1. Chromosomal abnormalities.

2. Syphilis.

3. Rhesus isoimmunisation.

4. Cervical incompetence.

1. Chromosomal abnormalities.

Reference

Test book of Obstetrics 4^th Edition D.C.Dutta Page 172

Spotter

Repeat

All books give this

Causes of First Trimester Abortion

1. Defective Germ Plasm

a. Chromosomal Abnormalities

i. Most common among this is Autosomal Trisomy

b. Congenital Malforamtion

c. Blighted Ovum

2. Chromosomal Abonormalities

3. Hormonal deficiency

4. Trauma

5. Acute Infection

Causes of Mid Trimester Abortion

1. Cervical Incompetence

2. Uterine Malformation - bicornuate or Septate uterus

3. Uterine Fibroid

4. Low implantation of Placenta

5. Twins

6. Hydramnios

1. Chromosomal abnormalities are the Most common cause of First Trimester Abortion.

2. In Syphilis the outcome improves with successive pregnancies..

3. In Rhesus isoimmunisation, the out come becomes grave with successive pregnancies.

4. Cervical incompetence. Is the Most common cause of Mid Trimester Abortion

In earlier weeks, the foetus dies and is then expelled

In the later period the foetus is expelled out and then dies as it is too small to survive

Cervical Abortion is a condition in which the external os fails to dilate and so the Ovum, with the decidual coverings is accommodated in the dilated cervical canal