• Fleischer AC, Andreotti RF, Bohm-Velez M, Fishman EK, Horrow MM, Hricak H, Thurmond A, Zelop C, Expert Panel on Women's Imaging. First trimester bleeding. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 9 p. [36 references]

This is the current release of the guideline.

It updates a previously published version: Laing F, Mendelson E, Bohm-Velez M, Bree R, Finberg H, Fishman EK, Hricak H, Sartoris D, Thurmond A, Goldstein S. First trimester bleeding. American College of Radiology. ACR Appropriateness Criteria. Radiology. 2000 Jun;215 Suppl:879-93.

The appropriateness criteria are reviewed annually and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

First trimester bleeding

Evaluation

Obstetrics and Gynecology
Radiology

Physicians

To evaluate the appropriateness of radiologic procedures for the evaluation of first trimester bleeding

Women with first trimester bleeding

1. Ultrasound
   • Transvaginal first with or without transabdominal
   • Follow-up scans
   • Adnexa, Doppler
   • Endometrium, Doppler
   • Transvaginal only
   • Transabdominal only
   • Transabdominal first with or without transvaginal
   • Mean sac diameters--crown-rump length
   • Uteroplacental circumference, Doppler
   • Yolk sac diameter
2. Beta human chorionic gonadotropin
3. Dilation and curettage
4. Laparoscopy

Utility of radiologic examinations in evaluation of first trimester bleeding

Searches of Electronic Databases

The guideline developer performed literature searches of recent peer-reviewed medical journals, and the major applicable articles were identified and collected.

The total number of source documents identified as the result of the literature search is not known.

Weighting According to a Rating Scheme (Scheme Not Given)

Not stated

Systematic Review with Evidence Tables

One or two topic leaders within a panel assume the responsibility of developing an evidence table for each clinical condition, based on analysis of the current literature. These tables serve as a basis for developing a narrative specific to each clinical condition.

Expert Consensus (Delphi)

Since data available from existing scientific studies are usually insufficient for meta-analysis, broad-based consensus techniques are needed for reaching agreement in the formulation of the appropriateness criteria. The American College of Radiology (ACR) Appropriateness Criteria panels use a modified Delphi technique to arrive at consensus. Serial surveys are conducted by distributing questionnaires to consolidate expert opinions within each panel. These questionnaires are distributed to the participants along with the evidence table and narrative as developed by the topic leader(s). Questionnaires are completed by participants in their own professional setting without influence of the other members. Voting is conducted using a scoring system from 1-9, indicating the least to the most appropriate imaging examination or therapeutic procedure. The survey results are collected, tabulated in anonymous fashion, and redistributed after each round. A maximum of three rounds is conducted and opinions are unified to the highest degree possible. Eighty percent agreement is considered a consensus. This modified Delphi technique enables individual, unbiased expression, is economical, easy to understand, and relatively simple to conduct.

If consensus cannot be reached by the Delphi technique, the panel is convened and group consensus techniques are utilized. The strengths and weaknesses of each test or procedure are discussed and consensus reached whenever possible. If "No consensus" appears in the rating column, reasons for this decision are added to the comment sections.

Not applicable

A formal cost analysis was not performed and published cost analyses were not reviewed.

Internal Peer Review

Criteria developed by the Expert Panels are reviewed by the American College of Radiology (ACR) Committee on Appropriateness.

ACR Appropriateness Criteria®

Clinical Condition: First Trimester Bleeding

Variant 1: +B HCG 5 weeks gestational age by history. No sac seen in uterus.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 2: 5 weeks gestational age. Fetal Heart Rate = 85.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 3: 5 weeks gestational age. Fetal Heart Rate = 110.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 4: 5 weeks gestational age. Fetal Heart Rate = 110. Moderate subchorionic hemorrhage.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 5: + B HCG 7 weeks gestational age by history. No sac seen in uterus.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 6: 7 weeks gestational age. CRL = 9 mm - FHM.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 7: 7 weeks gestational age. Fetal heart rate = 90.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 8: 7 weeks gestational age. Fetal heart rate = 130.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 9: +B HCG 9 weeks gestational age by history. No sac seen in uterus.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 10: 9 weeks gestational age. CRL = 23 mm -- FHM.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 11: 9 weeks gestational. Fetal heart rate = 90.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

Variant 12: 9 weeks gestational. Fetal heart rate = 130.

Note: Abbreviations used in the tables are listed at the end of the "Major Recommendations" field.

First trimester vaginal bleeding is very common, occurring in approximately 25% of patients who are known to be pregnant. In many patients the bleeding is self-limited and is probably due to implantation of the conceptus into the decidualized endometrium.

If the bleeding is not self-limited and is accompanied by severe pain, uterine contractions, and a dilated cervix, the clinical changes are irreversible and the pregnancy is doomed to failure. Because these clinical changes are irreversible, ultrasound has little to offer.

If bleeding and cramping are relatively mild and the cervix is long and closed, the diagnosis is threatened abortion. Analysis of this group reveals that 50% have an abnormal outcome, with the differential diagnosis encompassing a broad spectrum of conditions including a normal intrauterine pregnancy (IUP) (50% of patients), an abnormal living intrauterine pregnancy, a missed abortion, a blighted ovum, retained products of conception, ectopic pregnancy, and gestational trophoblastic disease. Ultrasound examination is especially important in these patients, because the findings may be pivotal not only for determining the precise cause of the bleeding but also for suggesting appropriate therapy.

In comparison to abdominal imaging, the literature emphasizes that in patients with threatened abortion, vaginal sonography is more effective not only for making the specific diagnosis of ectopic pregnancy but also for clarifying indeterminate findings noted on transabdominal scans. In general, if the gestational age is less than 8 or 9 weeks, the sonographic examination should begin using a vaginal approach. If the study is incomplete or inconclusive, an abdominal approach may offer complementary information. A transabdominal approach is often satisfactory in the late first trimester of 9 weeks or more. Nonetheless, in difficult, abnormal, or inconclusive cases, a vaginal examination should also be done in an effort to clarify the findings.

When evaluating a patient with threatened abortion, it is most important to determine if an intrauterine gestational sac is visible and whether or not it has a normal appearance. Using transabdominal ultrasound, an intrauterine sac should normally be visible when the beta hCG is >1800 mIU/mL (2nd International Standard [IS]) or >3240 mIU/mL (International Reference Preparation [IRP]), and a yolk sac and embryo should be detected when MSDs are 20 and 25 mm, respectively. Using a vaginal transducer, the discriminatory beta hCG level for sac detection is 1000 mIU/mL (2nd IS) or 1800 mIU/mL (IRP); and a yolk sac and embryo should be detected when their MSDs are 8 and 16 mm, respectively. In questionably abnormal cases, a follow-up ultrasound should be considered. Knowing that the MSD normally increases by 1 mm/day allows the sonologist to recommend an appropriate time interval between the initial and follow-up examination(s). Although not universally accepted, many sonologists also recommend a second trimester sonographic examination to screen for abnormalities that were unsuspected during the first trimester.

Once an embryo is detected, cardiac activity is normally visible by transabdominal imaging when the CRL is 9 mm; the corresponding CRL on a vaginal scan is 4-5 mm. Despite cardiac activity, sonography may reveal findings that suggest a poor outcome; these include bradycardia (abnormal at <6.2 weeks is <100 beats per minute (BPM); abnormal between 6.3-7 weeks is <120 BPM, an oligohydramniotic sac (abnormal = MSD - CRL <5 mm), or an abnormal appearing yolk sac (diameter >5 mm), and/or amnion (abnormally large amniotic cavity, or an "empty" amniotic cavity). Whether or not a subchorionic hemorrhage is associated with an abnormal outcome (either at the time of initial bleeding), or perinatally, is unclear. However, one study showed a correlation of size of subchorionic hemorrhage, age of patient, and time of bleeding with the likelihood of spontaneous abortion. Women who were over 35 years of age and had large bleeds before 8 weeks were most likely to spontaneously abort.

Ectopic pregnancy must be considered if a gestational sac is absent when the beta hCG level exceeds the discriminatory level for detecting a sac (especially if significant vaginal bleeding has not occurred), or historically, by 4 to 5 weeks gestational age. At least one investigator concludes that in patients with suspected ectopic pregnancy, vaginal sonography can and should be used alone for these examinations.

The role of Doppler ultrasound for evaluating patients with first trimester bleeding remains unclear. In the experience of some investigators, measuring the Resistive Index (RI) to evaluate uteroplacental blood flow has proven effective for differentiating normal from abnormal intrauterine pregnancies; the findings of other investigators, however, have not been similar. Color and pulsed Doppler have also been advocated by some investigators to improve the sensitivity for diagnosing ectopic pregnancy; this too, is not universally accepted. Some clinical and sonographic predictors of ectopic pregnancy outcome include longer times from last menstrual period (LMP), lower beta hCG, absence of gestational sac, and higher resistive indexes. In women with possible gestational trophoblastic disease, Doppler of trophoblastic tissue reveals a low impedance, high-flow state that differs from the lower-flow, higher impedance pattern seen in women with nonviable gestations or degenerating fibroids. Doppler may prove to be especially useful to evaluate myometrial invasion and during follow-up examinations for women receiving chemotherapy.

Abbreviations

• BhCG, beta human chorionic gonadotropin
• CR, crown-rump
• CRL, crown-rump length
• D & C, dilation and curettage
• FHM, fetal heart movement
• MSD, mean sac diameters
• TA, transabdominal
• TV, transvaginal
• US, ultrasound

Algorithms were not developed from criteria guidelines.

The recommendations are based on analysis of the current literature and expert panel consensus.

Selection of appropriate radiologic imaging procedures for the evaluation of first trimester bleeding

Not stated

An American College of Radiology (ACR) Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists, and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient's clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those exams generally used for evaluation of the patient's condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the U.S. Food and Drug Administration (FDA) have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination.

An implementation strategy was not provided.

Getting Better

Effectiveness

• Fleischer AC, Andreotti RF, Bohm-Velez M, Fishman EK, Horrow MM, Hricak H, Thurmond A, Zelop C, Expert Panel on Women's Imaging. First trimester bleeding. [online publication]. Reston (VA): American College of Radiology (ACR); 2005. 9 p. [36 references]

Not applicable: The guideline was not adapted from another source.

1996 (revised 2005)

American College of Radiology - Medical Specialty Society

The American College of Radiology (ACR) provided the funding and the resources for these ACR Appropriateness Criteria®.

Committee on Appropriateness Criteria, Expert Panel on Women's Imaging

Panel Members: Arthur C. Fleischer, MD (Principal Author and Panel Chair); Rochelle F. Andreotti, MD; Marcela Böhm-Vélez, MD; Elliot K. Fishman, MD; Mindy M. Horrow, MD; Hedvig Hricak, MD, PhD; Amy Thurmond, MD; Carolyn Zelop, MD

Not stated

This is the current release of the guideline.

It updates a previously published version: Laing F, Mendelson E, Bohm-Velez M, Bree R, Finberg H, Fishman EK, Hricak H, Sartoris D, Thurmond A, Goldstein S. First trimester bleeding. American College of Radiology. ACR Appropriateness Criteria. Radiology. 2000 Jun;215 Suppl:879-93.

The appropriateness criteria are reviewed annually and updated by the panels as needed, depending on introduction of new and highly significant scientific evidence.

None available

This NGC summary was completed by ECRI on February 10, 2006.