Brief Answer:
Can occur due to physiological reasons

Detailed Answer:
Thanks for asking on HealthcareMagic.

I have gone carefully through all your sister's reports. In the initial screening tests the risk of Down syndrome was found to be slightly higher. However, it needed follow up and confirmation. Renal pelvic dilatation can be found in a number of conditions including Down synrdome. The 20 week test has successfully ruled out Down syndrome or trisomy 21. Vesicoureteric reflux is another possible cause but antenatally detected renal pelvic dilatation, especially in isolation, is considered a weak predictor of vesicoureteric reflux. But most often renal pelvic dilation occurs due to physiological cause (in the course of normal functioning of the body) and resolves on its own. A repeat prenatal scan at 30-40 weeks gestation can be done in order to find out whether it has resolved or increased.

I would suggest not to worry about the pelvic dilatation.

Regards

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Brief Answer:
A screening test has a different scope than a confirmatory test

Detailed Answer:
Thanks for writing back.

1. The initial screening summates three parameters and tries to draw inference. But although it helps in screening where the emphasis is on inclusion of ALL possible cases who could test positive (but they not necessarily would). The emphasis here is not on being accurate and precise but on the fact that prospective cases should not be missed (broad).

2. The 20 week test relies on a different set of parameters and tries to be accurate rather than broad. This shows that the chances of Down to be low and you can rely on it.

I hope that I have been able to clear your doubts. Pardon me for not trying to be further explanatory because it would involve a lot of technical jargon and concepts which would require an expert training.

Regards

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Brief Answer:
A screening test positivity can be due to entirely unrelated reasons

Detailed Answer:
Thanks for your response. Rather than going into this case, let me try another scenario. Amenorrhea or lack of menstruation can be used for screening pregnancy. It can be estimated that all ladies who are pregnant will cease to have their periods. But that does not mean that the converse is true. One may cease having periods due to a number of reasons and pregnancy is just one of them. So, if the initial screen (as in case of the first test or amenorrhea) is positive, that does not mean that the variation is due to the stated cause (Downs or pregnancy). So, you need not worry if the screen shows a high likelihood but if the confirmatory one shows low likelihood.

I hope that would be able to clear your doubts. I am sure that your sister, being a medical person, already has the concepts and can ease things for you.

Regards

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