Department of Obstetrics and Gynaecology, Medical Faculty Division, Akershus University Hospital, Lørenskog, Norway.
BJOG. 2011 Mar;118(4):488-94. doi: 10.1111/j.1471-0528.2010.02819.x. Epub 2010 Dec 23.
To study changes in gestational-age-specific fetal death risks during a 40-year period.
Register-based observational study.
The Medical Birth Registry of Norway.
All pregnancies after 16 weeks of gestation in Norway from 1967 to 2006 (n = 2, 182, 756).
Changes in fetal death risk since 1967-1971 (reference) were estimated as absolute risks (rates) and relative risks (RR) in ongoing pregnancies at the following gestational weeks; 16-22, 23-29, 30-36 and 37-43.
Fetal death.
In all pregnancies lasting longer than 22 weeks, the fetal death rate decreased during 1967-2006. The greatest decline was in term pregnancies (37-43 weeks) from 10.8 to 3.3 fetal deaths per 1000 at risk (crude RR 0.35; 95% CI 0.31-0.38) comparing 1967-1971 with 2002-2006. In pregnancies at 30-36 weeks the fetal death rate declined from 4.5 to 1.1 per 1000 (crude RR 0.23; 95% CI 0.21-0.26). At 23-29 weeks, the rate declined from 2.8 to 1.3 per 1000 (crude RR 0.46; 95% CI 0.40-0.52). An opposite trend was observed at early gestation (16-22 weeks) with an increase from 1.7 to 3.4 fetal deaths per 1000 ongoing pregnancies (crude RR 2.05; 95% CI 1.84-2.27). Adjustments for maternal age, parity, multiple pregnancies, paternal age and pre-eclampsia did not significantly alter the estimated associations.
Since 1967 the risk of fetal death has been reduced by almost 70% in pregnancies lasting longer than 22 weeks; however, at 16-22 weeks of gestation there was an increase in risk. The causes of this increase should be further explored because it may be attributed to an increase in early delivery caused by the increased proportion of women being treated with cervical cone excision before pregnancy.
研究 40 年间特定胎龄胎儿死亡风险的变化。
基于注册的观察性研究。
挪威医学出生登记处。
1967 年至 2006 年挪威妊娠 16 周以上的所有孕妇（n=2182756）。
自 1967-1971 年（参考）以来，通过绝对风险（率）和相对风险（RR）在以下妊娠周数估计持续妊娠中胎儿死亡风险的变化：16-22、23-29、30-36 和 37-43。
胎儿死亡。
在所有持续 22 周以上的妊娠中，1967-2006 年期间胎儿死亡率下降。最大的降幅发生在足月妊娠（37-43 周），从每 1000 名风险妊娠 10.8 例降至 3.3 例（粗 RR 0.35；95%CI 0.31-0.38），1967-1971 年与 2002-2006 年相比。在 30-36 周妊娠中，胎儿死亡率从每 1000 例 4.5 例降至 1.1 例（粗 RR 0.23；95%CI 0.21-0.26）。在 23-29 周时，从每 1000 例 2.8 例降至 1.3 例（粗 RR 0.46；95%CI 0.40-0.52）。在妊娠早期（16-22 周）观察到相反的趋势，每 1000 例持续妊娠的胎儿死亡数从 1.7 例增加到 3.4 例（粗 RR 2.05；95%CI 1.84-2.27）。调整母亲年龄、产次、多胎妊娠、父亲年龄和子痫前期后，估计的相关性没有显著改变。
自 1967 年以来，22 周以上妊娠的胎儿死亡风险降低了近 70%；然而，在 16-22 周时，风险增加。应进一步探讨这种增加的原因，因为这可能归因于在妊娠前接受宫颈锥形切除术治疗的妇女比例增加导致早期分娩增加。
