Ectopic Pregnancy 异位妊娠

Prevalence of ectopic pregnancy is increasing with widening use of ART and better diagnosis due to ongoing improvements in ultrasound technology. In spite of this, the latest mortality rate was the lowest registered since 1988, with 1.65/10000 deaths between 2006 and 2008 (1). Women undergoing fertility treatment often have uterine or tubal pathology and possibly a history of previous ectopic pregnancy or tubal surgery, which are all considered risk factors for extra uterine implantation. The incidence of ectopic pregnancy in assisted conception is higher than when compared to the general population, ranging from 2% to 11% (2,3). It is difficult to determine whether this increase is due to treatment or the cause of infertility itself. Furthermore, these patients are at particular risk of simultaneous occurrence of pregnancies on two or more implantation sites, with an incidence of 1/100 (4).

随着辅助生殖技术的广泛应用及B超诊断技术的持续改善，异位妊娠的现象变得越来越常见。尽管如此，最新的死亡率是1988年以来的最低记录，即2006年至2008年间每10000例患者只有1.65例死亡(数据参考见1)。接受生育治疗的患者通常存在子宫或输卵管病理情况，并可能有异位妊娠或输卵管手术史，这些都被视为导致子宫外妊娠的风险因素。辅助受孕中异位妊娠的发病率高于一般人群，从2%到11%不等(数据参考见2，3)。很难确定高发病率是试管治疗还是不孕不育本身所导致的。此外，这些患者出现两个或多个位置同时发生妊娠的风险特别高，发病率为1%(数据参考见4)。

The difficulty with heterotopic pregnancy is that there usually is an intrauterine pregnancy, which gives false reassurance when initially identified on the scan, and diagnosis is usually late. As a result, a thorough ultrasound assessment is essential, not only to exclude extrauterine implantation, but also to identify ectopics early, so as to improve outcome and consequent fertility.

诊断宫内外同时妊娠的难点在于，通常情况下宫内妊娠也会存在，最初B超诊断仪上显示的结果往往会让人做出错误的判断，通常在之后才能确诊。因此，全面的B超评估是非常有必要的，不仅可以排除宫外妊娠，也可以较早的辨别异位妊娠，从而改善结果和随后的生育治疗。

Transvaginal ultrasound is the gold standard for diagnosis of ectopic pregnancy and offers sensitivity of 87% and specificity of 94% (5). Suspicion should arise if the uterine cavity appears empty. In 15% of cases of ectopic pregnancy, a pseudogestational sac may be present, which should not be misdiagnosed as an early intrauterine pregnancy. It is important to ensure that the entire uterine cavity has been assessed, including the cervical canal and interstitial portion of the tubes. For patients with a previous Cesarean section, the uterine scar should always be reviewed. Diagnosis of ectopic pregnancy should only be made if a gestational sac or RPOC are visualized outside the uterine cavity

阴道超声波检查是诊断异位妊娠的黄金标准，灵敏度为87%，特异性为94%(数据参考见5)。如果子宫腔显示为空腔，应怀疑是否为异位妊娠。在15%的异位妊娠病例中，可能存在伪妊娠囊，不应误诊为早期宫内妊娠。对子宫进行全面的评估至关重要，包括宫颈管和管间部分。对于先前剖腹产的患者，应始终进行子宫疤痕的检查。只有在子宫腔外显示妊娠囊或妊娠物残留时，才应诊断为异位妊娠。

Reference 数据参考：

1. Wilkinson H, Trustees and Medical Advisers. Saving Mother’s Lives: reviewing maternal deaths to make motherhood safer: 2006-2008. BJOG 2011; 118:1402-1403

2. Mg e, Yeung W, So W, Ho P. An analysis of ectopic pregnancies following IVF treatment in a 10-year period. J Obstet Gynaecol 1998; 18: 359-365

3. Dubuisson J, Aubriot F, Mathieu L, et al. Rish factors for ectopic pregnancy in 556 pregnancies after IVF: implications for preventive management. Fertil Steril 1991; 56:686-690

4. Tal J, Haddad, S, Gordon N, Timor-Tritsch I. Heterotopic pregnancies after ovulation induction and ART: a literature review from 1971 to 1993. Fertil Steril 1996; 66:1-12

5. Shalev E, Yarom I, Bustan M, Weiner E, Ben-Shlomo I, Transvaginal sonography as the ultimate diagnostic tool for the management of ectopic pregnancy: experience with 840 cases. Fertil Steril 1998;69:62-65