The rise in ectopic pregnancy--exploration of possible reasons

The natural history of Chlamydia trachomatis infection in women: a multi-parameter evidence synthesis

BACKGROUND AND OBJECTIVES

The evidence base supporting the National Chlamydia Screening Programme, initiated in 2003, has been questioned repeatedly, with little consensus on modelling assumptions, parameter values or evidence sources to be used in cost-effectiveness analyses. The purpose of this project was to assemble all available evidence on the prevalence and incidence of Chlamydia trachomatis (CT) in the UK and its sequelae, pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI) to review the evidence base in its entirety, assess its consistency and, if possible, arrive at a coherent set of estimates consistent with all the evidence.

METHODS

Evidence was identified using 'high-yield' strategies. Bayesian Multi-Parameter Evidence Synthesis models were constructed for separate subparts of the clinical and population epidemiology of CT. Where possible, different types of data sources were statistically combined to derive coherent estimates. Where evidence was inconsistent, evidence sources were re-interpreted and new estimates derived on a post-hoc basis.

RESULTS

An internally coherent set of estimates was generated, consistent with a multifaceted evidence base, fertility surveys and routine UK statistics on PID and EP. Among the key findings were that the risk of PID (symptomatic or asymptomatic) following an untreated CT infection is 17.1% [95% credible interval (CrI) 6% to 29%] and the risk of salpingitis is 7.3% (95% CrI 2.2% to 14.0%). In women aged 16-24 years, screened at annual intervals, at best, 61% (95% CrI 55% to 67%) of CT-related PID and 22% (95% CrI 7% to 43%) of all PID could be directly prevented. For women aged 16-44 years, the proportions of PID, EP and TFI that are attributable to CT are estimated to be 20% (95% CrI 6% to 38%), 4.9% (95% CrI 1.2% to 12%) and 29% (95% CrI 9% to 56%), respectively. The prevalence of TFI in the UK in women at the end of their reproductive lives is 1.1%: this is consistent with all PID carrying a relatively high risk of reproductive damage, whether diagnosed or not. Every 1000 CT infections in women aged 16-44 years, on average, gives rise to approximately 171 episodes of PID and 73 of salpingitis, 2.0 EPs and 5.1 women with TFI at age 44 years.

CONCLUSIONS AND RESEARCH RECOMMENDATIONS

The study establishes a set of interpretations of the major studies and study designs, under which a coherent set of estimates can be generated. CT is a significant cause of PID and TFI. CT screening is of benefit to the individual, but detection and treatment of incident infection may be more beneficial. Women with lower abdominal pain need better advice on when to seek early medical attention to avoid risk of reproductive damage. The study provides new insights into the reproductive risks of PID and the role of CT. Further research is required on the proportions of PID, EP and TFI attributable to CT to confirm predictions made in this report, and to improve the precision of key estimates. The cost-effectiveness of screening should be re-evaluated using the findings of this report.

FUNDING

The Medical Research Council grant G0801947.

Subperitoneal placenta accreta succenturiate in the case of a successful near-term extrauterine abdominal pregnancy

Placenta from an extrauterine abdominal pregnancy was examined after a 37-week healthy infant gestation. The placenta, with its fetal surface down and maternal surface up, protruded from the pelvic area to peritoneal cavity in the wall of the amniotic sac containing fetus. The placenta was implanted under the thin subperitoneal layer of maternal tissue completely covered by peritoneal serosa and was formed by several small lobes connected by intramembranous placental vessels. Insertion of the trivascular umbilical cord was velamentous. Partially remodeled arteries infiltrated by intermediate trophoblast and frequent veins directly communicating with the placental intervillous space were identified in the subperitoneal maternal tissue. The term "placenta accreta" is appropriate in this case because villi in the basal plate implanted directly in the maternal subserosal connective tissue without intervening decidua.

Ectopic pregnancy among non-medicated and copper-containing intrauterine device users: a 10-year follow-up

OBJECTIVE

To compare ectopic pregnancy (EP) rates among users of non-medicated and copper-containing IUDs.

STUDY DESIGN

The number of women with non-medicated and copper devices were 3491 and 11,682, respectively. Cumulative woman-months of use (CWMU), Pearl Index (PI) and gross cumulative lifetable EP rates for 1000 women were calculated.

RESULTS

The numbers of users at the end of the 10th year were 550 and 569 for non-medicated and copper-containing IUDs, respectively. CWMU for plastic and copper devices was 191,678 and 473,533, respectively, at the 169th month of maximum follow-up. The PIs were 0.8 and 1.0 calculated for 1000 users per year. The gross cumulative lifetable EP rates for 1000 women were 1.4 and 0.9 at 12 months, and 6.8 and 8.9 at the end of the 10th year, respectively, for the plastic and the copper IUDs.

CONCLUSION

Although the rates were lower for the plastic IUD in the majority of the observations, there were no statistically significant differences between the two groups.

Epidemiology of ectopic pregnancy during a 28 year period and the role of pelvic inflammatory disease

OBJECTIVES

We analysed the epidemiology of ectopic pregnancy (EP) during a 28 year period, 1970-97, using methods applicable to ecological studies in order to test the hypothesis that a reduction of pelvic inflammatory disease (PID) will be associated with a decrease of EP.

METHODS

Hospital records of patients aged 15-54 admitted to our department of gynaecology were reviewed for EP and PID for the period 1 January 1970 to 31 December 1997. EP for the period 1970-4 was based on available statistics. The total number for EP was 1270 and for PID 2559. The total population for the catchment area was 100,000-120,000 during the study period. Incidences were age standardised and calculated using official population statistics to represent the average female population in the five 5 year periods 1970-4, 1975-9, 1980-4, 1985-9, 1990-4, and in each of the consecutive years 1995, 1996, and 1997. Incidences for EP were calculated per 1000 women and per 1000 pregnancies while those for PID per 1000 women. National statistical data of EP were available for 1975-94 and were used for comparison with the local study.

RESULTS

The EP incidences increased from 7.7 per 1000 pregnancies in the first 5 year period to 13.4 in the second, and continued to rise for another decade reaching the peak figures of 16.6 in 1985-9--that is, more than a twofold increase. Since then and to 1997 the EP incidence has decreased by 30%. PID admissions increased during the study period from 2.7 per 1000 women in the first 5 year period to 3.2 in the second. From then on they continuously decreased and reached a low of 0.5 in 1997. The greatest changes occurred in women < or = 24 years of age. The peak incidence for this age group was 7.7 in 1975-9, and the lowest was 0.4 per 1000 women in 1996. The greatest reduction of EPs was noted for women < or = 24 years old, from a high of 10.0 in 1975-9, coinciding with the peak incidence of PID, to a low of 4.0 in 1997, a reduction of 58.4%. The incidence of EP was two to three times higher in women > or = 25 years old, most obvious in those > or = 30 years, with peak figures of 20.9 per 1000 pregnancies in 1985-9, and 13.9 in 1997, a reduction of 33.4% and the lowest figures for the past 23 years. For women aged 25-29 years the incidence peaked in the previous 5 year period 1980-4--that is, one 5 year period later than for those < or = 24 years, which we interpret as cohort effects in relation to PID.

CONCLUSIONS

Reduction of PID was strongly associated with a decline of EP. The decline was greater and immediate for women < or = 24 years old, than for those > or = 25 years. The two to three times higher EP incidence in women > or = 25 years of age was most probably due to a cohort effect as the peak of PID occurred a decade earlier in women < or = 24 years old. Prevention of PID may not only reduce EP but also reduce adverse effects on tubal patency.

An epidemiological study on the relationship of ectopic pregnancy and the use of contraceptives in Beijing--the incidence of ectopic pregnancy in the Beijing area. Beijing Collaborating Study Group for Ectopic Pregnancy

The incidence of ectopic pregnancy (EP) was studied through a 3-level monitoring network of maternal and child health care (MCH) in the entire Beijing area, including 82 hospitals, 19 MCH centers and 2 institutes for family planning. A total of 1,420 cases of EP were collected in a sample of 2.7 million women of reproductive age (15-49) during a one-year period from January 1 to December 31, 1990. The cases were confirmed by pathological examination or laparoscopy. In addition, epidemiological surveillance method was used. The results showed that the overall incidence of EP was 0.52 per thousand women of reproductive age (W = Women of reproductive age (15-49)) in the Beijing area, 0.6/1000W in the urban districts and 0.41/1000 in the rural area; 0.67/1000W married women, and 0.05/1000W in the unmarried. For married women, 0.54/1000W for those women using various contraceptive measures and 1.80/1000W for women using no contraceptives. The incidence of EP varies with different contraceptive methods. Female sterilization had the lowest incidence (0.18/1000W) and natural contraceptive measures (rhythm or withdrawal method) had the highest (2.43/1000W). It was 0.65/1000W in IUD users, 0.21/1000W in OC users and 0.57/1000W in couples using condoms or spermicides.

Atypical ectopic pregnancy

Most emergency physicians will agree that bleeding and abdominal pain in women of child-bearing age is considered an ectopic pregnancy until proven otherwise. Ectopic pregnancy remains the leading cause of maternal mortality in the United States. A high index of suspicion is necessary for early intervention and reduction in morbidity and mortality. Risk factors for ectopic pregnancy include previous salpingo-oophoritis, ectopic pregnancy, tubal surgery or ligation, use of an intrauterine device, hormonal therapy, and, more recently, in vitro fertilization. In addition, this case emphasizes the possibility of ectopic pregnancy in women with a history of hysterectomy without bilateral oophorectomy.

The occurrence of ectopic pregnancy with and without clomiphene citrate use in assisted and nonassisted reproductive technology

An eleven-year review of treatment records of patients who became pregnant as a result of infertility treatment (n = 3692) was conducted. All records were examined to determine whether clomiphene citrate (CC) was used in the cycle of conception and whether or not an ectopic pregnancy occurred. Data were additionally analyzed for the incidence of ectopic pregnancy with and without assisted reproductive technology (ART). The incidence of ectopic pregnancy was similar between CC (3.4%) and non-CC (3.4%) treatment groups receiving non-ART treatment. For non-ART treatments, tubal disease and severe endometriosis resulted in an increase in ectopic pregnancies independent of CC use. The incidence of ectopic pregnancy in patients receiving CC + human menopausal gonadotropin (hMG) for in vitro fertilization (5.4%) and gamete intrafallopian transfer (3.1%) was similar compared to ART treatments with hMG alone. The incidence of ectopic pregnancy was more closely associated with infertility diagnosis rather than CC use.

Management of tubal pregnancy with methotrexate

Ten women with tubal ectopic pregnancy were treated by the injection of methotrexate into the gestational sac under direct laparoscopic vision followed by a course of intramuscular therapy including folinic acid rescue. One course of treatment induced resolution of the extrauterine pregnancy in eight women. Complete resolution (beta-hCG less than 10 miu/ml) was achieved within 6-47 days (mean 14.5 days). Serum beta-hCG levels started to decline 3.4 days from the beginning of therapy. Length of hospital stay was 5-11 days (mean 6.4 days). Treatment failed in two patients. One woman had a laparoscopic tubal clip sterilization concomitantly with methotrexate treatment. Tubal patency was demonstrated in all the other seven women (100%) tested subsequently. There is a need to establish criteria for patient selection before methotrexate becomes a routine treatment for tubal pregnancy.

The regional versus national incidence of ectopic pregnancy in Finland from 1966 to 1986

The annual incidence of ectopic pregnancy (EP) per deliveries, per all diagnosed pregnancies and per female population at fertile age (15-44 years) were measured from 1966 to 1986 in a well-defined urban area of Southwestern Finland, the Turku Region. The incidence rates increased markedly, and were, in the mid-80s, among the highest in the world: 2.6 per 100 deliveries, 1.8 per 100 diagnosed pregnancies and 153 per 100,000 fertile-aged women. The regional incidence rate exceeded the national one in the 1970s, whereas in the 1980s the regional rate which has levelled-off during recent years has been equal to, and currently even lower than the national one. This suggests that changes in the incidence of EP in urban area(s) preceed those in the whole country.

Causes of the increase in the incidence of ectopic pregnancy. A study on 1017 patients from 1966 to 1985 in Turku, Finland

The relationship between the increased incidence of ectopic pregnancy and the known risk factors of this disorder was examined by 5-year age groups and equivalent calendar periods to determine the causes of the recent "epidemic" of ectopic pregnancy. None of the known risk factors would alone explain the observed increase. Consequently, multivariate analysis by log-linear models was applied: age, past pelvic operation, previous pelvic inflammatory disease, antecedent legal abortion, and current use of an intrauterine contraceptive device were responsible for the increase in the occurrence of the disease. The strongest association with the observed temporal trend in the increase of ectopic pregnancy was found for pelvic operation (including previous ectopic pregnancy), pelvic inflammatory disease, and current use of an intrauterine contraceptive device. Improved diagnosis and changing demographic patterns also contributed to the increase in the annual number of ectopic pregnancies.

Ectopic pregnancy: a case-control study of aetiological risk factors

Aetiological risk factors for ectopic pregnancies were evaluated in a prospective study of 86 consecutive patients with ectopic pregnancy and two age- and parity-matched control groups of women in normal early pregnancy; those with planned pregnancy (65 pairs) and those having legal abortion (51 pairs). Compared with women with planned pregnancy, the patients with ectopic pregnancy more often had an IUD in situ, they had less frequently used hormonal contraception, and they had more legal abortions, curettages, previous ectopic pregnancies, gynaecological operations and salpingo-oophoritis. Compared with women having legal abortion, the patients with ectopic pregnancy had favoured IUD-usage, or they had been without any contraception, and they had an increased frequency of previous ectopic pregnancies. The frequency of fertility problems was also increased in patients with ectopic pregnancy. Our results show that gynaecological pelvic operations, endometrial curettage and evacuation, gynaecological infections, and usage of IUD are important risk factors for ectopic pregnancy, and that infertility seems to be a sign of this risk. In addition, the clinical characteristics of the patients with ectopic pregnancy were similar to those of the patients having legal abortion.

Increasing trend in the monozygotic twinning rate

Recent changes in the estimated incidence of monozygotic twinning in 15 European populations are described. The overall trend was an increase in the monozygotic twinning rate (MZTR) since the 1960s, particularly in those countries in which the use of oral contraceptives (OC) was widespread. A slower increase or even a decrease in the MZTR was observed in countries with low use of OC. Some countries, eg, Sweden, demonstrated an unexpectedly sharp increase since the 1960s. In Poland and the Federal Republic of Germany the MZTR was already strongly increasing as early as in the 1950s, clearly before the introduction of the pill. The influence of several other factors on the MZTR is discussed, such as toxic and teratogenic agents, pelvic infection diseases caused by the use of intrauterine devices, the increased use of ovulation inducers and neuroleptics as well as changes in the registration of perinatal deaths.

The intrauterine device and ectopic pregnancy

Based on data given by case-control and cohort studies the relationships between current and past IUD use, duration of IUD use and the type of IUD were evaluated to determine the risk of ectopic pregnancy among IUD users. The results of this review indicate that current and past IUD users do not have an increased risk of ectopic pregnancy. No relationship was found between the duration of IUD use, for either current or past IUD users, and the risk of ectopic pregnancy. Pooled data from clinical studies of different types of IUD showed that the lowest risk of ectopic pregnancy was for users of copper-bearing IUDs, and the highest risk was for users of progesterone-releasing IUDs. Further research is needed to evaluate the ectopic pregnancy risks to past IUD users, especially in view of recent studies which have shown that these women may be at a higher risk of infertility.

Time trends of ectopic pregnancies

Whether the increase of ectopic pregnancies could be explained by methodological problems or by changing age structure was examined in data from one hospital (Tampere, Finland) between 1972 and 1984. Numbers of ectopic pregnancies, births, and induced and spontaneous abortions were obtained by 5-year age-groups and county of residence from the hospital discharge register. Introduction of a more sensitive pregnancy test in 1979 was coincident with the most rapid increase in the role of ectopic pregnancies. Use of incomplete denominators and varying catchment areas and correction of changing age-distribution of pregnant women did not markedly influence the time trends. Our analysis suggests that the observed increase in ectopic pregnancies in this area was partly real and partly due to better diagnosis.

Background factors of ectopic pregnancy. I. Frequency distribution in a case-control study

Two hundred and five patients with ectopic pregnancy in a well-defined Swedish population were interviewed with respect to prior disease and pregnancy histories as well as various constitutional and socioeconomic factors. The results were compared with those of two control groups, i.e. 110 early pregnant women intending to continue the gestation to term as well as 101 women seeking voluntary interruption of pregnancy. The results provide evidence that several may be involved in the etiology of ectopic pregnancy, including abdominal (or pelvic) surgery, previous ectopic pregnancy and pelvic inflammatory disease. Furthermore, a history of infertility is strongly correlated to ectopic pregnancy. On the other hand, there is no evidence that uncomplicated spontaneous or induced abortion, parity or marital status are important factors.

Ectopic pregnancy presenting as intermittent rectal bleeding and anemia. A case report

A case report is presented of a patient with anemia and intermittent rectal hemorrhage caused by a tubal pregnancy eroding into the rectum. A search through the clinical literature on ectopic gestation reveals the rarity of such an occurrence.

The intrauterine device and ectopic pregnancy

Based on data given by case-control and cohort studies the relationships between current and past IUD use, duration of IUD use and the type of IUD were evaluated to determine the risk of ectopic pregnancy among IUD users. The results of this review indicate that current and past IUD users do not have an increased risk of ectopic pregnancy. No relationship was found between the duration of IUD use, for either current or past IUD users, and the risk of ectopic pregnancy. Pooled data from clinical studies of different types of IUD showed that the lowest risk of ectopic pregnancy was for users of copper-bearing IUDs, and the highest risk was for users of progesterone-releasing IUDs. Further research is needed to evaluate the ectopic pregnancy risks to past IUD users, especially in view of recent studies which have shown that these women may be at a higher risk of infertility.

Ectopic pregnancy--an analysis of the etiology, diagnosis and treatment in 552 cases

An analysis of the clinical data of 552 patients treated for ectopic pregnancy during 1973-82 in our hospital showed that the prevalence of this complication rose twofold (P less than 0.01) from an annual rate of 10.9 per thousand in 1973 to 20.9 per thousand in 1982. As regards parity distribution, the proportion of the 2-paras increased significantly (P less than 0.05) and this increase was significantly greater (P less than 0.001) than in the total population of parturients during this period. The increasing incidence of ectopic pregnancies had a significant positive correlation (P less than 0.05) with the use of an intrauterine device (IUD), but not with previous or present pelvic inflammatory disease or gynaecological or abdominal surgery. Because the 158 patients with an IUD in situ (34%) had a significantly less frequent past history of salpingitis, pelvic operation, infertility, ectopic pregnancy or spontaneous abortion and had less actual pelvic inflammatory changes than the 259 patients without contraception (57%), the IUD seemed to be directly involved with the increased risk of ectopic pregnancy. In the present study lower abdominal pain occurred in 97% of the patients and menstrual disorders in 93%; pelvic examination revealed adnexal mass in 63% and adnexal tenderness in 90% of the patients. Laparoscopy, a sensitive urinary pregnancy test (detection limit 75 IU/1) and culdocentesis were the most important factors in the diagnosis of ectopic pregnancy as evidenced by positive results in 97, 90 and 83% of the cases, respectively. Due to improved diagnostic procedures the annual rate of an unruptured tube at operation increased from 49% to 73% during the study period.