福州地区8463例正常分娩新生儿实际出生日期与预产期差异的研究

A Study on the Expected Date of Confinement for 8463 Newborn Babies in Fuzhou Area

目的：研究福州地区新生儿实际出生日期与预产期差异（“预产日差”DBED）的基本规律，以及与传统预产期计算公式的异同点。方法：作者收集福州地区一家大型综合性医院1982～1995年单胎活产、非早产、无并发症、非手术产的正常分娩8463例新生儿登记资料，以SPSSforWindows（V7.5）软件包进行统计分析。结果：发现总平均预产期比传统算法提早近1.5日（1.47日）;各年份、月份、性别、城乡、常见胎产次、常见胎位（枕）和各周日多有此趋势。结论：建议“以末次月经的月份加9（或减3）、日数加5或6”作为预产期，可比传统的章法更准确1.5日。

OBJECTIVE To study on a new calculation method of newborn baby's expected date of confinement (EDC), reporting the difference between birth and expected date (DBED). METHODS The SPSS for Windows (V7. 5) Package was used for processing the database of registered item for 8463 babies in Fuzhou area. RESULTS (1 ) The mean DBED is about 1. 5 days (1. 47 days) earlier than traditional calculation method, that is, last menstrual period (LMP) adds 9 months (or subtracts 3 months when the month sum is bigger than 12 months) and adds 7 days. (2) There are the same DBED trend mentioned above for different year, sex, area, order of fetal, position of fetal, the mother's age and weekdays. (3) It has been found by our analysis that a new EDC calculation method is more accurate than traditional calculation method of EDC. CONCLUSION The new calculation method, 'LMP adds 9 monthsll (or 'subtracts 3n months) and 'adds 5 days' (traditionally 'adds 7 days' ), will be more accurate.