TABLE 3.
Associations between serum folate and vitamin B-12 concentrations and early ART outcomes in 100 women (141 fresh IVF cycles with egg retrieval) from the Environment and Reproductive Health Study (2007–2013)1
| Adjusted mean (95% CI) |
||||
| Quartile (minimum–maximum) | Total oocyte yield | M2 oocytes | Fertilization rate | Proportion with ≥1 best-quality embryo |
| Serum folate, ng/mL | ||||
| Q1 (9.7–16.6) | 10.9 (9.3, 12.8) | 9.4 (8.0, 11.2) | 0.59 (0.51, 0.69) | 0.45 (0.32, 0.64) |
| Q2 (16.6–20.2) | 13.0 (11.2, 15.1) | 11.2 (9.6, 13.0) | 0.65 (0.58, 0.72) | 0.45 (0.30, 0.68) |
| Q3 (20.3–26.3) | 10.7 (9.0, 12.7) | 8.5 (7.3, 9.9) | 0.69 (0.62, 0.78) | 0.62 (0.46, 0.84) |
| Q4 (26.4–154.2) | 12.4 (10.0, 15.6) | 10.8 (8.7, 13.5) | 0.70 (0.63, 0.78) | 0.52 (0.38, 0.72) |
| P-trend | 0.58 | 0.61 | 0.07 | 0.50 |
| Serum vitamin B-12, pg/mL | ||||
| Q1 (162–438) | 11.3 (9.5, 13.4) | 9.7 (8.2, 11.5) | 0.67 (0.60, 0.75) | 0.52 (0.37, 0.74) |
| Q2 (439–534) | 12.5 (10.4, 15.0) | 10.3 (8.7, 12.3) | 0.65 (0.58, 0.72) | 0.47 (0.36, 0.63) |
| Q3 (535–701) | 10.1 (8.1, 12.8) | 8.7 (6.8, 11.2) | 0.72 (0.66, 0.80) | 0.51 (0.35, 0.74) |
| Q4 (702–2176) | 12.1 (10.6, 13.9) | 10.2 (8.8, 12.0) | 0.60 (0.51, 0.72) | 0.56 (0.38, 0.84) |
| P-trend | 0.92 | 0.91 | 0.47 | 0.68 |
| Low folate, low vitamin B-12 | 12.2 (10.6, 14.1) | 10.4 (9.0, 11.9) | 0.62 (0.56, 0.68) | 0.52 (0.33, 0.81) |
| Low folate, high vitamin B-12 | 10.9 (9.0, 13.2) | 9.8 (7.7, 12.5) | 0.62 (0.50, 0.77) | 0.60 (0.44, 0.80) |
| High folate, low vitamin B-12 | 11.5 (9.0, 14.7) | 9.6 (7.7, 12.5) | 0.72 (0.66, 0.80) | 0.54 (0.38, 0.77) |
| High folate, high vitamin B-12 | 11.4 (9.6, 13.4) | 9.4 (7.9, 11.2) | 0.67 (0.59, 0.76) | 0.42 (0.31, 0.58) |
1
All analyses were conducted by using generalized estimating equations with Poisson distribution for oocyte counts and binomial distribution for rates and proportions and the log link function for all outcomes. All models were adjusted for age (continuous), BMI (continuous), and race (white, other). Tests for trend across quartiles were conducted by using a variable with the median serum concentration in each quartile as a continuous variable. ART, assisted reproductive technology; IVF, in vitro fertilization; Q, quartile.