Dear Editor

Elangovan and Pek (1) presented in their published case report, an interesting case report of ruptured cornual pregnancy (CP) at 30 weeks^+6d, and mentioned that CP tends to present at 7-12 gestational weeks. Elangovan and Pek (1) reported in a published case report that CP occurs in the interstitial segment of the fallopian tube and invades the uterine muscles.

The published Elangovan and Pek (1) case reports are confusing to readers. William’s textbook considers CP to be a pregnancy that occurs in the rudimentary horn of the uterus with Müllerian anomaly (2-4), while interstitial ectopic pregnancy (IEP) is a pregnancy that occurs in the interstitial segment of the fallopian tube, where it crosses the uterine muscles to enter the uterine cavity (5, 6).

Cornual pregnancies (CPs) are usually diagnosed at mid-trimester of pregnancy (16 weeks for un-ruptured CPs, and 20-21 weeks for ruptured CPs) (7). In the past, interstitial ectopic pregnancies (IEPs) were usually diagnosed at 8-16 gestational weeks following ruptured IEPs (8-10). After advancements in sonographic techniques, IEPs can be diagnosed early (<8-16 weeks), and before rupture using the IEPs diagnostic sonographic findings/criteria which includes an empty uterus with a gestational sac located >1 cm away from the endometrial margin and surrounded by <5 mm myometrium (8-10). The interstitial line is a sonographic line that extends from the gestational sac to the endometrium and represents the interstitial segment of the fallopian tube with 80% sensitivity for diagnosing IEPs (8-10).