Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland, Oregon.
Am J Perinatol. 2024 Feb;41(3):270-275. doi: 10.1055/a-1673-0527. Epub 2021 Oct 19.
The aim of this study was to determine the rate of perinatal mortality among nulliparous women compared with primiparous women at term and further characterize the risk of stillbirth by each week of gestation.
This is a retrospective cohort study of all term, singleton, nonanomalous births comparing perinatal mortality (stillbirth and neonatal death [NND]) between primiparous (parity = 1, with no history of abortion) and nulliparous (parity = 0) women who delivered in California between 2007 and 2011. Chi-squared tests and multivariable logistic regression analyses were performed to determine the frequencies and strength of association of perinatal mortality with parity, adjusting for maternal age, race, body mass index, pregestational diabetes, chronic hypertension, fetal sex, smoking status, and socioeconomic status. The risk of stillbirth at each gestational age at term was calculated using a pregnancies-at-risk life table method. A -value less than 0.05 was used to indicate statistical significance.
Of 1,317,761 total deliveries, 765,995 (58.1%) were to nulliparous women and 551,766 (41.9%) were to primiparous women with one prior birth. Nulliparous women had increased odds of stillbirth (adjusted odds ratio [aOR], 3.30; 95% confidence interval [CI], 2.93-3.72) and NND (aOR, 1.54; 95% CI, 1.19-1.98) compared with primiparous women. The risk of stillbirth in nulliparous women was greater at every gestational age between 37 and 41 weeks compared with primiparous women. Nulliparous women also had increased odds of small for gestational age infants at less than 10% birth weight (aOR, 1.76; 95% CI, 1.72-1.79), less than 5% birth weight (aOR, 1.91; 95% CI, 1.86-1.98), and less than 3% birth weight (aOR, 2.02; 95% CI, 1.93-2.11).
Perinatal mortality is significantly greater in nulliparous women compared with primiparous women with term deliveries. These findings suggest that low-risk nulliparous women may require increased surveillance. There may be a role in improving maternal health by maximizing physiologic adaptation in nulliparous women.
· Parity is associated with perinatal mortality.. · Perinatal mortality is significantly greater in nulliparous women compared with primiparous women.. · The risk of stillbirth in nulliparous women is greater at every gestational age compared with primiparous women..
本研究旨在比较足月单胎无畸形分娩的初产妇和经产妇的围产儿死亡率，并进一步按每孕周特征分析死产风险。
这是一项回顾性队列研究，纳入了 2007 年至 2011 年加利福尼亚州所有足月、单胎、非畸形分娩的初产妇（产次=1，无流产史）和经产妇（产次=0），比较了围产儿死亡率（死产和新生儿死亡[NND]）。采用卡方检验和多变量逻辑回归分析，调整了母亲年龄、种族、体重指数、孕前糖尿病、慢性高血压、胎儿性别、吸烟状况和社会经济地位后，评估围产儿死亡率与产次的关联频率和关联强度。采用妊娠风险生命表法计算了每个足月妊娠时的死产风险。P 值小于 0.05 表示有统计学意义。
在 1317761 例总分娩中，765995 例（58.1%）为经产妇，551766 例（41.9%）为初产妇，有 1 次既往分娩。与初产妇相比，经产妇死产（调整优势比[aOR]，3.30；95%置信区间[CI]，2.93-3.72）和 NND（aOR，1.54；95% CI，1.19-1.98）的风险更高。与初产妇相比，37-41 周时每个孕周经产妇死产的风险均更高。经产妇小于 10%出生体重（aOR，1.76；95% CI，1.72-1.79）、小于 5%出生体重（aOR，1.91；95% CI，1.86-1.98）和小于 3%出生体重（aOR，2.02；95% CI，1.93-2.11）的小于胎龄儿的风险也更高。
与足月分娩的初产妇相比，经产妇的围产儿死亡率显著更高。这些发现表明，低风险的经产妇可能需要加强监测。通过最大限度地促进经产妇的生理适应，可能改善母婴健康，从而降低围产儿死亡率。
· 产次与围产儿死亡率相关。· 与初产妇相比，经产妇的围产儿死亡率显著更高。· 与初产妇相比，经产妇的死产风险在每个孕周都更高。
