Fertility and Natural Law

My wife and I have discussed this issue several times over the past few years. Is it "good", "right", "smart", or "moral", to conceive a child through artificial means? www.nytimes.com.../05/11/health/11FERT.html?th" target="_blank" class="postlink" rel="nofollow">www.nytimes.com...://www.nytimes.com/2004/05/11/health/11FERT.html?th/05/11/health/11FERT.html?th
Does forcing fertility weaken the gene pool? Are children born of artificial means more susceptible to disease, birth defect, and genetic anomilies? Aren't the excessive means used to conceive an example of the arrogance of humanity trying to shape the world befitting our own skewed perspective? Where does human desire supercede Natural Law?