Hyperechogenic bowel diagnosed in the 31. week of gestation

Question

Dear expert team,

I am mother of a child suffering from CF. After 12 years I am pregnant again (however in my second marriage, that means the father of the child is not the father of my child with CF). Unfortunately, at the 3rd detailed preventive chek-up a hyperechognic bowel with dilated intestinal loops has now been diagnosed. Down's syndrome has been nearly completely excluded at two Degum II investigations [translators comment: type Degum II is a German qualification standard for ultrasound investigations]. How high is the statistic probability to get a child suffering from CF with a new partner and a heterozygous mother?

Answer

Dear questioner,

the frequency of carriers of an illness-causing mutation in the CF-gene is estimated to be "1 in 20" in the German population. Provided that your second husband belongs to this ethnic group, the probability that he carries a CF-causing mutation is 1/20. Only, if this would be the case - thus your second husband is carrying for instance such a CF-causing mutation - the possibility exists, that your unborn child may suffer from CF (the probability of a CF-child in this case, when both parents are carriers, is "1 in 4", thus 1/4, as CF is a so-called recessive disease).

In case your husband would be one of the statistically seen "19 of 20" persons, who cannot give a CF-mutation to their offspring, your unborn child does not suffer from CF in any case.
These are numbers which do not help you further in the concrete situation - please address to your gynaecologist, who cares for the pregnancy, in order to discuss which kind of approach makes sense here now. To perform a genetic test for CF-mutations to your second husband is, for example, quickly possible- today it is possible to detect most of (unfortunately not all) the CF-causing mutations. Dependent on the clinical picture a specialist for human genetics and your gynecologist will agree on the ongoing diagnostic procedure.

Best regards,
Frauke Stanke

22.01.2013