Centre of Haemophilia and Thrombosis, Department of Clinical Biochemistry, Aarhus University Hospital, Brendstrupgaardsvej 100, Aarhus N 8200, Denmark.
Hum Reprod. 2014 Mar;29(3):611-7. doi: 10.1093/humrep/det458. Epub 2014 Jan 6.
Is venous thrombosis risk increased in pregnancies after in vitro fertilization?
The venous thrombosis incidence was significantly increased in pregnancies after in vitro fertilization; especially in the first trimester and in the first 6 weeks post-partum.
In vitro fertilization without pregnancy is not associated with increased venous thrombosis incidence.
STUDY DESIGN, SIZE, DURATION: This national register-based cohort study covered the period from 1995 to 2005.
PARTICIPANTS/MATERIALS, SETTING, METHODS: All Danish pregnancies conceived by in vitro fertilization (n = 18 787) were included. Venous thrombosis incidence rates in pregnancies after in vitro fertilization were compared with venous thrombosis incidence rates in reference pregnancies, by calculating incidence rate ratios.
In total, 48 cases were identified. In pregnancies after in vitro fertilization, the overall venous thrombosis incidence rate was 28.6 per 10 000 pregnancy-years (95% confidence interval (CI) 20.6-39.6) in comparison to 10.7 per 10 000 woman-years in reference pregnancies. Post-partum, the venous thrombosis incidence rate was 27.9 per 10 000 woman-years (95% CI 15.8-49.1) after in vitro fertilization in comparison to 17.5 per 10 000 woman-years in reference pregnancies. The overall venous thrombosis incidence rate ratio during in vitro fertilization (IVF) pregnancies compared with reference pregnancies was 3.0 (95% CI 2.1-4.3). The venous thrombosis incidence rate ratios during pregnancy were 2.8 (95% CI 1.9-4.1) in singleton IVF pregnancies and 4.4 (95% CI 2.4-8.3) in multiple IVF pregnancies, compared with reference pregnancies. The venous thrombosis incidence rate ratio post-partum was 1.2 (95% CI 0.6-2.8) for singleton IVF pregnancies and 3.9 (95% CI 1.7-8.8) for multiple IVF pregnancies compared with reference pregnancies. The post-partum venous thrombosis risk was higher in multiple IVF pregnancies compared with singleton IVF pregnancies. Maternal age, smoking and parity did not significantly affect the venous thrombosis risk. Ovarian hyperstimulation syndrome and polycystic ovarian syndrome did increase the risk of venous thrombosis during pregnancy. Caesarean section also increased the post-partum venous thromboembolism risk, but the increase was not significant.
LIMITATIONS, REASONS FOR CAUTION: Other known confounders in our reference population could have contributed to the results. Access to such data may have helped to explain the observations, but would not have changed the conclusion that IVF pregnancies have an increased risk of venous thrombosis compared with other pregnancies.
Our study adds new insights by demonstrating an excess venous thrombosis incidence post-partum after in vitro fertilization. The high venous thrombosis incidence in first trimester after in vitro fertilization supports previous studies. Our findings are generalizable to other Western Countries.
STUDY FUNDING/COMPETING INTERESTS: Expenses for the acquirement of data were covered by a grant from The Secretary of Doctors further education, Central Denmark Region. None of the authors have any competing interests to declare.
Not applicable.
体外受精后妊娠的静脉血栓形成风险是否增加？
体外受精后妊娠的静脉血栓形成发生率显著增加；尤其是在妊娠早期和产后 6 周内。
体外受精而未妊娠与静脉血栓形成发生率增加无关。
研究设计、大小、持续时间：本全国登记队列研究涵盖了 1995 年至 2005 年期间。
参与者/材料、设置、方法：纳入所有通过体外受精（IVF）受孕的丹麦妊娠（n=18787）。通过计算发病率比值，比较体外受精后妊娠的静脉血栓形成发生率与参考妊娠的静脉血栓形成发生率。
总共确定了 48 例病例。与参考妊娠相比，体外受精后妊娠的总体静脉血栓形成发生率为每 10000 妊娠年 28.6（95%置信区间[CI]20.6-39.6），而参考妊娠为每 10000 妇女年 10.7。产后，与参考妊娠相比，体外受精后产后静脉血栓形成发生率为每 10000 妇女年 27.9（95%CI15.8-49.1）。与参考妊娠相比，体外受精（IVF）妊娠期间的总体静脉血栓形成发生率比值为 3.0（95%CI2.1-4.3）。与参考妊娠相比，单胎 IVF 妊娠期间的静脉血栓形成发生率比值为 2.8（95%CI1.9-4.1），多胎 IVF 妊娠期间的静脉血栓形成发生率比值为 4.4（95%CI2.4-8.3）。与参考妊娠相比，单胎 IVF 妊娠产后静脉血栓形成发生率比值为 1.2（95%CI0.6-2.8），多胎 IVF 妊娠产后静脉血栓形成发生率比值为 3.9（95%CI1.7-8.8）。与单胎 IVF 妊娠相比，多胎 IVF 妊娠产后静脉血栓形成风险更高。产妇年龄、吸烟和产次并没有显著影响静脉血栓形成风险。卵巢过度刺激综合征和多囊卵巢综合征会增加妊娠期间静脉血栓形成的风险。剖宫产也会增加产后静脉血栓栓塞的风险，但增加不显著。
局限性、谨慎的原因：我们参考人群中的其他已知混杂因素可能导致了结果。获得这些数据可能有助于解释观察结果，但不会改变与其他妊娠相比，体外受精妊娠的静脉血栓形成风险增加的结论。
我们的研究通过证明体外受精后产后静脉血栓形成发生率增加提供了新的见解。体外受精后妊娠早期静脉血栓形成发生率高支持了之前的研究。我们的研究结果可推广至其他西方国家。
研究经费/利益冲突：数据获取费用由丹麦中央大区医生继续教育秘书资助。作者均无任何利益冲突。
不适用。
