Risk Factors for Ectopic Pregnancy
Date First Published:
June 17, 2005
Last Updated:
July 22, 2005
Report by:
Emma Shawkat, 4th Year Medical Student (Manchester Royal Infirmary)
Three-Part Question:
In [pregnant women who present with PV bleeding to A&E] what are the [risk factors] for an [ectopic pregnancy]?
Clinical Scenario:
A 24 year old woman presents to accident and emergency with vaginal bleeding. She tells you she did a home pregnancy test and it was positive. You want to assess her clinical risk of having an ectopic pregnancy.
Search Strategy:
Medline 1966-06/05 using Ovid Interface
Embase 1980-06/05
CINAHL 1982-06/05
The Cochrane Library Issue 2, 2005
Embase 1980-06/05
CINAHL 1982-06/05
The Cochrane Library Issue 2, 2005
Search Details:
({[tubal pregnancy.mp or exp PREGNANCY, TUBAL or ectopic pregnancy.mp exp or PREGNANCY, ECTOPIC or abdominal pregnancy.mp or exp PREGNANCY, ABDOMINAL or extrauterine pregnancy.mp] AND [risk factors.mp or exp Risk Factors or risk assessment.mp. or exp Risk Assessment or risk.mp. or exp RISK]} LIMIT to humans and english)
Cochrane ('ectopic pregnancy' or 'tubal pregnancy') AND 'risk factors'
Cochrane ('ectopic pregnancy' or 'tubal pregnancy') AND 'risk factors'
Outcome:
997 papers were identified from medline or which 8 were relevant. 3 meta-analyses were found
No additional papers found from the other databases
No additional papers found from the other databases
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Risk factors for ectopic pregnancy in Lagos, Nigeria. Anorlu RI. Oluwole A. Abudu OO. Adebajo S 2005 Feb Denmark | Cases;100 consecutive patients who had laparotomy for ectopic pregnancy in 1 of three hospitals Controls;280 randomly selected consenting women who attended the family planning and gynaecology clinics at the same hospitals as the patients |
Case-control study (3b) | Risk factors | Adjusted odds ratio (95% CI): Miscarriage 3.35 (1.93-5.83), Induced abortion 14.71 (5.57-27.96), Complicated induced abortion 4.13 (3.14-7.29), Previous pelvic surgery 2.09 (1.07-3.83), Previous EP 1.2 (0.47-7.2), Infertility treatment 1.69 (0.78-3.56), IUCD 3.76 (2.12-6.69), 15-19 years (sexual debut) 1.93 (1.71-2.93), Multiple sexual partners 3.2 (1.67-5.01) STD 9.06 (4.57-18.59) and PID 5.61 (3.64-10.52) | These risk factors have been found in women from Nigeria. |
| Risk factors of ectopic pregnancy Bunyavejchevin S. Havanond P. Wisawasukmongchol W 2003 Jun Thailand | 208 cases of ectopic pregnancy and 781 controls | Case-control study (3b) | Risk factors | Odds ratio (95% CI): Sexual partners >1 3.02 (1.75-5.23), Hx of PID 3.17 (1.40-7.19), Smoking 2.49 (1.36-4.58), Infertility 2.74 (1.35-5.54) | Population studied was Thai women only |
| Risk factors for ectopic pregnancy: a comprehensive analysis based on a large case-control, population-based study in France Bouyer J. Coste J. Shojaei T. Pouly JL. Fernandez H. Gerbaud L. Job-Spira N 2003 Feb 1 United States | 803 cases of ectopic pregnancy 2 controls; a woman who gave birth at the same centre at which the case was treated and a woman whose delivery occured shortly after treatment of the case. |
Case-control study (3b) | Risk factors | Odds ratio (95% CI): Age; 30-34 1.3 (1.0-1.7), 35-39 1.4 (1.0-2.0), >40 2.9 (1.4-6.1), Smoking: Past 1.5 (1.1-2.2), 1-9/day 1.7 (1.2-2.4), 10-19/day 3.1 (2.2-4.3), >20/day 3.9 (2.6-5.9), Prior spontaneous abortion: 1-2 1.2 (0.9-1.6), >2 3.0 (1.3-6.9), Prior induced abortion: Surgical 1.1 (0.8-1.6), Medical (or medical and surgical) 2.8 (1.1-7.2), Appendectomy (ruptured appendix) 1.4 (0.8-2.4), Prior STD: without salpingitis 1.0 (0.8-1.3), with probable PID 2.1 (0.8-5.4), confirmed PID 3.4 (2.4-5.0), Prior tubal surgery 4.0 (2.6-6.1), Previous use of OC 0.7 (0.5-1.0), Previous IUD 1.3 (1.0-1.8), Infertility: <1 year 2.1 (1.2-3.6), 1-2 years 2.6 (1.6-4.2) and >2 years 2.7 (1.8-4.2) | This study was carrid out on french women only |
| Risk factor for ectopic pregnancy Anonymous 1999 Feb Canada | Only reference available at present | ||||
| Risk factors for ectopic pregnancy in a rural population Garrett AM. Vukov LF 1996 Feb United States | Medical records of all patients with ectopic pregnancy who presented from 1986 through 1992 to the emergency department of a large, rural referral hospital with 65,000 annual visits (n=126) | Retrospective case review | Risk factors | Prior tubal surgery 38%, Hx of infertility 35%, PID 17%, Previous EP 16%, Appendectomy/pelvic operation 13%, Fertility drugs 9% & IUD in situ 1% | Data collection was retrospective No odds ratios calculated |
| Single risk factor: 17% | |||||
| No risk factor: 47% | |||||
| Risk factors for ectopic pregnancy: a meta-analysis Ankum WM. Mol BW. Van der Veen F. Bossuyt PM. 1996 Jun Untied States | A total number of 6,718 cases of EP in 27 case control studies and 13,049 exposed women in 9 cohort studies | Meta-analysis | Risk factors (cohort studies) | Common odds ratio (95% CI): Pelvic and/or abdominal surgery 1.5 (1.1-2.6), In utero DES-exposure 5.6 (2.4-13), PID 5.7 (2.5-13), Medical abortion 1.2 (0.78-1.2), Infertility 2.0 (1.2-3.4) | Individual papers do not provide sufficient data to allow multivariate analysis They did not look at contraceptive methods |
| Risk factors not covered by the cohort studies (case-control, with pregnant controls) | Common odds ratio (95% CI): Previous; Gonorrhoea 2.9 (1.9-4.4), Chlamydia: IgG>1:32 2.8 (2.0-4.0), IgG>1:64 3.7 (2.9-4.7), Ectopic pregnancy 8.3 (6.0-11.5), Tubal surgery 21 (9.3-47), Tubal pathology 3.5, Current smoking 2.3 (2.0-2.8), Ever smoking 2.5 (1.8-3.4), Vaginal douching 1.1, Lifetime no. sexual partners >1 2.1 (1.4-4.8), Age at first sexual intercourse <18 1.6 (1.1-2.5) | ||||
| Contraception and the risk of ectopic pregnancy: a meta-analysis Mol BW. Ankum WM. Bossuyt PM. Van der Veen F 1995 UNITED STATES | Case-control and cohort studies published between 1978 and 1994 in English, French, German and Dutch were retrieved by a search in Medline, a hand-search on recent medical journals and cross-references | Meta-analysis | Risk factors (pregnant controls) | Common Odds Ratios (95% CI): Oral contraception: current use 1.8 (0.9-3.4), IUCD: current use 4.2-45, past use 1.6 (1.4-1.8), Sterilization: 9.3 (4.9-18), Condom: 0.97 (0.24-4.0) | No common odds ratio could be calculated for current IUCD use |
| P values: Oral contraception current use 0.502, IUCD current use 0.001, past use 0.849, sterilization 0.753 | |||||
| IUD use and the risk of ectopic pregnancy: a meta-analysis of case-control studies Xiong, X. Buekens, P. Wollast, E 1995 UNITED STATES | From 1977 through 1994, 19 publications regarding 16 studies of ectopic pregnancy and IUD use were found by MEDLINE and manual search | Meta-analysis | Current IUD use as a risk for ectopic pregnancy (pregnant controls) | Pooled odds ratio: 10.63, 95% CI: 7.66-14.74 (p<0.01) | |
| Past IUD use as a risk factor for ectopic pregnancy (pregnant controls) | Pooled odds ratio: 1.33, 95% CI: 1.08-1.63 |
Author Commentary:
Originally only papers that looked at risk factors as a whole, as opposed to papers that looked at individual risk factors were going to be included in this bet. However because the meta-analysis did not report on contraceptive methods as a risk factor, two further meta-analyses had to be included. These reported on the risks associated with contraception as a whole and use of an IUD.
When pregnant and non-pregnant controls were used, the odds ratios associated with the pregnant controls are used. This is because an A&E physician has to determine the risk of a pregnant woman having an ectopic gestation.
When pregnant and non-pregnant controls were used, the odds ratios associated with the pregnant controls are used. This is because an A&E physician has to determine the risk of a pregnant woman having an ectopic gestation.
Bottom Line:
There are numerous risk factors associated with an ectopic pregnancy they are (followed by the range of odds ratios): Pelvic inflammatory disease 3.17-5.7, Infertility 2.0-2.74, In utero DES exposure 5.6, Tubal surgery 4.0-21, Current smoking, 1.7-6.0 Previous ectopic pregnancy 1.2-8.3, Multiple sexual partners 2.1-3.2, Current IUD use 4.2-45, Sterilization 9.3 and Previous abortion 0.95-14.71
References:
- Anorlu RI. Oluwole A. Abudu OO. Adebajo S. Risk factors for ectopic pregnancy in Lagos, Nigeria.
- Bunyavejchevin S. Havanond P. Wisawasukmongchol W. Risk factors of ectopic pregnancy
- Bouyer J. Coste J. Shojaei T. Pouly JL. Fernandez H. Gerbaud L. Job-Spira N. Risk factors for ectopic pregnancy: a comprehensive analysis based on a large case-control, population-based study in France
- Anonymous. Risk factor for ectopic pregnancy
- Garrett AM. Vukov LF. Risk factors for ectopic pregnancy in a rural population
- Ankum WM. Mol BW. Van der Veen F. Bossuyt PM.. Risk factors for ectopic pregnancy: a meta-analysis
- Mol BW. Ankum WM. Bossuyt PM. Van der Veen F. Contraception and the risk of ectopic pregnancy: a meta-analysis
- Xiong, X. Buekens, P. Wollast, E. IUD use and the risk of ectopic pregnancy: a meta-analysis of case-control studies