Assessing growth and development, maintaining health and diagnosing of illness and abnormalities in the foetus is known as Foetal Medicine. With technological advancements, prenatal diagnosis has seen a significant upgrade. Through foetal medicine, the foetus is now treated as an individual patient apart from the mother.
As a relatively new specialty, foetal medicine requires an expert team including obstetricians, Perinatologists, Neonatologists, Pediatric Cardiologists, Pediatric Surgical Specialists, Geneticists and others.
Fetal Medicine deals with two aspects:
01. Prenatal Diagnosis
Detecting abnormal conditions in the foetus and differentiating them from normal foetal growth and development is referred to as prenatal diagnosis.
The purpose of prenatal diagnosis includes:
- To provide reassurance and reduce anxiety, especially among high risk groups
- To inform and prepare the parents for the birth of an affected child
- To allow treatment in the uterus
- To plan for transfer to a tertiary centre
- To make the decision of discontinuing pregnancy with an affected foetus
Prenatal diagnosis typically consists of two methods:
This consists of:
- Maternal Serum Screening
Ultrasonography is an ultrasound-based diagnostic imaging technique used for visualizing the embryo or foetus in the motherï¿½s uterus (womb). Unlike an X-ray, sonography uses sound waves to produce a moving picture of the foetus. This picture is generated from an instrument that is placed either on the motherï¿½s abdomen or on the vagina. This is done to get all the possible information regarding the health of the mother and foetus, the progress of pregnancy and any further information on the baby. Under Ultrasonography, a variety of tests and scans are done which reveals vital information about the growth and development of the foetus. They include:
- Nuchal translucency scan
This scan is usually carried out between 11 to 13 weeks to:
- Determine the pregnancy dating
- Assess risk for Down Syndrome and other chromosomal abnormalities
- Diagnose multiple pregnancy
- Diagnose certain foetal structural anomalies
- Diagnose early pregnancy failure
- Targeted imaging for fetal anomalies (TIFA) scan
This scan is usually done between 18-23 weeks. A detailed analysis of the foetus is done during this scan where each and every part of the foetus is imaged. In case of any abnormality, a medicine specialist will discuss further options with the couple.
- Interval growth scan
Usually done between 28-30 weeks, this scan assesses the foetal growth in women who have developed or who are at a potential risk of developing hypertension or diabetes during pregnancy.
- Foetal well being scan
This scan is done between 34-36 weeks to assess the well being of the foetus by assessing the blood flow to the placenta and foetus by color Doppler Ultrasonography.
- Fetal Echocardiography
A detailed foetal Echocardiography scan is recommended in women with family history of heart abnormalities or if a previous child is affected by the same. The scan is also required for women who are under the category of increased nuchal translucency.
Maternal Serum Screening:
- The second phase of non-invasive testing is the Maternal Serum Screening (MSS) test – a blood test to help determine the risk of Down syndrome, Edward syndrome or neural tube defects in the foetus.
- All women, irrespective of age, have a risk of delivering a baby with physical or mental abnormalities. However, age does play an important role in the health of your child. Down syndrome, one of the most common disorders that can develop during a late pregnancy, can also be detected with an early diagnosis.
- Maternal age at delivery and risk
- Early testing can help prevent the possibilities of delivering an unhealthy baby. Hence, screening tests are suggested for all pregnant women.
- The First Trimester Screening test (FTS) is done between 11-14 weeks. It is a combination of Ultrasound (Nuchal Translucency) and a maternal blood test. This helps in picking up 90%, 9 out of 10 cases, of Down syndrome.
- If women miss out on the first trimester serum screening, a quadruple test could be offered for women between 16th to 22nd weeks.
- Second Trimester Screening test or the Triple Screen Test (TST) is usually done between 15-21 weeks. It detects Down syndrome in 6 out of 10 cases, but is still offered to women who are booked later in pregnancy.
- These tests help determine if the women are at high or low risk of delivering a baby with Down syndrome. The high risk women are subjected to more definitive invasive testing which involves direct fetal sample testing.
- Chorionic Villus Sampling (CVS)
Chronic Villous refers to the part that attaches the placenta to the lining of the uterus or womb. CVS is a form of prenatal diagnosis to determine chromosomal or genetic disorders. Done between 11-14 weeks, CVS involves the examination of chorionic villi (placental tissue). Both the baby and placenta (after birth) originate from the same cell and so the chromosomes present in the cells of the placenta are the same as those of the baby.
Done between 15-20 weeks, Amniocentesis involves passing a thin needle into the uterus in order to remove fluid from around the foetus. This test provides reliable information about:
Rh disease, or blood compatibilities between the mother and the baby
Abnormal brain or spinal cord development, or neural tube defects
Foetal maturity towards the end of pregnancy
- Foetal blood sampling or Cordocentesis
Foetal blood sampling involves passing a thin needle into the uterus down to the umbilical cord, where it attaches to the placenta. A small amount of blood is taken for the test and the results are known within 4-5 days.
- Alpha-fetoprotein (AFP) test:
Performed during 15 to 20 weeks of pregnancy, this blood test detects neural tube defects. Neural tube defects are abnormalities in the brain or spinal cord of the foetus. Defects in the Central Nervous System of the foetus occur when the neural tube fails to close as the foetus develops. A high AFP reading may be due to miscalculation of the babyï¿½s age, or if the mother is carrying twins.
With a family history or previous pregnancies with the same problem, the foetus is at a greater risk of developing a high AFP reading. All prenatal tests do not help diagnose these defects. About 20% of babies with neural tube defects have normal AFP levels. Abnormal AFP levels are frequent ï¿½ occurring in about 50 of every 1000 women tested. Only 1 or 2 of 50 babies actually have neural tube problems. Various other temporary foetal conditions can also cause a high AFP reading.
- Tri Screen Test (Triple marker test)
This test combines the Alpha-fetoprotein results with two other blood substances to give us the Tri-screen Test. The results are obtained from a blood sample of the mother at 16-20 weeks of pregnancy. Majority of neural tube defects and two out of three babies with Downï¿½s syndrome can be diagnosed with this test.
- Glucose tolerance Test
This is a simple test performed during 24 and 28 weeks of pregnancy to look for signs of Gestational Diabetes. A concentrated solution is given to the mother-to-be to drink, following which the blood is drawn for testing at timed intervals. This test is conduct to determine how well the motherï¿½s body uses or metabolizes sugar.
- Fetal Maturity Test
Several tests can be performed with the amniotic fluid to determine the maturity of foetal lungs. The maturity of the babyï¿½s lungs has more to do with its ability to survive than with the weight of the baby after delivery. Babies born with immature lungs can suffer from a condition referred to as Respiratory Distress Syndrome or Hyaline Membrane Disease, which is the leading cause of death in newborns. This condition results from lack of certain chemical substances that make the oxygen we breathe transfer into our blood, where it is carried to the cells throughout the body.
Amino drainage in cases of tense Polyhydramnios (increased fluid around the foetus) to prevent preterm delivery and decrease maternal discomfort.
Embryo reduction in case of multiple pregnancy, usually reduction to twins, so as to decrease perinatal morbidity and mortality.
At The Nest, utmost importance is given to foetal medicine to detect, prevent and treat illness and abnormalities in the foetus at an early stage. Highly skilled and qualified professionals, who treat patients with compassion and care, are involved ensuring that the best care is given to the mother and the child. Our expert teams of doctors for foetal medicine include:
- Foetal Medicine Specialists
- Obstetricians and Gynaecologists
- Pediatric Surgeons
- Pediatric Cardiologists