To characterize risks for early pregnancy loss after fresh and frozen IVF cycles and to investigate whether risk is modified by infertility diagnoses or transfer of embryos in fresh versus frozen cycles.
Retrospective cohort study using data from the National Assisted Reproductive Technology (ART) Surveillance System.
U.S. fertility centers.
Clinical pregnancies achieved with fresh and frozen IVF cycles between 2007 and 2012 (N = 249,630).
None.
First trimester pregnancy loss.
A diagnosis of uterine factor was associated with an increased risk of loss in women aged 40 years and younger (<30 years: adjusted risk ratio (aRR) = 1.24, 95% confidence interval (CI) 1.04-1.48; 30-34 years: aRR = 1.27, 95% CI 1.17-1.38; 35-37 years: aRR = 1.12, 95% CI 1.03-1.21; 38-40 years: aRR = 1.08, 95% CI 1.01-1.17). There was an increased risk of loss in women with diminished ovarian reserve aged 30-34 years (aRR = 1.08, 95% CI 1.01-1.15) and in women with ovulatory dysfunction younger than 35 years (<30 years: aRR = 1.12, 95% CI 1.05-1.19; 30-34 years: aRR = 1.07, 95% CI 1.02-1.13). There was an increased risk of loss after frozen ETs versus fresh among women younger than 38 years, but this remained significant in the subanalysis of similar quality embryos only in women younger than 30 years (aRR = 1.16, 95% CI 1.04-1.32).
Uterine factor had the largest increased risk of loss among infertility diagnoses, although the magnitudes of all risks were small. When transferring embryos of similar quality, the risks of loss were similar between fresh and frozen cycles.
This research output has an Altmetric Attention Score of 23. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 24 November 2024.
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Altmetric has tracked 34,410,315 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 93rd percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
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