Table 4.
Associations Between Maternal Peripartum Urinary Concentrations of Pyrethroid Metabolites and Birth Outcomes (Based on Marginal Structural Models), Venda Health Examination of Mothers, Babies and Their Environment, Limpopo Province, South Africa, 2012–2013a
| Birth Outcome and Sex | No. of Persons | Pyrethroid Metabolite | |||||||
|---|---|---|---|---|---|---|---|---|---|
| cis-DBCA | cis-DCCA | trans-DCCA | 3-PBA | ||||||
| βb | 95% CI | β | 95% CI | β | 95% CI | β | 95% CI | ||
| Birth weight, g | |||||||||
| All children | 738 | 4.8 | −65.4, 79.8 | 15.8 | −52.9, 83.4 | 5.2 | −57.0, 65.1 | 7.5 | −83.3, 99.8 |
| Boys | 383 | −21.6 | −106.5, 65.6 | 4.7 | −81.5, 90.2 | −16.7 | −95.4, 58.5 | −25.0 | −127.2, 75.9 |
| Girls | 355 | 30.7 | −84.2, 145.7 | 28.3 | −71.8, 131.1 | 32.5 | −52.3, 132.4 | 51.2 | −108.4, 201.3 |
| P for interaction | 0.518 | 0.714 | 0.382 | 0.428 | |||||
| Birth length, cm | |||||||||
| All children | 733 | 0.03 | −0.26, 0.33 | 0.11 | −0.18, 0.37 | 0.02 | −0.24, 0.26 | 0.12 | −0.20, 0.45 |
| Boys | 379 | −0.08 | −0.48, 0.33 | −0.07 | −0.48, 0.28 | −0.15 | −0.48, 0.14 | −0.03 | −0.40, 0.37 |
| Girls | 354 | 0.12 | −0.25, 0.58 | 0.31 | −0.11, 0.70 | 0.23 | −0.15, 0.60 | 0.31 | −0.16, 0.78 |
| P for interaction | 0.474 | 0.156 | 0.088 | 0.274 | |||||
| Head circumference, cm | |||||||||
| All children | 733 | 0.04 | −0.20, 0.27 | 0.06 | −0.20, 0.28 | −0.02 | −0.25, 0.18 | −0.01 | −0.30, 0.27 |
| Boys | 379 | −0.09 | −0.41, 0.19 | −0.02 | −0.41, 0.28 | −0.03 | −0.35, 0.21 | −0.09 | −0.45, 0.27 |
| Girls | 354 | 0.17 | −0.09, 0.46 | 0.15 | −0.13, 0.45 | −0.01 | −0.29, 0.28 | 0.10 | −0.28, 0.46 |
| P for interaction | 0.182 | 0.440 | 0.938 | 0.540 | |||||
| Gestational age, weeks | |||||||||
| All children | 738 | −0.11 | −0.49, 0.27 | 0.07 | −0.26, 0.39 | 0.01 | −0.27, 0.29 | −0.11 | −0.56, 0.29 |
| Boys | 383 | −0.13 | −0.57, 0.33 | 0.11 | −0.34, 0.56 | 0.01 | −0.38, 0.37 | −0.11 | −0.64, 0.34 |
| Girls | 355 | −0.08 | −0.70, 0.50 | 0.02 | −0.48, 0.54 | 0.02 | −0.40, 0.46 | −0.10 | −0.86, 0.62 |
| P for interaction | 0.820 | 0.784 | 0.910 | 0.962 | |||||
| ORc | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI | ||
| Low birth weight | |||||||||
| All children | 738 | 0.97 | 0.45, 2.01 | 0.70 | 0.41, 1.12 | 0.81 | 0.51, 1.22 | 0.73 | 0.36, 1.56 |
| Boys | 383 | 0.75 | 0.32, 1.68 | 0.83 | 0.35, 1.67 | 1.00 | 0.51, 1.77 | 0.98 | 0.41, 2.24 |
| Girls | 355 | 1.09 | 0.37, 2.48 | 0.61 | 0.30, 1.13 | 0.68 | 0.35, 1.17 | 0.57 | 0.19, 1.90 |
| P for interaction | 0.638 | 0.554 | 0.334 | 0.444 | |||||
| Preterm birth | |||||||||
| All children | 738 | 1.11 | 0.69, 1.82 | 0.83 | 0.52, 1.27 | 0.98 | 0.67, 1.44 | 1.12 | 0.66, 1.99 |
| Boys | 383 | 1.22 | 0.72, 2.09 | 0.98 | 0.53, 1.64 | 1.15 | 0.71, 1.75 | 1.31 | 0.71, 2.60 |
| Girls | 355 | 0.99 | 0.43, 2.19 | 0.68 | 0.34, 1.33 | 0.80 | 0.43, 1.47 | 0.90 | 0.33, 2.21 |
| P for interaction | 0.622 | 0.440 | 0.362 | 0.524 | |||||
| Small size for gestational age | |||||||||
| All children | 738 | 0.97 | 0.70, 1.33 | 0.91 | 0.65, 1.32 | 0.99 | 0.72, 1.36 | 1.01 | 0.71, 1.49 |
| Boys | 383 | 1.23 | 0.82, 1.86 | 1.15 | 0.78, 1.84 | 1.16 | 0.81, 1.73 | 1.22 | 0.80, 2.00 |
| Girls | 355 | 0.69 | 0.38, 1.19 | 0.62 | 0.31, 1.19 | 0.73 | 0.41, 1.26 | 0.68 | 0.34, 1.43 |
| P for interaction | 0.088 | 0.082 | 0.140 | 0.186 | |||||
| Large size for gestational age | |||||||||
| All children | 738 | 0.78 | 0.47, 1.34 | 0.91 | 0.45, 1.70 | 0.91 | 0.49, 1.61 | 0.88 | 0.39, 1.84 |
| Boys | 383 | 0.86 | 0.40, 1.92 | 1.25 | 0.44, 2.91 | 1.12 | 0.42, 2.55 | 0.99 | 0.29, 2.99 |
| Girls | 355 | 0.71 | 0.32, 1.58 | 0.60 | 0.21, 1.60 | 0.69 | 0.28, 1.61 | 0.78 | 0.29, 2.02 |
| P for interaction | 0.730 | 0.300 | 0.448 | 0.750 | |||||
Abbreviations: CI, confidence interval; DBCA, (2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid; DCCA, (2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid; OR, odds ratio; 3-PBA, 3-phenoxybenzoic acid.
a Propensity scores and inverse-probability-of-treatment weights were based on conditional probability density functions determined using the Super Learner algorithm (53).
b Change in mean outcome for each 10-fold increase in maternal peripartum pyrethroid metabolite concentration.
c OR for each 10-fold increase in maternal peripartum pyrethroid metabolite concentration.