This is especially important for women who cannot remember the date of their last period, have irregular menstruation, or have conceived while breast-feeding or immediately after discontinuing a contraceptive tablet. We measure the size of the fetus and from this we calculate the probable date of birth (WHO – 40 weeks).
Significant abnormalities may be visible at this gestational age, but the 20-week ultrasound is necessary.
About 2% of natural conceptions and 10% of IVF conceptions lead to multiple pregnancies. This ultrasound can determine whether both embryos develop normally and whether babies share the same placenta, which can lead to pregnancy problems. In such cases, it would be advisable to monitor pregnancy more closely.
Unfortunately, 2% of women who are having the nuchal translucency test get the diagnosis of missed miscarriage, often several weeks before the test and without any warning. Couples will receive full advice on the possible causes of this problem and the options for the next actions and precautions that might be needed.
The risk of preterm birth (before 37 weeks) can be assessed by measuring the cervical length. It is recommended to all pregnant women, but especially in cases of increased risk for preterm birth, such as multiple pregnancies, previous preterm birth history, congenital uterine abnormalities, history of cervical interventions (LLETZ, cone biopsy) and conditions such as maternal connective tissue / collagen diseases.
Cervical length is being measured via the vagina and it is recommended to repeat the measurement during the pregnancy time period between 20 and 22 weeks.
Each exam includes the uterine artery flow assessment in combination with biochemical markers, such as PAPP-A and PLGF and takes into account the risk of slowdown of the fetal development. This slowdown can be mainly observed in the third trimester, when more Doppler ultrasounds get scheduled at the beginning of the third trimester, starting from 28 weeks of gestation.
Each woman should receive an assessment of her individual risk during her pregnancy. This is calculated by taking into account maternal age, measurements of hormones in the mother’s blood and ultrasound indicators, such as nuchal translucency, nasal bone, blood flow through the fetal heart and the fetal liver. Parents will receive full advice on the significance of this risk and the various options for further testing, such as invasive or cell free DNA testing.
|Nuchal Translucency||Chromosomal Abnormalities||Fetal Death||Major Anomalies||Cardiovascular Anomalies||Healthy neonates|