Table 4. Characteristics of the study groups.
| ID (RPL type) | Age at index pregnancy (yrs): F, M | Live births prior index pregnancy (n) | Miscarriages prior index pregnancy (n) | Available placental samples (n) | Index pregnancy: gest. age (d) |
|---|---|---|---|---|---|
| Recurrent pregnancy loss female patientsa: the index pregnancy ending with a miscarriage | |||||
| RPL18 (prim) | 34, 37 | 0 | 7 | 1 | 130 |
| RPL63b (sec) | 42, 46 | 1 | 4 | n.a. | 84 |
| RPL69 (sec) | 25, 26 | 1 | 4 | n.a. | 41 |
| RPL71c (sec) | 37/38, 33/34 | 1 | 3/5 | 2 | 53/44 |
| RPL89c (prim) | 31/32, 30/31 | 0 | 5/6 | 2 | 44/67 |
| RPL30 (sec) | 32, n.a. | 1 | 2 | 1 | 49 |
| RPL70 (sec) | 34, n.a. | 2 | 2 | 1 | 119 |
| Recurrent pregnancy loss couples: the index pregnancy ending with a miscarriage | |||||
| RPL7b (prim) | 30, 35 | 0 | 2 | n.a. | 54 |
| RPL16 (prim) | 31, 40 | 0 | 2 | n.a. | 47 |
| RPL45b (prim) | 37, 32 | 0 | 2 | n.a. | 63 |
| RPL50 (prim) | 32, 31 | 0 | 2 | 1 | 56 |
| RPL60 (sec) | 31, 33 | 2 | 2 | 1 | 45 |
| RPL67 (prim) | 29, 30 | 0 | 3 | 1 | 42 |
| Recurrent pregnancy loss couples: the index pregnancy ending with a live birth | |||||
| RPL3b (sec) | 36, 39 | 2 | 3 | 1 | 286 |
| RPL11b (prim) | 23, 24 | 0 | 3 | 1 | 287 |
| RPL12b (prim) | 34, 29 | 0 | 4 | 1 | 284 |
| Reference data for normal pregnancies (8 1st trimester women, 8 term pregnancy couples) | |||||
| 1st trimester pregnancy | 27 (18–33),n.a. | 1 (0–3) | 0 (0–0) | 9 | 60 (51–81) |
| Term pregnancy | 33 (18–37), 34 (22–38) | 1 (0–2) | 0 (0–1) | 8 | 284 (260–291) |
aPaternal blood DNA samples were not available for genotyping;
bparental blood DNA samples were analysed in a previous CNV study using a low resolution SNP array7, but were re-genotyped in the current study (see Methods);
cavailable placental samples from two miscarriages were analysed. Reference data are given as median (range) and include maternal-placental duos for the 1st trimester and maternal-paternal-placental trios for the term pregnancies. d, days; F, female partner; M, male partner; n, number; n.a., not available; prim, primary RPL (no live births); sec, secondary RPL (occurrence of consecutive miscarriages after a live birth); yrs, years.