Recurrent abortion has been defined as the loss of three or more previable (< 500 g) pregnancies in succession. Recurrent abortion occurs in about 0.4-0.8% of all pregnancies. Abnormalities related to recurrent abortion can be identified in approximately half of the couples. If a woman has lost three previous pregnancies without identifiable cause, she still has a 70-80% chance of carrying a fetus to viability. If she has aborted four or five times, the likelihood of a successful pregnancy is 65-70%.
Recurrent abortion is a clinical rather than pathologic diagnosis. The clinical findings are similar to those observed in other types of abortion (see above).
A. Preconception Therapy
Preconception therapy is aimed at detection of maternal or paternal defects that may contribute to abortion. A thorough general and gynecologic examination is essential. Polycystic ovaries should be ruled out. A random blood glucose test and thyroid function studies (including thyroid antibodies) should be done. Detection of lupus anticoagulant and other hemostatic abnormalities (proteins S and C and antithrombin III deficiency, hyperhomocysteinemia, anticardiolipin antibody, factor V Leiden mutations) and an antinuclear antibody test may be indicated with second trimester losses. Endometrial tissue should be examined in the postovulation stage of the cycle to determine the adequacy of the response of the endometrium to hormones. The competency of the cervix must be determined and hysteroscopy or hysterography used to exclude submucous myomas and congenital anomalies. Chromosomal (karyotype) analysis of both partners rules out balanced translocations (found in 5% of infertile couples).
Studies have focused on the major histocompatibility complex (MHC) of chromosome 6, which carries HLA loci and other genes that may influence reproductive success. Some women demonstrate a lack of maternal antibody response to paternal lymphocytes, which is customarily found in normal women after successful childbearing. However, several randomized controlled trials have found no benefit of IGIV therapy for recurrent spontaneous abortion.
B. Postconception Therapy
Provide early prenatal care and schedule frequent office visits. Complete bed rest is justified only for bleeding or pain. Empiric sex steroid hormone therapy is contraindicated.
The prognosis is excellent if the cause of abortion can be corrected.
Management of recurrent pregnancy loss. ACOG Practice Bulletin No. 24, 2001. Int J Gynaecol Obstet 2002;78:179.
Revision date: June 18, 2011
Last revised: by Tatiana Kuznetsova, D.M.D.