<p>SAN FRANCISCO (AP) — Investigators searching for a link between the bodies of a woman and an infant boy that washed ashore separately on the Richmond waterfront may find clues in an unusual medical phenomenon called "coffin birth."</p>
<p>Coffin birth is a term used by coroners for a spontaneous birth by a dead pregnant woman.It occurs when the gas that naturally builds up in the abdomen and pelvic area of a decomposing body produces enough pressure to push the unborn baby through the birth canal and out the corpse.</p>
