The Center for Women

 

Physicians & Surgeons for Women

 

 

4139 Boardman-Canfield Road • Canfield, OH 44406 • 330.702.1281

923 Columbiana-Canfield Road • Columbiana, OH 44408 • 330.892.8185


 

 

Genetic Screening


You will be asked about risk factors for genetic disorders. This helps your doctor to determine if your baby is at risk for a genetic defect. Couples with an increased genetic risk can have healthy children with no genetic disorders. However, genetic defects can occur with no family history. Testing for Cystic Fibrosis, Down's Syndrome and Spina Bifida is offered to all patients. However, testing is your personal choice. Some couples would rather not know, while others may want to know in advance. Make sure you understand what the results mean.

Risk factors for genetic disorders:

  • If you are 35 or older when your baby is due
  • If the father of the baby is 50 years or older when the baby is due
  • If you or your partner are of Mediterranean, Asian, or African descent. If either of you or anyone in your families have thalassemia (an inherited disorder that causes anemia)
  • A family history of neural tube defects (Spina Bifida)
  • Family history of Down Syndrome
  • If you or the baby's father are of Eastern, Jewish, French Canadian, or Cajun descent, or if there is a family history of Tay-Sachs disease
  • If you or the baby's father are of eastern European Jewish descent, if there is a family history of Canavan descent
  • If you or the father of the baby is of African-American descent or if there is a history of sickle cell anemia or sickle cell trait
  • If there is a family history of hemophilia
  • If there is a family history of muscular dystrophy
  • If there is a family history of cystic fibrosis
  • If there is a family history of Huntington's disease
  • If you have a metabolic disorder such as Type 1 or Type 2 Diabetes or Phenylketouria
  • If you have a history of pregnancy issues (miscarriage or a stillborn baby)

 

Cystic Fibrosis

Genetic testing for Cystic Fibrosis is offered at the beginning of the pregnancy.

What is Cystic Fibrosis (CF)?

  • A genetic condition that affects children from birth
  • It affects 1 in 2500 babies in the United States
  • The body organs most affected by the disease are the lungs, pancreas and sweat glands
      – There is a thick mucous that coats the cells
      – This leads to problems with digestion and breathing
      – Symptoms will vary by child but include constant cough or wheezing, recurrent pneumonia, and poor weight gain
  • Life expectancy is shortened
      – Some may live into their 40's
      – Others may die in childhood
  • It is inherited from the parents
      – Both parents must be carriers of the CF gene
      – The gene must be passed by both parents at the time of conception

What is the Cystic Fibrosis Screening?

  • It is a blood test
  • It is an optional test in pregnancy
  • It is done to determine if a couple is at a higher risk of having a child with CF

 

Down Syndrome & Spina Bifida

Screening tests are done when there are no known risk factors or symptoms. These tests can assess the chances of having a child with certain birth defects. If the screening shows an increased risk, further testing is offered to diagnose the problem. An abnormal test only states a possibility of a problem. In most cases, the baby is healthy even though the screening was abnormal. Only 2-3% of women whose screening tested positive for Down Syndrome will have a child with Down Syndrome. However, a birth defect can occur even if the screening is negative. Not all disorders can be found by testing. Your doctor can explain your results to you.

A new screening, called the First Trimester Screen or the Ultrascreen, can be done to test for Down Syndrome. The test is performed between 11 and 14 weeks pregnant. This test is done through ultrasound measurements and blood work.

Testing for neural tube defects such as spina bifida can be done between 15 and 20 weeks pregnant with blood work.

It is important for these tests to be drawn in the appropriate time to avoid any errors.

 

Delivering A Baby When You Become 35 Years Old

When you deliver a baby after the age of 35 years old, you have a higher risk that there could be a problem with the baby's chromosomes. There is a higher risk than the average person (under 35 years old) that too much genetic information (chromosomes) or too little genetic information will be passed to the baby in the early development. As women age, her risks gradually increase. Each age has a different risk level.

Increased Risk of Down Syndrome, Trisomy 13, Trisomy 18:

  • An extra copy of a chromosome is passed to the baby
  • This causes the baby to be mentally retarded and possibly have some medical problems

Testing is available to see if the baby has a genetic problem such as Down Syndrome

  • Testing is optional, decided by the parents

1st Trimester Genetic Testing (i.e. Harmony, Matern 21) is early detection of free DNS or fetal cells circulating in the mother's blood stream that can be analyzed to determing chromosome abnormalities pertaining to T13, T18, T21, and gender X or Y chromosomes.

 

What are the tests?

  • Chorionic Villi Sampling (CVS)
      – It is done between the 10th and 13th week of pregnancy
      – A small sample of the early placenta is obtained
      – It is done one of two ways:
        • Transcervical (through the vagina and cervix)
        • Transabdominal (through the abdomen)
      – The sample is analyzed to determine the baby's chromosome make-up
      – It is not always possible due to:
        • The position of the placenta
        • Being too early or too late by your dates
      – Results are usually available in 8-10 days
  • * Advantages:
    - It can be done earlier in the pregnancy
    - It may assist in deciding about termination

    * Disadvantages:
    - The decision to have CVS is based on your risk by age alone

  • Amniocentesis
      – It is done between the 16th and 18th week
      – A sample of amniotic fluid from around the baby is obtained through a small needle in to the abdomen
      – It is not always possible due to the position of the baby or the placenta
      – Results usually range from 10-14 days

    * Advantages
    - You may have additional information available to help you make your decision
    - Detailed ultrasound is done before the amniocentesis - this can look for physical characteristics that may be a result of a chromosome abnormality

    * Disadvantages
    - It is done later than the CVS
    - This may make decision about termination more difficult for some, the decision for termination needs to be made quickly after the results

 

Risks of Procedures

  • CVS and amniocentesis each carry a 1 in 200 risk that you could have a miscarriage
  • The results of the CVS may not be representative of the baby's chromosomes (placenta mosaicism)
      – Seen in 1 in 100 cases
      – Amniocentesis could be used later to confirm the results if this were to happen

 

Consideration Prior to Testing

  • Would it be reassuring to have the information prior to the delivery?
  • Would you change the course of your pregnancy (terminate) if you learned the baby had a genetic problem?
  • Do you feel you need the information prior to delivery to prepare in advance?
  • Are you willing to accept the risk of the procedures?

 

Our Recommendations

  • Each couple must choose for themselves
  • We can assist you in arranging testing if you choose
  • We do recommend and request that you have a Level II Ultrasound at about 18-20 weeks whether you plan CVS/amniocentesis or not
  • This provides a more detailed survey of the baby's anatomy
  • It may detect some for the characteristics of a genetic problem
  • If they are detected, it may help us to plan better for delivery and managing your pregnancy

 


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