The Multiple Marker Test – Why Pregnant Women Need One?

In the time periods from the fifteenth to the twentieth weeks of gestation, pregnant women are normally recommended to undergo a blood analysis testing known as the multiple marker test. It is occasionally known as the triple or quad screen test depending on the kind of measurement being intended.

Why is it is carried out?

• This blood test is conducted for measuring placental production of the amounts of hCG or human chorionic gonadotropin, estriol and at times inhibin-A. The amount of AFP or alpha-fetoprotein production by the foetus is also checked. By checking these levels, the doctors are able to detect whether the unborn child is at any risk of developing particular congenital anomalies inclusive of neural tube flaws (e.g. spina bifida) and chromosomal anomalies such as Down’s syndrome.
• For ascertaining the outcome of the tests, the following factors of the pregnant woman are taken into consideration, namely:
  • Age, body weight and race.
  • In case diabetic or not.
  • Whether the women is having multiple pregnancies.
  • The gestational age of the unborn child.

Majority of the above mentioned factors are observed to affect the amounts of substances being produced by the foetus and the placenta, the measurement and analysis of which are vital for the test outcomes, hence preciseness of this data is crucial. In case any of the above data are imprecise, then the outcomes too could be incorrect.

Irregular Outcomes:

In case irregular outcomes of the multiple marker test are found, there are bound to be apprehensions. However, one need not get worried as simply an anomalous outcome does not necessarily translate to the fact that one is going to give birth to a child with a congenital anomaly. Instead an anomalous outcome is suggestive of the fact that foetus requires additional evaluation.

Generally, when elevated AFP levels are found in the test outcome, it is suggestive of a probable likelihood of spina bifida or other kinds of neural tube anomalies then a comprehensive ultrasound scan would be suggested for foetal examination inclusive of fetal skull and spine. Additionally, an ultrasound examination could corroborate the foetal age and if multiple pregnancies are likely.

The doctor could additionally suggest undergoing an amniocentesis test wherein the amniotic fluid is drawn from the uterus for additional testing.

Down’s syndrome is indicated in case the test outcome show depleted AFP and estriol levels and elevated hCG and inhibin-A levels. The subsequent step is generally to undergo an ultrasound scan for confirming the foetal due date and for spotting any apparent anomalies. Regrettably, ultrasound is not quite accurate in diagnosing Down’s syndrome. Hence, women are suggested to undergo amniocentesis to carry out test on the fetal cells present in the amniotic fluid.

One must bear in mind, that the multiple marker test is merely a screening procedure that could detect numerous foetuses that are likely to develop particular congenital anomalies though would not detect all of them. An affirmative outcome is not essentially an indicator of a congenital anomaly but rather a requirement for additional assessment.