Table 2. Maternal Characteristics According to Offspring’s Congenital Heart Disease (CHD) Statusa.
| Demographic characteristics | Participants, No. (%) | P value | |
|---|---|---|---|
| CHD cases (n = 129) | Controls (n = 516) | ||
| Age, mean (SD), y | 31.5 (5.45) | 31.6 (5.25) | .93 |
| Education, y | |||
| ≤12 | 3 (2.3) | 10 (1.9) | .78 |
| >12 | 126 (97.7) | 506 (98.1) | |
| Unemployed | |||
| Yes | 16 (12.5) | 42 (8.2) | .13 |
| No | 113 (87.5) | 474 (91.8) | |
| Reproductive history | |||
| Nulliparous | |||
| Yes | 72 (55.8) | 306 (59.3) | .16 |
| No | 57 (44.2) | 210 (40.7) | |
| Elective/spontaneous abortion history | |||
| Yes | 53 (41.1) | 176 (34.1) | .13 |
| No | 76 (58.9) | 340 (65.9) | |
| Obstetrical complications | |||
| Prepregnancy body mass index, mean (SD)b | 20.7 (3.0) | 20.8 (3.2) | .82 |
| Pregnancy with diabetes | |||
| Yes | 18 (14.0) | 103 (20.0) | .11 |
| No | 111 (86.0) | 413 (80.0) | |
| Pregnancy with hypertension | |||
| Yes | 10 (7.8) | 35 (6.8) | .70 |
| No | 119 (92.2) | 481 (93.2) | |
| Pregnancy with cardiac disease | |||
| Yes | 15 (11.6) | 52 (10.1) | .61 |
| No | 114 (88.4) | 464 (89.9) | |
| Pregnancy with infection | |||
| Yes | 16 (12.4) | 50 (9.7) | .37 |
| No | 113 (87.6) | 466 (90.3) | |
| IVF-ET | |||
| Yes | 6 (4.7) | 26 (5.0) | .86 |
| No | 123 (95.3) | 490 (95.0) | |
| Medication usage during pregnancy | |||
| Periconceptional folic acid supplementation | |||
| Yes | 122 (94.6) | 489 (94.8) | .93 |
| No | 7 (5.4) | 27 (5.2) | |
| Antibiotics use | |||
| Yes | 7 (5.4) | 26 (5.0) | .28 |
| No | 122 (94.6) | 490 (95.0) | |
| Antimiscarriage medicine uses | |||
| Yes | 11 (8.5) | 68 (13.2) | .62 |
| No | 118 (91.5) | 448 (86.8) | |
| Gestational weeks at blood collection, mean (SD) | 16.45 (5.57) | 16.85 (2.55) | .51 |
| Serum folate, ng/mL, median (IQR)c | 16.0 (10.6-18.6) | 17.2 (14.4-18.5) | .06 |
| Serum vitamin B12, pg/mL, median (IQR) | 280 (208-399) | 395 (307-512) | <.001 |
| Serum homocysteine, mg/L, median (IQR) | 0.9 (0.7-1.2) | 0.7 (0.6-0.8) | <.001 |
| Folate metabolism-related gene polymorphisms | |||
| MTHFR 677 | |||
| CC | 74 (60.7) | 255 (53.5) | .43 |
| CT | 35 (28.7) | 181 (37.9) | |
| TT | 13 (10.7) | 41 (8.6) | |
| MTHFR 1298 | |||
| AA | 78 (63.9) | 275 (57.7) | .43 |
| AC | 37 (30.3) | 179 (37.5) | |
| CC | 7 (5.7) | 23 (4.8) | |
| MTRR 66 | |||
| AA | 66 (54.1) | 265 (55.6) | .94 |
| AG | 48 (39.3) | 168 (35.2) | |
| GG | 8 (6.6) | 44 (9.2) | |
Abbreviations: IVF-ET, in vitro fertilization and embryo transfer; MTHFR, 5,10-methylenetetrahydrofolate reductase; MTRR, 5-methyltetrahydrofolate-homocysteine methyltransferase reductase.
SI Conversion factors: To convert folate to nmol/L, multiply by 2.266; homocysteine to μmol/L, multiply by 7.397; vitamin B12 to pmol/L, multiply by 0.7378.
The comparison of maternal characteristics between CHD cases and non-CHD controls was conducted using univariate conditional logistic regression.
Calculated as weight in kilograms divided by height in meters squared.
The P value was .06 in the crude model; .08 in the model with adjustment for gene polymorphisms of MTHFR 677, MTHFR 1298, and MTRR 66; and .99 in the model with additional adjustment for periconceptional folic acid supplementation.