Table 2.
Characteristics of the studies included in the systematic review.
| Author | Study Design | Country | n | Gestational Age (Weeks) | Analysis Method | Alpha-Tocopherol (mmol/L) in the Umbilical Cord Blood *** Mean ± Standard Deviation |
% VED | VED Cutoff (mmol/Ll) | Use of Maternal Supplement | Factors Related to Alpha-TOH | QualityAssessment ** | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Preterm | Full-Term | |||||||||||
| Wu; Chou [20] (2001) |
Cross-Sectional | NA | 35 PTN 34 TN |
PTN: 28 to 34 TN: 38 to 42 |
HPLC | 3.9 ± 2.1 | 4.9 ± 2.9 | PTN: 100% TN: 94% |
<11.6 | NA | Circulating lipids | 5 |
| Chan et al. [21] (1999) |
Cross-Sectional | NA | 40 PTN 180 TN |
NA | HPLC | 6.1 * | 6.4 * | PTN: 38% TN: 19% |
<3.5 | NA | Gestational Age and tocopherol in the umbilical cord | 4 |
| Gonzalez-Corbella et al. [24] (1998) |
Cohort | Spain | 8 PTN 48 TN |
PTN: 34 to 36 TN: >37 |
HPLC | 8.2 ± 2.2 | 12.1 ± 7.3 | NA | NA | NA | Income | 6 |
| Rodrigues [25] (2016) |
Cohort | Brazil | 124 PTN 111 TN |
PTN: <37 TN: >37 |
HPLC | 6.4 ± 3.1 | 5.5 ± 3.0 | PTN: 94% TN: 92% |
<11.6 | None | Maternal alpha-tocopherol | 7 |
| Ghany et al. [28] (2016) |
Case-Control | Egypt | 100 PTN 100 TN |
PTN: 27 to 34 TN: 37 to 40 |
HPLC | 5.2 * | 14.9 * | NA | NA | NA | Gestational age | 7 |
| Kiely et al. [22] (1999) |
Cross-Sectional | Ireland | 40 PTN | NA | HPLC | NA | 7.2 * | NA | NA | None | Circulating Triglycerides | 5 |
| Gutcher [26] (1984) |
Cohort | USA | 62 PTN | 31 | HPLC | 5.8 ± 2.5 | NA | NA | NA | NA | Hemolysis | 6 |
| Kaempf et al. [27] (1998) |
Cohort | NA | 14 PTN | 30 | HPLC | 8.5 ± 3.0 | NA | NA | NA | NA | Gestational age and alpha-tocopherol in the umbilical cord | 5 |
| Okolo et al. [23] (1989) |
Cross-Sectional | Nigeria | 25 TN | 37 to 42 | HPLC | NA | 11.1 ± 4.7 | NA | NA | NA | NA | 5 |
| Didenco et al. [8] | Cross-Sectional | USA | 19 TN | ≥38 | HPLC | NA | 6.7 ± 2.5 | NA | NA | Yes | Maternal alpha-tocopherol (after adjustment for total lipids) | 2 |
NA—Not evaluated/presented. * No standard deviation. ** Newcastle–Ottawa Scale. n—sample number. *** All studies used umbilical cord serum for alpha-tocopherol analysis. VED—Vitamin E deficiency. PTN—Preterm newborn. TN—Term newborn. Alpha-TOH—Alpha-tocopherol.