Maternal Serum Testing

I had the maternal serum blood testing done a few weeks ago and got my results, which are low risk, but i just wondered if anyone else has had this testing done, its not something that people seem to know much about, but just wondered what other peoples results were like? I have been told that the results are 80% accurate vs the nuchal which is only 40% if thats the case why don't they tell more people about the maternal serum testing?

i did a google search and found this info out:

The blood test will give you an estimate of the chances (known as a risk estimate) of a chromosome abnormality or neural tube defect in your baby. The risk estimate will be given to you in one of four ways. You will be told there either is an "increased risk" or a "low risk" of a chromosome abnormality; and you will be told there is either an "increased risk" or low risk" of a neural tube defect.


Low Risk Result
......................................................

More often than not the blood test will give you a "low risk" estimate. Your chances of having a baby with a chromosome abnormality or neural tube defect are low. These problems, or any other congenital abnormalities, could still happen, even though the blood test showed you had a "low risk".





so from what i can gather the maternal serum blood test may tell if YOU are at risk or not of having a baby with abnormalities but the nuchal fold test actually looks at the baby and gives a risk assessment based on the thickness of the nuchal fold of the BABY.

i would assume that mothers who have incidences of abnormalities in their families may be offered the maternal serum blood tests as opposed to joe blow public.

I was going to say its probably a cost thing too Tiff.

if i was offered it i would have done it..so maybe the secret is being offered it at least ? as i said i asked 9 pregnant women today and none had been offered it:(

Yeah I think it should be offered too but I think the cost thing isn't just the cost to us but to the goverment too (?).

This from our resident obstetrician Dr Anil Sharma:
Maternal Serum Screening

"This test is done at 15-17 weeks and is a screening test for chromosomal abnormalities such as Down syndrome. The test measures the levels of 3 chemical substances in the pregnant woman’s blood (which in turn are due to the baby and are influenced by the possibility of the baby having a problem). A risk is then estimated, also using information based on a woman's age, weight, race, and how far along her pregnancy is. Again, depending on the risk that is worked out, your next decision would be whether to have diagnostic testing, such as amniocentesis."

Maternal serum screening is usually carried out later in pregnancy than the NT scan which is performed between 11-13 weeks. If the NT scan comes back higher risk then I guess you could elect to have the maternal serum screening done before electing to have an amnio or CVS.

That said, there are a lot of factors which can affect the accuracy of maternal serum screening, for example it can't be used in twin/higher order multiple pregnancies as the hormone levels in the mothers blood are skewed and therefore affects the results.

So from a general perspective, for women with a statistically low chance of defects (no family history/age factors etc.) the NT scan is perfectly sufficient as a screening test and most couples prefer it to the maternal serum test as it can be done sooner, and it gives them a chance to see their unborn baby on ultrasound.

I think this test is usually only recommended (in NZ) if there are certain risk factors, e.g. age?

kawwww wrote: Maya.. do you know why all the American's have a blood test..they go on and on at me how it's not accurate without the blood test..but no-one here has one..?

The American view of pregnancy and childbirth tends towards the medical intervention side of things, this extends from antenatal testing right thru to a high rate of intervention during labour/delivery and a higher rate of c/s. The vast majority of American women have their pregnancies overseen by an obstetrician, and in many states midwifery as it is practised in NZ is illegal, and midwives are restricted to providing antenatal and postnatal care alongside obstetricians, and do not perform deliveries.

In NZ, we tend to take the view that pregnancy is an extension of the normal state, and as such interventions should be as minimal as possible unless clinically indicated, which is why the majority of NZ women choose a midwife to oversee their pregnancy and birth. Unless there are complications during either pregnancy or delivery there will be no contact with an OB at all. Midwives tend to have a more conservative view of antenatal testing, in many areas women who are considered low-risk (due to age, family history etc) aren't even routinely offered the NT scan. If you ask for any sort of antenatal testing, whether it be u/s, maternal serum screening etc. your midwife will refer you on, but she will probably not suggest such testing unless asked or unless your family history warrants it. If you choose an OB as your LMC you will probably be offered the maternal serum screening routinely, partly because OB's traditionally take a more medical approach to pregnancy than midwives, and partly because obstetricians tend to work with women who are higher risk rather than those expected to have a normal pregnancy and birth.

Hope this helps!