Integrated Prenatal Screening (IPS)
What is IPS?
Integrated prenatal screening is an optional genetic screen that is offered to all pregnant
women. It screens for three genetic conditions: trisomy 21 (Down syndrome), trisomy 18
(Edward’s syndrome) and open neural tube defects. IPS is not a diagnostic test. This
means that the screen doesn’t tell you if your baby has one of these three conditions.
What the screen will tell you is if your baby has an increased CHANCE of having Down
syndrome, Edward’s syndrome, or an open neural tube defect. Further diagnostic testing
is available for women whose screen results are positive. IPS cannot identify every birth
defect; it only detects which babies are at a higher risk of having the three conditions
mentioned above.
What is Trisomy 21 (Down Syndrome)?
Down syndrome usually involves mild to moderate intellectual delay and greater risk of
certain health conditions or defects involving the heart, stomach, bowel, thyroid, vision,
and ears/hearing. There is no way to determine prenatally how severe the disability will
be. Individuals with Down syndrome usually live into their fifties. The incidence of Down
syndrome is 1/1000 births and the risk of having a baby with Down syndrome increases
with maternal age.
What is Trisomy 18 (Edward’s Syndrome)?
Infants with trisomy 18 have mental and physical disabilities. The majority of babies who
have trisomy 18 will miscarry or be stillborn. Babies born with trisomy 18 usually do not
live past the first few months of life. The incidence of trisomy 18 is 1/6000 births and the
risk of having a baby with trisomy 18 increases with maternal age.
What Are Open Neural Tube Defects?
Open neural tube defects occur when the spinal cord or brain does not develop properly.
When the open neural tube defect involves the spinal cord the condition is called spina
bifida. Spina bifida can cause mental as well as physical disabilities such as difficulty
walking and controlling the bladder and bowels. Treatment can help many of these
disabilities. When the open neural tube defect involves the brain it is called anencephaly.
Babies with anencephaly will be born stillborn or will die shortly after birth. The incidence
of open neural tube defect is 1/2000 births.
What Does Integrated Prenatal Screening Involve?
Integrated prenatal screening involves an early ultrasound between 11 and 14 weeks of
pregnancy. The ultrasound measures a fluid filled pocket at the back of the baby’s neck
called the nuchal fold. When the measurement is larger than expected the chance of the
baby having Down syndrome is increased.
The screen also involves two sets of blood work: one done with the ultrasound, and the
second done between 15 and 20 weeks of pregnancy (but ideally between 15 and 16
weeks for the earliest possible result). The blood work looks at levels of certain proteins
that are present in all pregnant women’s blood.
What Does A Screen Positive Result Mean?
Approximately 24% of women will have a positive screen for IPS which means that they
are at higher risk for having a baby with Down syndrome, trisomy 18 and open neural
tube defects. The majority of people with a positive screen will have a healthy baby. Out
of 100 pregnancies with Down syndrome IPS will detect 8590 and will miss 1015 babies
with Down syndrome. The results for IPS are not guaranteed due to the fact that 10% of
affected babies will screen negative (false negative result).
What Are The Options For Diagnostic Testing
If A Screen Comes Back Positive?
The diagnostic test available for Down syndrome and trisomy 18 is called amniocentesis.
This test can detect major chromosome abnormalities and may be offered if the IPS
screen is positive. In some cases amniocentesis can also diagnose a baby who has an
open neural tube defect. Amniocentesis involves a fine needle being placed through the
abdominal wall and into the uterus to extract approximately 15 mL of amniotic fluid.
Ultrasound is used as a guide so that the needle is not placed through the placenta or
near the baby.
There are some risks to amniocentesis. One risk of amniocentesis is miscarriage. The
risk of miscarriage for amniocentesis is 1/200. The procedure may also cause cramping
that usually settles within 12 hours. There is a small risk of injury to the baby or infection,
however these complications are rare. In rare circumstances, repeat testing may be
needed if a sufficient amount of amniotic fluid is not obtained.
Diagnostic testing for open neural tube defects involves a detailed ultrasound of the
infant’s spine and in some cases may involve amniocentesis. The detailed ultrasound can
detect the seriousness of the neural tube defect and whether other complications are
present.
Things To Consider When Deciding If IPS Is Right For You:
● Are you interested in knowing the chance of your baby having one of the conditions
mentioned above?
● If you have a positive IPS screen will you continue to have further diagnostic testing?
● How will the information that IPS or diagnostic testing provides affect your feelings about
the pregnancy?
● What will you do with the information provided to you?
Some women do not want to know the information and choose not to do IPS; some
women would like to know the information in order to be prepared for a baby with a
genetic condition, and some women would like to know because they would choose to
terminate the pregnancy if their baby had a genetic condition.
When you are making your appointment for IPS please inform the ultrasound clinic that
you are going for an “NT” or “IPS” ultrasound. This ultrasound requires a technician with
special training to measure a small fold in the baby’s neck.
The Following Are Ultrasound Labs That Do This Measurement:
Lakeridge Health Oshawa Hospital
Taunton Ultrasound - 1290 Keith Ross Crt Oshawa Ultrasound - 11 Gibb St Whitby Medical - Whitby Mall (Thickson Rd) North Whitby Ultrasound - 5959 Anderson St Dundas Center - 220 Dundas St W Courtice Imaging - 1450 Hwy #2 Durham Radiology - 222 King St E (Bowmanville) Bowmanville Hospital Pickering Ultrasound - 1450 Kingston Rd (Ajax) Port Perry Imaging - 462 Paxton St Dr Peter Maskins 205849 Alexander (Peterborough) RDS Diagnostics - 5400 Young St Suite 300 Glenhurst Ultrasound - 700 Bay St suite 1801 |
- 905-721-4717
- 905-721-7702 - 905-516-0200 - 905-576-9729 - 905-655-8313 - 905-430-1781 - 905-721-4932 - 905-623-4512 - 905-623-3331(7009) - 905-831-2255 - 905-985-9727 - 705-741-5510 - 416-225-0431 - 416-225-0431 |