIN II-III in an unselected population showed a low overall complication rate (8%) and very high efficacy (CIN II 100%, CIN III 98.1%) of the treatment.

Epidemiology of repeat ectopic pregnancy: a population-based prospective cohort study

OBJECTIVE

To study infectious pathology at index ectopic pregnancy and to determine what other factors predispose a woman to repeat ectopic pregnancy.

METHODS

All women (n = 697) with their first (index) ectopic pregnancy histologically verified between January 1, 1978, and December 31,1993, at the only two hospitals in one Norwegian county were eligible. Included were permanent residents of the county who were 37 years of age or younger and who had not had tubal surgery before the index pregnancy. When the study closed on November 1, 1994, the participants had been observed prospectively for fertility events from approximately 1 to 17 years. Included in the final analyses were 353 women who had from one to five natural conceptions, for a total of 555 pregnancies. Chi-square test was used in univariate analysis, and the generalized estimating equations approach was used to analyze correlated responses and covariates that changed over time.

RESULTS

Pregnancy order is the stronger correlate of subsequent ectopic pregnancy. The frequency of repeat ectopic pregnancy decreased by one-third for each pregnancy from the first to the third pregnancy. The odds of having another ectopic pregnancy were nearly three times higher for women with a diagnosis of infectious pathology than for women who had no infectious pathology. Other correlates of repeat ectopic pregnancy include age 24 years or younger at first ectopic pregnancy, history of repeat ectopic pregnancy, initiation of infertility work-up, and conception with an intrauterine device at index pregnancy. Method of surgery was not associated with repeat ectopic pregnancy.

CONCLUSION

The most crucial reproductive event after first ectopic pregnancy is the first event to occur. Women who have experienced two ectopic pregnancies should be considered candidates for assisted reproduction.

Residual and recurrent disease after laser conization for cervical intraepithelial neoplasia

OBJECTIVE

To assess the risk of residual and recurrent disease after carbon dioxide laser conization treatment for high-grade lesions of the cervix uteri, and thus to refine intervals for follow-up.

METHODS

The study population comprised all women treated for cervical intraepithelial neoplasia grade II-III over a 10-year period (1983-1992). All women who resided within the county for the entire follow-up period were followed for residual or recurrent disease, verified histologically until the closure date of January 31, 1996. The cumulative incidence of recurrent disease was assessed by survival analyses, and logistic regression was used to predict clinical features at initial treatment that were associated with the risk of residual or recurrent disease.

RESULTS

Only 19 of 1081 women (1.8%) were lost to follow-up. Residual disease was diagnosed in 20 (1.9%) study participants. The cumulative incidence of recurrent disease was extremely low, increasing nearly linearly with an annual incidence of three per 1000 woman-years observed. Involved resection margins were associated significantly with both residual disease (crude odds ratio [OR] 18.1; 95% confidence interval [CI] 5.2, 64.0) and recurrent disease (adjusted OR 3.0; 95% CI 1.2, 7.5) when compared with disease-free resection margins as reference.

CONCLUSION

We recommend a differential follow-up interval depending upon the histologic evaluation of cone margins. If there is no residual disease, women who have free resection margins should return at a 3-year interval for follow-up. Women who have disease extended to the cone margins are recommended Papanicolaou smears at annual intervals through the fourth postoperative year before returning at a 3-year interval as practiced in the general screening program.

How effectively do copper intrauterine devices prevent ectopic pregnancy?

OBJECTIVE

To assess the risk of ectopic pregnancy when using copper intrauterine devices relative to non-use of contraception and female sterilization.

DESIGN

Case-control study.

MATERIAL AND METHODS

All cases diagnosed with a histologically verified extrauterine pregnancy and who became spontaneously pregnant in one Norwegian county from January 1, 1987 through to December 31, 1990 were eligible. Non-pregnant control women were chosen at random from the Norwegian Population Registry. Eligible for study were sexually active women, from 20 to 39 years of age, and who defined themselves as fecund. Included in the final analyses were 168 cases and 1,169 controls, who had all been previously pregnant.

STATISTICAL METHODS

Chi square test and unconditional logistic regression.

RESULTS

Compared with non-users of contraception, the adjusted odds ratio (aOR) among current users of copper intrauterine devices was 0.09 (95%, confidence intervals (CI); 0.06-0.13). Compared with women who were sterilized, the aOR of having an ectopic pregnancy among current copper IUD users was 1.6 (95% CI; 0.7-3.5).

CONCLUSION

Relative to non-users of contraception, current copper IUD users had a 91% (95% CI; 87-94%) protection against ectopic pregnancy, while compared with women who had had a tubal sterilization, current copper IUD users had a 60% non-significant increased risk of ectopic pregnancy.

Multiple induced abortions as risk factor for ectopic pregnancy. A prospective study

OBJECTIVE

To assess the risk of ectopic pregnancy by the number of previous induced abortions.

DESIGN

Prospective cohort study.

METHODS

Three thousand seven hundred and fifty-four women, 39 years old or younger, living permanently in one Norwegian county, who had had at least one induced abortion between January 1, 1987 and December 31, 1992, at the University Hospital of Trondheim, Norway were followed prospectively for histologically verified ectopic pregnancies until December 31, 1993. Exposure time was measured from the most recent induced abortion (index abortion) until the ectopic pregnancy, closure date, or the subject's 40th birthday. Statistical analyses were done in SAS applying survival analyses and poisson regression.

RESULTS

During the follow-up period of 164,167 women-months, we observed 24 ectopic pregnancies in 3,754 women. The adjusted incidence density ratio (aIDR) for women who had had two or more induced abortions was 1.2 (95% CI: 0.5-3.1) in comparison with the reference group of women who had had one induced abortion. Measuring exposure as increasing number of consecutive induced abortions, no dose-response to ectopic pregnancy was found between two consecutive (aIDR 0.9) and three or more consecutive abortions (aIDR 1.1) in comparison with the reference group.

CONCLUSION

In our setting, no excess risk of ectopic pregnancy was associated with multiple previous induced abortions compared with one previous induced abortion.

The relation between induced abortion and ectopic pregnancy

OBJECTIVE

To determine whether having had one or more induced abortions increases a woman's risk of having an ectopic pregnancy.

METHODS

We conducted a case-control study of all women admitted to a major metropolitan hospital in Georgia with a surgical diagnosis of ectopic pregnancy during the period of October 1988 to August 1990. Controls were randomly selected from women seeking an induced abortion or delivering an infant at the same hospital. After exclusions, this analysis included 182 cases and 1056 controls. Stratified analysis and unconditional logistic regression were used to control for confounding and to estimate the relative risks.

RESULTS

Approximately 90% of cases and controls were non-Hispanic, black women; 34% of the cases and 36% of the controls reported a history of induced abortion. The crude odds ratio for having an ectopic pregnancy associated with a history of induced abortion was 0.9 (95% confidence interval 0.6, 1.3). The odds ratio remained the same after adjusting for selected confounding variables and stratifying by the number of induced abortions, gestational age at the time of abortion, place where the abortion was performed, and the woman's report of medical complications of the abortion.

CONCLUSION

We found no evidence that having one or more induced abortions increases a woman's risk of having an ectopic pregnancy.

Treatment of pre-invasive conditions during opportunistic screening and its effectiveness on cervical cancer incidence in one Norwegian county

Norway had until recently no organized screening programme for cervical cancer, but opportunistic screening was common. This study focuses on the effectiveness of treatment of pre-malignant cervical conditions (CIN III) on cervical-cancer incidence in the county of Sør-Trøndelag in Norway, prior to the introduction of organized mass screening. The study is based on cervical-cancer incidence rates during the years 1965-92 and treatment data for CIN III. The expected number of cervical-cancer cases prevented due to early intervention was expressed in a regression model with 2 unknown parameters: the probability, p, of cancer development in case of CIN III, and the time lag, t, between treatment and when clinical cancer would otherwise have been diagnosed. The estimated probability that a patient treated for CIN III would have developed cervical cancer if not treated was found to be approximately 20%, and the mean time delay was around 16 years. In the last period of study (1988-92), the incidence was reduced by nearly 40% of what would have been expected without early intervention. Based on equal treatment rates as in 1990, parameter estimates were used to predict future incidence reduction. Maximum effectiveness will be achieved around the year 2005, with a nearly 70% reduction. Opportunistic screening and treatment of CIN III seems to have had considerable influence on cervical-cancer incidence. The costs, however, are substantial over-treatment, since our results indicate that 4 of 5 women treated for CIN III would not progress into the invasive state.

Increasing incidence of ectopic pregnancy in one Norwegian county--a population based study, 1970-1993

OBJECTIVE

To estimate time trends related to ectopic pregnancy while considering the contribution of repeat ectopic pregnancy and changing treatment for infertile couples over the past 24 years.

METHODS

Population based incidence data on ectopic pregnancy were collected from the only two hospitals in one Norwegian county from 1970 through 1993. Cases were identified through hospital discharge registries and all medical records were reviewed. Only females, aged 15-44 years, living permanently in the county and having a histologically verified ectopic pregnancy were eligible for the study. Data were analyzed in 5-year periods and 5-year age-groups.

RESULTS

The incidence of ectopic pregnancy (per 1,000 woman-years) increased fourfold from the first to the last period. When we restricted the analyses to women with no previous ectopic pregnancy and no previous infertility surgery or treatment, we observed a linear threefold increase in the number of ectopic pregnancies.

CONCLUSIONS

Repeat ectopic pregnancy and increased infertility treatment in the late 1970s and early 1980s might explain at most 25% of the increase in the incidence of ectopic pregnancy. After 1985, assisted reproduction might contribute to 4-5% of ectopic pregnancies diagnosed. The introduction of laparoscopy might explain some of this increase in the 1970s; however, we doubt that the introduction of more sensitive pregnancy tests or vaginal ultrasound in the 1980s contributed to the observed increase in ectopic pregnancy.

Comparison of light microscopy, in situ hybridization and polymerase chain reaction for detection of human papillomavirus in histological tissue of cervical intraepithelial neoplasia

The aims of the study were to estimate the prevalence of HPV infection in patients treated for high grade lesions of the cervix uteri (HG CIN), and to evaluate the validity of the histological criteria used for detection of HPV infection. The study comprised 203 women treated for HG CIN by laser conization. Forty-three preoperative biopsies and 160 cone specimens were examined for HPV infection using light microscopy (LM), in situ hybridization (ISH), and polymerase chain reaction (PCR). ISH was performed using commercial biotinylated probes for HPV types 6/11, 16/18, and 31/33/35 (Vira-Type In Situ Kits, Digene Diagnostics, Silver Spring, MD). HPV-PCR was performed with the L1 consensus primers Gp5+/6+. The prevalence of HPV detected by LM was 70%; by ISH 48% and by PCR 83%. Using PCR as the gold standard, LM had a sensitivity of 0.71 and specificity of 0.41. The corresponding results for ISH were 0.51 and 0.65, respectively. The positive predictive value for both tests reached over 80%, but the negative predictive value was less than 25%. This study demonstrates that morphology is an unspecific method of identifying HPV infections. LM identification of HPV infections has no clinical implications. Our analyses comparing test performances of LM, ISH and PCR show that PCR is the superior method.

Sentinel surveillance of Chlamydia trachomatis infection in women terminating pregnancy

AIMS

To evaluate demographic characteristics of women terminating their pregnancy for sentinel surveillance of Chlamydia trachomatis infection and to report changing prevalences of C trachomatis over time within this study population.

DESIGN

Screening for C trachomatis in women seeking induced abortion was introduced in 1984 at the Department of Gynecology, Regional Hospital, Trondheim, Norway. Over the study years our department has used a precoded medical record covering sociodemographic, medically relevant data, also recording outcome of the C trachomatis test. Throughout the study the Department of Microbiology applied cell culture, enzyme immunoassay, and, during the most recent years a nucleic acid test to identify C trachomatis.

STATISTICAL METHODS

Chi square test for linear trend and unconditional logistic regression.

RESULTS

Over the study period, women having induced abortion were characterised by being most often single and more often at younger age. The overall age-adjusted prevalence of C trachomatis declined from 9.2% in 1985 to 3.6% in 1995, the major decline occurring from 1987 to 1991, and affected all age-groups simultaneously. There was a 60% decrease in odds ratio of having a C trachomatis infection from 1985 to 1991, and the crude and the adjusted odds ratios did not differ for any year examined.

CONCLUSION

Women deciding on pregnancy termination have demographic characteristics that identify high-risk groups for C trachomatis infection. Despite these characteristics, which were relatively constant over the study period, the study population changed from being a high- to a low-prevalence population of C trachomatis.

Evaluation of induced abortion as a risk factor for ectopic pregnancy. A case-control study

OBJECTIVE

To assess the risk of ectopic pregnancy after one or more induced abortions.

DESIGN

Population-based case-control study.

METHODS

We studied all women who had a histologically verified ectopic pregnancy in one Norwegian county between January 1, 1987, and December 31, 1990. We identified population-based control sets of women among participants in the second Norwegian fertility study (1988-1989). Gravida women 20-39 years of age, who were not using contraceptives and had become spontaneously pregnant, were eligible for analysis. The final analyses included 174 women with ectopic pregnancy, 115 pregnant control women and 227 nonpregnant control women.

STATISTICAL METHODS

Chi-square test and unconditional logistic regression.

RESULTS

Fifty-three (30.5%) of women with ectopic pregnancy, 18 (15.7%) of pregnant control women and 51 (22.5%) of nonpregnant control women had had one or more previous induced abortions. The adjusted odds ratio of ectopic pregnancy among women with one previous induced abortion was 1.3 (95% confidence interval; 0.9 to 1.8) and 1.2 (95% CI; 0.8 to 1.7) compared with pregnant and nonpregnant control women, respectively. Among women who had two or more induced abortions, the adjusted odds ratio of ectopic pregnancy was 0.2 (95% CI; 0.04 to 0.9) compared with pregnant control women and 1.8 (95% CI; 0.4 to 7.8) compared with nonpregnant control women. When we used the outcome of the most recent pregnancy, birth as reference, we found no association between an outcome of induced abortion and subsequent ectopic pregnancy regardless of whether the control women were pregnant.

CONCLUSION

We found no association between induced abortion and subsequent ectopic pregnancy. Women who had induced abortions were characterized as having several other risk factors for ectopic pregnancy.

Increased number of induced abortions in Norway after media coverage of adverse vascular events from the use of third-generation oral contraceptives

After the press release in Lancet (October 18, 1995) of increased risks for adverse vascular events in users of pills containing desogestrel and gestodene the total sales of oral contraceptives dropped over a two-month period by 17%, while sales of the only desogestrel brand available (Marvelon) dropped by over 70% in Norway. From sales, we can estimate that more than 45,000 women either changed from Marvelon to a second or first-generation brand or stopped using OCs. In total, more than 25,000 women discontinued OC use in Norway during November and December of 1995. Abortion data from one Norwegian county, representing 6-7% of the Norwegian population, show no statistically significant changes in the total number of induced abortions from the first quarter of 1996 as compared with that of the first quarter in preceding years. However, abortion rates that had been steadily decreasing from 1992 through 1995 in women 24 years old or younger, were promptly interrupted by a significant 36% increase during the first quarter of 1996. Most of the additional cases were found among single, childless students. The observed increased abortion rate among younger women is most probably linked to changes in contraceptive use during the pill scare of the late October through December of 1995, during which time these women conceived.

IUD users in Norway are at low risk for genital C. trachomatis infection

From May 1993 to April 1995, 30 general practitioners located at 13 general practice settings in the city of Trondheim, central Norway, recruited 957 eligible participants in a prospective use-effectiveness study on performance of two copper IUDs. In this report we focus on screening for C. trachomatis at insertion and its possible effect on cause-related terminations during the first 90 days after insertion. All women were screened at IUD insertion for C. trachomatis. All specimens were analyzed applying a nucleic acid test (rRNA, GenProbe). Five out of 957 women (0.5%) were positive for C. trachomatis. All were treated within two weeks of diagnosis. No cases of pelvic inflammatory disease were diagnosed during the first three months of the study. Screening of C. trachomatis at IUD insertion is not recommended in Norwegian women because of the extremely low prevalence of C. trachomatis in those who choose IUD as their primary contraceptive method. Recommendations for universally screening women for sexually transmitted diseases at IUD insertion should be based upon review of local/national prevalence data.

Evaluation of a risk of malignancy index based on serum CA125, ultrasound findings and menopausal status in the pre-operative diagnosis of pelvic masses

OBJECTIVE

To evaluate the ability of a risk of malignancy index (RMI), based on a serum CA125 level, ultrasound findings and menopausal status, to discriminate a benign from a malignant pelvic mass and to discriminate early stage (Figo Stage I) from Stages II, III and IV of ovarian cancer.

DESIGN

A prospective study.

SETTING

Department of Gynaecology, Trondheim University Hospital, Trondheim, Norway.

PARTICIPANTS

One hundred and seventy-three women, 30 years or older, consecutively admitted between February 1992 and February 1994 for primary laparotomy of a pelvic mass.

MAIN OUTCOME MEASURES

The sensitivity, specificity and positive predictive value of serum CA125 level, ultrasound findings and menopausal status, separately and combined into the RMI, to diagnose ovarian cancer.

RESULTS

The RMI was more accurate than any individual criterion in diagnosing cancer. Using a RMI cut-off level of 200 to indicate malignancy, the RMI derived from this dataset gave a sensitivity of 80%, specificity of 92% and positive predictive value of 83%. Applying RMI criteria developed by others, the following test performance was found: sensitivity 71%, specificity 96% and positive predictive value 89%. For the Stages II, III and IV of ovarian cancer the sensitivity increased to approximately 90% without any substantial loss in specificity.

CONCLUSIONS

The risk of malignancy index is able to correctly discriminate between malignant and benign pelvic masses. It is a scoring system which can be introduced easily into clinical practice to facilitate the selection of patients for primary surgery at an oncological unit.

Occurrence of human papillomavirus infection in cervical intraepithelial neoplasia. A retrospective histopathological study of 317 cases treated by laser conization

The aim of the study was to compare the histological outcome of the cone specimens with the diagnoses of the preoperative biopsies, to assess the distribution of histological features consistent with human papillomavirus (HPV) infection and, finally, to analyse the impact of cellular HPV features on classification of cervical intraepithelial neoplasia (CIN). The study comprised a population of 317 women treated for CIN by laser conization during the period 1983-85. A total of 634 cervical specimens (317 preoperative biopsies and their corresponding cones) were studied retrospectively for CIN classification and examined for morphological signs of HPV infection. For presentation of the results, we used a modified terminology for CIN. Low-grade (LG) CIN included borderline lesions and CIN I, while high-grade (HG) CIN included CIN II and CIN III. The blinded histopathological review revealed HG CIN both in the preoperative biopsies and the cones in 71% of the cases. LG CIN or benign lesions were found in the preoperative biopsies and their corresponding cone specimens in 6% of the study population. HPV features were present in 65% of the preoperative biopsies, and were most prevalent in women under 29 years of age (p < 0.001). Thirteen percent of the total biopsy material was downgraded. The downgrading was most prevalent among original CIN II (p = 0.009) and HPV-negative biopsies (p < 0.001). This study demonstrates that CIN lesions are frequently associated with HPV features, which are significantly more prevalent in the youngest women. Concomitant HPV features do not influence the CIN classification.

[Oral contraceptives and elective surgery. Strategies in Norwegian hospitals, thromboembolic complications and perioperative conception]

It is widely accepted that treatment with combined oral contraceptives may increase the risk of venous thromboembolism perioperatively. Serious adverse effects such as allergic reactions or bleeding may result from thromboprophylaxis, while stopping the pill may lead to unwanted pregnancy. The objectives of this study were to examine how women on oral contraceptives were treated in Norwegian hospitals in relation to elective surgery, the number of spontaneously reported adverse drug reactions related to thromboprophylaxis, the number of diagnoses of venous thrombo-embolism combined with elective surgery in Norwegian hospitals, and the pregnancy rate in the perioperative pill-free period in this group of women. The study showed that Norwegian hospitals treated women on oral contraceptives in accordance with widely accepted guidelines. No serious adverse drug reactions related to thromboprophylaxis were found, and the frequency of venous thromboembolism in relation to elective surgery seemed to be remarkably small. The pregnancy rate in a perioperative pill-free period appeared to be low, since the women resumed contraception relatively soon after their first postoperative menstrual cycle. It is concluded that the procedures applied in Norwegian hospitals in 1989-90 were safe for this group of patients.

Using induced abortion to measure contraceptive efficacy

Data from a 1989-1990 case-control study of contraceptive efficacy in Norway compare contraceptive use among women who requested an abortion (1,386 cases) with women who responded to a general fertility survey (2,627 controls). In a logistic regression analysis measuring contraceptive efficacy as the odds of avoiding a pregnancy that terminated in an induced abortion compared with the odds for nonuse, consistent condom use was found to lower fecundity by 88.9%, diaphragm use by 89.3%, the pill by 97.8%, the IUD by 97.6%, vasectomy by 99.5%, and female sterilization by 99.8%. The relative contraceptive efficacy of the condom, the IUD and the pill did not vary by marital status or parity but did vary with age; the proportion by which each of these methods reduced fecundity declined among successively older age-groups.

The incidence of repeat induced abortion--a prospective cohort study

BACKGROUND

To measure the cumulative incidence of first and second repeat induced abortion and what differentiates first-time repeaters from non-repeaters.

METHODS

The study population comprised 2,925 women who had their first induced abortion at the University Hospital of Trondheim, Norway between January 1, 1987 and December 31, 1991. Repeat induced abortion within the study period was measured as a cumulative incidence of second and third induced abortion. Survival analyses and logistic regression analysis were applied using 'repeater' as the dependent variable.

RESULTS

The cumulative incidence of second induced abortion was 3.7% at end of first year, 7.1% at end of second year, 9.9% at the end of third year, and 12.3% at four completed years of observation. The cumulative incidence of third induced abortion was 0.1% at the end of first year, 0.6% at the end of second, 1.3% at the end of third and 2.0% at four years of observation. The cumulative incidence of the third abortion, measured as the time at risk from the second to the third abortion, remained twice that of the cumulative incidence of the second abortion after one year of observation (p < 0.001). At the first abortion, variables predicting a risk for repeat induced abortion were age, occupational status and becoming pregnant as a result of a contraceptive failure.

CONCLUSION

Repeat induced abortion in inevitable. The incidence of repeat induced abortions doubled from the second to the third abortion, indicating that the moral threshold for choosing an abortion after recognition of an unplanned pregnancy is the first induced abortion. More detailed studies on the effect of intensified contraceptive counselling programs after the first abortion are needed.

[Surgical treatment of cervix cancer. A 6-year material from a regional hospital]

The results are reported for 75 patients treated with radical hysterectomy and pelvic lymphadenectomy (Wertheim-Meigs' operation) for cervical carcinoma. There was no per- or postoperative death. Ten patients suffered immediate postoperative complications. One case of lower limb lymphoedema was observed. 17 patients (23%) had pelvic lymph node metastases. In eight patients the disease has recurred (median observation time 43 months). Overall recurrence-free survival was 89%: for patients without lymph node metastases 91%, and for patients with metastases 82%. Using a prognostic score based on stage, presence of lymph node metastases, blood or lymph vessel invasion, low differentiation, and tumour-involved resection margins; two groups could be identified, with a recurrence-free survival of 94% (score < or = 2) and 75% (score > or = 3), respectively (p < 0.02).

[The decision-making process and information needs among women seeking abortion. Results from 2 studies conducted with a 10-year interval, 1983-93]

The decision-making process and need for medical information during the consultation prior to abortion were examined among 183 women who sought abortion in 1983 and 160 in 1993 at the Department of Gynaecology, University Hospital, Trondheim, Norway. The father of the foetus participated significantly more often in the decision-making process in 1993 than in 1983. The final decision was taken either by the woman alone or together with the father of the foetus. More than 85% of the women had decided to terminate the pregnancy before requesting an abortion at the pre-abortion visit. Few women were under pressure when they decided to terminate the pregnancy. More women were under pressure to continue the pregnancy to term than to terminate (p < 0.05). Norwegian abortion law guarantees the right to medical information during the pre-abortion consultation. The general practitioners involved scored higher in 1993 compared with their colleagues in 1983, since they satisfied the demands of abortion-seeking women for medical information concerning the surgery and possible complications.

A prospective study of fertility and outcome of pregnancy after discontinuation of oral contraception in relation to elective orthopedic surgery

OBJECTIVE

To evaluate the risk of unwanted pregnancies, their outcome and the rate of resuming contraception after discontinuation of oral contraception (OC) prior to elective surgery.

DESIGN

A six months prospective follow-up study.

SETTING

Orthopedic unit, operating on a total of 897 women during a period of 24 months.

SUBJECTS

Seventy-eight healthy women in whom OC was stopped prior to elective orthopedic surgery.

OUTCOME

Pregnancy rate, pregnancy outcome and reinstitution rate of OC.

RESULTS

Complete outcome data are available for 73 (93.5%) of 78 women who were asked to participate in the study. Five pregnancies were reported, giving a cumulated six month pregnancy rate of 6.8%. Three pregnancies were completed to term, one was ectopic and one terminated by induced abortion. Within six months after the operation the cumulative user rate of oral contraceptives was 74.2%. None of the women were readmitted to hospitals for severe illness during the study period.

CONCLUSIONS

The women resumed oral contraceptives relatively soon after their first post-operative menstrual cycle. This may explain why the pregnancy rate during the first six postoperative months appears low.

Induced abortion. Effects of marital status, age and parity on choice of pregnancy termination

OBJECTIVE

To study the impact of marital status, age and parity on the decision regarding pregnancy termination over time among pregnant Norwegian women.

DESIGN

National surveillance data of induced abortions and births.

MATERIAL

All women terminating their pregnancies (n = 174,590) as registered in the Abortion File in the Central Bureau of Statistics and all women giving birth (n = 639,551) as registered in the Medical Birth Registry of Norway between January 1, 1979 and December 31, 1990 were eligible for the study. Included in the analysis of pregnancy outcome were records with complete information on marital status, age and parity, which comprise 93.8% (n = 163,826) of all women having had an induced abortion and 99.0% (n = 633,542) of all women giving birth during the time period.

OUTCOME MEASURE

The proportion of pregnancies terminated as induced abortions and the relative risk of pregnant women choosing abortion in strata of marital status, age and parity.

STATISTICAL METHODS

Trend analysis of the proportion of pregnancies terminated as induced abortions in different time periods in categories of marital status, age and parity.

RESULTS AND CONCLUSION

From the first three-year period 1979-81 to the last three-year period 1988-90 there was a decreasing tendency to choose abortion among unmarried pregnant women above 20 years of age and married women with two or more children. In the other strata of marital status, age and parity there were no changes over the time period, except for married women 20-24 years of age which was the only group that showed an increasing abortion tendency over the time period. The prospect of single parenthood was the strongest determinant for choosing abortion independent of age and parity. Within all age groups of married women the abortion tendency increased more with parity than age. Cohabiting women chose abortion significantly more often than married women did. However, the true estimate of choosing abortion among cohabiting women was closer to married women than to single women. In order to find out the importance of other social factors and attitudes in the decision making process regarding pregnancy outcome, adjustments must be made for marital status, age and parity.

When pregnant--why induced abortion?

STUDY OBJECTIVE

To study social differences between women seeking induced abortion (cases) and women completing their pregnancy (controls).

DESIGN

Case-control study.

STUDY SETTING

Data were collected through a structured personal interview of 404 abortion-seeking women and 404 women giving birth at the Gynaecological and Obstetric wards, University Hospital of Trondheim, Norway during 1983.

STATISTICAL METHOD

Logistic regression analyses.

RESULTS AND CONCLUSION

The prospect of single parenthood was the strongest determinant in describing the difference between abortion-seeking women and women giving birth. In addition, variables such as parity, age, housing situation, previous abortion history, attitudes towards abortion and occupational status were all found to be significant when describing the differences between the two study groups. After confirmation of a positive pregnancy test only women stating unplanned pregnancy face a real decision about what to do. By restricting the control group to women stating unintended pregnancy, the multivariate analyses showed a reduced estimate of the respective odds ratios of choosing abortion in all important variables, while parameters such as "age" and "occupational status" became insignificant. Women in favour of the liberal abortion legislation decided more often on pregnancy termination than women opposed to the law of abortion on demand. However, among those women opposed to the law who still underwent an induced abortion, the same social and demographic characteristics were significant for the decision regarding termination as for the total study group. The study demonstrates the heterogeneity of the group of women terminating their pregnancy and how complex the decision regarding pregnancy termination might be.

Trends in induced abortion during the 12 years since legalization in Norway

Data on 174,595 Norwegian women aged 15-44 who had an induced abortion between 1979 (when all abortions through 12 weeks of gestation were legalized) and 1990 reveals that the general abortion rate decreased by 12% among married women, while it remained unchanged among unmarried women. Unmarried women had higher abortion rates than did married women among all age-groups except teenagers, increasing from a difference of 11 abortions per 1,000 women in 1979-1981 to a difference of 13 per 1,000 in 1988-1990. Pregnancy terminations occurred at an earlier gestational age during the last three years of the study period, compared with the first three. Abortions beyond 12 gestational weeks, which require the approval of a hospital committee, decreased among unmarried women, while increasing somewhat among married women. A larger proportion of married women than unmarried women terminated pregnancies beyond 18 gestational weeks.

Choice of contraceptive modality by women in Norway

STUDY OBJECTIVE

To investigate the use of contraception in a representative sample of Norwegian women.

OUTCOME MEASURES

Frequency distribution of contraceptive methods by age, marital status and partly strata.

MATERIAL

A sample of 4,933 women were selected at random from the Central Population Register as participants in the second Norwegian fertility study (1988). The response rate was 81% (n = 4,019) and personal interviews of contraceptive use were carried out among 2,782 women who were fecund, sexually active and not pregnant. These women comprise the study population.

RESULTS

2,782 women were sexually active during the last month prior to the interview and thus in potential need of contraception. More than 50% of the women used either oral contraceptives (21%) or IUDs (30%). The use of oral contraceptives decreased linearly with age from a user rate of 60% among women 20-24 years old to 1.5% among women 40-44 years of age. The use of IUDs increased from 6% in the youngest age group to nearly 40% among women aged 30-39 years of age. Oral contraceptives were preferentially used by childless women or those with only one child, while IUDs were most often used by women with two or more children. The sterilisation rate increased by age and in the 40-44 age group one out of every three women was sterilised. Non-use was most frequent among the subgroups of women who planned children in the future. Use of condoms and other coitus-dependent contraceptives varied less with age, marital status and parity than did the use of OC, IUDs or sterilisation.

CONCLUSION

The user pattern concerning different contraceptive methods reflects the general guidelines for contraceptives in Norway. The fact that nearly 70% of the women were in one of the three categories--OC or IUD users, or one of the partners was sterilised--reveals that the awareness and knowledge of modern contraception is high in Norwegian society.

The outcome of pregnancy after CO2 laser conisation of the cervix

OBJECTIVE

To investigate the effect of laser conisation of the cervix on the outcome of subsequent pregnancy.

DESIGN

Case-control study.

SETTING

Department of Obstetrics & Gynaecology, University Hospital, Trondheim, Norway.

SUBJECTS

Three hundred and fifty-one women were treated for cervical intra-epithelial neoplasia (CIN) by laser conisation of the cervix between 1 January 1983 and 31 December 1985. The 56 women among them who had been delivered of live infants beyond 22 weeks gestation after the conisation and before 1 January 1991 were studied for the outcome of their pregnancies. For each case, two controls of equal parity and age (+/- 3 years) were selected.

MAIN OUTCOME MEASURES

The length of gestation and birthweight of the infants.

RESULTS

The median (range) length of gestation was 39 weeks (26-43) in cases compared with 40 weeks (34-42) in controls (z = -4.0, P < 0.001). The median (range) birthweight was 3330 g (1150-4940) in cases and 3630 g (1610-5080) in controls (z = -3.5, P < 0.001). Overall 38% of cases were delivered preterm (< or = 37 weeks gestation), compared with 6% of controls (P < 0.0001; odds ratio 9.0, 95% CI 3.7-21.7). A logistic regression analysis of a set of possible confounding factors revealed no significant risk factors in addition to conisation for the occurrence of preterm delivery. No correlation was found between the height of the cone and the occurrence of preterm delivery in subsequent pregnancy.

CONCLUSION

Conisation with microsurgical laser technique increases the risk of preterm delivery in subsequent pregnancies. Laser conisation in young women should be restricted to those with high grade CIN or a lesion extending into the endocervical canal.

[Contact tracing of genital Chlamydia infection]

The present study evaluates two strategies for partner notification among young women with genital Chlamydia trachomatis infection. The study included 443 women, aged 14-21 years, who visited one of 20 youth clinics during a two months period in 1991. The youth clinics were randomized to use patient referral or provider referral. In the latter group, 11 of 14 women with genital Chlamydia infection revealed their sexual partners. Only five of 24 sexual partners were notified by a letter, and six of 24 partners turned up for examination. In the patient referral group, 16 of 34 women asked to notify their partner, and ten of 31 partners were examined. Partner notification in young women with genital Chlamydia infection seems to be difficult.

[Demographic factors and pregnancy--who chooses abortion?]

The number of pregnancies terminated as induced abortions has been analysed from data recorded in the Norwegian Birth Registry and the Norwegian Abortion File at the Central Bureau of Statistics. During the time period 1 January 1979 to 31 December 1991, 871,439 pregnant women were registered. Among single women the proportion of pregnancies terminated as induced abortions varied between 40 and 75% throughout the study period. Cohabitant women chose abortion significantly more often than married women. Among married women the proportion of pregnancies interrupted varied with the woman's age and the number of children. Among women 20-34 years of age with one or no child, more than 97% of the pregnancies proceeded to term. Women undergoing abortion comprise a heterogeneous group, judged by demographic factors. Future studies must focus on social factors as well as demographic factors, in order to uncover the complexity of the reasons for choosing abortion.

[Chlamydia trachomatis and Neisseria gonorrhoeae among women seeking abortion in Norway. Results from a nationwide study]

In April and May 1991 all women requesting abortion in Norway were screened for Chlamydia trachomatis and Neisseria gonorrhoeae. During the study period 2,194 abortions were carried out. The study included 2,110 women with representative tests for C trachomatis from the cervix uteri. Only 1,702 women were tested for N gonorrhoeae. The prevalence of N gonorrhoeae was 0.5% (8:1,702), and of C trachomatis 5.4% (113:2,100). The prevalence of C trachomatis decreased from 9.1% among women less than or equal to 19 years to 2.0% among women greater than or equal to 35 years of age. Prevalence of C trachomatis was significantly lower among subjects resident in health region no. IV (mid-western part of Norway) than among candidates for abortion from the other four health regions. Being less than 25 years of age was the best single parameter for identifying chlamydia-positive cases. The prevalence of N gonorrhoeae among women seeking abortion in Norway is so low that screening is not recommended. However, the prevalence of C trachomatis is still high enough to recommend screening of all women less than 25 years of age who request abortion. Chlamydia-positive cases should be tested for N gonorrhoeae.

[Which women should be tested for Chlamydia trachomatis in general practice?]

Specimens to test for Chlamydia trachomatis and Neisseria gonorrhoeae were collected as a routine from female patients undergoing gynecological examinations in general practice. In 3.9% of 517 non-pregnant women the culture for C trachomatis was positive. None were infected with N gonorrhoeae. C trachomatis was detected in ten of 138 (7.2%) women with genital symptoms, compared with ten of 379 (2.6%) without symptoms. The annual incidence rate for C trachomatis in asymptomatic patients was 0.3% for women older than 25 years, and 5.4% for women younger than 25 years. Routine testing for C trachomatis is recommended during gynecological examination in general practice of asymptomatic women younger than 25 years. Tests should be taken at minimum two-year intervals. Routine tests for N gonorrhoeae are not recommended.

[The Chernobyl accident--did it influence the pregnancy outcome in Norway?]

The outcome of pregnancies in the county of Sør-Trøndelag, in Norway, during the 27 months preceding and 21 months after the Chernobyl accident has been analysed on the basis of time of conception. The analysis showed a significant decrease in the number of conceptions during the three months immediately after the accident (April-June 1986). This finding can be interpreted to mean fewer "planned" conceptions. The Chernobyl accident did not seem to have had any impact on the proportion of conceptions ending as spontaneous abortions or ectopic pregnancies. There was a significant drop in the proportion of pregnancies ending as induced abortions during the year after the accident compared with the year before. However, due to some variation during this year it is difficult to draw any definite conclusions concerning the impact of the accident on induced abortions in this county. The proportion of pregnancies ending as births increased significantly during the year after the Chernobyl accident compared with the year before.

[Variations in the waiting time for sterilization and sterilization rate in Norway]

A comparison of data from independent sources on numbers of sterilized women indicates that figures for sterilization in Norwegian hospitals are incomplete. More than 50% of the sterilized women are outpatients and nearly 50% of the inpatients are sterilized in connection with other treatment. Permanent geographical differences in sterilization rates are observed, as well as a large variation in the waiting time. We have been unable to verify a simple relation between sterilization rate and waiting time or length of waiting list.