Infertility and spontaneous abortion - Spontaneous abortion, habitual abortion
Etiologic factors of habitual abortion (195 couples)
| Causative factor | 1st trimester (%) | 2nd trimester (%) | Total (%) |
| Uterine defects | 12 | 21 | 15 |
| Cervical incompetence | 3 | 30 | 13 |
| Endocrine | 7 | 1 | 5 |
| Endometrial infection | 16 | 13 | 15 |
| Chromosomal | 4 | 0 | 3 |
| Systemic disorder | 0 | 3 | 1 |
| Sperm factor | 6 | 1 | 4 |
| Excessive smoking | 1 | 0 | 0 |
| Unknown | 51 | 31 | 44 |
Stray-Pedersen B, Stray-Pedersen S. Etiologic factors and subsequent reproductive performance in 195 couples with a prior history of habitual abortion. Am J Obstet Gynecol. 1984 Jan 15;148(2):140-6.