Association of fertilization strategy and embryo transfer time with the incidence of ectopic pregnancy / 中华男科学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the correlation of the fertilization strategy and embryo transfer (ET) time with the incidence of ectopic pregnancy.</p><p><b>METHODS</b>We selected 3,331 fresh and 2,706 frozen-thawed ET cycles for the patients undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). The fresh transfers included 2 546 IVF-ET and 785 ICSI-ET cycles and 2,220 day-3 embryo and 1,111 day-5 blastocyst transfers, while the frozen-thawed transfers included 2,080 IVF-ET and 626 ICSI-ET cycles and 741 day-3 embryo and 1 965 day-5 or -6 blastocyst transfers. We compared the incidence rate of ectopic pregnancy associated with different fertilization strategies and ET time.</p><p><b>RESULTS</b>The incidence rate of ectopic pregnancy was 1. 41% (36/2 546) in the IVF-ET cycles and 3.44% (27/785) in the ICSI-ET cycles of the fresh transfers, significantly lower in the IVF-ET than in the ICSI-ET cycles (P < 0.01), and it was 1.01% (21/2,080) in the IVF-ET cycles and 0.80% (5/626) in the ICSI-ET cycles of the frozen-thawed transfers, with no remarkable difference between the two groups (P > 0.05). The IVF-ET and ICSI-ET cycles included 2,220 fresh day-3 (F-D3) embryos, 1,111 F-D5 blastocysts, 741 frozen-thawed day-3 (T-D3) embryos, and 1,965 T-D5/6 blastocysts. The incidence rate of ectopic pregnancy was 1.71% (n = 38) in the F-D3, 2.25% (n = 25) in the F-D5, 1.35% (n = 10) in the T-D3, and 0.81% (n = 16) in the T-D5/6 group, respectively, significantly lower in the T-D5/6 than in the other three groups (P < 0.05).</p><p><b>CONCLUSION</b>The incidence rate of ectopic pregnancy is associated with fertilization strategies, which is significantly lower in frozen-thawed than in fresh embryo transfers.</p>