Endometrial cavity fluid is associated with deleterious pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection: a retrospective cohort study

BACKGROUND: The effects of endometrial cavity fluid (ECF) on in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) pregnancy outcomes following embryo transfer (ET) are still controversial. We conducted the present study to investigate whether the presence of ECF in infertile patients scheduled to undergo IVF or ICSI was associated with pregnancy outcomes. METHODS: A retrospective cohort study design was used. Among infertile patients undergoing IVF/ICSI, those with and without ECF were matched 1:1 using propensity score matching (PSM). After ensuring that the baseline levels of the two matched groups were consistent, the pregnancy and obstetrical outcomes of the two groups were compared. RESULTS: Patients with ECF had significantly lower clinical rates of pregnancy (1,061/1,862, 57% vs. 1,182/1,862, 63.5%; P<0.001), live birth (902/1,862, 48.4% vs. 1,033/1,862, 55.5%; P<0.001), biochemical pregnancy (1,182/1,862, 63.5% vs. 1,288/1,862, 69.2%; P<0.001), and embryo implantation (1,500/3,740, 40.1% vs. 1,661/3,740, 44.4%, P<0.001) than patients without ECF. Also, patients with ECF had a higher incidence of gestational diabetes (17/78, 22% vs. 8/94, 9%, P=0.014). However, there were no differences in gestational weeks at delivery or birth weight between the two groups. CONCLUSIONS: ECF was significantly associated with adverse pregnancy outcomes but showed no significant association with adverse obstetric outcomes (except for gestational diabetes).