Contact Name and Job Title (author) Consultant Obstetrician and Gynaecologist

Transcription

1 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 1 Title of Guideline (must include the word Guideline (not protocol, policy, procedure etc) Guidelines on Ultrasound features in early pregnancy Contact Name and Job Title (author) Dr. Shilpa Deb Consultant Obstetrician and Gynaecologist Directorate & Speciality Family Health Obstetrics and Gynaecology Date of submission March 2013 Date on which guideline must be reviewed (this should be one to three years) Explicit definition of patient group to which it applies (e.g. inclusion and exclusion criteria, diagnosis) March 2019 Patients with an early pregnancy of 12 weeks Abstract This guideline describes the ultrasound features of a normal and abnormal early pregnancy. It also provides guidelines for management of abnormal findings on USS Key Words Statement of the evidence base of the guideline has the guideline been peer reviewed by colleagues? Evidence base: (1-5) 1a meta analysis of randomised controlled trials 1b at least one randomised controlled trial 2a at least one well-designed controlled study without randomisation 2b at least one other type of well-designed quasiexperimental study 3 well designed non-experimental descriptive studies (ie comparative / correlation and case studies) 4 expert committee reports or opinions and / or clinical experiences of respected authorities 5 recommended best practise based on the clinical experience of the guideline developer Consultation Process Ultrasound, early pregnancy, miscarriage, intrauterine, ectopic Literature review, evidence ranging from 1 to 5. Peer-reviewed by the risk management group Risk Management Group Consultant Gynaecologists Ward Sisters Gynaecology Nurse Specialists Practice Development Matron

2 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 2 Target audience All the medical, nursing and admin staff involved with emergency gynaecology This guideline has been registered with the trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt contact a senior colleague or expert. Caution is advised when using guidelines after the review date.

3 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 3 Introduction Ultrasound diagnosis forms an integral part when managing women in early pregnancy. It assists in making an adequate diagnosis with regards to position and viability of pregnancy. This diagnosis is very important and further management depends on it. It is now a minimum standard for early pregnancy units (EPAU) to have easy access to ultrasound services with staff appropriately trained in its use. Ultrasound scan can be performed abdominally and transvaginally, however transvaginal scanning will be required in the majority of women referred to an EPAU. Ultrasound assessment is particularly reliable in confirming the diagnosis of complete miscarriage (positive predictive value 98%). The sonographer should be formally trained in the use of both transabdominal (TAS) and transvaginal ultrasound (TVS) and should ideally produce reports using standardised documentation, as proposed by the Joint Working Party of the Royal College of Radiologists and the Royal College of Obstetricians and Gynaecologists. Ultrasound practice must conform to the recommendations of the British Medical Ultrasound Society. TAS and TVS are complementary and the appropriate modality should be used. The RCOG Special Skills Module, Ultrasound Imaging in the Management of Gynaecological Conditions, includes appropriate training for early pregnancy assessment under the guidance of a preceptor. This guideline includes the normal and abnormal features of early pregnancy on ultrasound. It also provides guidance on management of early pregnancy problems diagnosed on ultrasound. Recent research suggests that given inter observer variability in ultrasound measurements and the greater variation in early embryonic growth than has hitherto

4 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 4 been assumed, a more conservative approach to the diagnosis of early pregnancy loss is warranted. An MSD cut off of 25 mm and a CRL cut off of 7 mm could be introduced to minimize the risk of a false positive diagnosis of miscarriage.

5 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 5 Ultrasound Features of Early Pregnancy Gestational Age Anatomical landmarks Comments 4 weeks 2 days Eccentrically placed Gestational sac with GSD 2 3mm May represent pseudosac 10 20% of ectopic pregnancies have an intrauterine pseudo GS 5 th week DDS Results from approximation of decidua capsularis and decidua vera. May be present in one third ectopics. 6 th week GSD 10mm Embryo 2 3mm Cardiac activity (CA) 7 th week GSD 20mm Head and trunk distinguishable 8 th week GSD 25mm Head size = YS Limb buds Midgut herniation Rhombencephalon Confirms IUP Confirms viability (97% of embryos with CA have a normal outcome) GS > 20mm, if no YS poor prognosis GS > 25mm, if no embryo poor prognosis 9 th week Choroid plexus, spine, limbs 10 weeks Cardiac chambers, Stomach, bladder, Skeletal ossificiation 11 weeks Gut returning Most structures identified GSD DDS IUP Gestational sac diameter Double decidual sign Intrauterine pregnancy

6 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 6 Algorithm for Ultrasound Scanning TA / TV Scan or Both (indicate as appropriate) Mean gestational sac diameter Less than 25 mm Mean gestational sac diameter More than or equal to 25 mm CRL More than or equal to 7mm with no FHM No contents seen or indeterminate/ Incomplete contents CRL less than 7mm with no FHM CRL More than or equal to 7mm with no FHM No contents seen within Offer repeat scan within 7 10 days Consider second opinion to confirm findings of miscarriage

7 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 7 BASIC DIAGNOSTIC ALGORITHM FOR EARLY PREGNANCY LOSS USS TAS / TVS Pregnancy of Known Location Pregnancy of Unknown Location Intrauterine Pregnancy Ectopic Pregnancy IUP Uncertain Viability Re scan in 7 10 days Viable IUP Resolved PUL Non viable IUP Diagnostic Algorithm for PUL Glossary USS Ultrasound Scan, TAS Trans Abdominal Scan, TVS Trans Vaginal Scan IUP Intra Uterine Pregnancy, PUL Pregnancy of Unknown Location

8 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 8 Guidelines on Management of Early Pregnancy Features on Ultrasound Ultrasound Appearance Diagnosis Plan of Management Intrauterine gestational sac (GS), embryo and cardiac activity (CA) If actively bleeding If a significant haematoma noted If 12 weeks Viable pregnancy Back to GP for referral to ANC Admit for reassurance Rescan 1 week later Check the need for Anti D immunoglobulin GS <25mm no foetal pole Early gestational sac (EGS) Rescan 1 week later GS 25mm no foetal pole Empty sac If any doubt Rescan 1 week later If no change on second scan discuss management (see under management of non viable pregnancy) Crown Rump Length (CRL) 7mm CA not demonstrated Empty uterus No adnexal abnormality Early foetal loss Pregnancy of unknown location (PUL) Serum hcg negative (<5) complete miscarriage or never pregnant Serum hcg positive possible early pregnancy possible ectopic pregnancy possible complete miscarriage Rescan 1 week later if in doubt If no change on second scan discuss management (see under management of non viable pregnancy) No follow up Repeat serum hcg 48 hours later. Rescan if necessary (see guidelines for PUL) Warn of the possibility of ectopic pregnancy. Give contact number to report if any pain

9 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 9 Empty uterus Adnexal mass Fluid in Pouch of Douglas (POD) Pain Empty uterus Adnexal mass <3cm Ruptured ectopic pregnancy Unruptured ectopic pregnancy Admit for assessment: Observation Laparoscopy / Laparotomy (refer to guidelines on ectopic pregnancy) Conservative / medical management / Laparoscopy (refer to guidelines on ectopic pregnancy) Endometrium/tissue diameter 15mm Complete miscarriage Advice follow up 2 weeks later if bleeding persists Endometrium/tissue diameter >15mm Incomplete miscarriage Discuss management (see guidelines on management of miscarriage) Homogeneous mass within the uterus Suspect trophoblastic disease Serum hcg assay Surgical evacuation (see guidelines for trophoblastic disease)

10 Emergency Gynaecology SSU_S.Deb Ultrasound features of early pregnancy Page 10 References Condous G, Okaro E, Bourne T. The conservative management of early pregnancy complications: a review of the literature. Ultrasound Obstet Gynecol2003;22: Hately W, Case J, Campbell S. Establishing the death of an embryo by ultrasound: report of public inquiry with recommendations. Ultrasound Obstet Gynecol1995;5: Jauniaux E, Johns J, Burton GJ. The role of ultrasound imaging in diagnosing and investigating early pregnancy failure. Ultrasound Obstet Gynecol2005;25: Royal college of Obstetrician and Gynaecologist. The management of early pregnancy loss. Guideline No. 25, London: RCOG; Royal College of Radiologists, Royal College of Obstetricians and Gynaecologists. Guidance on Ultrasound Procedures in Early Pregnancy. London: RCR/RCOG; Rulin MC, Bornstein SG, Campbell JD.The reliability of ultrasonography in the management of spontaneous abortion, clinically thought to be complete: a prospective study. Am J Obstet Gynecol 1993;168: Abdallah Y, Daemen A, Kirk E, Pexsters A, Naji O, Stalder C, Gould D, Ahmed S, Guha S, Syed S, Bottomley C, Timmerman D, Bourne T. Limitations of current definitions of miscarriage using mean gestational sac diameter and crown rump length measurements: a multicenter observational study. Ultrasound Obstet Gynecol Oct 13. doi: /uog [Epub ahead of print]