Growing in the womb: The effect of seismic activity on fetal growth

Secular Trends in Birth Weight in Chile and Its Regions Between 1990 and 2021

OBJECTIVE

The objective is to analyze secular trends in birth weight (BW) for Chile from 1990 to 2021, focusing on the mean BW and low birth weight (LBW) prevalence, and to assess differences across Chilean regions.

METHODS

Our sample, obtained from the Chilean National Statistics Office, contains information on 7 822 975 births, including the total births that took place in Chile from 1990 to 2021. We calculated mean BW and LBW prevalence at a national and a regional level. We also gathered national aggregates from 1974 to 1989 from secondary sources.

RESULTS

At a national level, mean BW increased sharply in Chile from 1983 to 1994 (6%), remained stagnant thereafter, and fell slightly during the last decade and a half. LBW prevalence declined substantially from the mid-1970s to the mid-1990s, from 12% to 5%. It stagnated during the early 1990s, after which there was a small but continuous increase to over 6.5%. Antofagasta is the only outlier: its mean BW and the percentage of LBW are permanently lower and higher, respectively.

CONCLUSIONS

A sharp increase in mean BW from the mid-1980s to the mid-1990s, together with the declining percentage of LBW from the mid-1970s to the mid-1990s, should be due to the better nutritional status of mothers. The decline in mean BW from the early 2000s (as well as the increasing percentage of LBW) may be due to an increasing proportion of preterm births and the increase in the age of women giving birth. The relatively poor performance of Antofagasta is explained by the region's high altitude, which affected large numbers of the population.

Association between earthquakes and perinatal outcomes: A systematic review and meta-analysis

BACKGROUND

Evidence for the association between earthquakes and adverse perinatal outcomes is limited.

OBJECTIVES

To evaluate the association between earthquakes and perinatal outcomes including preterm birth and low birth weight.

SEARCH STRATEGY

We searched studies using MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, World Health Organization International Clinical Trials Platform Search Portal, and ClinicalTrials.gov on February 9, 2023.

SELECTION CRITERIA

We included before-and-after studies that evaluated the associations between earthquakes and perinatal outcomes in women living in affected areas.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data. We calculated the pooled odds ratio (OR) with the random-effects model. We analyzed outcomes in subgroups of Asians and others. We evaluated the certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation system.

MAIN RESULTS

We included 2 607 405 women in 13 studies. Earthquakes may not increase preterm birth (nine studies, 1 761 760 participants: OR 1.10, 95% confidence interval [CI] 0.98-1.24, low certainty of evidence) or low birth weight (seven studies, 1 753 891 participants: OR 1.10, 95% CI 0.94-1.28, low certainty of evidence). Subgroup analyses showed that earthquakes may be associated with an increase of preterm birth among populations in Asia (OR 1.44, 95% CI 1.07-1.95), but this was not evident in others (OR 0.93, 95% CI 0.83-1.05).

CONCLUSIONS

Perinatal outcomes might not change after earthquakes. Further research on the association between earthquakes and perinatal outcomes, combined with an assessment of the characteristics of the region, is needed.

Dust to Feed, Dust to Gray: The Effect of in Utero Exposure to the Dust Bowl on Old-Age Longevity

Intensive agriculture and deep plowing caused topsoil erosion and dust storms during the 1930s, affecting agricultural income and land values for years. Given the growing literature on the relevance of in utero and early-life exposures, it is surprising that studies focusing on links between the Dust Bowl and later-life health have produced inconclusive and mixed results. We reevaluate this literature and study the long-term effects of in utero and early-life exposure to topsoil erosion caused by the 1930s Dust Bowl on old-age longevity. Specifically, using Social Security Administration death records linked with the full-count 1940 census, we conduct event studies with difference-in-differences designs to compare the longevity of individuals in high- versus low-topsoil-erosion counties before versus after 1930. We find intent-to-treat reductions in longevity of approximately 0.85 months for those born in high-erosion counties after 1930. We show that these effects are not an artifact of preexisting trends in longevity. Additional analyses suggest that the effects are more pronounced among children raised in farm households, females, and those whose mothers had lower education. We also provide suggestive evidence that reductions in adulthood income are a likely mechanism for the effects we document.

Terrorist attacks, Islamophobia and newborns' health

Islamophobia has increased in the last years, in part, due to terrorist attacks perpetrated by jihadist groups. This phenomenon might be a source of stress, being particularly problematic for pregnant (Muslim) women. We examine how stress generated by the 2017 Catalonia (Spain) attacks affected the health of newborns whose mothers are from a Muslim country (as the perpetrators). We use a difference-in-differences-in-differences model comparing newborns whose mothers come from a Muslim country and are residing in a municipality directly affected by the attacks, to other newborns, before-after the attacks. Results show that the share of low-birth-weight babies and deliveries with complications raise significantly by 23.77%, and 13.02%. We document a significant increase in Islamophobia and in emotional distress in our group of interest. We conclude that Islamophobia-related stress is possibly one of the channels affecting health at birth.