Are You at Risk of Giving Birth to A Baby with Chromosomal Abnormalities?


About 3-5% of babies are born with congenital disabilities or genetic conditions. During pregnancies, some women choose to undergo various tests to determine which pregnancies are at higher risks for these types of problems. The OC Fertility website offers information on genetic screening in Newport Beach to help you decide management options.

What are chromosomes?

Most human body cells have a nucleus (chromosomes) where genetic material (DNA) is stored. Each chromosome contains many genes responsible for all inherited traits, such as eye color or height. Typically, each cell has a total of 46 chromosomes arranged in 23 pairs. Half of the chromosomes, one from each pair, are maternally inherited, and the other half is from your father. The numbering of the first 22 pairs is from one through twenty-two, and the twenty-third pair contains the X and Y chromosomes, which determine whether someone is male or female. Typically, females are XX and men XY.

Chromosomal abnormalities

When a person’s body makes eggs or sperm, their chromosomes need sorting so that each egg or sperm will receive one chromosome from each of the person’s pairs for a total of 23 chromosomes in each egg and sperm. An abnormality can occur during fertilization resulting in an extra or missing chromosome in the baby. A missing chromosome is called a monosomy, and an extra chromosome is called a trisomy.  When there is a trisomy or monosomy, the additional or missing genes can change how an individual develops and can cause various health problems. Most trisomies and monosomies lead to miscarriage.

Age-related chance

The chance for a chromosomal abnormality to occur increases with age. Even though older women have a higher risk of babies with abnormalities, they can happen to women of all ages. Many women feel like they would like to know during the pregnancy if their babies have one of these conditions. The choice to test for abnormalities is entirely personal. Upon detection of anomalies, your doctor will carefully discuss the available management options, for example, educating you on how to care for a child with special needs and planning an adoption or termination of the pregnancy.

Different genetic screening tests

Screening tests can estimate the chance for a baby to be affected with the most common chromosome abnormalities. These tests pose no risk to the pregnancy but are not entirely accurate. One of the screening tests available at OC Fertility is:

Comprehensive Chromosome Screening (CCS)

The timeline for this procedure is:

  • Day 0: Eggs and sperm are collected.
  • Day 1: Intracytoplasmic sperm injection fertilizes each mature egg
  • Day 2-5: The embryo continues to grow as the cells divide.
  • Day 5-7: Not all embryos will reach the blastocyst stage. Your doctor will perform a biopsy to remove some cells from the trophectoderm and blastocyst.
  • Day 8-21: This test involves analyzing the cells from the embryo biopsy for abnormalities, and after reviewing your results, your doctor will schedule an embryo transfer.

For more information about comprehensive chromosome screening and how it could increase your chances of a successful pregnancy, please contact OC Fertility to book an appointment today.