Book excerpt: Practicing specialists in pathology, laboratory medicine, and obstetrics comprehensively summarize the latest scientific findings and their experiences in the use and interpretation of laboratory testing in patients who are pregnant or experiencing recurrent pregnancy loss. Topics of interest include the effects of normal physiological changes on test results, test selection for diagnosis, changes in reference ranges, monitoring the pregnant patient, new technologies, and the limitations of laboratory testing. The authors not only clearly explain currently used test methods and technologies for the nontechnical reader, but also provide comprehensive details for laboratory professionals. The comprehensive appendix that compiles published normal reference ranges by first, second, and third trimester consttitutes an excellent resource for professionals caring for pregnant women.