The first-trimester morphology scan is an examination whose main purpose is to screen for fetal syndromes and pre-eclampsia. In addition, this examination also aims to detect malformations and other congenital fetal anomalies. It is an examination that analyzes ultrasound markers for isolated syndromes and malformations.

The first-trimester morphology scan should be performed between the 11th and 14th week of gestation. Often, the greater the gestational age, the easier it is to recognize structures and, therefore, the better the sensitivity of the examination in detecting malformations. However, it is important to know that the quality and accuracy of the examination depend on technical conditions such as the type of maternal abdomen, the position of the uterus (retroverted uterus), and the ultrasound equipment.

In the first-trimester morphology scan, it is already possible to detect significant malformations such as anencephaly, gastroschisis, and omphalocele. Structures that allow for an understanding of normal fetal development can be clearly seen.

The second-trimester morphology scan is an examination to assess the entire fetal anatomy. It is performed within an optimal time window because most organs are well-developed and the baby's size still allows for complete observation via ultrasound. It is the most comprehensive examination for evaluating fetal anatomy.

The second-trimester morphology scan should be performed between the 20th and 24th week of gestation.

First, it's important to remember that tests should be recommended by your obstetrician. Tests that can be performed along with the second-trimester morphology scan include a transvaginal ultrasound to assess the cervix and a Doppler ultrasound to evaluate the correlation between maternal, placental, and fetal circulation.

The best time to determine the sex of the fetus is after the 14th week of gestation. By this time, the external genitalia should be well defined. It is sometimes possible to see the sex a little earlier, especially in cases of male genitalia.

All maternal nutrition tends to provide an energy supply to the baby, which responds mainly in the form of body movements. Obviously, there are foods that are low in calories and foods that are high in calories. Thus, foods such as sweets, juices, and other carbohydrates tend to provide a lot of energy to the baby. But this does not necessarily mean success in determining the baby's sex. Visualizing the baby's sex depends much more on the gestational age at which the examination is performed and the experience of the sonographer.

There is much controversy in the medical literature regarding the number of tests that should be performed during prenatal care. Many protocols depend on the conditions of the public and private healthcare systems.
Below are some of the tests that can be performed during pregnancy.
1 – Dating in the first trimester. From the 7th week onwards, the earlier the ultrasound examination is performed, the smaller its margin of error. This is essential for monitoring the entire pregnancy, as accurate dating allows you to know clearly when it is premature, full-term, or post-term.
2 – First-trimester morphology scan. Performed between the 11th and 14th week of gestation. A single examination for screening for syndromes and pre-eclampsia. It also allows for the detection of some malformations and other congenital anomalies.
3 – Second-trimester morphology scan. Performed between the 20th and 24th week of gestation. This exam aims to detect malformations or other congenital anomalies.
4 – Transvaginal ultrasound for cervical assessment. This exam is now considered universal for screening for premature birth, since a short cervix is strongly associated with premature delivery. It is performed at the same time as the second-trimester morphology scan.
5 – Obstetric examination. The obstetric examination aims to assess fetal growth, amniotic fluid, placenta, and fetal well-being. Its frequency depends on the findings and the physician's clinical suspicion.
6 – Doppler ultrasound. Used in the first and second trimesters to screen for pre-eclampsia. It is also used to assess placental function, fetal hemodynamic response to placental insufficiency, and placental flow resistance on the maternal side of the placenta.