预产期计算
UpBox优盒工具箱，免费在线预产期计算：输入末次月经首日与月经周期，按内格勒法则算出预产期、当前孕周与孕期阶段，并列出孕早期结束、进入足月等关键节点。
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日期与周期Dates
已换算
按内格勒法则算：末次月经首日加 280 天，周期不是 28 天时按差值前后调整；这只是按日期的估算，实际以超声与医生判断为准，本页不构成医疗建议
预产期与孕周Due date
预产期Due date
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当前孕周Gestation
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关键节点
孕周从末次月经首日算起，与临床上常用的算法一致；37 周起算足月，40 周为预产期，前后两周内出生都属正常范围
本工具所有运算在本地浏览器完成，你的文件、文本不会上传到服务器
工具介绍
产检单上写着「孕 12 周 + 3 天」，自己却算不清是从哪天开始数的；预产期也是医生说一个日期，回头就记不全。 A checkup note saying twelve weeks and three days is hard to square with your own calendar, and the due date a clinician mentions tends to slip your memory.
这里按末次月经首日与周期长度推算，预产期、当前孕周、所处孕期和后面几个节点一次列齐。 Enter the first day of the last period and the cycle length, and the due date, current gestation, trimester and later milestones come out together.
- 周期修正Cycle adjustment
- 孕周换算Gestation
- 阶段判定Trimester
- 节点清单Milestones
使用说明
- 填末次月经首日。Enter the last period date.
- 填周期长度。Set the cycle length.
- 填参考日期。Set the reference date.
- 读预产期与孕周。Read due date and gestation.
常见问题
为什么周期不是 28 天要调整？Why adjust for a cycle other than 28?
排卵日随周期长度前后移动，28 天按加 280 天算，周期每多一天预产期也顺延一天。Ovulation shifts with cycle length, so 280 days applies to a 28-day cycle and each extra day pushes the due date one day later.
这个结果能直接当诊断吗？Can this result be treated as a diagnosis?
不能，早孕期的超声测值通常比日期推算更准，最终以医生判断为准。No, an early ultrasound measurement is generally more reliable than date arithmetic, and a clinician makes the call.
孕周为什么从末次月经算而不管受孕日？Why count from the last period rather than conception?
受孕日往往说不准，临床上统一从末次月经首日计，比实际受孕时间约多两周。Conception dates are uncertain, so clinical practice counts from the last period, about two weeks before conception.
过了预产期还没生怎么办？What if the due date passes?
前后两周内都属常见范围，超过 41 周请按医生安排监护，本页只做日期估算。Two weeks either way is common, and beyond 41 weeks follow your clinician for monitoring; this page only does date arithmetic.