求翻译：现货尿液和肝素化全血标本采集当天，他们参观了生育健康检查医院在上午30-32孕周时，被保存在-20 ° C冻结，直到分析。是什么意思？

Spot urine and whole blood specimen collection of heparin on that day, they visited the hospital in reproductive health check 30-32 weeks of gestation, is kept frozen at-20 ° c until analysis.