Preterm birth and air pollution: Critical windows of exposure for women with asthma
Journal of Allergy and Clinical Immunology, DOI: http://dx.doi.org/10.1016/j.jaci.2015.12.1309
Pauline Mendola, PhD, Maeve Wallace, PhD, Beom Seuk Hwang, PhD, Danping Liu, PhD, Candace Robledo, PhD, Tuija Mӓnnistӧ, MD, PhD, Rajeshwari Sundaram, PhD, Seth Sherman, PhD, Qi Ying, PhD, Katherine L. Grantz, MD, MS
Asthmatics avoid air pollution and thus get less vitamin D
- Women with asthma 35X more likely to be vitamin D deficient – Oct 2013
- Overview Asthma and Vitamin D
- Pre-term birth - many of risk factors are associated with low vitamin D
- Fewer pre-term births after pollution reduction (vitamin D not mentioned) April 2014
- Air Pollution reduces Vitamin D
- Higher air pollution associated with 7 ng lower vitamin D levels – Aug 2013
- Air pollution associated with poor bone density (less vitamin D) – Nov 2017
Healthy pregnancies need lots of vitamin D has the following summary
Most were taking 2,000 to 7,000 IU daily for >50% of pregnancy
Click on hyperlinks for details
Problem | Vit. D Reduces | Evidence |
0. Chance of not conceiving | 3.4 times | Observe |
1. Miscarriage | 2.5 times | Observe |
2. Pre-eclampsia | 3.6 times | RCT |
3. Gestational Diabetes | 3 times | RCT |
4. Good 2nd trimester sleep quality | 3.5 times | Observe |
5. Premature birth | 2 times | RCT |
6. C-section - unplanned | 1.6 times | Observe |
Stillbirth - OMEGA-3 | 4 times | RCT - Omega-3 |
7. Depression AFTER pregnancy | 1.4 times | RCT |
8. Small for Gestational Age | 1.6 times | meta-analysis |
9. Infant height, weight, head size within normal limits | RCT | |
10. Childhood Wheezing | 1.3 times | RCT |
11. Additional child is Autistic | 4 times | Intervention |
12.Young adult Multiple Sclerosis | 1.9 times | Observe |
13. Preeclampsia in young adult | 3.5 times | RCT |
14. Good motor skills @ age 3 | 1.4 times | Observe |
15. Childhood Mite allergy | 5 times | RCT |
16. Childhood Respiratory Tract visits | 2.5 times | RCT |
RCT = Randomized Controlled Trial
Background
Ambient air pollutants may increase preterm birth (PTB) risk, but critical exposure windows are uncertain. The interaction of asthma and pollutant exposure is rarely studied.
Objective
We sought to assess the interaction of maternal asthma and air pollutant exposures in relation to PTB risk.
Methods
Electronic medical records for 223,502 US deliveries were linked with modified Community Multiscale Air Quality model outputs. Logistic regression with generalized estimating equations estimated the odds ratio and 95% CIs for PTB on the basis of the interaction of maternal asthma and particulate matter with aerodynamic diameter of less than 2.5 microns and particulate matter with aerodynamic diameter of less than 10 microns, ozone (O3), nitrogen oxides (NOx), sulfur dioxide (SO2), and carbon monoxide (CO) per interquartile range. For each gestational week 23 to 36, exposures among women who delivered were compared with those remaining pregnant. Three-month preconception, whole pregnancy, weeks 1 to 28, and the last 6 weeks of gestation averages were also evaluated.
Results
On assessing PTB by gestational week, we found that significant asthma interactions were sporadic before 30 weeks but more common during weeks 34 to 36, with higher risk among mothers with asthma for NOx, CO, and SO2 exposure and an inverse association with O3 in week 34. Odds of PTB were significantly higher among women with asthma for CO and NOx exposure preconception and early in pregnancy. In the last 6 weeks of pregnancy, PTB risk associated with particulate matter with aerodynamic diameter of less than 10 microns was higher among women with asthma.
Conclusions
Mothers with asthma may experience a higher risk for PTB after exposure to traffic-related pollutants such as CO and NOx, particularly for exposures 3-months preconception and in the early weeks of pregnancy.
Publisher wants $32 for the PDF
See also web
- Pollution Tied to Premature Births, Especially in Women With Asthma NYT March 2016
“Asthmatic women exposed to pollutants in the three months before conception were at a 28 percent higher risk for preterm birth than women without asthma exposed at the same time in the same conditions.”
Their recommendation appears to be wrong “pregnant women should avoid outdoor activity when pollution levels rise.”