From the Guidelines
An angular pregnancy is no longer a recommended term and should be avoided, instead, the term intrauterine pregnancy (IUP) should be used to describe a pregnancy implanted in a normal location, even if the gestational sac is eccentrically located. According to the most recent and highest quality study 1, the term "angular pregnancy" is considered outdated and confusing, and its use should be abandoned. This change in terminology aims to minimize potential harm resulting from misinterpretations and to provide clear and respectful language for diagnosis and management of first-trimester pregnancy.
The location of a pregnancy is divided into normal, abnormal, and unknown, and the essential word in the definition of intrauterine pregnancy and ectopic pregnancy is "implanted", which helps differentiate pregnancies that are temporarily located in the lower uterine segment 1. The term "intrauterine pregnancy" (IUP) refers to a pregnancy implanted in a normal location, and variants of IUP include eccentrically located gestational sacs completely surrounded by endometrium.
It is worth noting that the use of terms such as "angular pregnancy" or "cornual pregnancy" can lead to confusion with interstitial ectopic pregnancy, and therefore, these terms should be avoided 1. Instead, the term IUP should be used, and if desired, a description of the eccentric location of the gestational sac can be included, but it should be clear that it is an IUP.
In terms of management, pregnancies that are implanted in a normal location, including those with eccentrically located gestational sacs, should be monitored and managed according to standard protocols for intrauterine pregnancies. However, it is essential to be aware of the potential risks associated with abnormal implantation locations, such as cesarean scar pregnancy or interstitial ectopic pregnancy, and to take appropriate action if these conditions are suspected 1.
Key points to consider:
- The term "angular pregnancy" is no longer recommended and should be avoided.
- The term "intrauterine pregnancy" (IUP) should be used to describe a pregnancy implanted in a normal location.
- Eccentrically located gestational sacs completely surrounded by endometrium should be reported as IUP.
- The use of terms such as "angular pregnancy" or "cornual pregnancy" can lead to confusion with interstitial ectopic pregnancy.
- Pregnancies that are implanted in a normal location should be monitored and managed according to standard protocols for intrauterine pregnancies.
From the Research
Definition of Angular Pregnancy
- Angular pregnancy is a rare condition where the embryo is implanted in the lateral angle of the uterine cavity, medial to the uterotubal junction and round ligament 2, 3.
- It is essential to differentiate angular pregnancy from interstitial and cornual pregnancy, as they can result in emergency conditions 3, 4.
Characteristics and Complications
- Angular pregnancy can progress to term pregnancy, but it may be associated with major obstetric complications such as uterine rupture, placental retention, postpartum hemorrhage, or may need further surgery and hysterectomy 3.
- The condition is associated with a high rate of complications, including bleeding and ruptured uterus, due to delayed diagnosis 2.
Diagnosis and Differentiation
- The use of early first-trimester ultrasound can help correctly differentiate between eccentric pregnancy and interstitial ectopic pregnancy 4.
- Saline infusion sonohysterography (SIS) can aid in the differential diagnosis between interstitial and angular pregnancies, especially in unusual cases 5.
- 3D ultrasound features can also be used to distinguish angular pregnancy from interstitial and cornual pregnancies 6.
Management and Outcomes
- Expectant management of eccentric pregnancies can often result in a healthy term pregnancy, while interstitial ectopic pregnancies have a poor likelihood of progressing to viability 4.
- Standardizing the classification of pregnancies near the uterotubal junction is crucial to unify conservative, yet safe and effective management strategies 4.