PREGNANCY OF UNKNOWN LOCATION: EVIDENCE-BASED EVALUATION AND MANAGEMENT
IRIS G. INSOGNA, MD, AND PAULA C. BRADY, MD (AUGUST 2020)
I would like to thank Dr. Iris Insogna and Dr. Paula Brady for their very informative article on pregnancy of unknown location. However, please allow me to make a suggestion that will clarify terminology for all practicing ObGyns.
The medical literature uses the terms cornual pregnancy and interstitial pregnancy interchangeably, although they are actually very different conditions and have significant different implications. Clinicians are often confused about which is an intrauterine pregnancy and which is a true ectopic pregnancy. This confusion was addressed in a 2006 article in Fertility and Sterility, which explains that a cornual pregnancy refers to the implantation and development of a gestation in one of the upper and lateral portions of the uterus.1 This may occur in a rudimentary horn or in one horn of a septate or bicornuate uterus. Conversely, an interstitial pregnancy is a gestation that implants within the proximal, intramural portion of the fallopian tube that is enveloped by myometrium. Therefore, a cornual pregnancy is actually an intrauterine pregnancy, whereas an interstitial pregnancy is a true ectopic pregnancy.
I hope that all clinicians will read the article in Fertility and Sterility and adopt this terminology to avoid future confusion and misunderstandings.
Alan D. Rosen, MD
Houston, Texas
Reference
1. Malinowski A, Bates SK. Semantics and pitfalls in the diagnosis of cornual/interstitial pregnancy. Fertil Steril. 2006;86:1764.e11-1764.e14.