Sonographic characteristics associated with early pregnancy loss in pregnancies conceived via in vitro fertilization

Can gestational age-based sonographic criteria with near 100% positive predictive value (PPV) for early pregnancy loss (EPL) be established in pregnancies conceived via in vitro fertilization (IVF)?

A retrospective cohort study was conducted at a single academic IVF clinic, including all patients with a positive pregnancy test following embryo transfer between 2014 and 2021. Logistic regression assessed associations between gestational age and presence of sonographic markers (gestational sac, embryo, cardiac activity) with EPL. Youden's Index identified optimal gestational age cut-points for each marker.

The study included 913 patients (mean age 35.5 ± 4.8 years; mean BMI 27.6 ± 6.5 kg/m²). Most underwent frozen single embryo transfer at the blastocyst stage; 15.1 % had preimplantation genetic testing for aneuploidy (PGT-A). Outcomes included 727 live births (79.6 %), 176 EPLs (19.3 %), 3 stillbirths, and 7 terminations. Absence of a gestational sac or embryo by 44 days, or cardiac activity by 46 days, yielded PPVs for EPL of 100 %, 100 %, and 97 %, respectively. Logistic regression confirmed increased odds of EPL with absent markers at the specified gestational age cut-points: absence of a gestational sac at 44 days (OR 5.52, 95 % CI [3.40-8.94]), absence of an embryo at 44 days (OR 5.88, CI [3.64-9.49]), and absence of cardiac activity at 46 days (OR 2.86, CI [1.99-4.12]).

In IVF pregnancies, known gestational age may allow for earlier diagnosis of EPL, as compared to traditional criteria, which are based upon sonographic markers alone. Larger studies are needed to validate these proposed criteria and compare them to traditional criteria for diagnosis of EPL.