Obstetrics /4D Ultrasound Scans
Obstetrics
PRE-CONCEPTION CONSULTATION
Pre-conception care is a medical consultation with the aim of improving the health of the woman and her future children. This consultation is based on assessing the reproductive risks and the actions taken due to the risks and illnesses discovered. We recommend this to take place a year prior to the start of the pregnancy.
Pre-pregnancy risk assessment: it is performed by gathering information on the medical, personal, reproductive, family, social habits and environmental exposure background. s ambientales.
Laboratory tests to be evaluated by a specialist: Haemoglobin, haematocrit, blood type and Rh, blood sugar, proteinuria, smear test, serology tests.
PREGNANCY CHECK-UPS
Prenatal medical check-ups must be performed during the entire pregnancy. Their aim is to monitor the evolution of the pregnancy and advise the woman so mother and foetus can be as healthy as possible. The frequency of consultations depends on the specific needs of each woman and the associated risk factors.
Throughout the process, the specialist will advise the patient regarding the pregnancy, birth and post-birth care, indicating different ways to improve their health.
Blood Tests: Three blood tests are performed during the pregnancy, one per trimester. Each test includes analyses to rule out certain problems which can occur during pregnancy.
In the first trimester
complete haemogram, blood type and Rh, indirect Coombs test if applicable, LUES, HIV and CHV serology, urine sediment and urine culture, O’Sullivan test if applicable.
In the second trimester
(at 24-28 gestational weeks): complete haemogram, urine sediment and urine culture, O’Sullivan test, indirect Coombs test if applicable.
In the third trimester
(at 32-36 gestational weeks): complete haemogram, coagulation tests, urine sediment and urine culture, vaginal and rectal swabs for screening Streptococcus B.
ULTRASOUND SCAN
The number and frequency of ultrasound scans depends on the characteristics of each woman and pregnancy. However, this test is essential at week 12, week 20 and between weeks 32 and 34.
An initial ultrasound scan is recommended to check if the foetus has implanted correctly. It must be performed after week 6 of the pregnancy. In that same appointment, the gestational sac, the yolk sac, the embryo and heartbeat can be observed. Furthermore, it can help us to determine the gestation date and to estimate an approximated date for the birth.
Another important ultrasound scan that can be recommended by the obstetrician is on week 9-10. In this scan the first foetal movements can be observed. It must be noted that after these weeks, the risk of miscarriage decreases.
In the ultrasound scan on week 12-13, the nuchal translucency is measured, which together with the blood test performed on the first trimester and other data from the mother will provide the screening results for the risk of the main chromosome disorders (trisomy 21, 13 and 18).
As the pregnancy progresses, several scans are performed in order to check its correct development. They include foetal measurements (biometry), placental location and characteristics and foetal position.
PRENATAL DIAGNOSIS
First trimester screening: This is not a diagnostic test. It is a mathematical estimate of the risk of the foetus having chromosome disorders. On the one hand, two biochemical parameters are measured in the mother’s blood. The data obtained is associated with the nuchal translucency ultrasound results. Considering all these parameters together provides a risk index. In this way, if a high risk is estimated, the patient will be able to decide, taking into account risks and benefits, if they wish to undergo a diagnostic test known as amniocentesis.
Morphological ultrasound scan: it is performed at 20 gestational weeks. This is important in order to detect pregnancies with a high risk of chromosome disorders, and for diagnosing major and minor foetal defects. If this test reveals a high risk of chromosome disorders, the patient will be offered an amniocentesis. It is a non-invasive pre-natal test.
Amniocentesis: this is an invasive test which is generally performed from 15 gestational weeks. It involves taking 15-20 cc of amniotic fluid through a transabdominal puncture and suction of the amniotic cavity. The chromosomes most frequently involved in chromosome disorders suffered by newborns are analysed in this sample.
Chorionic villus sampling: it is a prenatal diagnostic method which involves taking a sample of the chorionic villi for subsequent genetic study. It must be performed between gestational weeks 10 and 14, and never before week 10.
Non-invasive prenatal test: this is a genetic screening test to detect the most frequent chromosome anomalies by studying the free foetal DNA present in the mother’s blood. It can be performed from the 10th gestational week (10 weeks + 0 days). It is suitable for pregnancies achieved through assisted reproduction, including IVF through gamete donation and it can also be performed in twin pregnancies. This test must always be explained by a specialist doctor.
Preimplantation Genetic Test (PGT): This detects and prevents the transmission of severe diseases caused by genetic and chromosome alterations in the embryos, before being transferred to the uterus. This prevents transmitting severe hereditary diseases to the children. There are different types of Preimplantation Genetic Tests:
PGT-A or Aneuploidy Preimplantation Genetic Test: this tells us whether the embryo has the correct number of chromosomes. The most well-known chromosome disorder is Down’s Syndrome. The following anomalies could be clinically relevant since they are associated with miscarriages and foetus defects.
PGT-M or Molecular Preimplantation Genetic Test: This study in conducted in patients who have a hereditary disease (whether in the couple or in the family) or in patients who have tested as compatible with that disease in order to prevent transmission to their children. Usually, these are monogenic hereditary diseases like fragile-X syndrome, Huntington’s disease, muscular dystrophy, etc. Within an assisted reproduction treatment, this diagnosis must be performed analysing the DNA of each embryo, identifying the healthy ones and transferring it to the mother’s uterus after having ruled out the assessed disease. It must be noted that prior to performing a PGT-M, information about the disease or mutated gene must be available. Therefore, prior genetic studies are required.
4-D ultrasound scan
This has no diagnostic value, but it gives a moving image of the baby before birth. With the application of new technologies to obstetrics, it is now possible to view the foetus in 3D. This provides realistic high-quality images. Additionally, we can see images of the foetus in real time to observe the movements and enjoy the expressions on his/her face, etc…
