title: Risk factors for recurrent ectopic pregnancy: a case-control study.
abstract: OBJECTIVE
  To study the risk factors for recurrent ectopic pregnancy (REP).
  
  
  METHODS
  A retrospective case-control study.
  
  
  METHODS
  A university medical centre.
  
  
  METHODS
  554 women with a history of ectopic pregnancy (EP) were included. Among them were 181 women with current EP, 184 women with current intrauterine pregnancy (IUP) and 189 nonpregnant women (NonP).
  
  
  METHODS
  The three groups were matched at a ratio of 1:1 with respect to current age, age of initial EP and gestational week of initial EP. Socio-demographic characteristics, reproductive history, gynaecological and surgical history, and experience of contraception were compared among the three groups. A multivariable logistic regression analysis was used to adjust for confounders and calculate adjusted odds ratios (AORs).
  
  
  RESULTS
  The risk of REP increased with history of infertility (AOR = 3.84, 95%CI 2.16-6.86) in REP women compared with IUP controls. Compared with NonP controls, salpingotomy (AOR = 3.04, 95%CI 1.21-36.51) for previous EP was a risk factor for REP. Multiparous women were less likely to suffer REP when compared with NonP women (AOR = 0.36, 95%CI 0.18-0.62) or IUP controls (AOR = 0.35, 95%CI 0.20-0.62). Current use of an intrauterine device (IUD) (REP versus NonP, AOR = 0.02, 95%CI 0.00-0.08) or condoms (REP versus NonP, AOR = 0.16, 95%CI 0.07-0.38) significantly reduced the risk of REP compared with those not using any contraception. Similarly, previous use of condoms also prevented REP compared with those with no previous condom use (REP versus NonP, AOR = 0.20, 95%CI 0.08-0.49; REP versus IUP, AOR = 0.40, 95%CI 0.22-0.71).
  
  
  CONCLUSIONS
  Women with history of infertility or salpingotomy should be alert for the recurrence of EP. Multiparous women are less likely to suffer REP. We propose the use of condoms for effective prevention of REP.
  
  
  CONCLUSIONS
  History of infertility and salpingotomy for last EP are risk factors for recurrent EP.
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: W
authors.initials: W
authors.lastname: Shi
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: J-J
authors.initials: JJ
authors.lastname: Yuan
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: W
authors.initials: W
authors.lastname: Xia
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: R-H
authors.initials: RH
authors.lastname: Xue
authors.affiliation: Department of Obstetrics and Gynaecology, Shanghai First Maternity and Infant Hospital, Tong Ji University School of Medicine, Shanghai, China. sunjing61867@126.com.
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Obstetrics and Gynaecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China. zhangjian_ipmch@sjtu.edu.cn.|Institute of Embryo-Fetal Original Adult Disease Affiliated to School of Medicine, Shanghai Jiaotong University, Shanghai, China. zhangjian_ipmch@sjtu.edu.cn.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002681:China; D017280:Condoms / Q000706:statistics & numerical data; D003268:Contraception Behavior; D037001:Directive Counseling; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000150:complications / Q000628:therapy*; D007434:Intrauterine Devices / Q000009:adverse effects*; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D012489:Salpingostomy / Q000009:adverse effects*; D055502:Secondary Prevention; D055815:Young Adult
keywords: Case-control study; contraception; recurrent ectopic pregnancy; risk factors