Healthy preconception and early-pregnancy lifestyle and risk of preterm birth: a prospective cohort study

Relation of preconception eating behaviours to dietary pattern trajectories and gestational weight gain from preconception to late pregnancy

Studies examining preconception eating behaviours with longitudinal dietary patterns from preconception to late pregnancy as well as gestational weight gain (GWG) are limited. We derived dietary pattern trajectories from preconception to late-pregnancy, and related preconception eating behaviours to these trajectories and GWG. Preconception eating behaviours were assessed using the Three-Factor Eating Questionnaire measuring cognitive restraint (CR) - conscious restriction of food intake, emotional eating (EE) - overeating in response to negative emotions, and uncontrolled eating (UE) - overeating with a feeling of lack of control. Dietary intakes were measured at preconception, 20-21 and 34-36 weeks' gestation with food frequency questionnaires. Dietary patterns were determined using factor analysis, and trajectories derived using group-based trajectory modelling. Inadequate and excessive GWG were defined according to Institute of Medicine guidelines based on weights at preconception and the last antenatal visit (median: 38 weeks' gestation). Two dietary patterns were derived: 'Fast Food, Fried Snacks and Desserts (FFD)' and 'Soup, Fish and Vegetables (SFV)'. Adherence trajectories from preconception to late-pregnancy were characterised as consistently high ("stable-high") and low ("stable-low"). Women with higher UE scores had higher odds of being in the "stable-high" trajectory (n = 34) of the FFD pattern [Odds Ratio (OR): 1.25, 95% Confidence Interval (CI): 1.03, 1.51], compared to "stable-low" (n = 260). Percentages of women with inadequate, adequate or excessive GWG were 21.7% (n = 70), 25.8% (n = 83), and 52.5% (n = 169), respectively; women with higher EE scores had a higher likelihood of excessive GWG [Relative Risk Ratio (RRR): 1.35, 95% CI: 1.02, 1.80], but this association was attenuated after adjusting for preconception body mass index. Eating behaviour interventions to improve dietary patterns among pregnant women may need to start as early as preconception, incorporating strategies to manage UE.

Prepregnancy Healthy Lifestyle and Adverse Pregnancy Outcomes

OBJECTIVE

To investigate the association of healthy lifestyle factors before pregnancy (body mass index [BMI] 18.5-24.9, nonsmoking, 150 min/wk or more of moderate-to-vigorous physical activity, healthy eating [top 40% of Dietary Approaches to Stop Hypertension score], no or low-to-moderate alcohol intake [less than 15 g/d], and use of multivitamins) with risk of adverse pregnancy outcomes.

METHODS

We conducted a secondary analysis of prospectively collected data for women without chronic diseases who are participating in an ongoing cohort in the United States (the NHSII [Nurses' Health Study II]). Healthy lifestyle factors preceding pregnancy were prospectively assessed every 2-4 years from 1991 to 2009 with validated measures. Reproductive history was self-reported in 2001 and 2009. A composite outcome of adverse pregnancy outcomes that included miscarriage, ectopic pregnancy, gestational diabetes, gestational hypertension, preeclampsia, preterm birth, stillbirth, or low birth weight was assessed.

RESULTS

Overall, 15,509 women with 27,135 pregnancies were included. The mean maternal age was 35.1±4.2 years. Approximately one in three pregnancies (n=9,702, 35.8%) was complicated by one or more adverse pregnancy outcomes. The combination of six low-risk factors was inversely associated with risk of adverse pregnancy outcomes in a dose-dependent manner ( P for trend <.001). Compared with women who had zero or one healthy lifestyle factor, those with six had a 37% lower risk of adverse pregnancy outcomes (relative risk 0.63, 95% CI 0.55-0.72), driven primarily by lower risks of gestational diabetes, gestational hypertension, and low birth weight. All prepregnancy healthy lifestyle factors, except avoiding harmful alcohol consumption and regular physical activity, were independently associated with lower risk of adverse pregnancy outcomes after mutual adjustment for each other. Healthy BMI, high-quality diet, and multivitamin supplementation showed the strongest inverse associations with adverse pregnancy outcomes. If the observed relationships were causal, 19% of adverse pregnancy outcomes could have been prevented by the adoption of all six healthy lifestyle factors (population attributable risk 19%, 95% CI 13-26%).

CONCLUSION

Prepregnancy healthy lifestyle is associated with a substantially lower risk of adverse pregnancy outcomes and could be an effective intervention for the prevention of adverse pregnancy outcomes.

Combined healthy lifestyle in early pregnancy and risk of gestational diabetes mellitus: A prospective cohort study

OBJECTIVE

To examine the association of a combined healthy lifestyle in early pregnancy with gestational diabetes mellitus (GDM) risk.

DESIGN, SETTING AND POPULATION

A Chinese prospective cohort study with 6980 pregnant women.

METHODS

Individual modifiable lifestyle factors were assessed in early pregnancy and a combined lifestyle score was derived from the sum of the lifestyle factors, with a higher score indicating a healthier lifestyle. The association of a combined healthy lifestyle with GDM risk was examined.

MAIN OUTCOME MEASURES

Gestational diabetes mellitus was diagnosed in middle pregnancy according to the International Association of Diabetes and Pregnancy Study Group criteria or diagnoses in medical records.

RESULTS

Overall, 501 (7.2%) pregnant women were diagnosed with GDM. Being physically active (total energy expenditure in upper three quintiles, i.e. ≥100.1 metabolic equivalent of task [MET]-hours/week; odds ratio [OR] 0.76, 95% confidence interval [CI] 0.63-0.92), healthy diet (total intake of vegetables and fruits ≥5 times/day; OR 0.74, 95% CI 0.59-0.94), sufficient sleep (night-time sleep duration ≥7 hours/night; OR 0.66, 95% CI 0.48-0.90) and healthy weight (early-pregnancy BMI <24.0 kg/m2 ; OR 0.57, 95% CI 0.46-0.71) were associated with lower GDM risk. The GDM risk decreased linearly across the combined lifestyle score (Ptrend  <0.001): women with 2, 3 and 4 lifestyle factors compared with those with 0-1 factor had 38% (OR 0.62, 95% CI 0.46-0.84), 57% (OR 0.43, 95% CI 0.31-0.58) and 66% (OR 0.34, 95% CI 0.22-0.52) lower risks of GDM, respectively.

CONCLUSION

A healthy lifestyle in early pregnancy was associated with a substantially lower GDM risk.

Intrinsic motivation for physical activity, healthy eating, and self-weighing in association with corresponding behaviors in early pregnancy

Healthy lifestyle behaviors influence maternal cardiovascular health, but motivation for them in pregnancy is poorly understood. We examined whether intrinsic motivation (assessed on 5-point scales for each behavior) is associated with three lifestyle behaviors in early pregnancy: physical activity, by intensity level; healthy eating, quantified with the Alternate Healthy Eating Index for Pregnancy (AHEI-P); and weight self-monitoring, a standard weight management technique. Participants in the Northern California Pregnancy, Lifestyle and Environment Study (PETALS) population-based cohort completed validated surveys in early pregnancy (2017-18; N = 472; 22 % Asian, 6 % Black, 30 % Hispanic, 13 % multiracial, 30 % White). Cross-sectional data were analyzed in 2021-22. Overall, 40.7 % (n = 192) met United States national physical activity guidelines; the average AHEI-P score was 62.3 out of 130 (SD 11.4); and 36.9 % reported regular self-weighing (≥once/week; n = 174). In models adjusted for participant characteristics, 1-unit increases in intrinsic motivation were associated with increased likelihood of meeting physical activity guidelines (risk ratio [95 % CI]: 1.66 [1.48, 1.86], p < 0.0001); meeting sample-specific 75th percentiles for vigorous physical activity (1.70 [1.44, 1.99], p < 0.0001) and AHEI-P (1.75 [1.33, 2.31], p < 0.0001); and regular self-weighing (2.13 [1.92, 2.37], p < 0.0001). A 1-unit increase in intrinsic motivation lowered the risk of meeting the 75th percentile for sedentary behavior (0.79 [0.67, 0.92], p < 0.003). Intrinsic motivation was not associated with reaching 75th percentiles for total, light, or moderate activity. Intrinsic motivation is associated with physical activity, healthy eating, and self-weighing among diverse individuals in early pregnancy. Results can inform intervention design to promote maternal health via increased enjoyment of lifestyle behaviors.

Trajectories of depressive symptoms during pregnancy and risk of premature birth: A multicenter and prospective cohort study

Previous studies only assessed the association between depressive symptoms and risk of preterm birth (PTB) at a time-point during pregnancy, resulting in inconsistent or contradictory results. Therefore, we aimed to explore the associations between the trajectories of depressive symptoms during pregnancy and risk of PTB. In total, 7732 pregnant women were included in 24 hospitals from 15 provinces of China. The Edinburgh Postpartum Depression Scale (EPDS) was used to evaluate depressive symptoms in the first, second, and third trimesters. Associations between depressive symptoms and risk of PTB were performed by group-based trajectory modeling (GBTM), propensity score-based inverse probability of treatment weighting (IPTW), and logistic regression. GBTM identified five trajectories: compared with persistently low-stable trajectory of depressive symptoms, women with moderate-stable (OR = 1.23, 95% CI: 1.02-1.76), high-falling (OR = 1.35, 95% CI: 1.11-2.21), moderate-rising (OR = 1.38, 95% CI: 1.06-2.04), and high-stable trajectory of depressive symptoms (OR = 1.40, 95% CI: 1.16-3.28) had an increased risk of PTB. In addition, the associations between trajectories of depressive symptoms and risk of PTB were most significant in multiparous women with a history of PTB. There was no difference in the risk of early-moderate PTB among different trajectories of depressive symptoms and only the risk of late PTB was different among different trajectories. In conclusion, the depressive symptoms of pregnant women were not constant during pregnancy, and different trajectories of depressive symptoms were associated with different risks of PTB.

Diet Quality and Its Relationship with Weight Characteristics in Pregnant Japanese Women: A Single-Center Birth Cohort Study

Maternal underweight and inadequate gestational weight gain (GWG) are problems in Japan. However, increases in food intake aimed at weight gain alone are not sufficient for mother-child health. This study assessed diet quality based on the 3-day dietary records of pregnant women in an urban area of Japan in order to show the importance of evaluating diet quality, using the Nutrient-Rich Food Index 9.3 (NRF9.3), which is one metric based on nutrition profiling, and the Japanese Food Guide Spinning Top (JFGST). After excluding misreporters of energy intake, we stratified women (n = 91) by pre-pregnancy body mass index (BMI) and determined energy intake, diet quality status, and their relationship with GWG. Intakes of carbohydrate-containing staple foods, vegetable dishes, and fruit were insufficient regardless of BMI. Most of the underweight women with inadequate GWG had insufficient energy intake but high diet quality, as assessed by NRF9.3. In contrast, most women who consumed energy within the recommended range had low diet quality and gained weight at inappropriate levels. These results highlight the importance for pregnant Japanese women to maintain diet quality through a nutrient-dense diet, while simultaneously increasing energy intake after evaluation of their individual diet quality.

Clinical analysis on the influencing factors related to preterm twin pregnancy

OBJECTIVE

The aim of this study was to explore the influencing factors of preterm twin pregnancy.

METHODS

In total, 602 twin-pregnant women delivered from February 2016 to February 2020 were analyzed retrospectively. According to whether the pregnant women were preterm or not, they were divided into preterm group (n=363) and term group (n=239). Baseline information, such as maternal age, address, and education level of the pregnant women, were collected. The clinical information of pregnant women, such as chorionic, preeclampsia, gestational diabetes, premature rupture of membranes, abnormal fetal position, and fetal weight, were analyzed. Logistic regression analysis was used to analyze the risk factors. p-value <0.05 was considered statistically significant.

RESULTS

In the preterm group, monochorionic diamniotic comorbidities were significantly higher compared with the control group (p<0.05). Higher risks of preterm group have lower education (p<0.05). Multiple logistic regression analysis demonstrated that education, preeclampsia, and premature rupture of membranes were risk factors for preterm twin pregnancy.

CONCLUSIONS

Preterm birth in twin pregnancy is associated with many risk factors, such as education, preeclampsia, and premature rupture of membranes. Pregnancy supervision and prenatal guidance for twin pregnancy should be strengthened. Furthermore, early detection and diagnosis of comorbidities can improve maternal and neonatal outcomes.

Disordered Maternal and Fetal Iron Metabolism Occurs in Preterm Births in Human

Background. Increasing evidence reveals that iron deficiency during pregnancy causes adverse pregnancy outcomes. Thus far, the mechanisms underlying iron deficiency-associated preterm birth are mostly limited to animal studies. Whether the suggested mechanisms exist in human requires further investigation. The goal of this study was to characterize the iron metabolism in both the maternal side and fetal side in pregnant women with preterm birth. Methods. Serum and placenta samples were collected from 42 pregnant women divided into four groups according to the gestational week. Indicators of iron metabolism, including serum iron, serum hepcidin, placental tissue iron, ferroportin (FPN), transferrin receptor 1 (TfR1), and ferritin, were surveyed using enzyme-linked immunosorbent assays (Elisa), Western blots, and real-time quantitative polymerase chain reactions (qRT-PCR). Results. Significant reduction of maternal serum iron was observed in women with preterm birth relative to those with full-term birth, indicative of worsen iron deficiency in those mothers with preterm birth. Meanwhile, the maternal hepcidin levels were notably diminished in women with preterm birth, whereas the fetal hepcidin levels were comparable between the two groups. Moreover, the placental iron stores were remarkably reduced in the preterm group, associated with reduced concentration of TfR1 and increased FPN concentration relative to the normal controls. In other words, the ratio of placental FPN mass to TfR1 mass (PIDI index) was strikingly increased in the preterm group. Conclusions. Dysregulated iron homeostasis in both the maternal and fetal sides was implicated in preterm births, and disordered regulations in maintaining the placental iron equilibrium were also presumed to account for the compromised fetal iron supply.

RAGE against the Machine: Can Increasing Our Understanding of RAGE Help Us to Battle SARS-CoV-2 Infection in Pregnancy?

The receptor of advanced glycation end products (RAGE) is a receptor that is thought to be a key driver of inflammation in pregnancy, SARS-CoV-2, and also in the comorbidities that are known to aggravate these afflictions. In addition to this, vulnerable populations are particularly susceptible to the negative health outcomes when these afflictions are experienced in concert. RAGE binds a number of ligands produced by tissue damage and cellular stress, and its activation triggers the proinflammatory transcription factor Nuclear Factor Kappa B (NF-κB), with the subsequent generation of key proinflammatory cytokines. While this is important for fetal membrane weakening, RAGE is also activated at the end of pregnancy in the uterus, placenta, and cervix. The comorbidities of hypertension, cardiovascular disease, diabetes, and obesity are known to lead to poor pregnancy outcomes, and particularly in populations such as Native Hawaiians and Pacific Islanders. They have also been linked to RAGE activation when individuals are infected with SARS-CoV-2. Therefore, we propose that increasing our understanding of this receptor system will help us to understand how these various afflictions converge, how forms of RAGE could be used as a biomarker, and if its manipulation could be used to develop future therapeutic targets to help those at risk.

Contribution of maternal cardiometabolic risk factors to racial-ethnicity disparities in preterm birth subtypes

BACKGROUND

There are recognized racial-ethnic disparities in preterm birth and in maternal cardiometabolic risk factors likely linked to systemic racism. However, it is unclear the extent to which cardiometabolic risk factors contribute to the higher rates of preterm birth among minoritized populations.

OBJECTIVE

This study aimed to evaluate racial-ethnic disparities in preterm birth subtypes and the role of maternal cardiometabolic risk factors as mediators of the association between maternal race-ethnicity and preterm birth subtypes.

STUDY DESIGN

This was a retrospective cohort study of 295,210 singleton live births from 2011 to 2018. Preterm birth subtypes were defined as medically indicated and spontaneous preterm birth. Poisson regression with robust standard errors were used to provide estimates of the relative risks and 95% confidence intervals for preterm birth subtypes. Causal mediation analysis used logistic regression models to estimate the natural direct and natural indirect (mediated) effects of maternal cardiometabolic risk factors.

RESULTS

Compared with White individuals, Black, Asian, and Hispanic individuals were at increased risk for having both medically indicated preterm birth (1.45, 1.30-1.61; 1.21, 1.12-1.31; and 1.13, 1.05-1.22, respectively) (risk ratios, 95% confidence intervals, respectively) and spontaneous preterm birth (1.20, 1.08-1.34; 1.34, 1.26-1.43; and 1.16, (1.08-1.23), independent of established risk factors. The extent to which cardiometabolic risk factors mediated the associations between race-ethnicity (each group vs White in separate analyses) and preterm birth subtypes varied by race-ethnicity. Hypertensive disorders mediated 30.1% of the association between Black race-ethnicity and medically indicated preterm birth, but it did not mediate the association for other racial-ethnic groups or for spontaneous preterm birth. Any glucose disorder in pregnancy was a mediator of medically indicated preterm birth and spontaneous preterm birth for Asian (65.8% and 13.9%, respectively) and Hispanic (17.3% and 11.9%) race-ethnicity but not for Black race-ethnicity. Overweight or obesity mediated the association between race-ethnicity and medically indicated preterm birth (15.5% among Black individuals and 25.1% among Hispanic individuals) and spontaneous preterm birth (10.7% among Hispanic individuals) but was not a mediator among Asian individuals.

CONCLUSION

Black, Asian, and Hispanic individuals are at increased risk for preterm birth. Maternal cardiometabolic risk factors partially mediate the associations between race-ethnicity and preterm birth subtypes but the extent varies by race-ethnicity. These findings suggest that strategies that improve and diminish differences in cardiometabolic health between race-ethnicity populations may diminish disparities in preterm birth.

Are pre- and early pregnancy lifestyle factors associated with the risk of preterm birth? A secondary cohort analysis of the cluster-randomised GeliS trial

Background

Maternal lifestyle is discussed as a modifiable determinant in the prevention of preterm birth. However, previous research on associations between individual lifestyle factors and preterm birth risk is inconclusive. In this secondary analysis, we investigated the associations between several modifiable antenatal lifestyle factors and the odds of preterm birth.

Methods

This secondary cohort analysis used data from the cluster-randomised controlled “healthy living in pregnancy” (GeliS) trial. Data were collected from early pregnancy to birth with maternity records, validated questionnaires and birth protocols. Women with complete datasets for all covariates were eligible for analysis. Multivariate logistic regression models, adjusted for recognised risk factors, were fitted to determine whether dietary quality, assessed with a healthy eating index (HEI), physical activity (PA) levels and antenatal anxiety/distress influenced the odds of preterm birth. Moreover, the combined association between pre-pregnancy body mass index (BMI) and HEI on the odds of preterm birth was explored. The independent associations of individual dietary components and types of PA on prematurity were assessed by adjusted logistic regression models.

Results

Overall, 1738 women were included in the analysis. A low HEI significantly increased the odds of preterm birth (OR 1.54 (CI 1.04 – 2.30), p = 0.033), while no associations with either low PA levels or antenatal anxiety/distress were observed. BMI significantly interacted with HEI on the association with prematurity (p = 0.036). Energy % from protein and the intake of average portions of vegetables and cereals were significantly negatively associated with the odds of preterm birth. There was no significant evidence of an association between different types of PA and prematurity.

Conclusions

This cohort analysis revealed that low dietary quality in early pregnancy may increase the chance of giving birth prematurely, while healthier dietary choices may help to prevent preterm birth. More research on pre- and early pregnancy modifiable lifestyle factors is warranted.

Trial registration

This trial is registered with the Clinical Trial Registry ClinicalTrials.gov (NCT01958307). Registration date 09 October 2013, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04513-5.