|Year : 2012 | Volume
| Issue : 3 | Page : 151-155
Role of transvaginal ultrasound in detection of retained products of conception after abortion
Ahmed Maged, Hassan Gaffar, Walaa Mostafa
Department of Obstetrics and Gynecology, Kasr Aini Hospital Cairo University, Cairo, Egypt
|Date of Web Publication||15-Jan-2013|
135 King Faisal Street Haram Giza, Postal code 12151, Haram, Cairo
Source of Support: None, Conflict of Interest: None
Objectives: To evaluate risk factors for retained products of conception (RPOC) after surgical evacuation (SE) using transvaginal sonography (TVS) and success of medical and surgical management. Study Design: Retrospective open-label study included 270 women after SE done for abortion; 204 were completely evacuated and 66 had RPOC randomly equally subjected to medical or surgical treatment. Results: There was a significant difference between the two study groups regarding GA at SE (lower in the complete evacuation group) 7.32 ± 1.352 vs. 10.23 ± 1.572, experience of the obstetrician (higher in complete evacuation group) and adverse effects as vaginal bleeding, abdominal pain, and fever (lower in the complete evacuation group). Success of both medical and surgical treatment of retained products showed a statistically nonsignificant difference. Nausea and headache showed nonsignificant difference between the two groups while most side effects reported were more in the medical group as diarrhea (12 vs. 1), fever (9 vs. 0), hot flushes (10 vs. 0), abdominal pain (9 vs. 2), and vaginal bleeding (9 vs. 2). Few side effects were reported more in the surgical group such as vomiting (13 vs. 2) and tiredness (12 vs. 2). Conclusion: TVS is recommended following D and E in patients at high risk for RPOC for whom medical and surgical treatment are effective.
Keywords: Misoprostol, retained products of conception, surgical evacuation, transvaginal ultrasound
|How to cite this article:|
Maged A, Gaffar H, Mostafa W. Role of transvaginal ultrasound in detection of retained products of conception after abortion. Saudi J Health Sci 2012;1:151-5
| Introduction|| |
Abortion is premature birth before a live birth is possible, and in this sense it is synonymous with miscarriage. National Center for Health Statistics, the Centers for Disease Control and Prevention, and the World Health Organization define abortion as pregnancy termination prior to 20 weeks' gestation or with a fetus born weighing less than 500 g. 
The prevalence of spontaneous abortion varies according to diligence used in its identification Wilcox and colleagues 1988 found that 31% of pregnancies were lost after implantation. Two thirds of these were designated as clinically silent. 
Spontaneous abortion can be classified into threatened, inevitable, incomplete, and missed abortion. Septic abortion is the condition when the products of conception and uterus are infected. 
Management can be more individualized. Expectant, medical, and surgical management are all reasonable options unless there is serious bleeding or infection. Surgical dilatation and evacuation is an effective and prompt line of management of early pregnancy failure.  But this is invasive and not necessary for all women. Expectant and medical management may obviate curettage, but are associated with unpredictable bleeding, and some women will need unscheduled surgery.
The incidence of incomplete abortion after curettage may be reduced through transvaginal sonography following uterine drainage during the first trimester of pregnancy.  Some patients may have persistent bleeding or fever after abortion and often be referred for ultrasound evaluation to detect abnormalities such as retained products of conception (RPOC).  While ultrasound plays a major role in assessing the post-abortive problems, there is a lack of consensus on the best sonographic feature to use.  Endometrial thickness is a commonly used parameter for detection of RPOC. 
The combined clinical and sonographic evaluation protocol offers a high sensitivity for the accurate diagnosis of RPOC.  A repeated D and C is a relatively safe procedure, but it can result in any of the same complications risked by the initial D and C, including cervical laceration, uterine perforation, hemorrhage, or the initiation of uterine synechia.  Medical management with misoprostol is an effective and safe alternative to surgical management. 
The aim of this thesis is to study the endovaginal ultrasound in detection of risk factors of RPOC (incomplete evacuation) after surgical evacuation and success of medical and surgical management of these RPOC.
| Materials and Methods|| |
The present retrospective open-label study included 270 women who attended the obstetrics outpatient clinic and obstetric emergency department at Kasr El-Aini Hospital in Cairo, Egypt, between 1 April 2010 and 3 March 2012. The study was approved by the local Ethics Committee and informed consent was obtained from all participants.
The 270 women included in the present study had surgical evacuation done for treating abortion. Their age ranged between 18 and 35 years old with singleton pregnancy and duration of pregnancy between 6 and 12 weeks.
Exclusion criteria were cases with multiple pregnancy, history of bleeding disorder as hemophilia or purpura, congenital uterine anomalies as bicornate or septate uterus, and cases with spontaneous abortion.
The women in the study were classified into two groups: Group I: (complete evacuation group) it included 204 cases of post-evacuation women in whom post-operative vaginal ultrasound has shown complete evacuation of their uteri. Group II: (incomplete evacuation group) it included 66 cases of post-evacuation women in whom post-operative vaginal ultrasound has showed incomplete evacuation of their uteri. The women in this group were subdivided randomly into two subgroups: Group A treated by surgical re-evacuation and Group B treated medically by oral misoprostol 200 μg three times daily for 1 week.
The transvaginal ultrasound was done again for both groups to evaluate the success of management in both groups.
All patients are subjected to full personal, present, past, family, obstetrical, and menstrual histories with specific inquiries as to the presence of any intervening vaginal bleeding, abdominal pain, and/or fever.
General examination was done, including pulse, temperature and blood pressure, chest, heart, and abdominal examinations.
The surgical experience of the physicians performing surgical evacuation (either more or less than 1 year) was recorded.
Transvaginal ultrasound was done 5-7 days after surgical evacuation for evaluation of size of the uterus, endometrial thickness, volume of contents if present, douglas pouch, and adenexae.
The position of the patients on a standard ultrasonographic table was slightly reversed trendelenburg position during examination.
The ultrasound equipment is Toshiba Sonolayer SS-270A with a transvaginal curvilinear transducer of frequency 5 MH2. The probe was inserted into mid vagina after being covered with a sterile gel (to avoid air trapping that causes unwanted artifacts) then covered with a sterile lubricated condom (covered with a sterile ultrasound lubricant).
The imaging portion of the examination was directed toward evaluation of the uterus and any intrauterine contents Sagittal and transverse images of the uterus were obtained. Endometrial thickness and the dimensions of any intrauterine contents were measured by using the sagittal images.
RPOC were considered when the endometrial thickness is more than 15 mm or there are focal heterogonous contents.
The results of the incomplete evacuation group were compared with those of the complete evacuation group, and success of medical and surgical management of incomplete evacuation.
Data were statistically described in terms of range, mean ± standard deviation (± SD), frequencies (number of cases), and percentages when appropriate.
A comparison of quantitative variables between the study groups was done using the Student t test for independent samples. For comparing categorical data, the chi square (χ2 ) test was performed. The exact test was used instead when the expected frequency is less than 5. A probability value (P value) less than 0.05 was considered statistically significant. All statistical calculations were done using computer programs Microsoft Excel 2007 (Microsoft Corporation, NY, USA) and SPSS (Statistical Package for the Social Science; SPSS Inc., Chicago, IL, USA) version 15 for Microsoft Windows.
| Results|| |
The women in the study were classified into two groups: Group I included 204 cases (complete evacuation group) and Group II included 66 cases (incomplete evacuation group). The women in this group were subdivided randomly into two subgroups: Group A treated by surgical re-evacuation and Group B treated medically by oral misoprostol 200 μg three times daily for 1 week.
There were no significant differences in age, gravidity, parity, the occurrence of previous abortion and body mass index between the two study groups at baseline [Table 1]. There was a significant difference between the two study groups regarding gestational age at which the surgical evacuation was done being lower in the complete evacuation group [Table 1].
There was no significant difference between the two study groups considering type of abortion [Table 2]. There was a significant difference between the two study groups regarding experience of the obstetrician (higher experience in complete evacuation group) and adverse effects such as vaginal bleeding, abdominal pain, and fever (lower in complete evacuation group) [Table 2].
Success of both medical and surgical treatment of retained products showed a statistically nonsignificant difference [Table 3]. Some side effects such as nausea and headache showed no significant difference between the two study groups while most side effects reported were more in the medical group such as diarrhea (12 vs. 1), fever (9 vs. 0), hot flushes (10 vs. 0), abdominal pain (9 vs. 2), and vaginal bleeding (9 vs. 2). Few side effects were reported more in the surgical group such as vomiting (13 vs. 2) and tiredness (12 vs. 2) [Table 3].
|Table 3: Comparison between medical and surgical management of retained products of conception after D and C |
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Few patients in medically treated women needed bed rest for more than 2 days 2 versus 11 patients treated by surgical reevacuation [Table 3].
Early pregnancy loss occurs in about 15% of clinically recognized pregnancies.  Surgical evacuation is the standard practice for the management of abortion. Although it is effective with a high success rate, it may be associated with serious complications such as post abortion infection, perforation of the uterus, cervical injury, RPOC, and Asherman's syndrome. 
Misoprostol was tried in several randomized controlled trials as a method for medical evacuation of first trimester pregnancy failure with highly effective and safe outcomes. However, several regimens with different doses and routes of administration have been described in the literature, with variable results. 
Some patients may have persistent bleeding or fever after abortion and often referred for ultrasound evaluation to detect abnormalities such as RPOC. 
Ultrasonography is commonly used to determine if expulsion of the gestational sac has occurred after treatment. Some investigators have used endometrial thickness to guide the clinical management. 
Assessment of patients with post-abortive symptoms by clinical as well as sonographic finding of RPOC is important to reduce the number of unnecessary surgical procedures. 
A repeated DandC is a relatively safe procedure, but it can result in any of the same complications risked by the initial D and C. 
In our study, endovaginal ultrasonography was done for 270 cases; after surgical evacuation of the uterus 90 of them had missed abortion, 90 had inevitable abortion, and 90 had incomplete abortion. This was done for assessment of the uterine cavity, endometrial thickness, and volume of contents if present. Out of 270 studied cases, 66 cases (24.4%) were found to have incomplete evacuation (endometrial thickness is more than 15 mm or the presence of focal heterogonous contents detected by endovaginal ultrasonography).
Women in the incomplete evacuation group were randomly treated with either medical or reevacuation then endovaginal ultrasonography was done for both groups. Medical treatment was effective in 80% and failed in 20% of cases but the surgical treatment was effective in all cases.
The findings in the incomplete evacuation group (66 cases) were compared to the complete evacuation group (204 cases) to detect the risk factors of incomplete evacuation.
As regards the maternal age, gravidity, parity, history of previous abortion, and type of abortion, there was no statistically significant difference between the complete evacuation group and the incomplete evacuation group.
As regards the gestational age in weeks, there was statistically significant difference between the complete evacuation group and the incomplete evacuation group. This indicates that the possibility of incomplete evacuation increases with the increase in the gestational age.
This can be explained on the basis that with an increase in the duration of pregnancy, the volume of conceptus increases and the placenta will be more developed, so the possibility of missed part of the product of conception will increase.
As regards the surgical experience of physicians, there was statistically significant difference between the complete evacuation group and the incomplete evacuation group.
This indicates that the possibility of incomplete evacuation increases with the decrease in the surgical experience of the physicians.
In a study performed by Inal et al. (2006) to detect risk factors of RPOC after surgical evacuation during first trimester of pregnancy, RPOC were significantly associated with patient's age (P = 0.026), body mass index (BMI) (P = 0.017), and week of gestation applied (P = 0.012), but not associated with parity (P = 0.063), history of previous evacuation (P = 0.845), and history of previous abortion (P = 0.918). They concluded that the frequency of RPOC after surgical evacuation has been affected by current pregnancy-related factors such as patient's age, (BMI), and gestational age rather than the prior obstetric history of patients. 
As regards the presence of any post-evacuation symptoms in the form of vaginal bleeding, abdominal pain, and/or fever, there was statistically significant difference between the complete evacuation group and the incomplete evacuation group.
This indicates that the presence of vaginal bleeding, abdominal pain, and/or fever after surgical evacuation combined with ultrasound finding indicate the presence of RPOC.
In a study performed by Abassi et al. (2008, vaginal bleeding as a predictor of RPOC gave a sensitivity 93% but low specificity 50%. They suggested that it should be used as a predictor in combination with ultrasound finding which raised the sensitivity to 98% and negative predictive value to 95%. Thus, the absence of ultrasound finding and vaginal bleeding excludes RPOC in 95% of cases. 
Ben-Ami et al. (2005) recommended using a combination of both sonographic and clinical findings for the detection of RPOC before any surgical intervention. 
As regards success of management of RPOC after D and C, there was no statistically significant difference between medical (80%) and surgical (100%) groups.
This indicates that the medical treatment of RPOC after D and C is an effective alternative method to surgical treatment.
In a randomized outpatient clinical trial, the efficacy and safety of misoprostol in outpatient medical evacuation with surgical curettage in uncomplicated incomplete spontaneous miscarriage were compared. Eighty women with a history of vaginal bleeding and passage of some products of the conceptus were randomized into two groups. 40 patients in group 1 received 200 mg intravaginal misoprostol for 5 days; 40 patients in group 2 had a surgical curettage performed. All the patients were re-evaluated after 10 days. The success rate in the misoprostol administrated group was 95%. The conclusion was that the use of misoprostol in the outpatient treatment of uncomplicated incomplete spontaneous miscarriage is safe and effective and can be alternative to surgical evacuation and expectant management. 
Pang et al. (2001) studied repeated doses of 800 μg misoprostol orally with 64.4% success rate and concluded that the medical treatment of abortion by misoprostol was found in several studies, trials, and reviews to be an effective and safer alternative to surgical evacuation in the management of early pregnancy failure, particularly incomplete abortion. 
Pandian et al. (2001) studied the effectiveness of three sequential oral doses of misoprostol with 85% complete uterine evacuation without surgical intervention. 
In conclusion, transvaginal ultrasonography is a simple and effective method in the evaluation of patients after surgical evacuation of abortion. It is useful in detecting post-abortive complications and together with clinical symptoms and signs should be considered before any additional surgical procedures. There is a higher incidence of retained products of conception after surgical evacuation among patients who underwent curettage by junior surgeons, with advancement of pregnancy.
So, transvaginal ultrasonography is recommended to be done following surgical evacuation of abortion especially in the following condition:
- Those done by junior staff (less than one year).
- As gestational age increase especially more than 10 weeks.
- If there is post-abortive bleeding.
In management of retained products of conception after surgical evacuation, surgical re-evacuation is done in patients with heavy bleeding or uterine cramping, especially when abundant material is present in endometrial cavity. Medical treatment with uterotonics as misoprostol is preferred in patients with mild symptoms, smaller gestational weeks or sonographic findings suggesting minimal residual gestational tissue to avoid possible risks of re-evacuation.
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[Table 1], [Table 2], [Table 3]