The anomaly scan will be performed between week 19 and 22. This is the optimal moment for this scan, since the baby's structures have already developed and are large enough for us to evaluate them adequately by ultrasound. 

What are the goals of this ultrasound?

1. Detection of fetal anomalies:

In this scan we will carry out a detailed assessment of the entire fetal anatomy in order to detect the presence of any malformation. In addition, we will determine where the placenta is located and assess the amount of amniotic fluid. 

We must bear in mind that ultrasound, like other diagnostic techniques, has its limitations, and therefore there are certain abnormalities that will not be detectable. On the other hand, there are other anomalies that appear during the third trimester of pregnancy; thus, we will not be able to detect them in this ultrasound either. 

2. Screening for preeclampsia and fetal growth restriction

In this same ultrasound we can evaluate the blood flow through the uterine arteries, the blood vessels that nourish the placenta. This evaluation will provide us with information on how the placenta is working and will allow us to predict your risk of developing the two most important complications of placental origin: preeclampsia (high blood pressure during pregnancy) and fetal intrauterine growth restriction (when the baby not growing at the rate it should). 

3. Screening for prematurity

Finally, by measuring the cervix we can estimate the risk you have of having premature labor (that labor begins before 37 weeks). 

After the scan we will comment on it. If any abnormality is detected, we will discuss the prognosis, as well as the diagnostic options available to us to extend the study (amniocentesis, fetal magnetic resonance). In the event of a high-risk result for pre-eclampsia, fetal growth restriction or prematurity, we will consider the possibility of establishing a treatment to prevent these complications and we will determine an individualized follow-up plan.