{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T12:48:30Z","timestamp":1783428510914,"version":"3.54.6"},"reference-count":35,"publisher":"BMJ","issue":"12","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2014,10,10]]},"published-print":{"date-parts":[[2014,12]]},"abstract":"<jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>To identify risk factors for ovarian pregnancy (OP) and compare clinical features between OP and tubal pregnancy (TP) patients.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Design<\/jats:title>\n                  <jats:p>Case\u2013control study.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Setting<\/jats:title>\n                  <jats:p>University hospital.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Participants<\/jats:title>\n                  <jats:p>A case\u2013control study was conducted from January 2005 to May 2014. Women diagnosed with OP were recruited as the case group (n=71), 145 women with TP and 146 with intrauterine pregnancy (IUP) were matched as controls at a ratio of 1:2:2. Women who refused interviews or provided incomplete information were excluded.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>OP risk was lower than TP risk in women with serological evidence of <jats:italic>Chlamydia trachomatis<\/jats:italic> infection (adjusted OR<jats:sub>1<\/jats:sub> 0.17, 95% CI 0.06 to 0.52), previous adnexal surgery (adjusted OR<jats:sub>1<\/jats:sub> 0.25, 95% CI 0.07 to 0.95), and current levonorgestrel emergency contraceptive use (adjusted OR<jats:sub>1<\/jats:sub> 0.24, 95% CI 0.07 to 0.78). In vitro fertilisation-embryo transfer (IVF-ET) carried a higher risk of OP (adjusted OR<jats:sub>1<\/jats:sub> 12.18, 95% CI 2.23 to 66.58) than natural conception. When Controlled by IUP women, current users of intrauterine devices (IUDs) carried a higher risk of OP than non-users of any contraceptives (adjusted OR<jats:sub>2<\/jats:sub> 9.60, 95% CI 1.76 to 42.20). \u03b2-Human chorionic gonadotropin (hCG) levels on the day of surgery were higher in OP patients than in TP patients (p&lt;0.01). Women with OP were less likely to initially present with vaginal bleeding than those with TP (p=0.02). Moreover, shock (p=0.02), rupture (p&lt;0.01), haemoperitoneum (p&lt;0.01) and emergency laparotomy (p&lt;0.01) were more common in the OP group than in the TP group.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>IVF-ET and IUD use may be risk factors for OP, and OP patients tend to have high \u03b2-hCG levels and a poor clinical outcome (shock, rupture, haemoperitoneum and need for emergency laparotomy). Our findings may contribute to the prevention and early diagnosis of OP.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjopen-2014-006447","type":"journal-article","created":{"date-parts":[[2014,12,3]],"date-time":"2014-12-03T23:58:51Z","timestamp":1417651131000},"page":"e006447","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":34,"title":["Risk factors and clinical features of ovarian pregnancy: a case\u2013control study"],"prefix":"10.1136","volume":"4","author":[{"given":"Qian","family":"Zhu","sequence":"first","affiliation":[{"name":"Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cheng","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei-Hong","family":"Zhao","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiang-Jing","family":"Yuan","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ming-Xing","family":"Yan","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guo-Juan","family":"Qin","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Minhang Central Hospital, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jian","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2014,12,3]]},"reference":[{"key":"2025101815041141000_4.12.e006447.1","doi-asserted-by":"publisher","DOI":"10.1093\/humrep\/12.3.608"},{"key":"2025101815041141000_4.12.e006447.2","first-page":"174","article-title":"Ovarian pregnancy: a series of 24 cases","volume":"61","author":"Grimes","year":"1983","journal-title":"Obstet Gynecol"},{"key":"2025101815041141000_4.12.e006447.3","doi-asserted-by":"publisher","DOI":"10.1016\/0028-2243(92)90235-Q"},{"key":"2025101815041141000_4.12.e006447.4","first-page":"320","article-title":"Ovarian pregnancy without definitive pathologic confirmation: a case report","volume":"52","author":"Abidi","year":"2007","journal-title":"J Reprod Med"},{"key":"2025101815041141000_4.12.e006447.5","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejogrb.2003.09.038"},{"key":"2025101815041141000_4.12.e006447.6","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.ijgo.2006.09.031","article-title":"Primary ovarian pregnancy","volume":"96","author":"Shiau","year":"2007","journal-title":"Int J Gynaecol Obstet"},{"key":"2025101815041141000_4.12.e006447.7","first-page":"169","article-title":"Laparoscopic management of ovarian pregnancy","volume":"12","author":"Tinelli","year":"2008","journal-title":"JSLS"},{"key":"2025101815041141000_4.12.e006447.8","unstructured":"O S: Casuistry in ovarian pregnancy. 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