Tubal rupture happens because of the infiltration of the trophoblastic tissue into the tubal wall. The fallopian tube is not intact. It is common at the isthmus of fallopian tube. Tubal abortion is characterized by the extrusion of an ectopic product of conception implanted in the fallopian tube entering into the peritoneal cavity through the abdominal ostium. It is common at the ampulla of fallopian tube. It can be either complete or incomplete [2] and the fallopian tube is intact. The villus of complete tubal abortion patients may grow at abdomen, leading to abdominal pregnancy. The rupture and abortion of tubal pregnancy can both lead to severe bleeding, even hemorrhagic shock and death.
According to former studies, the rupture rate of tubal pregnancy is about 28.75%ཞ65%. According to the study of Nina A. Bickell [5], the rupture rate is 32%. According to Michael Sindos [6], the rupture rate is 65%. From the study of Pasquale Berlingieri [7], the rupture rate is 29.5%. The study of abortion rate is rare. According to Lijuan Li [13], among 181 tubal pregnancy patients, tubal abortion happens in 57 cases, the abortion rate is about 31.49%. The rupture rate is 17.48% and the abortion rate is 14.67% in my hospital, which is obviously lower than the data of former studies. It might be related to the rise of health awareness in China and the more active management and guardianship of ectopic pregnancy. When women get pregnant, they will go to hospital for an ultrasound test, which leads to the rise of the early detection rate of ectopic pregnancy. Ectopic pregnancy can be treated before rupture or abortion.
There are controversial opinions of the risk factors of tubal rupture. According to Pasquale [7], the patients with age > 35 and isthmus pregnancy have higher rupture risks than others. With the detailed analysis of symptoms from the study of Cyrille Huchon [8], vomiting during pain, diffuse abdominal pain, acute pain for longer than 30 minutes, and flashing pain are the risk factors of tubal rupture. According to B. Pınar Cilesiz Goksedef [9], higher HCG level and higher gestational age seem to be significant risk factors for rupture of an ectopic pregnancy. The mean gestational age of ruptured ectopic pregnancy is 7.8 weeks; the mean HCG is 8735.3U/L. While the mean gestational age of ruptured ectopic pregnancy is 6.4 weeks; the mean HCG is 4506U/L. Logistic regression analysis revealed that weeks of amenorrhoea > 8 weeks (OR: 46.46; 95% CI: 14.20–152.05) and HCG level > 5000 IU/ml (OR: 4.40; 95% CI: 1.69–11.46) were the significant risk factors for tubal rupture. Michael [6] conducted a study about past history, the patients with ectopic pregnancy history and childbearing history have a higher risk to rupture. According to the study of Gregory Latchaw [4], HCG ≥ 5000U/L and ectopic pregnancy history are the risk factors of rupture.
After analyzed the risk factors from case history, clinical manifestations, signs and tests, abdominal pain(OR:3.101, 95%CI:1.812–5.306, P < 0.001), cervical lifting pain(OR:2.942, 95%CI:2.046–4.231, P < 0.001), mass diameter ≥ 4cm(OR:2.874, 95%CI: 2.095–3.941, P < 0.001), HCG ≥ 5000U/L(OR:2.588, 95%CI:1.900-3.526, P < 0.001), adnexal tenderness(OR:1.893, 95%CI:1.296–2.764, P = 0.001), age ≥ 35(OR:1.781, 95%CI:1.232–2.573, P = 0.002), aspirating blood during culdocentesis (OR:1.497, 95%CI:1.081–2.074, P = 0.015) are the risk factors of tubal rupture, while vaginal bleeding(OR:0.271, 95%CI:0.196–0.375, P < 0.001) is the protective factor of tubal rupture. Patients with these risk factors should be treated more actively.
HCG and mass diameter are the criterion of surgery or conservative treatment. According to the ACOG guide [10], the indication of conservative treatment is HCG < 5000 and mass diameter < 4cm. According to my study, the risk of rupture of patients with HCG ≥ 5000U/L is 2.588 times than the patients with HCG < 5000U/L (95%CI:1.900-3.526, P < 0.001). The risk of rupture of the patients with mass diameter ≥ 4cm is 2.874 times than the patients with mass diameter < 4cm (95%CI:1.900-3.526, P < 0.001). The data supports that the indication of conservative treatment is HCG < 5000 and mass diameter < 4cm.
A few scholars put forward the opinion that age ≥ 35 is the risk factor of tubal rupture, and they all agree that it should be further studied [7]. It may be related to the higher health awareness of young patients. They are more willing to go to hospital when amenorrhea, abdominal pain and vaginal bleeding happens, which leads to the higher early detective rate of ectopic pregnancy, to reduce the rupture rate.
There are few studies about the risk factors of tubal abortion, most of which are case reports. For aborted ectopic pregnancy patients, they may show the manifestation of low HCG and the decrease of HCG during the course of disease [5]. According to Lijuan Li [13], tubal rupture patients’ possibility of massive hemorrhage is higher than tubal abortion patients and much higher than ectopic pregnancy patients without rupture or abortion. In addition, the HCG of patients without rupture or abortion is higher than tubal abortion patients and lower than tubal rupture patients.
According to my study, HCG < 2000U/L (OR:3.554, 95%CI:2.401–5.260, P < 0.001) and mass diameter ≥ 4cm (OR:2.732, 95%CI:1.900-3.929, P < 0.001) are the risk factors of tubal abortion. The patients with tubal abortion can also be treated by expectant treatment. The indication of expectant treatment is: the condition of patient is stable without abdominal pain or with slight abdominal pain, without obvious intra-abdominal hemorrhage; HCG < 1000ཞ2000U/L; mass diameter < 30mm without fetal heartbeat [11]. As the risk factors of tubal abortion are HCG < 2000U/L and mass diameter ≥ 4cm, and as the HCG of tubal abortion patients can reduce to normal spontaneously, I proposed that although mass diameter ≥ 4cm is not the indication of expectant treatment, for patients with HCG < 2000U/L and mass diameter ≥ 4cm, after their informed consent, they could be treated by expectant treatment and HCG should be tested constantly.
The patients of tubal rupture and tubal abortion have similar clinical manifestations and signs, for example, abdominal pain, adnexal tenderness, cervical lifting pain, aspirating blood during culdocentesis. Tubal rupture patients are more likely to happen massive hemorrhage. The pelvic blood volume of 30.53% tubal rupture patients is 1000 ~ 2000ml, the pelvic blood volume of 15.09% tubal rupture patients is more than 2000ml. While the possibility of massive hemorrhage of tubal abortion patients is much lower than tubal rupture patients. For tubal abortion patients with slight intra-abdominal hemorrhage, it is possible that they may be treated by expectant treatment [12]. But tubal rupture patients always need to be treated by surgery. It is important to differentiate tubal rupture and tubal abortion for a better treatment strategy. According to my study, the point of differentiating tubal rupture and tubal abortion is the HCG. The mean HCG of tubal abortion patients and tubal rupture patients is 4412.98U/L and 11441.85U/L, the mean HCG of patients without abortion or rupture is 6812.26U/L. The HCG of each group is statistically different. It may be related to the difference of villus activity. Higher HCG means higher villus activity, which leads to a higher possibility of rupture. While the embryo death always happens in tubal abortion patients, which leads to the loss of villus activity and the decease of HCG synthesis and secretion [13].
Combined with the results that HCG ≥ 5000U/L is the risk factor of tubal rupture and HCG < 2000U/L is the risk factor of tubal abortion, when facing an ectopic pregnancy patient with intra-abdominal hemorrhage, if HCG ≥ 5000U/L, it is more likely to be tubal rupture. If HCG < 2000U/L, it is more likely to be tubal abortion, we should observe her clinical manifestation and test HCG frequently.