dd><p>identification number</p>
</dd>
<dt><code>plurality</code></dt><dd><p>all &quot;single fetus&quot; in this data set</p>
</dd>
<dt><code>outcome</code></dt><dd><p>all &quot;live birth&quot; (survived at least 28 days) in this data set</p>
</dd>
<dt><code>date</code></dt><dd><p>birth date where 1096=January 1, 1961</p>
</dd>
<dt><code>gestation</code></dt><dd><p>length of gestation (in days)</p>
</dd>
<dt><code>wt</code></dt><dd><p>birth weight (in ounces)</p>
</dd>
<dt><code>parity</code></dt><dd><p>to