Types of Abortion for NEET PG: Sorted by Cervix Status and What's Actually Been Passed

Every type of abortion in this classification is really answering the same two questions: is the cervix open or closed, and has the pregnancy tissue been fully passed, partially passed, or not passed at all? Once you can answer both from a vignette, naming the specific type becomes almost mechanical.

Threatened Abortion

Threatened abortion presents with vaginal bleeding with a closed cervix, in a pregnancy that remains viable on ultrasound — fetal cardiac activity is present. This is the only category in the whole classification where the pregnancy genuinely might continue normally; management is typically expectant, since there's no product of conception to remove and no cervical change indicating the process has become irreversible.

Inevitable Abortion

Inevitable abortion presents with bleeding and a dilated (open) cervix, with the pregnancy still in utero but no longer salvageable — the open cervix is what separates this from threatened abortion, and it's what makes continuation of the pregnancy essentially impossible, regardless of whether fetal cardiac activity is still detectable at this exact moment.

Incomplete Abortion

Incomplete abortion is defined by partial passage of the products of conception — some tissue has passed, but some remains in the uterus, with the cervix typically still open. This retained tissue is clinically significant: it can cause ongoing bleeding and is a real infection risk if not addressed, which is why incomplete abortion typically requires active management (medical or surgical evacuation) rather than simply waiting.

Complete Abortion

Complete abortion means all products of conception have passed, and the cervix has typically closed again by the time of examination. Bleeding and cramping usually subside once passage is complete, and unlike incomplete abortion, there's no retained tissue requiring intervention — confirmation is usually made by ultrasound showing an empty uterus.

Missed Abortion

Missed abortion is the category that most often surprises patients: fetal death has occurred, but the products of conception have not been expelled, and the cervix remains closed. Unlike the other categories, this can present with minimal or no bleeding at all — the diagnosis is often made incidentally on a routine ultrasound showing absent fetal cardiac activity in a patient who felt entirely normal, rather than through a bleeding presentation the way the other types typically are found.

Septic Abortion

Septic abortion describes any of the above categories complicated by infection of the uterine contents, presenting with fever, uterine tenderness, and foul-smelling discharge alongside bleeding. It's the one category defined by a complication overlaid on the others rather than by cervical status or completeness of passage, and it carries genuine risk of progression to sepsis and disseminated intravascular coagulation if not treated promptly — historically associated with unsafe or incomplete illegal abortion procedures, though it can complicate any of the categories above if infection sets in.

The Six Types, Side by Side

Type	Cervix	Products of Conception	Fetal Viability
Threatened	Closed	None passed	Viable
Inevitable	Open	None passed yet	Non-viable outcome expected
Incomplete	Open	Partially passed	Non-viable
Complete	Closed (re-closed)	Fully passed	Non-viable
Missed	Closed	None passed	Non-viable, often asymptomatic
Septic	Variable	Variable	Non-viable, with infection

Recurrent Pregnancy Loss: A Related Definition Worth Knowing

Separate from the acute classification above, recurrent pregnancy loss is conventionally defined as two or more consecutive pregnancy losses, and it's this definition — not any single abortion type above — that triggers a dedicated workup for underlying causes: anatomical uterine abnormalities, antiphospholipid syndrome, chromosomal abnormalities in either partner, and uncontrolled endocrine conditions like thyroid dysfunction or poorly controlled diabetes are among the recognized categories investigated. A single missed or incomplete abortion, in isolation, doesn't meet this threshold on its own.

FAQs

What is the difference between threatened and inevitable abortion?

Cervical status. Threatened abortion has a closed cervix and a viable pregnancy that may continue. Inevitable abortion has an open (dilated) cervix, meaning the pregnancy is no longer salvageable regardless of current fetal status.

How is missed abortion different from the other types?

Missed abortion can present with minimal or no bleeding at all, since fetal death has occurred but nothing has been expelled and the cervix remains closed. It's often discovered incidentally on routine ultrasound rather than through a bleeding presentation.

Why does incomplete abortion require active management while complete abortion doesn't?

Incomplete abortion leaves retained tissue in the uterus, which can cause ongoing bleeding and carries real infection risk. Complete abortion means all tissue has already passed, so there's nothing retained to evacuate.

What defines septic abortion?

Infection of the uterine contents complicating any of the other abortion types, presenting with fever, uterine tenderness, and foul-smelling discharge. It carries real risk of progression to sepsis and DIC if not treated promptly.

How many pregnancy losses define recurrent pregnancy loss?

Two or more consecutive losses. This threshold, not any single abortion, is what triggers a dedicated workup for underlying causes like anatomical abnormalities, antiphospholipid syndrome, or chromosomal factors.

For the same cervix-and-completeness reasoning applied elsewhere in OBG, see our guide to anemia classification, and for how much of the paper OBG carries overall, our subject-wise weightage breakdown.