Your doctor may recommend many screenings, tests, and imaging techniques throughout your pregnancy. These pregnancy screening tests are intended to offer information regarding the health of your baby and might help you maximize your child’s health care and development. Often before any of these other tests start, the very first tests they may request is a standard HIV or STD tests. If an expectant mother has an STD it may affect her health, the baby health, or the medical staff may need to protect themselves.
General Pregnancy Screening Tests
- Genetic screening can help diagnose the possibility of specific genetic disorders before birth.
- First-trimester testing is a blend of maternal blood testing and fetal ultrasound. This screening method can assist define the probability of the fetus with some birth defects.
- Second-trimester prenatal screening may consist of different blood tests also known as multiple markers. These markers produce information concerning the risks of having a baby with certain genetic conditions or birth defects.
- You might have ultrasounds performed at various times in your pregnancy to test for fetal growth, evaluate your due date and look for any structural abnormalities in the baby.
- Further testing during pregnancy may include amniocentesis, chorionic villus sampling (CVS), fetal monitoring, glucose testing, and Group B strep culture.
Genetic Screening Tests
Many genetic abnormalities can be detected before birth. Your doctor or midwife may suggest genetic testing for the pregnancy period if you or your spouse has family records of genetic dysfunctions. You may also decide to have a genetic test if you have had a fetus or baby with a genetic abnormality.
Below are the examples of genetic disorders that can be diagnosed earlier birth include:
- Duchenne muscular dystrophy
- Polycystic kidney disease
- Cystic fibrosis
- Hemophilia A
- Thalassemia
- Tay-Sachs disease
- Sickle cell disease
The next pregnancy screening tests method:
- Alpha-fetoprotein (AFP) tests or multiple marker tests
- Amniocentesis
- Chorionic villus sampling
- The cell-free fetal DNA screening
- Percutaneous umbilical blood sampling (taking a little sample of the fetal blood from the umbilical cord)
- Ultrasound scan
First Trimester Prenatal Screening Tests
First-trimester screening is the incorporation of maternal blood testing and fetal ultrasound. This testing process can help find the risk of a fetus with several birth defects. Screening tests may be used by itself or with other evaluations.
First Trimester Screening Includes:
- Ultrasound for fetal nuchal translucency. This kind of screening utilizes ultrasound to monitor the region in the rear of the fetal neck for rising thickening or fluid.
- Ultrasound for Fetal Nasal Bone Detection. The nasal bone might not be reflected in some infants with specific chromosome anomalies, such as Down syndrome. This screen is done using ultrasound between 11 and 13 weeks gestation.
- Maternal serum (blood) tests. These blood tests measure two materials found in the bloodstream of all pregnant women:
- Pregnancy-associated plasma protein A. A protein made by the placenta in early pregnancy. Abnormal levels are related to a higher chance of chromosomal defects.
- Human Chorionic Gonadotropin. The placenta produced this hormone in pregnancy at a first stage. Abnormal levels are associated with a higher risk of chromosomal abnormality.
When used together as nuchal translucency screening, maternal blood tests and first-trimester screening tests have a better ability to ascertain if the fetus may have a birth defect, such as Down syndrome (trisomy 21) and trisomy 18.
If the reports of the first-trimester screening tests are strange, genetic counseling is suggested. Another testing, such as amniocentesis, cell-free fetal DNA, chorionic villus sampling, or other ultrasounds might be necessary for an actual diagnosis.
Second Trimester Prenatal Screening Tests
This kind of screening may involve different blood tests known as multiple markers. These markers give a report about your possible uncertainty of having a baby with specific genetic diseases or birthmarks. Testing is usually done by obtaining your blood sample between 15 and 20 weeks of pregnancy (16 to 18 weeks is ideal). The multiple markers consist of:
AFP screening. It is also known as maternal serum AFP. This kind of blood analysis estimates the amount of AFP in your blood while you are pregnant. AFP is a protein usually generated by the fetal liver that’s found in the fluid covering the fetus (amniotic fluid). It travels through the placenta and enters your bloodstream. Abnormal levels of AFP may symbolize:
- A misjudged due date, as the levels vary during pregnancy
- Injuries in the abdominal wall of the embryo
- Down syndrome or other chromosomal anomalies
- Open neural tube deficiencies, such as spina bifida
- Twins (more than one fetus is generating the protein)
- This hormone is produced by the placenta. It may be measured in maternal blood or urine to be used to determine fetal wellbeing.
- This hormone is made by the placenta.
- Human chorionic gonadotropin. The placenta produced this hormone also.
Abnormal test reports of AFP and other markers may indicate that additional testing is necessary. An ultrasound is used to verify the milestones of your pregnancy and to look at the fetal spine and other body parts for deficiencies. An amniocentesis may be necessary for an actual diagnosis.
As multiple marker screening is not diagnostic, it isn’t 100 percent right. It helps decide who in the population should be provided with further screening during pregnancy. False-positive results may signal a problem once the fetus is truly healthy. On the other hand, false-negative results show a normal effect when the fetus actually does have a health issue.
For those who have both first and second-trimester screening tests carried o, the ability of the tests to determine an abnormality is more notable than using only one screening independently. Most cases of Down syndrome can be identified when both first and second-trimester screenings are utilized.
Ultrasound
A technician shows a Mother and dad their fetus when performing an ultrasound.
An ultrasound scan is a diagnostic method that uses high-frequency sound waves to produce an image of the internal organs. A screening ultrasound is seldom done during your pregnancy to check normal fetal growth and check the due date.
When Are Ultrasounds Done During Pregnancy?
Ultrasounds may be performed at various times during pregnancy for many purposes, but most of all to see the development of the unborn baby:
First Trimester
- Set the due date (this is the most appropriate way of managing the due date)
- Identify placental arrangements and evaluate the number of fetuses.
- Diagnose miscarriage or an ectopic pregnancy
- Examine the uterus and another pelvic anatomy
- Detect fetal abnormalities (Sometimes )
Midtrimester (also Known as the 18- to 20-week scan)
- Confirm the expected date (a due date set in the first trimester is infrequently changed)
- Know the number of fetuses and check the placental compositions
- Help in prenatal tests, like an amniocentesis
- Study the fetal anatomy for abnormalities
- Examine the volume of amniotic fluid
- Analyze patterns of blood flow
- Recognize fetal behavior and action
- Estimate the height of the cervix
- Observe fetal growth
Third Trimester
- Monitor fetal growth
- Check the amount of amniotic fluid
- Run the biophysical profile evaluation
- Determine the position of the fetus
- Assess the placenta
How is An Ultrasound Scan Performed?
During pregnancy, two types of ultrasounds can be performed:
- Abdominal ultrasound. In this kind of ultrasound, the gel is rubbed on your stomach. The ultrasound transducer trips over the gel on the abdomen to produce the image.
- Transvaginal ultrasound. In this sort of ultrasound, a modest ultrasound transducer is injected into your vagina and holds upon the back of the vagina to produce an image. A transvaginal ultrasound creates a sharper picture than abdominal ultrasound and is commonly utilized in early pregnancy.
Which Ultrasound Imaging Methods Are Available?
There are lots of types of ultrasound imaging methods. As the most frequent type, the 2-D ultrasound gives a flat picture of one aspect of the infant.
If more information is required, a 3-D ultrasound test can be done. This technique, which gives a 3-D image, requires a particular machine and specialized training. The 3-D image enables the medical care provider to find the width, height, and thickness of the pictures, which can be helpful during the diagnosis. The 3-D images can also be recorded and stored for later review.
The latest technology is a 4-D ultrasound, which enables health professionals to envision the unborn baby movement in real time. Using 4-D imaging, a three-dimensional image is continuously updated, offering a “live action” picture. These images usually have a golden color, which helps display highlights and shadows.
Ultrasound images may be taken in still pictures or on the video to document conclusions.
What are the Dangers and Advantages of Ultrasound Imaging?
Fetal ultrasound has no known dangers Aside from mild discomfort because of pressure from the transducer in your stomach or in your vagina. No radiation is used throughout the process.
Transvaginal ultrasound involves covering the ultrasound transducer in latex or plastic sheath, which might cause an effect in women having a latex allergy.
Ultrasound imaging is continually being improved and refined. As with any evaluation, the results might not be totally accurate. However, an ultrasound can provide valuable advice to parents and medical care providers, helping them manage and care for the pregnancy and the infant. Moreover, ultrasound imaging offers parents a unique opportunity to see their baby before birth, supporting them to bond and develop an early relationship.
Fetal ultrasound is often offered in nonmedical settings. To submit keepsake pictures or videos for parents. While the ultrasound procedure itself is deemed safe, it’s possible that untrained employees may miss an anomaly or provide parents false assurances about their child’s health. It’s ideal to have an ultrasound conducted by qualified medical staff who can correctly evaluate the results. Ask your midwife or physician if you have questions.
Amniocentesis
Amniocentesis involves obtaining a small sample of the Amniotic fluid which surrounds the fetus. It’s used to diagnose chromosomal ailments and open neural tube defects, such as spina bifida. Testing is available for other genetic problems and disorders depending upon your family history and the laboratory testing availability at the time of this process.
Who’s An Ideal Candidate For Amniocentesis?
An amniocentesis is usually provided to women between the 15th and 20th week of pregnancy that have a higher chance of chromosomal abnormalities. Applicants involve women who have an age of 35 or above at the time of delivery or people who have had an essential maternal serum screening test.
How Is An Amniocentesis Performed?
Amniocentesis requires inserting a long thin needle through your abdomen into the amniotic sac to take out a sample of amniotic fluid. The amniotic fluid includes cells shed by the fetus, which include genetic knowledge.
Although particular details of each procedure may vary, a normal amniocentesis follows this process:
- Cleaning your abdomen using an antiseptic.
- Your doctor might or might not provide a local anesthetic to anesthetize the skin.
- The physician will use ultrasound technology to help guide a hollow needle into the amniotic sac. He or she’ll draw a small sample of fluid for laboratory testing.
You may feel some pains during or after the amniocentesis. Strenuous exercises should be avoided for 24 hours after the process.
Women that are pregnant with twins or multiples require sampling from each amniotic sac to examine each baby. Depending upon the position of the placenta and baby, a woman’s anatomy and amount of fluid,, sometimes a genetics laboratory so the cells can grow and be tested. AFP is also estimated to handle an open neural tube problem. Results are commonly available in about 10 days to 2 weeks, based on the laboratory.
Chorionic Villus Sampling (CVS)?
CVS is a prenatal test that involves obtaining a sample of a few of the placental tissue. This tissue holds the same genetic stuff as the fetus and can be examined for chromosomal anomalies and some other genetic issues. Testing is available for other genetic disorders and defects, based upon your family records and the lab testing available at the time of this process. Unlike amniocentesis, CVS doesn’t give information on open neural tube deficiencies. Therefore, women who undergo CVS also require a follow-up blood test between 16 and 18 weeks of pregnancy to screen for these defects.
How Is CVS Performed?
CVS may be provided to women with an improved risk of chromosomal anomalies or who possess a family history of a hereditary problem that is testable with the placental tissue. CVS is generally conducted between the 10th and 13th week of pregnancy. However exact processes may differ, the method includes the following steps:
- Your doctor will put a small tube (catheter) into your vagina to your cervix.
- Using ultrasound technology, your physician will manage the catheter into place near the placenta.
- Your doctor will eliminate some tissue with a syringe on the other end of the catheter.
Your physician may also wish to conduct a transabdominal CVS, that involves putting a needle through your abdomen and into your uterus to test the placental cells. You can feel some cramping during and after either sort of CVS process. The tissue samples are transferred to a genetic laboratory for analysis and growth. Results are regularly available in about 10 days to 2 weeks, depending on the laboratory.
What If CVS Isn’t Possible?
Women with twins or multiples usually require sampling from each placenta. However, due to the process complexity and the positioning of the placentas, CVS isn’t always feasible or successful with multiples.
Ladies who are not candidates for CVS or who didn’t get accurate results from the process may need a follow-up amniocentesis. An ongoing vaginal disease, such as gonorrhea or herpes, will inhibit the process. In other cases, the doctor may collect a sample that doesn’t have enough tissue to grow in the laboratory, generating inconclusive or incomplete results.
Fetal Monitoring
At the time of late pregnancy and labor, your doctor may want to monitor the fetal heart rate and other functions. Fetal heart rate tracking is a way of determining the rhythm and speed of the heartbeat of fetal. The standard fetal heart rate is within 120 and 160 beats per minute. This rate can vary as the fetus reacts to requirements in the uterus. An irregular fetal heart rate or pattern may mean the fetus isn’t getting enough oxygen or signal other issues. An unusual pattern also may indicate that an emergency cesarean delivery is required.
How Is Fetal Examination Carried Out?
Using a fetoscope to monitor the fetal heartbeat is the most fundamental kind of fetal heart rate detection. Another sort of examining is done using a hand-held Doppler apparatus. This is frequently used during prenatal visits to count the fetal heart rate. During labor, continuous electronic fetal monitoring is commonly used. However, the particular aspects of each procedure may differ, regular electronic fetal monitoring follows this process:
- The gel is applied to your abdomen to act as a medium for the ultrasound transducer.
- The ultrasound transducer is connected to your abdomen with straps so that it can send the fetal heartbeat to a recorder. The fetal heart rate is illustrated on a screen and printed onto special paper.
- During contractions, an external tocodynamometer (a tracking device that’s placed over the surface of the uterus using a belt) can read the patterns of contractions.
When Inner Fetal Monitoring Is Required?
On occasion, internal fetal testing is needed to give a more precise reading of the fetal heartbeat. Your bag of waters (amniotic fluid) should be broken, and your cervix needs to be somewhat expanded to use internal monitoring. Inner fetal tracking is carried out by inserting an electrode into the dilated cervix and joining the electrode to the fetus’s scalp.
Glucose Testing
Glucose testing is utilized to measure the amount of sugar in your blood.
A glucose challenge test is often carried between 24 and 28 weeks of pregnancy. Irregular glucose levels may show gestational diabetes.
What’s Involved In A Glucose Challenge Test?
The first one-hour evaluation is a glucose challenge test. If the results are unusual, a glucose tolerance test is necessary.
How Is A Glucose Tolerance Test Performed?
You may be asked only to drink water on the day the sugar tolerance test is given. However the particular details of each procedure may vary, a Normal glucose tolerance test comprises the following measures:
- The first fasting sample of blood will be taken from your vein.
- You’ll be given a particular glucose solution to drink.
- Blood will be drawn at different times throughout several hours to measure the glucose levels in the body.
Group B Strep Culture
It is a kind of bacteria observed in the lower genital region of about 20 percent of women. Even though a GBS disease does not usually cause problems in women before pregnancy, it can cause severe illness in pregnant women. GBS may develop Chorioamnionitis (critical placental tissues infection) and postpartum infection. Urinary tract diseases induced by GBS can result in preterm labor and birth or pyelonephritis and sepsis.
GBS is the most usual cause of deadly infections in newborns, including meningitis and pneumonia. Newborn babies catch the infection during pregnancy or from the genital tract of the mother during labor and delivery.
The CDC suggests testing all pregnant women for rectal GBS and vaginal colonization between 35 and 37 weeks gestation. The treatment of mothers with several risk factors or positive cultures is essential to decrease the uncertainty of transmission of GBS to the baby. Babies whose mothers get antibiotic treatment for a positive GBS test are 20 times less possible to contract the disease than those without treatment.