Curtin School of Population Health, Curtin University, Perth, Western Australia, Australia
Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.
BMJ Open. 2021 Dec 2;11(12):e046962. doi: 10.1136/bmjopen-2020-046962.
To examine if the association between interpregnancy interval (IPI) and pregnancy complications varies by the presence or absence of previous complications.
Population-based longitudinally linked cohort study in Western Australia (WA).
Mothers who had their first two (n=252 368) and three (n=96 315) consecutive singleton births in WA between 1980 and 2015.
We estimated absolute risks (AR) of preeclampsia (PE) and gestational diabetes (GDM) for 3-60 months of IPI according to history of each outcome. We modelled IPI using restricted cubic splines and reported adjusted relative risk (RRs) with 95% CI at 3, 6, 12, 24, 36, 48 and 60 months, with 18 months as reference.
Risks of PE and GDM were 9.5%, 2.6% in first pregnancies, with recurrence rates of 19.3% and 41.5% in second pregnancy for PE and GDM, respectively. The AR of GDM ranged from 30% to 43% across the IPI range for mothers with previous GDM compared with 2%-8% for mothers without previous GDM. For mothers with no previous PE, greater risks were observed for IPIs at 3 months (RR 1.24, 95% CI 1.07 to 1.43) and 60 months (RR 1.40, 95% CI 1.29 to 1.53) compared with 18 months. There was insufficient evidence for increased risk of PE at shorter IPIs of <18 months for mothers with previous PE. Shorter IPIs of <18 months were associated with lower risk than at IPIs of 18 months for mothers with no previous GDM.
The associations between IPIs and risk of PE or GDM on subsequent pregnancies are modified by previous experience with these conditions. Mothers with previous complications had higher absolute, but lower RRs than mothers with no previous complications. However, IPI remains a potentially modifiable risk factor for mothers with previous complicated pregnancies.
探讨妊娠间隔（interpregnancy interval，IPI）与妊娠并发症之间的关联是否因既往并发症的存在与否而有所不同。
西澳大利亚州（WA）基于人群的纵向队列研究。
1980 年至 2015 年期间在 WA 连续分娩两次（n=252368）和三次（n=96315）单胎妊娠的母亲。
我们根据每个结局的既往史，估计 IPI 为 3-60 个月时子痫前期（PE）和妊娠期糖尿病（GDM）的绝对风险（AR）。我们使用限制立方样条模型来拟合 IPI，并报告了 3、6、12、24、36、48 和 60 个月时调整后的相对风险（RR）及其 95%可信区间，以 18 个月为参考。
首次妊娠中 PE 和 GDM 的风险分别为 9.5%和 2.6%，PE 和 GDM 的复发率分别为 19.3%和 41.5%。与无既往 GDM 的母亲相比，既往 GDM 母亲的 GDM 范围在整个 IPI 范围内的 AR 为 30%-43%，而 2%-8%。对于既往无 PE 的母亲，与 18 个月相比，3 个月（RR 1.24，95%CI 1.07-1.43）和 60 个月（RR 1.40，95%CI 1.29-1.53）的 IPI 风险更高。既往 PE 母亲的较短 IPI（<18 个月）与较短 IPI（<18 个月）与较长 IPI（18 个月）相比，PE 风险增加的证据不足。对于既往无 GDM 的母亲，较短的 IPI（<18 个月）的风险低于 IPI（18 个月）。
IPI 与后续妊娠中 PE 或 GDM 风险之间的关联因既往这些疾病的经历而发生改变。既往有并发症的母亲的绝对风险更高，但 RR 低于既往无并发症的母亲。然而，IPI 仍然是既往复杂妊娠母亲的一个潜在可改变的危险因素。
