For patients with recurrent pregnancy loss

Examination and causes of RPL

• （1）Definition of recurrent miscarriage and recurrent pregnancy loss and results of the Japan Environment and Children’s Study (JECS)
• INDEX
• （3）Antiphospholipid syndrome

The four major causes of miscarriage are antiphospholipid syndrome (APS), a congenital uterine anomaly, chromosomal structural rearrangement in either partner, and fetal (embryonic) chromosomal aneuploidy (1, 4-6). Antiphospholipid antibodies are found in 10% of cases, chromosomal rearrangement abnormalities in 6%, and uterine malformations in 3.2% (Fig. 2-A). The prevalence of APS that meets the definition of the International Society for Antiphospholipid Antibodies is about 4% (6). Endocrine abnormalities include diabetes hypothyroidism, as well as polycystic ovary syndrome, but the latter is still controversial.

Figure 2:Distribution of causes of recurrent pregnancy loss

1676 couples
Sugiura-Ogasawara et al. Fertil Steril 2010

 

482 couples
Sugiura-Ogasawara et al. Hum Reprod 2012

The four major causes of RPL at this time are listed below (Table 3).

1. Antiphospholipid syndrome
2. Congenital uterine anomaly
3. Chromosomal structural rearrangement in either husband or wife
4. Fetal or embryonic chromosome aneuploidy

Because fetal chromosome testing is not covered by health insurance in Japan and can only be performed in a limited number of facilities, it is rarely performed on fetuses of past miscarriages in patients who come in for their first visit. Therefore, RPL of "unknown cause" comprised 69 % of the cases (Fig. 2-A). However, when properly examined, 41% of fetuses showed chromosome aneuploidy, a rate which increased with the age of the woman (Fig. 2-B, ref. 5). The frequency of cases with a truly unknown cause was about 25%. Recommended tests are listed in Table 3 and the details are explained item by item.