追加：第 27 节第 19、20 条，孕晚期侧着入睡；产后避孕与下一胎间隔

2026-10-14。主任务给的两个候选，都追加在第 27 节末尾，没有插在中间。加完本节从 18 条到 20 条，按规则补了节首导览，第 19 条挂「孕前和孕期自己能做的」，第 20 条挂「生完以后」。

查重与四问

  • 全书 grep「仰睡、侧睡、侧卧、仰卧、死产、死胎」：没有讲孕妇睡姿的条目。第 20 节第 1 条讲的是婴儿仰睡，对象不同。
  • 全书 grep「避孕、生育间隔、哺乳期」：第 13 节第 42 条讲的是被性侵后的紧急避孕，不是同一件事。本节第 16 条（产后 42 天复查）备注末尾只有一句「避孕方案也在这次谈：产后不来月经，不等于不会怀孕」，没有动作细节和数字。
  • 第 20 条为什么新开而不并进第 16 条：第 16 条的动作是「去做 42 天复查」，第 20 条的动作是「同房就避孕、下一胎隔开」，动作不同。而且「喂奶就不会怀」流传很广，值得在标题里出现；并进第 16 条备注只能留在最不显眼的位置。两条互相指路：第 20 条备注指向第 16 条（产后 42 天那次复查）。第 16 条备注本来就提了避孕，没有再改它。
  • 四问：两条都是孕产妇普遍会碰上的；读者普遍不知道（仰睡和死胎的关联是 2010 年代才有的研究，「喂奶不会怀孕」是常见误解）；动作是新的；有原始来源。

第 19 条：孕 28 周以后侧着入睡

1. Cronin RS, et al. (2019). EClinicalMedicine 10:49-57. doi:10.1016/j.eclinm.2019.03.014（PMC6543252）

  • Europe PMC 摘要与全文 XML，2026-10-14 取到。
  • 「Six case-control studies were identified, with data obtained from five (cases, n = 851; controls, n = 2257).」
  • 「Supine going-to-sleep position was associated with increased odds of late stillbirth (adjusted odds ratio [aOR] 2.63, 95% CI 1.72-4.04, p < 0.0001) compared with left side. Right side had similar odds to left (aOR 1.04, 95% CI 0.83-1.31, p = 0.75).」
  • 「There were no significant interactions between supine going-to-sleep position and assessed indicators of fetal vulnerability, including small-for-gestational-age infants (p = 0.32), maternal obesity (p = 0.08), and smoking (p = 0.86). The population attributable risk for supine going-to-sleep position was 5.8% (3.2-9.2).」
  • 「This finding could reduce late stillbirth by 5.8% if every pregnant woman ≥ 28 weeks' gestation settled to sleep on her side.」
  • 五项研究的地点（全文表 1）：Auckland, New Zealand；Sydney, Australia；New Zealand；United Kingdom；STARS 为 International，「Online survey」。条目写成「四项在新西兰、澳大利亚、英国，一项是网上的国际调查」。
  • 作者自述局限：「the exposure data and data about a number of prespecified confounders were collected retrospectively in the included case–control studies and subject to potential recall bias」；「there were no randomised trials or eligible prospective cohort studies identified for this IPD」。
  • 基线：「Differences in the rates of late stillbirth between high-income countries [1] ranging from 1.3–8.8/1000 births」。

2. Silver RM, et al. (2019). Obstet Gynecol 134(4):667-676. doi:10.1097/AOG.0000000000003458（反方）

  • Europe PMC 摘要。卷期页码经 Crossref 核对。
  • 「A total of 8,706 (of 10,038) women had data from at least one sleep questionnaire and for pregnancy outcomes」，研究对象为「nulliparous women with singleton gestations」（条目写「头胎孕妇」）。
  • 「There was no association between reported non-left lateral or supine sleep during the last week of the first visit (adjusted odds ratio [aOR] 1.00 [95% CI 0.89-1.14]) or third visit (aOR 0.99 [95% CI 0.89-1.11] and the composite or any individual outcome, except for an apparent protective effect for stillbirth at the third visit (aOR 0.27 (95% CI 0.09-0.75).」
  • 「Going to sleep in the supine or right lateral position, as self-reported before the development of pregnancy outcome and objectively assessed through 30 weeks of gestation, was not associated with an increased risk of stillbirth, a small-for-gestational-age newborn, or gestational hypertensive disorders.」
  • 条目只写「它只看到孕 30 周，后面几周的睡姿没有记录」，这是标题和结论里写明的范围。McCowan 等人 2020 年给这篇写的批评信没取到全文，批评的具体内容没写。

3. NHS. Stillbirth. https://www.nhs.uk/conditions/stillbirth/（Page last reviewed: 24 April 2024）

  • 「not going to sleep on your back after 28 weeks – don't worry if you wake up on your back, just turn onto your side before you go back to sleep」
  • 子页 https://www.nhs.uk/conditions/stillbirth/prevention/ 也有「going to sleep on your side, not on your back」，没另引。
  • RCOG 指南原文没去取，NHS 已能逐字核对同一建议。

等级与量级

  • 证据 B、争议：全部数字来自病例对照研究、靠事后回忆，唯一一项提前记录睡姿的大型研究只看到孕 30 周、结果为无关联。
  • 收益「大」：死亡率口径按相对变化机械套，aOR 2.63 远超 20% 的门槛。绝对风险很小（晚期死胎每 1000 次分娩 1.3 到 8.8 例，人群归因 5.8%），备注已写明。没有改成「中」，是因为全书量级只按相对降幅套，证据可信度另由证据等级管。
  • 成本：不花钱、改姿势要点毅力，毅力=些。

第 20 条：产后避孕与下一胎间隔

4. NHS. Sex and contraception after birth. https://www.nhs.uk/baby/support-and-services/sex-and-contraception-after-birth/（Media last reviewed: 2 February 2026）

  • 「You can get pregnant 3 weeks after the birth of a baby, including if you're breastfeeding and your periods haven't started again. You need to use contraception every time you have sex after giving birth unless you want to get pregnant again.」
  • 「It's usually recommended that you wait at least 12 months after giving birth before becoming pregnant again.」
  • 「You can start these types of contraception straight after the birth, including if you're breastfeeding: contraceptive implant contraceptive injection progestogen-only pill condoms female (internal) condoms IUD (coil) or IUS (hormonal coil)」；「If you're breastfeeding, you'll usually be advised to wait until at least 6 weeks after the birth before starting the combined pill, ring or patch.」
  • 「You're unlikely to have any periods if you breastfeed exclusively (give your baby breast milk only) and your baby is under 6 months old. ... This is known as the lactational amenorrhoea method, or LAM.」
  • 「It's important to start using another form of contraception if: your baby is more than 6 months old you give them anything else apart from breast milk, such as a dummy, formula or solid foods your periods start again (even light spotting counts) you stop night feeding you start to breastfeed less often there are longer intervals between feeds」

5. NHS. Natural family planning. https://www.nhs.uk/contraception/methods-of-contraception/natural-family-planning/

  • 「If you are breastfeeding and follow lactational amenorrhea method correctly all the time, it is more than 99% effective at preventing pregnancy. If you do not follow the instructions exactly, it's 98% effective and 2 in 100 women will get pregnant again within 6 months of giving birth.」

6. Conde-Agudelo A, et al. (2006). JAMA 295(15):1809. doi:10.1001/jama.295.15.1809

  • Europe PMC 摘要。
  • 「Included studies were cohort, cross-sectional, and case-control studies with results adjusted for at least maternal age and socioeconomic status ... Of 130 articles identified in the search, 67 (52%) were included.」
  • 「Compared with interpregnancy intervals of 18 to 23 months, interpregnancy intervals shorter than 6 months were associated with increased risks of preterm birth, low birth weight, and small for gestational age (pooled adjusted odds ratios [95% confidence intervals]: 1.40 [1.24-1.58], 1.61 [1.39-1.86], and 1.26 [1.18-1.33], respectively). Intervals of 6 to 17 months and longer than 59 months were also associated with a significantly greater risk for the 3 adverse perinatal outcomes.」
  • 结束页码 Crossref 只给了起始页 1809，来源栏只写起始页。

7. Schummers L, et al. (2018). JAMA Intern Med 178(12):1661. doi:10.1001/jamainternmed.2018.4696

  • 主任务提示里把它列为反方，读摘要后发现它是支持方：结论是「short interpregnancy intervals are associated with increased risks for adverse pregnancy outcomes for women of all ages」。条目把它放在收益栏，反方换成 Ball 2014（见下）。
  • 「Among 148 544 pregnancies, maternal mortality or severe morbidity risks were increased at 6-month compared with 18-month interpregnancy intervals for women aged 35 years or older (0.62% at 6 months vs 0.26% at 18 months; aRR, 2.39; 95% CI, 2.03-2.80), but not for women aged 20 to 34 years (0.23% at 6 months vs 0.25% at 18 months; aRR, 0.92; 95% CI, 0.83-1.02).」
  • 「Increased adverse fetal and infant outcome risks were more pronounced for women aged 20 to 34 years (2.0% at 6 months vs 1.4% at 18 months; aRR, 1.42; 95% CI, 1.36-1.47)」；这个合并结局的定义是「stillbirth, infant death, <third birthweight percentile for gestational age and sex, delivery <28 weeks」，条目写成「死胎、夭折、极小或极早产合计」。
  • 研究地点 British Columbia, Canada。

8. World Health Organization (2007). Report of a WHO Technical Consultation on Birth Spacing, Geneva, 13–15 June 2005（WHO/RHR/07.1）

  • 页面 https://www.who.int/publications/i/item/WHO-RHR-07.1，PDF https://iris.who.int/server/api/core/bitstreams/58173bae-0761-4d56-aebf-1e959f88da1d/content，pdftotext 取到英文全文。
  • 「After a live birth, the recommended interval before attempting the next pregnancy is at least 24 months in order to reduce the risk of adverse maternal, perinatal and infant outcomes.」
  • 「After a miscarriage or induced abortion, the recommended minimum interval to next pregnancy is at least six months in order to reduce risks of adverse maternal and perinatal outcomes.」
  • 「the participants fell into two groups: those who considered that the evidence indicated that the most suitable recommended interval was 18 months, and those who considered that the evidence supported a recommended interval of 27 months. Participants were, however, unanimous in agreeing that birth-to-pregnancy intervals shorter than 18 months should be avoided.」；「At the meeting, a compromise was reached between the two groups」。
  • 标题里的「至少隔 18 个月」取的是与会专家一致同意的这条下限，不是 24 个月的妥协值。

9. Ball SJ, et al. (2014). BMJ 349:g4333. doi:10.1136/bmj.g4333（反方）

  • Europe PMC 摘要。地点 Perth, Western Australia，「40 441 mothers who each delivered three liveborn singleton neonates」，「matching two intervals per mother so each mother acts as her own control」。
  • 「The traditional unmatched design estimated an adjusted odds ratio for an interpregnancy interval of 0-5 months (relative to the reference category of 18-23 months) of 1.41 (95% confidence interval 1.31 to 1.51) for preterm birth ... In comparison, the matched design showed a much weaker effect of short interpregnancy interval on preterm birth (odds ratio 1.07, 0.86 to 1.34) and low birth weight (1.03, 0.79 to 1.34)」
  • 「This study questions the causal effect of short interpregnancy intervals on adverse birth outcomes and points to the possibility of unmeasured or inadequately specified maternal factors in previous studies.」

等级与量级

  • 证据 B、争议：全是跟踪记录的研究，没有随机分组；用同一位母亲自己比的研究看不出短间隔的害处；各机构建议的间隔从 12 个月到 24 个月不等。「喂奶不等于避孕」这部分没有争议，来自 NHS。
  • 收益「中」凭判断：按阈值机械套，早产 OR 1.40 已过 20%，应是「大」。没这么定，因为 Ball 2014 用母亲自身对照后，早产和低出生体重都缩到看不出差别；Schummers 2018 里母亲死亡或重病的升高只出在 35 岁以上。效应有多少是间隔本身造成的说不准，所以降一档。
  • 成本：避孕套几十元，钱=少；毅力=些（每次都要用）。人群=怀孕（规范里怀孕含产后一年）。
  • 没找到国内官方的产后避孕或生育间隔文件（gov.cn 政策库按标题搜「产后避孕」「避孕节育」「哺乳期避孕」无结果），所以全用 NHS 和 WHO。

节首导览

本节从 18 条涨到 20 条，按规则补导览，短名都和标题有连续三个汉字相同，每条恰好出现一次：孕前和孕期自己能做的（第 1、4、17、18、19 条），产检和筛查（第 2、3、5、6 条），出事了马上去医院（第 7、8 条），生孩子的时候（第 9、10 条），生完以后（第 16、20 条），钱和证件（第 11 到 15 条）。