prenatal down's screening test

my age is 28 yrs and i am 16 weeks pregnant. primi, my blood group is b-ve and my husband is b+ve,one of my husbands uncle suffers from down's syndrome. my ultrasound at 11 weeks for nasal bone and nucal translucency was normal. However my triple marker at 14 weeks 3 days was Hcg- 78206, UE3 -2.27 and AFP- 14.98 Age related risk was-1:882, trisomy 21 screening risk is-1:332, Trisomy 18 Screening risk is 1:10,000, Neural tube defects screening is 1:4245. does my child suffer from risk of down's? if yes, what can i do further? Please advice taking into consideration my blood type as amniocentesis can be fairly risky for me.Please help i am in a big fix.....

[eureka254]

Although down syndrome is a genetic condition, because your husband's uncle is affected does not necessarily mean that your baby is at increased risk for down syndrome. Down syndrome is more often the result of spontaneous mutation and less often passed down through family inheritance.  The triple marker can be a useful screening tool, but generally it is drawn after 15 weeks GA (gestational age) for best accuracy, and even then, it is only estimated to have a 60-70% sensitivity.  Keep in mind that blood screening, even those with more sensitivity than the triple marker, will not diagnose the presence or absence of down syndrome, only give you risk percentages.  (In your case, your triple marker is estimating the possibility of your baby having down syndrome at about 1/3 of 1% chance.)  

Only you (with your doctor) can decide what is best for you.  Amniocentesis does carry risks, but it will give you a definite answer if you need one. Perhaps you and your husband need to discuss the question of raising a child with down syndrome and weigh the risks and benefits of the amnio procedure, and whether or not it would be worthwhile and beneficial for you to obtain chromosome information at this point in your pregnancy.  

Best wishes to you,
~eureka