Table 1.
Characteristics of the mothers of Avon Longitudinal Study of Parents and Children (ALSPAC) (1991–1992) sub-study population (N = 905) by maternal serum concentrations of perfluoroalkyl substance (ng/mL).
| Characteristica | Frequency n (%) |
PFOA Median (IQR) |
PFOS Median (IQR) |
PFHxS Median (IQR) |
PFNA Median (IQR) |
|---|---|---|---|---|---|
| Mothers of sons (N = 457) | |||||
| Overall | 457 (100) | 3.0 (2.3–3.8) | 13.8 (11.0–17.7) | 1.9 (1.4–2.5) | 0.4 (0.3–0.5) |
| Maternal race | nb | ||||
| White | 441b | 3.0 (2.3–3.8) | 13.9 (11.0–17.9) | 1.9 (1.4–2.5) | 0.4 (0.3–0.5) |
| Non-white | < 5b | 2.1 (2.0–6.3) | 12.7 (9.1–15.6) | 1.3 (1.0–4.1) | 0.2 (0.2–0.3) |
| Maternal educationc | n = 446 | ||||
| < O-level | 96 (21.5) | 2.8 (2.4–3.6) | 13.9 (11.0–17.3) | 1.9 (1.5–2.3) | 0.4 (0.3–0.5) |
| O-level | 154 (34.5) | 3.1 (2.3–3.8) | 14.8 (11.9–18.9) | 1.8 (1.3–2.3) | 0.4 (0.3–0.4) |
| > O-level | 196 (43.9) | 3.0 (2.3–3.9) | 13.6 (10.7–17.2) | 1.9 (1.4–2.5) | 0.3 (0.3–0.4) |
| Pre-pregnancy BMI, kg/m2 | |||||
| <18.5 (underweight) | 46 (11.1) | 3.0 (2.2–3.7) | 13.8 (10.1–18.4) | 1.9 (1.5–2.3) | 0.3 (0.2–0.4) |
| 18.5–24.99 (normal weight) | 282 (68.3) | 3.0 (2.3–3.8) | 14.2 (11.2–18.6) | 1.9 (1.4–2.5) | 0.4 (0.3–0.5) |
| 25–29.99 (overweight) | 63 (15.3) | 2.8 (2.4–3.6) | 13.5 (10.6–17.1) | 2.0 (1.5–2.5) | 0.3 (0.3–0.4) |
| ≥30 (obese) | 22 (5.3) | 2.8 (2.4–3.9) | 12.0 (10.1–15.6) | 1.7 (1.1–1.9) | 0.3 (0.3–0.4) |
| Prenatal smoking | n = 441 | ||||
| Any | 44 (10.0) | 3.0 (2.4–3.6) | 13.2 (11.0–17.2) | 2.0 (1.7–2.6) | 0.4 (0.3–0.5) |
| None | 397 (90.0) | 3.0 (2.3–3.8) | 14.0 (11.1–17.9) | 1.9 (1.4–2.4) | 0.4 (0.3–0.5) |
| Maternal age at delivery, years | n = 453 | ||||
| < 25 | 54 (11.9) | 3.0 (2.3–3.7) | 12.6 (10.6–16.9) | 1.6 (1.1–1.9)* | 0.4 (0.3–0.4) |
| 25–29 | 188 (41.5) | 3.2 (2.5–4.0) | 14.1 (11.9–18.8) | 1.8 (1.4–2.5)* | 0.4 (0.3–0.5) |
| ≥30 | 211 (46.6) | 2.9 (2.2–3.7) | 13.9 (10.8–17.3) | 1.9 (1.4–2.5)* | 0.4 (0.3–0.5) |
| Gestational age, weeks | n = 457 | ||||
| <37 weeks | 26 (5.7) | 3.4 (2.4–3.9) | 13.8 (12.8–17.0) | 1.8 (1.5–2.7) | 0.4 (0.3–0.5) |
| ≥37 weeks | 431 (94.3) | 2.9 (2.3–3.8) | 13.8 (10.9–17.9) | 1.9 (1.4–2.5) | 0.4 (0.3–0.5) |
| Parity | n = 442 | ||||
| Nulliparous | 213 (48.2) | 3.4 (2.7–4.2)* | 14.3 (11.8–18.0)* | 2.0 (1.5–2.6)* | 0.4 (0.3–0.5)* |
| Multiparous | 229 (51.8) | 2.6 (2.2–3.3)* | 13.6 (10.6–17.0)* | 1.8 (1.3–2.3)* | 0.3 (0.2–0.4)* |
| Gestational weight gaind | n = 391 | ||||
| Below | 115 (29.4) | 2.8 (2.3–3.7) | 13.9 (11.2–17.6) | 1.9 (1.4–2.5) | 0.4 (0.3–0.5) |
| Within | 171 (43.7) | 3.0 (2.3–3.8) | 13.8 (11.0–17.7) | 1.9 (1.4–2.5) | 0.4 (0.3–0.5) |
| Above | 105 (26.9) | 3.1 (2.5–3.8) | 13.6 (11.0–17.6) | 1.9 (1.4–2.5) | 0.4 (0.4–0.6) |
| Mothers of daughters (N = 448) | |||||
| Overall | 448 (100) | 3.7 (2.8–4.8) | 19.8 (15.1–24.9) | 1.6 (1.2–2.2) | 0.5 (0.4–0.7) |
| Maternal race | n = 431 | ||||
| White | 423 (98.1) | 3.8 (2.9–4.8)* | 19.9 (15.2–25.3)* | 1.6 (1.2–2.2) | 0.5 (0.4–0.7) |
| Non-white | 8 (1.9) | 2.3 (1.6–2.9)* | 14.6 (8.1–18.4)* | 1.4 (0.9–1.7) | 0.5 (0.2–0.7) |
| Maternal educationc | n = 429 | ||||
| < O-level | 89 (20.7) | 3.6 (2.8–4.4) | 18.2 (14.9–23.3) | 1.6 (1.3–2.2) | 0.5 (0.4–0.7) |
| O-level | 140 (32.6) | 3.7 (2.9–5.0) | 19.6 (15.1–26.0) | 1.6 (1.2–2.3) | 0.6 (0.4–0.7) |
| > O-level | 200 (46.6) | 3.9 (2.8–4.8) | 20.4 (15.2–25.3) | 1.7 (1.2–2.2) | 0.5 (0.4–0.7) |
| Pre-pregnancy BMI, kg/m2 | n = 401 | ||||
| < 18.5 (underweight) | 43 (10.7) | 3.1 (2.4–4.7) | 17.0 (14.0–24.7) | 1.6 (1.0–2.7) | 0.5 (0.3–0.6) |
| 18.5–24.99 (normal weight) | 268 (66.8) | 3.8 (2.8–4.8) | 20.2 (15.3–25.2) | 1.6 (1.2–2.2) | 0.5 (0.4–0.7) |
| 25–29.99 (overweight) | 63 (15.7) | 3.5 (2.9–4.4) | 19.2 (15.2–24.8) | 1.7 (1.3–2.3) | 0.5 (0.4–0.7) |
| ≥30 (obese) | 27 (6.7) | 4.1 (3.3–5.0) | 20.4 (17.0–27.9) | 1.5 (1.3–2.2) | 0.7 (0.4–0.7) |
| Prenatal smoking | n = 427 | ||||
| Any | 79 (18.5) | 3.4 (2.9–4.4) | 17.2 (13.4–21.4)* | 1.7 (1.3–2.4) | 0.5 (0.3–0.7)* |
| None | 348 (81.5) | 3.8 (2.8–4.9) | 20.5 (15.4–25.6)* | 1.6 (1.2–2.2) | 0.6 (0.4–0.7)* |
| Maternal age at delivery, years | n = 445 | ||||
| < 25 | 92 (20.7) | 3.9 (3.0–4.8) | 18.5 (14.1–23.1) | 1.6 (1.2–2.1) | 0.5 (0.4–0.6) |
| 25–29 | 164 (36.9) | 3.8 (3.0–4.9) | 20.7 (15.4–25.4) | 1.6 (1.2–2.1) | 0.6 (0.4–0.7) |
| ≥30 | 189 (42.5) | 3.6 (2.5–4.6) | 19.7 (15.1–25.5) | 1.7 (1.2–2.4) | 0.5 (0.4–0.7) |
| Gestational age, weeks | n = 448 | ||||
| < 37 weeks | 17 (3.8) | 4.4 (2.8–5.3) | 22.7 (15.3–27.5) | 1.7 (1.2–1.9) | 0.6 (0.4–0.7) |
| ≥37 weeks | 431 (96.2) | 3.7 (2.8–4.8) | 19.6 (15.0–24.8) | 1.6 (1.2–2.3) | 0.5 (0.4–0.7) |
| Parity | n = 419 | ||||
| Nulliparous | 208 (49.6) | 4.4 (3.4–5.4)* | 21.5 (17.0–26.4)* | 1.8 (1.4–2.4)* | 0.6 (0.4–0.7)* |
| Multiparous | 211 (50.4) | 3.1 (2.4–4.0)* | 18.2 (14.2–23.7)* | 1.5 (1.1–2.2)* | 0.5 (0.3–0.7)* |
| Gestational weight gaind | n = 379 | ||||
| Below | 120 (31.7) | 3.6 (2.8–4.6) | 21.4 (15.7–25.6) | 1.6 (1.2–2.4) | 0.5 (0.4–0.7) |
| Within | 141 (37.2) | 3.9 (2.8–4.8) | 20.4 (15.2–24.8) | 1.6 (1.2–2.2) | 0.5 (0.4–0.7) |
| Above | 118 (31.3) | 3.9 (2.9–4.9) | 20.0 (15.5–25.6) | 1.7 (1.3–2.3) | 0.6 (0.4–0.7) |
Abbreviations: n, number; g, grams; kg, kilograms; kg/m2, kilograms per meter-squared; IQR, interquartile range.
Compared using Kruskal–Wallis or Wilcoxon Rank Sum tests.
Counts and percents suppressed due to small cell sizes.
< O-level = none, Certificate of Secondary Education, and vocational education, which are equivalent to no diploma or a GED in the United States. O-levels (ordinary levels) are required and completed at the age of 16. > O-level = A-levels (advanced levels) completed at 18, which are optional, but required to get into university; and a university degree.
Refers to below, within, or above IOM recommended total gestational weight gain. For underweight women (BMI < 18.5), recommendations are 12.5–18 kg total weight gain; for normal weight women (BMI 18.5–24.9): 11.5–16 kg; for overweight women (BMI 25.0–29.9): 7–11.5 kg; and for obese women (BMI ≥ 30.0): 5–9 kg [28].
Indicates p < 0.05.