TABLE 4.
Quartiles of prepregnancy dietary adherence scores and RRs (95% CIs) of spontaneous abortion and stillbirth1
| SAB |
Stillbirth |
|||
| Q (median) | No. of SABs/total pregnancies (%) | Multivariate RR (95% CI)2 | No. of stillbirths/total pregnancies (%) | Multivariate RR (95% CI)2 |
| aMED | ||||
| Q1 (2) | 551/3355 (16.4) | 1.0 (reference) | 17/2664 (0.6) | 1.0 (reference) |
| Q2 (4) | 981/5786 (17.0) | 1.03 (0.94, 1.14) | 49/4543 (1.1) | 1.71 (0.98, 2.99) |
| Q3 (5) | 529/2923 (19.2) | 1.10 (0.98, 1.22) | 17/2263 (0.8) | 1.15 (0.58, 2.29) |
| Q4 (6) | 695/3886 (17.9) | 1.05 (0.94, 1.17) | 37/2973 (1.2) | 1.82 (0.98, 3.37) |
| P-trend | — | 0.27 | — | 0.13 |
| aHEI-2010 | ||||
| Q1 (36) | 625/4036 (15.5) | 1.0 (reference) | 27/3270 (0.8) | 1.0 (reference) |
| Q2 (44) | 676/24.5 (17.4) | 1.09 (0.98, 1.20) | 27/3034 (0.9) | 1.04 (0.61, 1.78) |
| Q3 (51) | 682/3950 (17.3) | 1.04 (0.94, 1.15) | 28/3105 (0.9) | 0.97 (0.56, 1.66) |
| Q4 (61) | 773/4088 (18.9) | 1.07 (0.97, 1.19) | 38/3034 (1.3) | 1.28 (0.76, 2.15) |
| P-trend | — | 0.29 | — | 0.36 |
| FD | ||||
| Q1 (19) | 632/3548 (17.8) | 1.0 (reference) | 32/2730 (1.2) | 1.0 (reference) |
| Q2 (22) | 692/4074 (17.0) | 0.96 (0.87, 1.05) | 26/3215 (0.8) | 0.71 (0.42, 1.19) |
| Q3 (25) | 697/4092 (17.0) | 0.94 (0.86, 1.04) | 25/3196 (0.8) | 0.65 (0.39, 1.10) |
| Q4 (29) | 735/4236 (17.4) | 0.95 (0.86, 1.05) | 37/3302 (1.1) | 0.95 (0.59, 1.53) |
| P-trend | — | 0.32 | — | 0.97 |
Analyses were run by using a log-binomial generalized linear model with an exchangeable working correlation structure to compute RR estimates. The reference group for spontaneous abortions was all pregnancies, and the reference group for stillbirths was all pregnancies that lasted >20 wk. aHEI-2010, alternate Healthy Eating Index 2010; aMED, alternate Mediterranean diet; FD, Fertility Diet; SAB, spontaneous abortion; Q, quartile.
Multivariate models were adjusted for age (continuous), total energy intake (continuous), BMI (in kg/m2; <18.5, 18.5–24.9, 25–29.9, ≥30, and missing), smoking status (never, former, current, and missing), physical activity (<3, 3–8.9, 9–17.9, 18–26.9, 27–41.9, and ≥42 metabolic equivalent task-hours per week, and missing), history of infertility (no, yes, and missing), year (continuous), marital status (married and not married), and race (white and nonwhite).