Medical experts have launched a research project aimed at helping thousands of couples avoid repeated miscarriages and pregnancy complications.
The "Baby Bio Bank" will collect blood from mothers and fathers and samples from the umbilical cord and placentas of babies. Other detailed medical history will also be considered.
Expectant couples in London will be invited to participate in the project.
The bank is designed to act as a global research resource for studies into miscarriage, growth problems in the womb, pre-eclampsia, and preterm delivery.
Professor Lesley Regan of St Mary's Hospital in London said the four pregnancy complications targeted by the bank all had a link. "I think the change in our understanding is that you don't look at them in isolation," she said.
Organisers said that research midwives would approach families at their first antenatal clinic and the data collected would be anonymous.
Currently around 250,000 UK pregnancies end in miscarriage and more than 50% of stillbirths remain unexplained.
Statistics also show that one in 13 live births in England and Wales are preterm and 25% of premature births are caused by pre-eclampsia.