Blood tests make birth dates more predictable

Trials show they are an accurate way of maternal screening

Women could soon know how far along they are in pregnancy and their risk of premature delivery by having simple blood tests, according to US researchers.


Based on foetal RNA, they say the tests can predict how much time is left in a pregnancy with about the same accuracy and lower cost than current methods.

The study authors, from Stanford University in California, previously showed that the maternal blood contains free-floating RNA molecules, each one a transcript of genes that are active in both foetus and mother, and that the types and amounts of these molecules