FETAL MEDICINE

Prenatal screening is aimed at early diagnosis and treatment of pathological conditions that could affect the normal course of pregnancy and the health of the mother and fetus.

Dr. Alexanros Traianos, Fetal Medicine Diploma holder (holder of Fetal Medicine Diploma) provides all invasive and non-invasive methods that cover the spectrum of prenatal screening.

ultrasound scans

FIRST TRIMESTER-  NUCHAL TRANSLUCENCY

This ultrasound is performed from 11 weeks and 1 day to 13 weeks and six days (CRL 45mm – 84mm).It is usually done transabdominally, bBut in some cases it may be necessary to have the scan transvaginally.

Objectives of ultrasound

Exact Pregnancy Age Determined: This is especially important for women who cannot remember the date of their last period, have irregular menstrual periods, or have conceived while breast-feeding or just after discontinuing the contraceptive pill. We measure the size of the fetus and then calculate the probable date of birth (40 weeks).

Risk Assessment for Down Syndrome and Other Chromosomal Abnormalities: Every woman should receive an assessment of her individual risk for this pregnancy. This is calculated taking into account the mother’s age, the measurement of two hormones in her blood (Papp-a and free beta-chorionic gonadotropin) and 4 ultrasound markers, which are: nuchal traranslucenecy (the fluid behind the fetal neck) that is and the most important marker, the nasal bone, the blood flow to the right side of the fetal heart (in the tricuspid valve) and the blood flow to the fetal ductus venosus canal (a small vessel in his liver). Parents will receive full advice on the importance of this risk and the various options for further testing.

Diagnosis of Multiple Pregnancy: About 2% of natural pregnancies and 10% of IVF conceptions result in multiple pregnancies. An ultrasound scan can determine if both fetuses are developing properly and if babies share the same placenta, which can lead to pregnancy problems. In such cases, it would be advisable to monitor pregnancy more closely.

Diagnosis of some major congenital abnormalities: Significant abnormalities may be visible at this gestational age, but a 20-week ultrasound scan is also required.

Diagnosing Early Pregnancy Failure (regression): Unfortunately, 2% of women who come for cervical ultrasound are found to have died, often several weeks before and without any warning. Couples will receive full advice on the possible causes of this problem and the options for future action that may be necessary.

Estimation of risk of preeclampsia and intrauterine growth retardation: In all patients at the end of the examination blood flow to the mother’s arteries will be measured ultrasound by Doppler examination. The result of this test can tell us which women are at increased risk of developing preeclampsia before 34 weeks, as well as which embryos are at risk of delaying their development in the third trimester.

Early Childbirth Risk Calculation: In all patients at the end of the test if they wish, the cervical length will be intermittently measured. We know that during pregnancy, the cervix must be long and closed. Women who have a short cervical screening increase the risk of preterm birth. The treatment in this case is proportionate to the problem.

Personalized Risk for Down Syndrome

The vast majority of babies are normal. However, all women, regardless of their age, have a small risk of having a child with physical or mental disabilities. In some cases the abnormality is due to a chromosomal abnormality such as Down syndrome.

The only way to know for sure if the fetus has a chromosomal abnormality is through a diagnostic invasive examination, such as chorionic duct staining (CVS) or amniocentesis. However, these tests have the risk of elimination of 1%.

It is up to you and your partner to decide whether or not the risk for the fetus having chromosomal abnormalities is high enough to warrant an invasive test. As a guideline, an invasive examination is usually offered if the risk for Down Syndrome is 1 in 300 or more.

The most accurate method for assessing the risk of the fetus having Down syndrome is carried out from the 11th to the 14th week of pregnancy and depends on the following:

  • Mother’s age
  • Amount of fluid behind the fetal neck (cervical slide)
  • Presence or absence of fetal nasal bone
  • Fetal heart rate
  • The flow of blood through the tricuspid valve of the fetal heart
  • The flow of blood through the vein to the fetal liver
  • Presence or absence of any structural abnormalities

Level of the two hormones (free β-hCG and PAPP-A) in the mother’s bloodAfter the ultrasound, based on all of the above factors, the estimated risk for Down Syndrome will be discussed with you. Only you can decide whether you want to undergo an invasive diagnostic test. Regardless of whether or not you decide to have an invasive examination, a detailed ultrasound at 20 weeks is recommended to check for structural abnormalities in the fetus.

 2nd TRIMESTER – Anomaly scan

This is a detailed ultrasound at 20-22 weeks gestation.

During the ultrasound, we thoroughly examine the anatomy and all the fetal systems, determine the location of the placenta, evaluate the amount of amniotic fluid and the development of the fetus, calculating its weight. Special attention is given to the brain, face, spine, heart, stomach, intestine, kidneys and extremities. Gender determination is possible with the consent of the couple.

In high-risk women for preterm labor (multiple pregnancies, history of preterm labor, uterine or cervical abnormalities, previous surgery) we may also have an intercostal ultrasound to measure the length of the cervix.

If any abnormalities are identified, the significance of the findings will be discussed and parents will have the opportunity to provide further advice.

Further tests, including the Harmony test or invasive tests such as amniocentesis, can also be explained in depth.

What are the indications or reasons for this ultrasound?

Ultrasound is recommended for all pregnant mothers.

3RD TRIMESTER – GROWTH SCAN (DOPPLER)

It is a recommended test in all pregnancies.

The purpose of this examination is to:

  • the detection of a potential problem in the development of the fetus.
  • the confirmation of the good condition of the fetus.
  • examining the child’s third trimester anatomy.
  • determining the risk of preterm birth.
  • determining the risk of preeclampsia and residual fetal growth.

It is performed from the 28th week until birth, but usually at the 32nd week of pregnancy.

Doppler ultrasound includes a series of measurements (biometry) of the fetus that allow us to calculate its weight. The values ​​of the measurements are placed in the Astraia software, which with its large database can validate us if the child develops according to other children of his age.

Blood flow (with color Doppler) is examined in the umbilical cord blood vessels to assess placental adequacy and cerebral blood vessels to assess the oxygenation of the child’s brain.

We measure the amount of amniotic fluid and evaluate the movements of the fetus that provide us with information on the fetus’s well-being. In addition, the location and morphology of the placenta are checked.

The fetus is a developing organ and various pathological conditions may have an adverse effect on the development of its vital organs. For this reason the developmental ultrasound examines the fetal anatomy of the third trimester. Specifically, the skull and brain, eye lenses, palate, lips and facial profile, spine, neck, thoracic and lungs, heart, abdominal wall, and the other are checked for possible pathology. gastrointestinal system, the kidneys of the fetus. The examination of the anatomy of the 3rd trimester is performed using specific ultrasound scans, as determined by the respective Fetal Medicine Foundation (FMF) protocols, which have been shown to exhibit the highest sensitivity for detecting potential irregularities at this advanced age. of pregnancy.

In cases where the fetus is in a suitable position, it is imaged using 3D (4D and 4D) ultrasound.

Doppler ultrasound can be combined with cardiogram (biophysical profile – see corresponding section). This combination provides additional information on the condition of the fetus and the risk of endometrial death.

Exam time ~ 30 minutes.

 INVASIVE PROCEDURES

CHORION VILLUS SAMPLING – CVS

It is basically a placenta biopsy with choroidal lesions, that is, its structural components. The fetus and the placenta come from the same dividing cell, the fertilized egg, and so the chromosomes found in the placenta cells are the same as those of the baby.

When does it happen?

It’s a test done in 11-15 weeks.

How to Get a Trophoblast?

Abdominal antisepsis is carefully performed. The entry site is carefully selected and a local anesthetic (xylocaine) is given. A fine needle is then passed through the mother’s abdomen into the uterus and placenta and a suction sample is drawn by suction. The needle position is constantly monitored ultrasound. The process takes a few minutes. The needle does not enter the amniotic cavity and does not disturb the fetus. At the end of the examination the fetal heart rate is checked.

What can I expect after receiving a trophoblast?

The first 2-3 days you may experience some mild abdominal discomfort, such as period pain or a slight vaginal bleeding. These are relatively common symptoms and in the vast majority of cases pregnancy continues without problems. You can take simple painkillers such as paracetamol (Depon). If you feel very pain, have high bleeding, or if you have a high temperature, seek medical advice.

Is bed rest necessary?

We usually recommend bed rest for 1 day and restriction of vigorous physical activity for 2-3 days.

We should not forget the prophylactic administration of D γ globin to Rh negative women.

When can I expect the results?

First results (PCR-99%) for Down syndrome and other common chromosomal abnormalities are usually available the following day or the day after. The following results (molecular karyotype) for rarer chromosomal abnormalities are available in 1 week. The end result is available 2 weeks after the end of cell culture.

Could the process need to be repeated?

In about 1/1000 cases, the invasive procedure should be repeated because the results are usually unclear because of the mosaicism of the condition, that is, the placenta hosts normal and abnormal cells, sometimes in good proportion. Abnormal cells may or may not be related to embryonic tissues since nature was isolated in the placenta just in time. In this rare case, it is necessary to perform amniocentesis at a later time without the risk of mosaicism.

What Are The Risks Associated With Trophoblast Taking?

The risk of miscarriage due to trophoblast intake is approximately 1/300 and is the same as the risk of amniocentesis after 18 weeks. The risk recedes over the days and disappears after the first five days.

AMNIOCENTESIS

What is Amniocentesis?

It is a diagnostic invasive examination and involves the analysis of cells, DNA and metabolites in the fluid around the baby (amniotic fluid). The cells of the amniotic fluid are mainly derived from the embryo and thus the chromosomes of these cells are the same as those of the embryo.

How is amniocentesis done?

Under ultrasound examination, a very fine needle (thinner than that used in trophoblasts) passes through the skin of the mother’s abdomen and 15 – 20 ml of amniotic fluid is taken from the amniotic sac around the fetus and sent to the laboratory.

The amniotic fluid obtained consists of fetal urine and therefore the amount taken for examination is replenished in just a few hours.

The procedure takes one minute and we hear the baby’s heart immediately afterwards.

Does Amniocentesis Pain?

According to women’s testimonies, amniocentesis does not hurt. But a slight discomfort in the sense of pressure is justified. No local anesthetic is used, as the needle of the amniocentesis is thinner than the local anesthetic and lasts one minute

When and why is amniocentesis performed?

Amniocentesis occurs after the 15th week of pregnancy and until the end of pregnancy. However, between 16 and 20 weeks of gestation is ideally recommended, while a 32-week gestation is recommended as a chromosomal check because increased dissolution of amniotic fluid makes it more likely after this stage of gestation. do not work in the laboratory.

Indications

  • Examination is done after specific indications, such as:
  • Pathological examination of cervical transparency.
  • Alpha / Triple Pathological Test.
  • Suspected ultrasound findings.
  • Previous pregnancy with a fetus suffering from chromosomal abnormality.
  • Perinatal infection (toxoplasmosis, rubella, etc.).
  • Parents of carriers of gene diseases, such as Mediterranean anemia, fibrotic disease, etc.
  • Pregnant age (after 35 years).
  • Desired by the pregnant woman, due to excessive anxiety about chromosomal abnormalities.

What to expect after amniocentesis?

It is expected in the first 24 hours to experience periodic pain or even lower abdominal pain. It is normal, as well as normal it is sometimes described as dropsy vaginal hemorrhage.

Many times it is helpful to take some simple and safe painkillers for pregnancy such as paracetamol (Depon).

It is not normal to experience acute abdominal pain, fever, vaginal bleeding, or amniotic fluid exhaustion (” water breaks ”). In all these cases you should seek immediate medical advice.

When will I get the results?

The first results for chromosomal abnormalities such as Down syndrome are usually available in two to three days (PCR). Fetal karyotype (culture) and information on other abnormalities / syndromes / diseases / infections are available within two weeks of receiving the amniotic fluid. We will contact you as soon as we have the results.

What are the risks of amniocentesis?

The risk of miscarriage as described by international literature is in the order of 1/1000. There is a very low risk of a mother’s infection (1 in 1000) and this is a record of the mother’s temperature for the next two and a half hours. In case of fever, clinical evaluation and possible initiation of antibiotic treatment are recommended.

POLYMNI EQUIPMENT PRESENTATION

This procedure reduces the volume of amniotic fluid in cases of polyamide, in order to relieve the pregnant woman from severe discomfort and / or shortness of breath, and to reduce the risk of premature rupture of the films and premature birth.

The method used is similar to amniocentesis. The whole process takes about 10-15 minutes. Up to 1500ml of fluid can be drawn during this time, and a sample may be sent for further examination to a specific cytogenetic laboratory.

Emergency polyamide puncture is an invasive procedure and involves risks, with the most frequent being abortion at 1%. The risk is less when the operation is performed by a properly trained and certified physician.

NIPT

NON INVASIVE PRENATAL TEST (NIPT)

This is a recent method by which a blood sample from the 10th week of pregnancy can detect free embryonic DNA in the mother’s circulation.

What is the utility of NIPT?

Based on current data and the limitations of the test, we recommend it mainly to “intermediate” women of risk, that is, where cervical screening has a risk of 1: 250-1: 1000 and cervical transparency is within normal limits. In these cases we use NIPT because we want something more reliable than cervical transparency but we do not have enough worrying findings to recommend an invasive procedure (amniocentesis or CVS). Conversely, if cervical transparency is abnormal (elevated) NIPT is not a suitable screening for you and amniocentesis or trophoblast reception is recommended.

The American College of Obstetricians and Obstetricians (ACOG) extends the recommendation for chromosomal screening to other “high risk” cases for chromosomal abnormalities, including women older than 35, or with a previous medical history.

Finally, the test is offered to any pregnant woman who simply wants to do it without belonging to any of the above groups.

How is it done?

It is as simple a blood test of a woman’s hand as any other blood test. There are currently no sample testing laboratories in Greece, so the sample is packaged and shipped to the US.

When is it done?

Ideally the best time to do the test is around 11 weeks. At 12 weeks, the first trimester ultrasound will be followed by cervical transparency measurement and results will be taken into account. But practically it can be done at any age of pregnancy.

When do we expect the result?

Results are usually available within 10-14 days. There is a 5% chance that we will not work. This does not mean a positive or negative result: it is a failed test, mainly due to low fetal DNA in the mother’s blood. A re-examination will be offered free of charge.

How is the result expressed?

The result is expressed as a probability. It is a screening test (SCREENIN GTEST) and not a diagnostic test. A low risk result means that the risk of chromosomal abnormality is less than 1: 10000 and that> 99% of the fetus does not have the above chromosomal abnormalities. A high risk result means that> 99% of the embryo will have Trisomy 21, 18 or 13 and then an invasive test will be offered to confirm the result.

What is the difference from amniocentesis?

In medicine there are diagnostic tests that will confirm or exclude a pathological condition with 100% certainty and screening tests that will assess the probability or in other words the risk of a pathological condition. Screening tests may be more or less accurate in their estimation. For example a very good screening test is the PAP test which will substantially evaluate the possibility of cervical cancer. A diagnostic test will follow, namely cervical biopsy and other than clinical examinations.

What is the position of NIPT?

Expected to be fixed!

It is definitely a better screening test than cervical transparency and PAPPA measurement since the sensitivity of the method reaches 99% (versus 96%). In addition, screening relates to trisomies 18 and 13 (as well as cervical) but also 7 at present and according to the company genetic syndromes. But it is not a diagnostic test. Just like the cervical measurement.

In other words, if NIPT gives a reduced risk for Down syndrome, the probability of it being low is low and if the risk is increased, confirmation is needed with a diagnostic test ie Amniocentesis or CVS (placental biopsy).

In countries with an organized public health system such as the UK is looking for screening tests in the general population as these will determine which subgroups will undergo the diagnostic tests. The purpose is to identify a situation in good time and to prevent public health at the lowest possible cost.

For this screening test should be simpler and cheaper than diagnostic. This is not the case — at least with NIPT which requires very high technology and is just as expensive as amniocentesis and CVS.

The tendency seems to be to create a statistical model that combines the findings of cervical ultrasound with NIPT (when it becomes cheaper over time) to determine these minimal women undergoing Amniocentesis or CVS.

NIPT IS NOT SUBJECT TO AMNIOPRACULTURE

AMNOPARENTATION NOT

Prenatal screening is aimed at early diagnosis and treatment of pathological conditions that could affect the normal course of pregnancy and the health of the mother and fetus.