Using Scottish national registry data, Sohinee Bhattacharya and colleagues investigate pregnancy outcomes following ectopic pregnancy in comparison to livebirth, miscarriage, or termination in a first pregnancy.
We aimed to compare reproductive outcomes following ectopic pregnancy (EP) versus livebirth, miscarriage, or termination in a first pregnancy.
Methods And Findings
A retrospective cohort study design was used. Scottish national data on all women whose first pregnancy occurred between 1981 and 2000 were linked to records of a subsequent pregnancy. The exposed cohort comprised women with an EP in their first pregnancy. There were three unexposed cohorts: women with livebirth, miscarriage, and termination of their first pregnancies. Any differences in rates of second pregnancy, livebirth, EP, miscarriage, or terminations and complications of a second ongoing pregnancy and delivery were assessed among the different exposure groups. A total of 2,969 women had an initial EP; 667,299 had a livebirth, 39,705 women miscarried, and 78,697 terminated their first pregnancies. Women with an initial EP had an increased chance of another pregnancy within 2 years (adjusted hazard ratio (AHR) 2.76 [95% CI 2.58–2.95]) or after 6 years (AHR 1.57 [95% CI 1.29–1.91]) compared to women with a livebirth. In comparison with women with an initial miscarriage, women who had an EP had a lower chance of a second pregnancy (AHR 0.53 [95% CI 0.50–0.56]). Compared to women with an initial termination, women with an EP had an increased chance of a second pregnancy (AHR 2.38 [95% CI 2.23–2.55]) within 2 years. Women with an initial EP suffered an increased risk of another EP compared to women with a livebirth (AHR 13.0 [95% CI 11.63–16.86]), miscarriage (AHR 6.07 [95% CI 4.83–7.62]), or termination (AHR 12.84 [95% CI 10.07–16.37]). Perinatal complications in a pregnancy following EP were not significantly higher than those in primigravidae or in women with a previous miscarriage or termination.
Women with an initial EP have a lower chance of conception than those who miscarry but an increased risk of a repeat EP in comparison with all three comparison groups. A major limitation of this study was the inability to separate women using contraception from those who were intending to conceive.
Please see later in the article for the Editors' Summary
An ectopic pregnancy occurs when the embryo (fertilized egg) implants outside the uterine cavity, usually in the fallopian tubes but sometimes in the cervix, ovaries, or abdomen. The prevalence for this condition is between 1%–2% of all pregnancies, and risk factors are thought to include pelvic infection, smoking, previous pelvic surgery, and use of certain types of intrauterine contraceptive devices. Ectopic pregnancies are potentially life threatening because as the fetus grows, it can lead to tubal rupture and abdominal bleeding—for example, in the UK, ectopic pregnancies are responsible for almost three-quarters of early pregnancy-related deaths. However, due to improvements in early diagnosis, in high income countries, deaths from ectopic pregnancies have become increasingly rare.
Why Was This Study Done?
Having an ectopic pregnancy can have serious implications for future fertility and subsequent pregnancies but to date, there is little information on reproductive outcomes in women who have had an ectopic pregnancy. So in this study, the researchers used a population-based cohort of women in Scotland to examine future reproductive outcomes in women who had an initial ectopic pregnancy and then compare these outcomes to those in women following a successful (live birth) or unsuccessful (miscarriage or termination) intrauterine pregnancy.
What Did The Researchers Do And Find?
The researchers used a national database (The Scottish Morbidity Record) and hospital discharge information to identify women who had ectopic pregnancies, miscarriages, terminations, or on-going pregnancies between 1981–2000. Then, using unique linking identifiers, they were able to examine the outcomes of subsequent pregnancies and conducted a statistical analysis to investigate whether the first pregnancy outcome had any effect on second pregnancy outcomes.
The researchers found that during the time period studied, in their first pregnancy, 2,969 women had an ectopic pregnancy, 39,705 women miscarried, 78,697 women underwent termination, and the majority, 667,299, gave birth to a live infant. The researchers then found that compared to women with an initial live birth, women with an ectopic pregnancy were 2.76 times more likely to conceive a second pregnancy within two years. However, compared to women whose first pregnancies ended in miscarriage, women with an initial ectopic pregnancy were significantly less likely to conceive a second time but had an increased chance of a second pregnancy within two years compared to women who terminated their first pregnancy. Importantly, the researchers found that women with an initial ectopic pregnancy had a higher risk of a further ectopic pregnancy compared to all the other groups of women. Furthermore, these women had a significantly higher risk of preeclampsia, preterm delivery, and emergency cesarean delivery in their next continuing pregnancy compared to women who had a previous live birth. However, these risks were not significantly higher than women who had an early loss in a first pregnancy.
What Do These Findings Mean?
These findings suggest that women with an initial ectopic pregnancy have a lower chance of conception than those who miscarry and also have an increased risk of a repeat ectopic pregnancy compared to women who experience miscarriage, termination, or a live birth in their first pregnancy. However, as the researchers did not have any information on contraception use, a major limitation of this study is the inability to separate women using contraception from those who were intending to conceive—women who experienced an ectopic pregnancy may not want to conceive again after a traumatic experience rather than being unable to conceive because of tubal damage. However, the results of this study may help doctors to counsel women with an ectopic pregnancy at the time of initial diagnosis and treatment, and in those willing to conceive again, offer follow-up to discuss future fertility and possible risks of subsequent pregnancy. Further research will help to investigate whether the site of ectopic pregnancy affects future reproductive outcomes.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001243.
The American Pregnancy Association and the UK National Health Service (NHS) Choices give information on ectopic pregnancy
The UK nonprofit organization Ectopic Pregnancy Trust provides support for individuals affected by ectopic pregnancy