General considerations :
- The number of visits needs to be minimal and the patient should come alone.
- Triage based on risk factors and temperature at arrival should be performed before the patient enters the ultrasound unit.
- Non-urgent appointments should be postponed for 14 days.
- Monochorionic twin pregnancy should be managed as usual.
- Some high-risk pregnancy groups could have growth ultrasound less frequently, at 28 and/or 36 weeks.
- Biophysical profile without non-stress test is preferable to non-stress test using amniotic fluid assessment due to time considerations.
- Frequency of scans and non-stress tests should be individualized according to the the maternal underlying conditions and risk factors.
- Initial cervical-length can be assessed at 16 weeks instead of at 14 weeks for patients at risk of spontaneous preterm birth. Discharge is recommended at 20 weeks if the transvaginal measure is > 35mm and the prior preterm birth was at more than 34 weeks.
- Fetal echocardiography could be cancelled for low-risk patients if the routine anatomy scans are normal.
- The decision to proceed or to delay/cancel a fetal procedure needs to consider the theoretical risk of vertical transmission, the risk for healthcare providers, the risk of maternal ICU needs, the material required and the expected benefits for the mother and the foetus.
Considerations for low-risk obstetric patients :
- Limit unnecessary appointments
- 11+0 to 13+6 weeks : dating and nuchal translucency scan
- 18+0 to 23+0 : Anatomical scan
- Fetal growth scan in third trimester : Do not perform unless clinically indicated
Considerations for infected women :
- Hospitalized patients should have bedside scans.
- Experienced sonographers should perform the scan with dedicated material in an isolation room.
- Detailed morphology scan may be indicated at 18-23 weeks.
- Cardiotocography is recommended to assess fetal heart rate when the pregnancy is at the limit of viability.
- Recommendations about the assessment of fetal well-being post recovery are variable. Some authors suggest a monthly ultrasound, while others suggest a growth scan 4 weeks post-recovery.
- Patients at-risk for spontaneous preterm birth should have their appointment postponed until self-isolation is completed. Progesterone treatment could be administered in the meantime.
- Amniocentesis may be preferable to CVS considering unknown risk of viral shedding and intrauterine transmission. Consider delaying patients with suspected/probable infection by 14 days.
This data comes from multiple sources. ISUOG produced a consensus statement about obstetric ultrasound management in the time of COVID19. Boelig and al. wrote guidelines about pregnant women management in the time of COVID-19. The authors are part of the maternal-fetal-medicine division and Ob-Gyn Department at Thomas Jefferson University. Deprest and al. are fetal therapy specialists who produced guidelines about fetal interventions during the pandemic. The International Federation of Gynecology & Obstetrics wrote guidelines about the management of infected pregnant women. Experts from the Society for Maternal-Fetal Medicine redacted ultrasound practice suggestions.
- Abu-Rustum R.S., Akolekar R. et al. (March 31 2020). ISUOG Consensus Statement on organization of routine and specialist obstetric ultrasound services in the context of COVID-19. International Society of Ultrasound in Obstetrics and Gynecology. https://doi.org/10.1002/uog.22029
- Boelig RC., Saccone G. and al. (March 19 2020) MFM Guidance for COVID-19. American Journal of Obstetrics & Gynecology MFM. https://doi.org/10.1016/j.ajogmf.2020.100106
- Deprest J., Ranst MV. and al. (April 11 2020) Feto-placental surgeries during the covid-19 pandemic: starting the discussion. Prenatal Diagnosis. https://doi.org/10.1002/pd.5702
- Poon LC., Yang H., Kapur A. et al. (April 4 2020) Global interim guidance on coronavirus disease 2019 (COVID-19) during pregnancy and puerperium from FIGO and allied partners: Information for healthcare professionals. International Journal of Gynecology & Obstetrics. https://doi.org/10.1002/ijgo.13156
- Society for Maternal-Fetal Medicine. (March 24 2020) The Society for Maternal-Fetal Medicine COVID-19 Ultrasound Practice Suggestions. Retrieved from : https://s3.amazonaws.com/cdn.smfm.org/media/2272/Ultrasound_Covid19_Suggestions_(final)_03-24-20_(2)_PDF.pdf