Older Mothers and prenatal testing

[HotI]

Hi

I found a reference table that was published in JAMA in 1983. I am not sure if the figures have been revised since then, but here they are:

Mother age - frequency of DS fetus/non-DS fetus at 16 weeks - frequency of live births with DS/non-DS

35years - 1/250 - 1/75

37years - 1/150 - 1/225

40 years - 1/75 - 1/100

41 years - 1/60 - 1/85

42 years - 1/45 - 1/65

43 years - 1/35 - 1/50

44 years - 1/30 - 1/40

45 years plus - 1/20 - 1/25


1st column =maternal age (i think at birth)
2nd Column = frequency of DS fetus/non-DS fetus at 16 weeks
3rd Column = frequency of live births with DS/non-DS


The first figure is based at 16 weeks of gestation (time of amnio). The difference between the two figures is due to the increased spontaneous abortion with Down Syndrome pregnancies.