Antenatal Screening

What further tests will be offered if my screen test is positive?

An ultrasound scan provides the best estimate of your gestation (i.e. how advanced your pregnancy is), and ideally should be carried out before the screening test. If you obtain a screen-positive. result but have not had a scan earlier, then you should have one now.
If the result is screen-positive on account of an increased risk of Down's syndrome and the scan stimate of your gestation is within 17 days of the estimate by your 'dates' (time since the first day of your last menstrual period) then the result will remain screen positive. If the scan indicates a difference of more than 17 days from your 'dates' then the screening result will need to be re-interpreted using the scan information.
If the result is scren positive on account of a raised AFP level, suggesting an increased risk of neural tube defect, then the result will need to be re-interpreted whatever the difference is between your scan and 'dates' estimation of your gestation. If the final result is . screen-positive, you will be offered a diagnostic test. That will include an amniocentesis or 'Chorionic Villus' sampling and ultra sounds scan in detail. The diagnostic test will determine whether or not the pregnancy is actually affected.
Amniocentesis An amniocentesis is a simple and widely used procedure that usually takes only a few minutes to perform. It involves collecting a sample (about 4 teaspoons) of ,amniotic fluid from around "the baby by passing a thin needle through the abdominal wall and into the uterus. The needle will be inserted under tl;le guidance of an ultrasound scan. It does not usually involve a stay in the hospital.
The amniotic fluid contains cells from the baby that can be used to tell whether or not the baby has Down's syndrome. These cells must grow before they can be examined and so the results can take up to 3 or 4 weeks. A diagnostic test for neural tube defects can also be preformed on the amniotic fluid.
No test can guarantee that your baby will be free of all birth defects but if the result of the
amniocentesis is negative it will almost cer- 11"tainly rule out Down's syndrome or another chromosome abnormality. .
Amniocentesis is a procedure that has been Ii carried out over decades. Its safety has been carefully studied and it is estimated that 1 in 100 women who have an amniocentesis will have a miscarriage as a result ofthe procedure.
Chorionic Villus Sampling
This also is a diagnostic test for Down's syndrome. This test is offered early in pregnancy in some hospitals (about 11 weeks) but may also be offered as an alternative to amniocentesis following a screen positive result. This involves taking a sample of placental tissue, again by inserting a needle through the abdominal wall. Result is usually ready within a week. At this stage of pregnancy, the risk of misc,\rriage is thought to be the same as for amniocentesis.

Foetal Blood Sampling

A fine needle is guided by scan through the abdomen taking a blood sample from the umbilical cord. Looks for chromosome abnormalities lik Down's syndrome and other specific genetic conditions. It is carried out at 18 + weeks of pregnancy and results are available

in 2 to 4 days. The advantage that it is virtually 100% accurate and the result is available rapidly. The disadvantage is that it carries a miscarriage risk of 1 in 50.
Anencephaly and Spina Bifida
Nearly' all cases of anencephaly are detected by an ultrasound scan and over 90% of cases of spina bifida can be detected. The best detection of spina bifida is achieved by performing a detailed ultrasound scan and an amniocentesis' together, although amniocentesis carries a risk of miscarriage.

Down's Syndrome

It is not possible to make a diagnosis of Down's syndrome from an ultrasound scan. There are however, certain physical features that may be associated with Down's syndrome and that can be seen on ultrasound scan between 18 -20 weeks of pregnancy. It is thought that about half the babies with Down's syndrome will have one or more chromosomal markers present. The scan can detect This table shows at glance the main details of various diagnostic tests
Test When Miscarriage risk      Result
Early amnioentesis        14 -15 wks..    0.5 -1%           2 - 3 wks.
Routine amniocentesis   18+ wks;          0.5 - 1%          2 - 3 wks.
CVS    10 -13 wks.     1- 2%  1- 2 wks.
Fetal blood sampling     18+ wks.          2%       2

features on a baby that may be signs of Down's syndrome or other chromosomal problems. However these markers can be found even with normal babies and do not consistently appear with babies having problems. If any of these features are seen this would be a further indication for a diagnostic test but the absence of these features or a normal scan does not guarantee a normal baby or normal chromosomes.

Nuchal Translucency Scan

All babies have a'small amount of tissue fluid under the skin that can bt5 seen as a black space at the back of the babies' neck on scan. (Nuchal translucency). Nuchal translucency scans measure this gap between 10 -14 weeks. Research has shown that if there is more than the amount of fluid, the risk of chromosomal problems - like Down's syndrome or heart defects is increased.The combination of nuchal translucency, the size of the baby and the woman's 'age has been used in some hospitals in the U.K. to calculate the risk of having a Down's syndrome baby. Early results suggest that over 80% of all Down's babies can be detected by this scan.
Authorities are still con<;erned about the accuracy of the results. Small differences in the measured nuchal translucency have major affects on the calculated final risk and therefore a high quality ultrasound machine and a welltrained sonologist are essential if meaningful results are to be obtained.
If I do not have an affected pregnancy, can I still have a screen positive result?
Yes. The screening result is based on your age and the blood marker levels. You are therefore more likely to have a screen positive result if you are older, if your AFP or uE3 levels are lo and if your inhibin or BhCG levels are high. However, since the four markers also naturally vary between women, there is usually no apparent reason for women having either high or low levels and so most women with screen positive results will not have a affected pregnancy. A screen positive result only indicates who is in a higher risk group so tha.t we know who should be offered a diagnostic test.
Remember that the majority of amniocentesis results will show that the baby does not have Down's syndrome or a neural tube defect. If the baby did have one of these abnormalities, you would have the chance to discuss how your baby could be affected wherein ,.a termination of pregnancy could be offered ur if you decide to continue with the pregnancy you could discuss about special help and support to look after your baby.

Household  Hints

Before putting clothes into a drier, button them and turn them inside out. The buttons will not break.
2 Fingers scorched while holding or accidentally touching a hot vessel? Place the affected part on the ice in your freezer. There will be no blisters and no marks.

3 To ward off lizards, place egg shells in your kitchen window.
,4 To keep cockroaches away from shelves and cupboards keep a few cucumber slices
in the corners. Cucumber peels would do a better job.
4 To give a beautiful shine to .leather goods like suitcases, bags, etc., rub with a soft rug dipped in lemon juice.
S To clean copper or brass vessels or ornaments, rub thoroughly with a mixture of
vinega and salt. Rinse in water.  '
7 Soak rose petals in water and wash your face with it. It helps clear off skin blemishes. Mix in a little glycerine and use it as an effective skin lotion.