Screening during the second trimester: what doctors look for

During week 18-21, your doctor will schedule your second ultrasound. The main goal of screening during the second trimester is to identify the risk of congenital abnormalities and any circumstances which lead to a risk of premature birth [1].

What do they look for during the second trimester screening?

The doctor will be interested in:

• the size of the baby (whether it corresponds to the gestational age);

• possible developmental abnormalities;

• condition of the placenta;

• the amount of amniotic fluid;

• condition of the cervix.

What if I didn't have an ultrasound scan in the first trimester?

In this case, it may make sense to have a biochemical screening in addition to the ultrasound examination. In this procedure, a blood sample will be taken for the so-called triple test, which allows your doctor to identify any risks of congenital anomalies and miscarriage [1].

What if I didn't have an ultrasound scan in the first trimester?

In this case, it may make sense to have a biochemical screening in addition to the ultrasound examination. In this procedure, a blood sample will be taken for the so-called triple test, which allows your doctor to identify any risks of congenital anomalies and miscarriage [1].

Will this ultrasound show if I’m having a boy or a girl?

Yes — usually. If the baby is positioned in such a way that their genitals are visible, and it’s almost impossible to mistake [2]. In about 10% of cases, the baby lies in such a way that their genitals are not visible [2]. Since gender determination is not the reason for the ultrasound as it does not affect anything medically, your ultrasound will be considered complete even if the baby is not positioned to reveal their sex.