Table 1.
BMC and GENEVA preterm birth cohorts by APOL1 risk status
| BMC |
GENEVA |
|||||
|---|---|---|---|---|---|---|
| Mothers (n = 960; 13% HR APOL1) |
Infants (n = 867; 14% HR APOL1) |
Mothers (n = 519; 14% HR APOL1) |
||||
| LR APOL1a (n = 840) |
HR APOL1a (n = 120) |
LR APOL1 (n = 749) |
HR APOL1 (n = 118) |
LR APOL1 (n = 446) |
HR APOL1 (n = 73) |
|
| Birth characteristics | ||||||
| Preterm | 421 (50) | 63 (53) | 447 (60) | 73 (62) | 145 (33) | 25 (34) |
| Gestational age (weeks) | 37 (35–40) | 37 (34–40) | 32 (26–38) | 30 (26–38) | 38 (35–39) | 38 (35–39) |
| <28 | 58 (7) | 9 (8) | 277 (37) | 46 (39) | 28 (6) | 5 (7) |
| 28–33 | 101 (12) | 16 (13) | 110 (15) | 23 (19) | 58 (13) | 12 (16) |
| 34–36 | 170 (20) | 22 (18) | 60 (8) | 4 (3) | 59 (13) | 8 (11) |
| >36 | 511 (61) | 73 (61) | 302 (40) | 45 (38) | 301 (67) | 48 (66) |
| Birthweight (g) | 2865 (2089–3395) |
2715 (2132–3246) |
1773 (776–3104) |
1190 (741–3164) |
2989 (2363–3370) |
2990 (2504–3250) |
| Small for gestational age | 105 (13) | 12 (10) | 44/355 (12) | 3/61 (5) | 6/72 (8) | 0/15 (0) |
| C-section | 300 (36) | 35 (29) | 317 (42) | 55 (47) | 150 (34) | 49 (33) |
| Maternal characteristics | ||||||
| Age at birth (years) | 28 (22–33) | 28 (24–34) | 25 (21–30) | 24 (22–30) | 25 (21–30) | 26 (21–30) |
| Smoked in 2nd trimester | 115 (14) | 21 (18) | – | – | – | – |
| Second hand smoke during pregnancy | 190 (23) | 32 (27) | – | – | – | – |
| Preeclampsia/eclampsia/HTN | 86/388 (22) | 12/66 (18) | 5/73 (7) | 1/15 (7) | ||
| Preeclam: Mild | 24 (3) | 5 (4) | – | – | – | – |
| Preeclam: Severe | 79 (9) | 11 (9) | – | – | – | – |
| Eclampsia | 2 (<1) | 1 (1) | – | – | – | – |
| Chronic HTN | 49 (6) | 8 (7) | – | – | – | – |
| HELLPb | 10 (1) | 1 (1) | – | – | – | – |
| Body mass index | 26 (22–29) | 25 (22–29) | – | – | – | – |
| Study design | Matched case–control Frequency matched on maternal age, parity and birth year | Unmatched case–control | ||||
| Study site | Boston, MA, USA | Multiple sites, USA | ||||
| Study population ethnicity | African American and Haitian | African American | ||||
Data presented as median (IQR) for continuous traits and number (%) for binary traits. Data on preeclampsia/eclampsia/HTN and SGA were missing for some GENEVA subjects. Numbers of subjects with nonmissing data for these variables are indicated in the table.
aLR APOL1 indicates subjects with a low-risk APOL1 genotype; HR APOL1 indicates subjects with a high-risk APOL1 genotype.
bHELLP stands for hemolysis elevated liver enzymes and low platelet count.