US Echocardiography Fetal Multiple gestations are at higher risk for cardiac defects, and echocardiography is very useful in the second trimester. This is particularly relevant for DC twin pregnancies conceived using assisted reproductive technologies because these groups are at increased risk of congenital heart disease [46]. US Pregnant Uterus Biophysical Profile BPP is performed in late second and third trimesters, and there is no role in the first trimester. There is no role for BPP at the time of second trimester anatomy scan. US Pregnant Uterus Transvaginal Transvaginal examination of the pregnant uterus and cervix can be performed as an adjunct for limited transabdominal fetal evaluation. Additional indications include assessment of the cervix and placenta and detection of vasa previa. Typically, TVUS imaging is performed only if transabdominal evaluation is considered suboptimal Multiple Gestations or incomplete and never as the only approach for second trimester anatomy evaluation. If prior history of cesarean delivery or uterine instrumentation is present, assessment for placenta accreta spectrum can be performed. MRI Fetal Without and With IV Contrast MRI fetal without and with IV contrast does not have a role in the second trimester anatomy evaluation. Gadolinium contrast is usually not administered for fetal indications. MRI Fetal Without IV Contrast MRI fetal without IV contrast does not have a role in the second trimester anatomy evaluation. MRI fetal without IV contrast can be considered for the next imaging after an abnormality is noted on the second trimester anatomy sonogram. It can also be considered when maternal factors such as soft tissue attenuation limit evaluation of the fetus on US. In all cases, anatomy evaluation with MRI without IV contrast is performed after an US has previously been done. Historically, reports suggested measuring cervical length at each visit to triage for risk of preterm labor.
Multiple Gestations. US Echocardiography Fetal Multiple gestations are at higher risk for cardiac defects, and echocardiography is very useful in the second trimester. This is particularly relevant for DC twin pregnancies conceived using assisted reproductive technologies because these groups are at increased risk of congenital heart disease [46]. US Pregnant Uterus Biophysical Profile BPP is performed in late second and third trimesters, and there is no role in the first trimester. There is no role for BPP at the time of second trimester anatomy scan. US Pregnant Uterus Transvaginal Transvaginal examination of the pregnant uterus and cervix can be performed as an adjunct for limited transabdominal fetal evaluation. Additional indications include assessment of the cervix and placenta and detection of vasa previa. Typically, TVUS imaging is performed only if transabdominal evaluation is considered suboptimal Multiple Gestations or incomplete and never as the only approach for second trimester anatomy evaluation. If prior history of cesarean delivery or uterine instrumentation is present, assessment for placenta accreta spectrum can be performed. MRI Fetal Without and With IV Contrast MRI fetal without and with IV contrast does not have a role in the second trimester anatomy evaluation. Gadolinium contrast is usually not administered for fetal indications. MRI Fetal Without IV Contrast MRI fetal without IV contrast does not have a role in the second trimester anatomy evaluation. MRI fetal without IV contrast can be considered for the next imaging after an abnormality is noted on the second trimester anatomy sonogram. It can also be considered when maternal factors such as soft tissue attenuation limit evaluation of the fetus on US. In all cases, anatomy evaluation with MRI without IV contrast is performed after an US has previously been done. Historically, reports suggested measuring cervical length at each visit to triage for risk of preterm labor.