However, more recent literature has questioned the significance and usefulness of this practice because of a lack of proven effective interventions. In twin pregnancies, cervical length measuring <1.5 cm has been shown to be predictive of preterm labor, regardless of management strategies [43]. Multiple Gestations Vasa previa and velamentous cord insertion are more commonly present in MC multiple gestations. Both of these conditions are associated with adverse pregnancy outcome and deserve dedicated evaluation at this point in pregnancy [47]. There is also a higher frequency of vasa previa when velamentous cord insertion is found; if overlooked, this may result in acute fetal hemorrhage, distress, and potential demise at the time of delivery. For this reason, examiners should be aware of the possibility of vasa previa, especially in MC pregnancies [49]. US Duplex Doppler Fetal Middle Cerebral Artery Fetal MCA Doppler assessment is performed to detect the presence of TAPS [3,20,50,51]. In contrast to evaluation for TTTS, there are no clear established guidelines addressing whether evaluation for TAPS should be part of routine second trimester anatomy evaluation. This may be optionally considered on a case-by-case basis, for example, when imaging signs of TTTS are present [9]. Some authors are advocating for routine antenatal screening for TAPS in MC gestations [50]. US Duplex Doppler Fetal Umbilical Artery US duplex Doppler fetal UA is essential for second trimester evaluation of MC twins and should be performed at the time of anatomy evaluation [9]. This is helpful for the staging of TTTS, TAPS, and growth discordant twins. US Echocardiography Fetal Multiple gestations are at higher risk for cardiac defects, and an echocardiogram is recommended in the second trimester. The risk of cardiac anomalies has been reported to be 2% in uncomplicated MC twins and 5% in cases of TTTS, particularly among recipient twins [52,53].
Multiple Gestations. However, more recent literature has questioned the significance and usefulness of this practice because of a lack of proven effective interventions. In twin pregnancies, cervical length measuring <1.5 cm has been shown to be predictive of preterm labor, regardless of management strategies [43]. Multiple Gestations Vasa previa and velamentous cord insertion are more commonly present in MC multiple gestations. Both of these conditions are associated with adverse pregnancy outcome and deserve dedicated evaluation at this point in pregnancy [47]. There is also a higher frequency of vasa previa when velamentous cord insertion is found; if overlooked, this may result in acute fetal hemorrhage, distress, and potential demise at the time of delivery. For this reason, examiners should be aware of the possibility of vasa previa, especially in MC pregnancies [49]. US Duplex Doppler Fetal Middle Cerebral Artery Fetal MCA Doppler assessment is performed to detect the presence of TAPS [3,20,50,51]. In contrast to evaluation for TTTS, there are no clear established guidelines addressing whether evaluation for TAPS should be part of routine second trimester anatomy evaluation. This may be optionally considered on a case-by-case basis, for example, when imaging signs of TTTS are present [9]. Some authors are advocating for routine antenatal screening for TAPS in MC gestations [50]. US Duplex Doppler Fetal Umbilical Artery US duplex Doppler fetal UA is essential for second trimester evaluation of MC twins and should be performed at the time of anatomy evaluation [9]. This is helpful for the staging of TTTS, TAPS, and growth discordant twins. US Echocardiography Fetal Multiple gestations are at higher risk for cardiac defects, and an echocardiogram is recommended in the second trimester. The risk of cardiac anomalies has been reported to be 2% in uncomplicated MC twins and 5% in cases of TTTS, particularly among recipient twins [52,53].