TABLE 1.
Agreement Between Medical Records and Maternal Reports
| Medical records (%) | Frequency | Prenatal recall (%) | Frequency | Mother (N = 611)
|
Twin A (N = 287)
|
Twin B (N = 287)
|
|
|---|---|---|---|---|---|---|---|
| κ(95% CI)/ Pearson correlations | κ (95% CI)/ Pearson correlations | κ (95% CI)/ Pearson correlations | |||||
| Maternal history | |||||||
| Previous live births | |||||||
| No | 25.00 | 48 | 25.00 | 48 | |||
| Yes | 75.00 | 144 | 75.00 | 144 | 1.00 (1.00–1.00) | ||
| Medical problems during pregnancy | |||||||
| Respiratory infection | 16.7 | 1 | 0 | 0 | |||
| Urine infection | 66.7 | 4 | 66.7 | 4 | |||
| Asthma | 16.7 | 1 | 33.3 | 2 | 0.67 (0.24–1.00) | ||
| Bleeding during pregnancy | |||||||
| No | 73.20 | 30 | 80.50 | 33 | |||
| Yes | 26.80 | 11 | 19.50 | 8 | 0.39 (0.06–0.71) | ||
| Edema during the pregnancy (any swelling in face, fingers, legs or feet) | |||||||
| None | 48.19 | 40 | 44.58 | 37 | |||
| Yes | 51.81 | 43 | 55.42 | 46 | 0.30 (0.09–0.50) | ||
| Proteinuria during the pregnancy | |||||||
| None | 24.68 | 19 | 85.71 | 66 | |||
| Yes | 75.32 | 58 | 14.29 | 11 | 0.10 (0.03–0.17) | ||
| Pre-elampsia vs pre-elampsia + hypertension | |||||||
| No | 65.71 | 46 | 74.29 | 52 | |||
| Yes | 34.29 | 24 | 25.71 | 18 | 0.60 (0.39–0.80) | ||
| Medication taken during the pregnancy | |||||||
| Antibiotics | 71.43 | 5 | 71.43 | 5 | |||
| Anti-hypertension | 28.57 | 2 | 28.57 | 2 | 1.00 (−1.00–1.00) | ||
| Nausea and vomiting during pregnancy | |||||||
| No | 43.10 | 28 | 63.10 | 41 | |||
| Yes | 56.90 | 37 | 36.90 | 24 | 0.38 (0.17–0.58) | ||
| Weight gain during pregnancy | 0.30* | ||||||
| Substance use during pregnancy (continuous) | |||||||
| Smoking (number of cigarettes per day) | |||||||
| During the pregnancy | 0.25 | ||||||
| During the first trimester | 0.24 | ||||||
| During the second trimester | 0.001 | ||||||
| During the third trimester | 0.01 | ||||||
| Alcohol (number of alcoholic drinks per month) | |||||||
| During the pregnancy | −0.09 | ||||||
| During the first trimester | −0.07 | ||||||
| During the second trimester | −0.06 | ||||||
| During the third trimester | −0.07 | ||||||
| Substance use during pregnancy (dichotomized) | |||||||
| Smoking during pregnancy | |||||||
| No | 70.27 | 26 | 75.68 | 28 | |||
| Yes | 29.73 | 11 | 24.32 | 9 | 0.73 (0.48–0.98) | ||
| Smoking during the first trimester | |||||||
| No | 80.00 | 40 | 86.00 | 43 | |||
| Yes | 20.00 | 10 | 14.00 | 7 | 0.79 (0.56–1.00) | ||
| Smoking during the second trimester | |||||||
| No | 83.33 | 30 | 83.33 | 30 | |||
| Yes | 16.67 | 6 | 16.67 | 6 | 0.80 (0.53–1.00) | ||
| Smoking during the third trimester | |||||||
| No | 80.43 | 37 | 82.61 | 38 | |||
| Yes | 19.57 | 9 | 17.39 | 8 | 0.78 (0.55–1.00) | ||
| Alcohol during pregnancy | |||||||
| No | 72.97 | 27 | 94.59 | 35 | |||
| Yes | 27.03 | 10 | 5.41 | 2 | 0.08 (−0.18–0.35) | ||
| Alcohol in the first trimester | |||||||
| No | 85.71 | 42 | 93.88 | 43 | |||
| Yes | 14.29 | 7 | 6.12 | 6 | 0.13 (−0.22–0.47) | ||
| Alcohol in the second trimester | |||||||
| No | 86.49 | 32 | 97.30 | 36 | |||
| Yes | 13.51 | 5 | 2.70 | 1 | −0.05 (−0.13–0.03) | ||
| Alcohol in the third trimester | |||||||
| No | 82.98 | 39 | 95.74 | 45 | |||
| Yes | 17.02 | 8 | 4.26 | 2 | −0.073 (−0.16–0.01) | ||
| Vitamins during pregnancy | |||||||
| Prenatal vitamins | |||||||
| No | 0.82 | 1 | 12.30 | 15 | |||
| Yes | 99.18 | 121 | 87.70 | 107 | 0.11 (−0.09–0.31) | ||
| Iron supplement during the pregnancy | |||||||
| No | 1.56 | 1 | 37.50 | 24 | |||
| Yes | 98.44 | 63 | 62.50 | 40 | 0.05 (0.05–0.15) | ||
| Folic acid during the pregnancy | |||||||
| No | 16.67 | 1 | 66.67 | 4 | |||
| Yes | 83.33 | 5 | 33.33 | 2 | 0.18 (−0.19–0.56) | ||
| Medical procedures/method of delivery | |||||||
| Method of delivery (Twin A) | |||||||
| Vaginal | 38.20 | 100 | 37.80 | 99 | |||
| C-section | 61.80 | 162 | 62.20 | 163 | 0.94 (0.90–0.98) | ||
| Method of delivery (Twin B) | |||||||
| Vaginal | 32.90 | 85 | 34.50 | 89 | |||
| C-section | 67.10 | 173 | 65.50 | 169 | 0.97 (0.93–1.00) | ||
| Neonatal information | |||||||
| Birth weight | 0.84* | 0.82* | |||||
| Birth length | 0.17 | 0.21* | |||||
| Meconium (Twin A) | |||||||
| No | 91.40 | 170 | 97.80 | 182 | |||
| Yes | 8.6 | 16 | 2.20 | 4 | 0.17 (−0.06–0.4) | ||
| Meconium (Twin B) | |||||||
| No | 91.80 | 169 | 98.90 | 182 | |||
| Yes | 8.2 | 15 | 1.10 | 2 | −0.02 (−0.04—0.00) | ||
| Muscle tone (Twin A) | |||||||
| Limp and some flexion | 7.50 | 12 | 9.40 | 15 | |||
| Active motion | 92.50 | 147 | 90.60 | 144 | 0.70 (0.51–0.89) | ||
| Muscle tone (Twin B) | |||||||
| Limp and some flexion | 11.9 | 19 | 13.1 | 21 | |||
| Active motion | 88.1 | 141 | 86.9 | 139 | 0.26 (0.05–0.46) | ||
| Apgar score — Color (Twin A) | |||||||
| Pale/blue/body pink extra blue | 95.55 | 156 | 19.39 | 32 | |||
| All pink | 5.45 | 9 | 80.61 | 133 | −0.04 (−0.08–0.01) | ||
| Apgar score — Color (Twin B) | |||||||
| Pale/blue/ body pink extra blue | 94.71 | 161 | 22.35 | 38 | |||
| All pink | 5.29 | 9 | 77.65 | 132 | −0.03 (−0.08–0.02) | ||
| Respiratory distress (Twin A) | |||||||
| No | 67.80 | 139 | 83.90 | 172 | |||
| Yes | 32.20 | 66 | 16.10 | 33 | 0.32 (0.18–0.45) | ||
| Respiratory distress (Twin B) | |||||||
| No | 75.50 | 154 | 81.40 | 166 | |||
| Yes | 24.50 | 50 | 18.60 | 38 | 0.34 (0.19–0.49) | ||
| Post-delivery complications | |||||||
| Jaundice (Twin A) | |||||||
| No | 60.60 | 137 | 79.60 | 180 | |||
| Yes | 39.40 | 89 | 20.40 | 46 | 0.18 (0.06–0.30) | ||
| Jaundice (Twin B) | |||||||
| No | 58.3 | 127 | 78.0 | 170 | |||
| Yes | 41.7 | 91 | 22.0 | 48 | 0.28 (0.16–0.40) | ||
| NICU (Twin A) | |||||||
| No | 64.50 | 138 | 61.70 | 132 | |||
| Yes | 35.50 | 76 | 38.30 | 82 | 0.80 (0.72–0.88) | ||
| NICU (Twin B) | |||||||
| No | 67.90 | 146 | 59.10 | 127 | |||
| Yes | 32.10 | 69 | 40.90 | 88 | 0.65 (0.55–0.76) | ||
Note:
*
p < .05.
κ is not calculated for this dataset because observed concordance is smaller than mean-chance concordance.
NICU = neonatal intensive care unit.
In the prenatal recall record, seven different illnesses were combined into one variable (0 = none, 1 = respiratory infection, 2 = urinary tract infection, 3 = gall bladder inflammation, 4 = measles, 5 = TB, 6 = epilepsy, 7 = asthma). Due to limited data for some diseases, we only kept respiratory infection, urinary tract infection, and asthma when calculating the κ statistic. Two variables in prenatal record, pre-eclampsia and hypertension, were combined and paired with pre-eclampsia in medical records.