Ultrasound diagnosis of early pregnancy loss in an in vitro fertilization population.

Abstract

Currently, the diagnosis of early pregnancy loss is made primarily on the basis of ultrasonographic findings. In an in vitro fertilization population, the date of embryo transfer into the uterus is known accurately. This should allow for more specific guidelines for the diagnosis of early pregnancy loss in women with intrauterine pregnancies conceived through in vitro fertilization. The objective of this study was to develop accurate criteria for the diagnosis of early pregnancy loss after in-vitro fertilization. This was a retrospective cohort study of all patients who underwent embryo transfer at a tertiary medical center in the United States between January 1, 2012, and December 31, 2022, had a positive quantitative human chorionic gonadotropin result, and had at least 1 transvaginal ultrasound demonstrating a gestational sac. Multiple and ectopic pregnancies were excluded. Gestational age based on in vitro fertilization dating was calculated from the day of egg retrieval (expected ovulation). Gestational age estimated by ultrasound was calculated using Daya's formula. Data were retrieved from the infertility center database and ultrasound records. The primary outcome was early pregnancy loss. A total of 16,369 patients underwent in vitro fertilization at the center in the study period, and 6638 met the eligibility criteria. The initial analysis included 4926 patients; 997 had an early pregnancy loss. At or after 45 to 49 days' gestational age based on in vitro fertilization dating, 100% of the pregnancies in the ongoing pregnancy group had a yolk sac, embryo, and fetal cardiac activity visible on ultrasound. At or after 45 days' gestational age based on in vitro fertilization dating, the sonographic finding of either no embryo or an embryo without cardiac activity had a 100% positive predictive value that the pregnancy would end in early pregnancy loss. These findings were replicated in an additional cohort of 875 patients. In vitro fertilization dating can be used to accurately diagnose early pregnancy loss at an earlier gestational age compared with the currently used diagnostic criteria, allowing for quicker resolution. Adoption of these new diagnostic criteria would result in an important change in the management of in vitro fertilization pregnancies.