/code></dt>
<dd><p>Matched set number.
</p></dd>
<dt><code class="code">pooled_stratum</code></dt>
<dd><p>Stratum number.
</p></dd>
</dl>

<h4 class="subsubheading" id="Note"><span>Note<a class="copiable-link" href="#Note"> &para;</a></span></h4>

<p>One case with two prior spontaneous abortions and two prior induced abortions is omitted.
</p>
<h4 class="subsubheading" id="Source-29"><span>Source<a class="copiable-link" href="#Source-29"> &para;</a></span></h4>

<p>Trichopoulos et al (1976). <cite class="ci