Does Preconception Health Differ by Nativity?: Findings from the Los Angeles Mommy and Baby (LAMB) Study

The socioeconomic landscape of the exposome during pregnancy

BACKGROUND

While socioeconomic position (SEP) is consistently related to pregnancy and birth outcome disparities, relevant biological mechanisms are manifold, thus necessitating more comprehensive characterization of SEP-exposome associations during pregnancy.

OBJECTIVES

We implemented an exposomic approach to systematically characterize the socioeconomic landscape of prenatal exposures in a setting where social segregation was less distinct in a hypotheses-generating manner.

METHODS

We described the correlation structure of 134 prenatal exogenous and endogenous sources (e.g., micronutrients, hormones, immunomodulatory metabolites, environmental pollutants) collected in a diverse, population-representative, urban, high-income longitudinal mother-offspring cohort (N = 1341; 2009-2011). We examined the associations between maternal, paternal, household, and areal level SEP indicators and 134 exposures using multiple regressions adjusted for precision variables, as well as potential effect measure modification by ethnicity and nativity. Finally, we generated summary SEP indices using Multiple Correspondence Analysis to further explore possible curved relationships.

RESULTS

Individual and household SEP were associated with anthropometric/adiposity measures, folate, omega-3 fatty acids, insulin-like growth factor-II, fasting glucose, and neopterin, an inflammatory marker. We observed paternal education was more strongly and consistently related to maternal exposures than maternal education. This was most apparent amongst couples discordant on education. Analyses revealed additional non-linear associations between areal composite SEP and particulate matter. Environmental contaminants (e.g., per- and polyfluoroalkyl substances) and micronutrients (e.g., folate and copper) showed opposing associations by ethnicity and nativity, respectively.

DISCUSSION

SEP-exposome relationships are complex, non-linear, and context specific. Our findings reinforce the potential role of paternal contributions and context-specific modifiers of associations, such as between ethnicity and maternal diet-related exposures. Despite weak presumed areal clustering of individual exposures in our context, our approach reinforces subtle non-linearities in areal-level exposures.

Maternal Depressive Symptoms and Developmental Delay at Age 2: A Diverse Population-Based Longitudinal Study

OBJECTIVES

Children raised by depressed mothers perform lower on measures of cognitive, emotional, and behavioral skills, compared to children of non-depressed mothers. It is unclear how maternal depressive symptoms (MDS), which persist and accrue over time, impact child development. The purpose of this study was to determine whether cumulative MDS from pre-pregnancy to postpartum influences child development in children by age 2.5.

METHODS

Using a longitudinal population-based study design, 2679 racially and ethnically diverse mothers completed the 2014 Los Angeles Mommy and Baby (LAMB) and 2016 Follow-Up surveys. A total MDS score was created based on responses to standardized questions, including the Patient Health Questionnaire-2 (PHQ-2). Data was collected for before pregnancy, during pregnancy, and 4 months postpartum in the 2014 survey, and at 2.5 years postpartum in the 2016 survey. Child development was measured using the CDC's Learn the Signs. Act Early Milestones Checklist. Bivariate and multivariate logistic regressions were conducted.

RESULTS

The prevalence of any cumulative MDS was 45.2%. Language, cognitive/adaptive, motor, and social-emotional delays for surveyed toddlers were 7.7%, 4.0%, 1.2%, and 14.2%. After adjusting for covariates, mothers reporting depressive symptoms at all four time points were significantly more likely to report a social-emotional delay in their child (aOR = 4.39, 95% CI - 1.72 to 11.18).

CONCLUSIONS FOR PRACTICE

Mothers with cumulative depressive symptoms are at-risk of reporting social-emotional delays by age 2.5. Understanding these effects may help direct resources to target interventions that support mothers with depressive symptoms early-on and promote positive developmental outcomes among their children.

Comparing Birth Outcomes in Hawai'i between US- and Foreign-Born Women

The objective of this study is to examine the relationship between maternal nativity status and preterm birth (PTB) or low birth weight (LBW) for Hawai'i resident mothers, to compare these relationships across different maternal race/ethnicity groups, and to identify other potential risk and protective factors related to PTB and LBW. Using the 2004 Natality Birth Data from the National Vital Statistic System of the National Center for Health Statistics, crude and adjusted odds ratios were calculated using logistic regression to determine maternal racial/ethnic-specific nativity effects on PTB and LBW. Other Asian or Pacific Islander foreign-born mothers had higher unadjusted rates of PTB, and Samoan foreign-born mothers had lower rates of LBW after adjusting for the socio-demographic covariates compared to their native-born counterparts. Given the limitation of this study particularly relating to data quality, further research is needed to identify socio-contextual factors that are involved in the relationship between nativity status and PTB/LBW.

The role of obesity in the risk of gestational diabetes among immigrant and U.S.-born women in New York City

PURPOSE

To examine if the role of obesity in the risk of gestational diabetes differs between immigrant and U.S.-born women.

METHODS

We used New York City-linked 2010-2014 birth certificate and hospital data. We created four racial/ethnic groups (non-Hispanic black, Hispanic, non-Hispanic white, and Asian) and three subgroups (Mexican, Indian, and Chinese). Gestational diabetes mellitus (GDM) was ascertained by the birth certificate checkbox and discharge ICD-9 codes. We calculated relative risks for immigrant status and body mass index with GDM using covariate-adjusted log-binomial regression. We calculated multivariable population attributable risk to estimate the proportion of GDM that could be eliminated if overweight/obesity were eliminated by immigrant status.

RESULTS

Immigrant women had higher risk of GDM than U.S.-born women, with adjusted relative risks ranging from 1.2 among non-Hispanic black women (95% confidence interval, 1.2-1.3) to 1.6 among Hispanic women (95% confidence interval, 1.4-1.8). Increasing body mass index was associated with GDM risk in all groups, but relative risks were weaker among immigrants (P for interaction <.05). The population attributable risk for overweight/obesity was lower in immigrant women than in U.S.-born women in all racial/ethnic groups.

CONCLUSIONS

The lower proportion of GDM attributable to overweight/obesity among immigrant women may point to early life and migration influences on risk of GDM.

Preconception health behaviours: A scoping review

Preconception health refers to the health of males and females at any point in time prior to a potential pregnancy. A goal of preconception health research is to use preventive behaviour and healthcare to optimize the health of future offspring that result from both planned and unplanned pregnancies. This paper briefly reviews evidence of the importance of various preconception health behaviours, and examines the extent to which specific preconception health behaviours have been included in recent studies of such knowledge, behaviours, and intentions. To describe this recent research in highly developed countries, a scoping review of the literature was completed of studies published within the past seven years. A total of 94 studies on preconception health were identified and reviewed: (a) 15 examined knowledge and attitudes, (b) 68 studied behaviours, (c) 18 examined interventions designed to improve knowledge or behaviour, and (d) no studies examined intentions to engage in preconception health behaviours. Over 40% of studies examining preconception health behaviour focussed exclusively on folic acid. Overall, folic acid, alcohol, and cigarettes have consistently been topics of focus, while exposure to harmful environmental substances, stress, and sleep have been largely neglected. Despite strong evidence for the importance of men's health during the preconception period, only 11% of all studies included male participants. Based on existing gaps in the research, recommendations are provided, such as including men in future research, assessing a wider variety of behaviours, consideration of behavioural intentions, and consideration of the relationships between preconception health knowledge, intentions, and behaviour.