Maternal pre-pregnancy body mass index and risk of preterm birth: a collaboration using large routine health datasets

BACKGROUND

Preterm birth (PTB) is a leading cause of child morbidity and mortality. Evidence suggests an increased risk with both maternal underweight and obesity, with some studies suggesting underweight might be a greater factor in spontaneous PTB (SPTB) and that the relationship might vary by parity. Previous studies have largely explored established body mass index (BMI) categories. Our aim was to compare associations of maternal pre-pregnancy BMI with any PTB, SPTB and medically indicated PTB (MPTB) among nulliparous and parous women across populations with differing characteristics, and to identify the optimal BMI with lowest risk for these outcomes.

METHODS

We used three UK datasets, two USA datasets and one each from South Australia, Norway and Denmark, together including just under 29 million pregnancies resulting in a live birth or stillbirth after 24 completed weeks gestation. Fractional polynomial multivariable logistic regression was used to examine the relationship of maternal BMI with any PTB, SPTB and MPTB, among nulliparous and parous women separately. The results were combined using a random effects meta-analysis. The estimated BMI at which risk was lowest was calculated via differentiation and a 95% confidence interval (CI) obtained using bootstrapping.

RESULTS

We found non-linear associations between BMI and all three outcomes, across all datasets. The adjusted risk of any PTB and MPTB was elevated at both low and high BMIs, whereas the risk of SPTB was increased at lower levels of BMI but remained low or increased only slightly with higher BMI. In the meta-analysed data, the lowest risk of any PTB was at a BMI of 22.5 kg/m2 (95% CI 21.5, 23.5) among nulliparous women and 25.9 kg/m2 (95% CI 24.1, 31.7) among multiparous women, with values of 20.4 kg/m2 (20.0, 21.1) and 22.2 kg/m2 (21.1, 24.3), respectively, for MPTB; for SPTB, the risk remained roughly largely constant above a BMI of around 25-30 kg/m2 regardless of parity.

CONCLUSIONS

Consistency of findings across different populations, despite differences between them in terms of the time period covered, the BMI distribution, missing data and control for key confounders, suggests that severe under- and overweight may play a role in PTB risk.

The dynamic nexus: exploring the interplay of BMI before, during, and after pregnancy with Metabolic Syndrome (MetS) risk in Chinese lactating women

BACKGROUND AND AIM

The health implications of BMI and MetS in lactating women are significant. This study aims to investigate the relationship between risk of Mets in lactation and BMI in four stages: pre-pregnancy, prenatal period, 42 days postpartum, and current lactation.

METHODS AND RESULTS

A total of 1870 Lactating Women within 2 years after delivery were included from "China Child and Lactating Mother Nutrition Health Surveillance (2016-2017)". Logistic regression model and Restricted cubic spline (RCS) were used to estimate the relationship between BMI and risk of MetS. ROC analysis was used to determine the threshold for the risk of MetS. Chain mediating effect analysis was used to verify the mediating effect. BMI of MetS group in all stages were higher than non-MetS group (P < 0.0001). There were significant positive correlations between BMI in each stage and ORs of MetS during lactation (P < 0.05). The best cut-off values for BMI in the four stages were 23.47, 30.49, 26.04 and 25.47 kg/m2. The non-linear spline test at BMI in 42 days postpartum, current and MetS in lactation was statistically significant (P non-linear = 0.0223, 0.0003). The mediation effect of all chains have to work through lactation BMI. The total indirect effect accounted for 80.95% of the total effect.

CONCLUSIONS

The risk of MetS in lactating women is due to a high BMI base before pregnancy and postpartum. High BMI in all stages of pregnancy and postpartum were risk factors for MetS in lactation. BMI during lactation plays a key role in the risk of MetS.

Impact of pre-pregnancy weight on the risk of premature rupture of membranes in Chinese women

Objective

The objective of this study was to investigate the influence of pre-pregnancy body mass index (BMI) on the incidence of premature rupture of membranes (PROM) among Chinese women.

Methods

This was a hospital-based retrospective cohort study of 75,760 Chinese women who had live singleton births between 2016 and 2020. In this study, we utilized logistic regression analysis to estimate the association between pre-pregnancy BMI and PROM based on gestational age.

Results

Prior to pregnancy, being overweight or obese was found to be significantly associated with an increased risk of preterm premature rupture of membranes (PPROM), as evidenced by adjusted odds ratios and 95 % confidence intervals of 1.336 (1.173-1.522) and 1.411 (1.064-1.872), respectively. Those with PPROM were divided into three groups according to gestational age: 22-27, 28-31, and 32-36 weeks. Women who were overweight or obese prior to pregnancy had a higher likelihood of experiencing PROM between 22 and 27 weeks of gestation. This finding remained consistent even after controlling for potential confounding factors, such as gestational diabetes mellitus (GDM), gestational hypertension, preeclampsia, hydramnios, cervical abnormalities, and a history of preterm birth.

Conclusion

Our research findings indicate that being overweight or obese before pregnancy is linked to a higher likelihood of experiencing PPROM. Therefore, achieving optimal weight before pregnancy is important to prevent PPROM and its associated complications.

Determination of pre-pregnancy fear of childbirth levels in Turkish and Syrian refugee individuals with no children: A comparative study

Objective

This study was conducted to determine pre-pregnancy fear of childbirth levels and related factors in Turkish and Syrian refugee individuals with no children.

Study design

A cross-sectional-descriptive design was used. The study was carried out between September 29 and November 15, 2022 with Turkish and Syrian refugee women with no children who presented to the Obstetrics and Gynecology Polyclinic of a state hospital and their spouses. A total of 545 people, including the spouses of the women who wanted to participate, were included in the study. The data were collected by the researcher in the waiting room of the outpatient clinic by using the face-to-face interview method. A Personal Information Form and the Childbirth Fear-Prior to Pregnancy Scale were used to collect the research data.

Results

There was no statistically significant relationship between participants' culture and their age, education level, employment status, family type, income level, and birth preferences (p > 0.05), and the groups were independent and homogeneous in terms of the specified characteristics. It was determined that Syrian refugee women had a significantly higher total score on the Childbirth Fear-Prior to Pregnancy Scale than Turkish women. Also, the score of Syrian refugee men on the same scale was significantly higher than that of Turkish men. A statistically significant difference was found between the total scores of the Turkish and Syrian participants according to age, education level, and preferred mode of birth.

Conclusions

In the current study, it was determined that both genders and cultures had a fear of childbirth, although it was more common in women and Syrian refugees. According to the findings of the study, culture, gender, age, education level, and preferred mode of birth were factors related to childbirth fear prior to pregnancy.

Utility of the capability, opportunity, and motivation behaviour (COM-B) model in explaining the negative association between pre-pregnancy body mass index and exclusive breastfeeding at six weeks postpartum

The mechanisms underlying the negative associations between pre-pregnancy body mass index (BMI) and exclusive breastfeeding remain poorly understood. Thus, the study aimed to determine whether the negative associations between high pre-pregnancy BMI and exclusive breastfeeding at six weeks postpartum are mediated by components of the capability, opportunity, and motivation behaviour (COM-B) model. In this prospective observational study, we assigned 360 primiparous women to a pre-pregnancy overweight/obese group (n = 180) and a normal-BMI group (n = 180). A structural equation model was designed to study how capabilities (onset of lactogenesis II, perceived milk supply, breastfeeding knowledge, and postpartum depression), opportunities (pro-breastfeeding hospital practices, social influence, social support), and motivations (breastfeeding intention, breastfeeding self-efficacy, and attitudes towards breastfeeding) affected exclusive breastfeeding at six weeks postpartum in groups of women with different pre-pregnancy BMIs. In all, 342 participants (95.0%) possessed complete data. Women with high pre-pregnancy BMI were less likely to exclusively breastfeed at six weeks postpartum than women with a normal BMI were. We observed a significant negative direct effect of high pre-pregnancy BMI on exclusive breastfeeding at six weeks postpartum and a significantly negative indirect effect of high pre-pregnancy BMI via the explanatory mediating variables of capabilities (onset of lactogenesis II, perceived milk supply, and breastfeeding knowledge) and motivations (breastfeeding self-efficacy) on exclusive breastfeeding at six weeks postpartum. Our findings support certain capabilities (onset of lactogenesis II, perceived milk supply, and breastfeeding knowledge) and motivations (breastfeeding self-efficacy), partially explaining the negative association between high pre-pregnancy BMI and exclusive breastfeeding outcome. We suggest that interventions aimed at promoting exclusive breastfeeding among women with high pre-pregnancy BMI should address the capacity and motivation factors specific to this population.

Pre-pregnancy complications - associated factors and wellbeing in early pregnancy: a Swedish cohort study

BACKGROUND

Many couples experience difficulties to become pregnant or carry a pregnancy to term due to unknown causes. Here we define pre-pregnancy complications as having prior recurrent pregnancy loss, prior late miscarriages, time to pregnancy more than one year, or the use of artificial reproductive technologies. We aim to identify factors associated with pre-pregnancy complications and poor well-being in early pregnancy.

METHODS

Online questionnaire data from 5330 unique pregnancies in Sweden were collected from November 2017 - February 2021. Multivariable logistic regression modelling was used to investigate potential risk factors for pre-pregnancy complications and differences in early pregnancy symptoms.

RESULTS

Pre-pregnancy complications were identified in 1142 participants (21%). Risk factors included diagnosed endometriosis, thyroid medication, opioids and other strong pain medication, body mass index > 25 kg/m² and age over 35 years. Different subgroups of pre-pregnancy complications had unique risk factors. The groups also experienced different pregnancy symptoms in early pregnancy, where women that had experienced recurrent pregnancy loss were at higher risk of depression in their current pregnancy.

CONCLUSION

We report one of the largest pregnancy cohorts with high frequency of pre-pregnancy complications compared to the Swedish population. Prescribed drug use and body weight were the top potentially modifiable risk factors in all groups. Participants that experienced pre-pregnancy complications also had higher risk of depression and pregnancy problems in early pregnancy.

Association between pre-pregnancy tobacco smoking and postpartum depression: A nationwide cohort study

BACKGROUND

Prior literature examining the association between cigarette smoking and postpartum depression (PPD) has focused primarily on smoking behaviors during pregnancy or postpartum. However, there is a dearth of studies assessing pre-pregnancy smoking in relation to PPD.

METHOD

A retrospective national cohort data from the National Health Insurance of South Korea were analyzed. A total of 392,394 women who gave birth between 2011 and 2015 and received health checkups within a year before pregnancy without a history of diagnosed depression were included. During the health checkup, participants self-reported their smoking status, amount, and duration in a health questionnaire. The diagnosis of PPD was defined by ICD-10 codes F32 and F33 during hospital visits within two years postpartum.

RESULT

Overall, 24,441 (6.2 %) women were newly diagnosed with depression within two years postpartum. Those who reported that they had quit smoking or were currently smoking before pregnancy were more likely to be diagnosed with PPD compared to nonsmokers. A greater number of cigarettes smoked was associated with a higher risk of PPD for both current and former smokers. Results of cumulative lifetime smoking exposure demonstrated that even those with 2 pack-years of smoking had an increased risk of developing PPD within two years postpartum (HR: 1.44, 95 % CI: 1.29-1.60). Those who smoked >10 pack-years had the highest risk of developing PPD (HR: 1.86, 95 % CI: 1.14-3.04) compared to nonsmokers.

CONCLUSION

Greater amount and duration of cigarette smoking in pre-pregnancy can increase the risk of PPD.

PM2.5 exposure increases the risk of preterm birth in pre-pregnancy impaired fasting glucose women: A cohort study in a Southern province of China

Previous studies have indicated maternal exposure to particles with aerodynamic diameter <2.5 μm (PM_2.5) is associated with preterm birth (PTB). However, no study has investigated this effect in pre-pregnancy impaired fasting glucose (IFG) women. This study aimed to differentiate the effects of maternal PM_2.5 exposure on PTB between pre-pregnancy IFG and normoglycemia women, and to further identify the susceptible window. This cohort study was conducted between January 2014 and December 2017 in 21 Chinese cities. All the recruited women received pre-pregnancy fasting serum glucose (FSG) tests and were followed up for their delivery outcomes. The PM_2.5 exposures were estimated by the daily air pollution concentrations of the nearby monitors. Women with FSG below 7.0 mmol/L were included in the analysis. We employed the Cox proportional hazards models to examine whether PM_2.5 exposure was associated with PTB. 237957 women were included and 7055 (3.0%) of them were pre-pregnancy IFG. During the entire pregnancy, we found 24.1% (HR = 1.241; 95% CI: 1.069, 1.439), 61.8% (HR = 1.618; 95% CI: 1.311, 1.997) and 18.6% (HR = 1.186; 95% CI: 1.004, 1.402) of increases in risk for all PTB, early PTB (20-33 gestational weeks) and late PTB (34-36 gestational weeks) among the pre-pregnancy IFG women, and 15.9% (HR = 1.159; 95% CI: 1.127, 1.192), 33.9% (HR = 1.339; 95% CI: 1.255, 1.430) and 13.2% (HR = 1.132; 95% CI: 1.098, 1.168) of increases in risk for all PTB, early PTB and late PTB among the normoglycemia women, with each 10 μg/m³ increment of PM_2.5 exposure, respectively. Furthermore, PM_2.5 exposure had the strongest effect on all PTB during trimester 1 (0-12 gestational weeks) among the pre-pregnancy IFG women, compared with the less strong effect during trimester 1 among the normoglycemia women. In conclusion, pre-pregnancy IFG increases the risk of PTB attributed to PM_2.5, especially during trimester 1. Moreover, the effects of PM_2.5 are greater on early PTB than late PTB for both pre-pregnancy IFG and normoglycemia women.

Effect of maternal alcohol consumption during the pre-pregnancy/early-pregnancy period on congenital heart disease: A prospective cohort study in Central China

Evidence of associations between maternal alcohol consumption and congenital heart disease (CHD) are mixed. Previous studies have been potentially biased due to recall bias or unmeasured confounding. This study aimed to examine the association of maternal alcohol consumption in 3 months before pregnancy and in early pregnancy with risks of offspring congenital heart disease (CHD) and its seven common subtypes. A prospective cohort study was conducted in Central China. From 03/13/2013 to 12/31/2019, a total of 44,048 pregnant women with singleton pregnancies at 8-14 gestational weeks were included and followed to 3 months postpartum. 564 births were diagnosed with CHD at the end of follow-up. Multivariable modified Poisson regression models were used to estimate the relative risks (RRs) of CHD in offspring exposed to maternal alcohol consumption during the pre-pregnancy and early-pregnancy period, adjusting for confounders identified by directed acyclic graphs. In the multivariable analyses, increased risks of CHDs were found in offspring exposed to maternal alcohol consumption both in 3 months before pregnancy (adjusted-RR:3.14; 95% confidence intervals[CIs]:2.30-4.28) and in early pregnancy (adjusted-RR:1.86; 95%CIs:1.13-3.05). More specifically, the offspring exposed to maternal alcohol consumption in 3 months before pregnancy had the highest increased risk of Tetralogy of Fallot (adjusted-RR:8.62; 95%CIs:3.61-20.61). These findings persisted in analyses that were further adjusted for the other behavior variables other than the characteristic being assessed, and were also confirmed by sensitivity analyses. Our study supports the need for continued efforts for public health messages surrounding the potential risks of alcohol consumption prior to or during pregnancy.

When husband migrate: effects of international migration of husbands on fetal outcomes, body mass index and gestational weight of female spouses that stay behind

BACKGROUND

International labour migration continues to be an integral component in Sri Lanka's economic development. Previous research indicates an adverse perinatal outcome in association with low maternal pre-pregnancy body mass index (PBMI) and gestational weight gain (GWG). However, evidence of this association is limited in migrant families. This study aims to investigate the associations between PBMI, GWG among lactating mothers (LM), and fetal outcomes in migrant households, where the father is the migrant worker.

METHODS

A secondary data analysis was done using a nationally representative sample of 7,199 LM. There were 284 LM whose husbands were international migrant workers. Maternal factors were taken as PBMI<18.5 kg/m² and GWG<7kg. Preterm birth and low birth weight (LBW) were taken as fetal outcomes. Binary logistic regression was performed to assess the associated factors.

RESULTS

There was significant difference between LM from migrant and non-migrant households with regards to place of residency, ethnicity, household monthly income, household food security, average household members, husband's education and husband's age. Among migrant, PBMI<18.5 kg/m² was associated with current BMI and mode of delivery. Migrant LM had significantly higher weight gain (≥12 kg) during pregnancy (p=0.005), were multiparous (p=0.008), delivered in private hospital (p=0.000), lesser percentage of underweight (p=0.002) and higher birthweight (p=0.03) than non-migrant LM. Logistic regression model revealed that for each kilogram increment in birthweight and GWG, preterm delivery decreased by 89%(OR=0.11;95%CI:0.04-0.28) and LBW decreased by 12%(OR=0.89;95%CI:0.81-0.97) respectively. Caesarean deliveries were positively associated with low GWG.

CONCLUSION

Our study showed LM in migrant families had invested remittances to utilize private health facilities for deliveries, to improve weight gain during pregnancy and adequate PBMI to deliver higher birth weight babies. In depth study is needed to understand further utilisation of remittances to improve fetal outcomes by increasing birthweight and GWG in migrant families.

Risk of gestational diabetes mellitus by pre-pregnancy body mass index: A systematic review and meta-analysis

Gestational diabetes mellitus (GDM) is serious health challenges. This study aimed at determining the risk of GDM among pregnant women by pre-pregnancy BMI. Five electronic databases including Medline (PubMed), Scopus, Embase, Web of Science and Google Scholar were searched for literature published form 2015 to January 1, 2021. The pooled estimate risk of GDM among pregnant women was 16.8% (95% CI: 15.3-18.4). The risk of GDM in underweight/normal group and overweight/obese group were 10.7% (95% CI: 9.1-12.4) and 23% (95% CI: 20.2-25.9), respectively. The risk of GDM is high among overweight/obese pregnant women.

Relationship between maternal risk factors and occurrence of necrotizing enterocolitis in premature infants before and during the first trimester

BACKGROUND

Necrotizing enterocolitis (NEC) is a common inflammatory bowel disease. If not treated timely, NEC may increase the risk of serious infection and death. Epidemiological studies have shown that damage to the gastrointestinal mucosa, premature delivery, and intestinal bacterial action are the basic conditions for the occurrence of this disease. In addition, weakened intestinal barrier function, hypertonic milk formula feeding, hypoxic-ischemic injury, probiotic use, and premature rupture of membranes are also related to the onset of NEC.

AIM

To analyze the correlation between maternal risk factors and NEC in premature infants before and during the first trimester.

METHODS

The clinical data of 54 preterm infants with NEC treated at our hospital from September 2017 to June 2020 were collected as an NEC group, and 106 non-NEC preterm infants during the same period were selected as a non-NEC group. The clinical symptoms of NEC in preterm infants were analyzed, and the maternal risk factors affecting the occurrence of NEC in preterm infants were analyzed by univariate and multivariate logistic regression analyses.

RESULTS

The clinical symptoms of 54 children with NEC were mainly abdominal distension, weakened bowel sounds, and hematochezia, accounting for 77.78%, 74.07%, and 64.81% of cases, respectively. The unconditional multiple logistic regression analysis confirmed that history of smoking before pregnancy, respiratory infection in early pregnancy, intrahepatic cholestasis, neutrophil/lymphocyte ratio (NLR) ≥h3, and gestational diabetes may be risk factors for NEC (odds ratio [OR] > 1, P < 0.05), while taking vitamin D in the first trimester may be a protective factor (OR < 1, P < 0.05).

CONCLUSION

The occurrence of NEC in premature infants may be related to poor living habits before pregnancy, respiratory infections, intrahepatic cholestasis, NLR, etc; these risk factors should be avoided before and during pregnancy.

Genome-wide methylation analysis of pre-pregnancy women in hypothyroidism

BACKGROUND

Hypothyroidism is a systemic metabolic deficiency syndrome caused by a deficiency in thyroid hormone or a decrease in the action of thyroid hormones. It has a high incidence among women of child-bearing age, and pregnant women with hypothyroidism may have a higher risk of birth defects.

OBJECTIVE

To explore the specific biological mechanism affecting the occurrence of hypothyroidism.

METHODS

This study determined key molecules by comparing and analyzing the difference in methylation levels between pre-pregnancy women and normal controls using the Illumina Infinium MethylationEPIC BeadChip.

RESULTS

3493 Differential methylation positions (DMPs) related genes and 47 differentially methylated regions (DMRs) related genes were found between the Hypothyroidism group and the control group. Among them, miR-21 has been found to be closely related to thyroid hormone regulation. The results of enrichment analysis showed that the DMPs or DMRs-related genes are both significantly enriched in human T-cell leukemia virus 1 infection, osteoclast differentiation and sphingolipid signaling pathway, which were also closely related to the occurrence and development of hypothyroidism. In addition, the combined analysis of CNVs and DMRs showed that significant differences occurred near the regions of 16 M bp in chromosome 1 between the two groups, and the genes involved in these regions included NDUFS2, FCER1G and SHC1.

CONCLUSION

This work screened molecular markers and key signaling pathways that are involved in the development of hypothyroidism in pre-pregnancy women, which may provide new targets for the research and diagnosis of hypothyroidism in the future.

The role of gestational weight gain disorders in symptoms of maternal postpartum depression

OBJECTIVE

To examine the association of gestational weight gain (GWG), categorized according to 2009 IOM guidelines as adequate, inadequate, and excessive, with symptoms of mental disorders perceived by mothers after childbearing as anhedonia, anxiety, and depression, defined by the Edinburgh Postnatal Depression Scale (EPDS). Previous studies indicated that disorders related to GWG are associated with an increased risk of postpartum psychological distress.

METHODS

A prospective cohort study took place at the Policlinico Abano Terme, Italy, from May 2016 to November 2018.

RESULTS

The sample included 1268 healthy at term puerperae, 557 (43.9%) with adequate, 388 (30.6%) with inadequate, and 323 (25.5%) with excessive GWG. Mean EPDS scores were comparable among inadequate, adequate, and excessive GWG groups. However, mean factor scores for anhedonia and anxiety were significantly higher (P = 0.041 and P = 0.001, ANOVA) in mothers with excessive GWG. Conversely, factor scores for depression were significantly higher (P = 0.008, ANOVA) in mothers with inadequate GWG.

CONCLUSION

It was found that excessive GWG across an uncomplicated pregnancy is a warning sign of symptoms of anhedonia and anxiety, whereas inadequate GWG is a significant indicator of symptoms of depression. These relationships highlight the potential for interventions directed toward psychosocial support to have beneficial effects upon GWG.

The effect of pre-pregnancy body mass index on breastfeeding initiation, intention and duration: A systematic review and dose-response meta-analysis

Overweight and obesity not only are major risk factors for number of chronic diseases, but also a risk factor for pregnancy complications in women. The present study aims to investigate the association between pre-pregnancy BMI and the persistence and duration of BF. The electronic databases including Medline (PubMed), Scopus, Embase, Web of Science and Google Scholar were searched for papers with titles and/or abstracts including one of our keywords and published up to 15 April 2019. For dose-response relationship, the two-stage random-effects meta-analysis was performed using the “dosresmeta” function in R software. Thirty-two studies with the effect of pre-pregnancy BMI on BF initiation, intention and duration were included in the present study. Based on crude and adjusted OR models, the risk of BF cessation increased by 4% (OR = 1.04; 95% CI: 1.02–1.05) with an increase in a unit of BMI. In addition, based on crude and adjusted RR models, the risk of BF cessation increases by 2% and 1% (crude RR = 1.02; 95% CI: 1.01–1.03 and adjusted RR = 1.01; 95% CI: 0.99–1.02) with an increase in one unit of BMI. Based on the result, the health care professionals and other key stakeholders should be aware of the impact excess weight, and that women who are overweight or obese should be encouraged with continued access to guidance, counseling and support, starting from conception, to maximize BF outcomes.

Pre-pregnancy diet quality and its association with offspring behavioral problems

PURPOSE

The maternal diet has a critical role in epigenetic changes in the fetus, which has been associated with fetal brain tissue development and later onset of behavioral disorder. However, pre-pregnancy diet quality has not been examined in relation to offspring behavioral problems.

METHODS

1554 mother-child dyads with mothers from the Australian longitudinal study on women's health (ALSWH) and children from the mothers and their children's health Study (MatCH). The healthy eating index (HEI-2015) score was used to explore maternal diet quality before pregnancy. Childhood total behavioral difficulties, internalizing (emotional and peer) and externalizing problems (hyperactivity and conduct) were assessed using the Strengths and Difficulties Questionnaire (SDQ). Multivariable logistic regression was used.

RESULTS

211 children experienced a greater SDQ-score on total behavioral difficulties (13.6%) among the 1554 children. Better pre-pregnancy diet quality was associated with lower odds of offspring total behavioral difficulties after adjustment for potential confounders, highest vs lowest tertile (AOR = 0.52, 95% CI 0.32, 0.85) at p = 0.009. Greater adherence to the HEI-2015 score before pregnancy was also inversely associated with lower odds of offspring externalizing problems (AOR = 0.64, 95% CI 0.43, 0.94). Among the four subscales, hyperactivity and peer problems were negatively associated with better diet quality, (AOR = 0.67, 95% CI 0.47, 0.96) and (AOR = 0.63, 95% CI 0.42, 0.96), respectively.

CONCLUSIONS

We found that adherence to a diet of better quality in pre-pregnancy was associated with a lower risk of behavioral disorders in the offspring. Large prospective studies are warranted to confirm the findings.

Preconception Hb concentration with risk of spontaneous abortion: a population-based cohort study in over 3·9 million women across rural China

OBJECTIVE

Evidence on the relationship between maternal Hb concentration and spontaneous abortion (SA) risk is limited and conflicting. The purpose of the study was to evaluate whether maternal preconception anaemia or high Hb concentration is associated with risk of SA.

DESIGN

A population-based cohort study established between 2013 and 2017.

SETTINGS

Local maternal and child care service centres in each county.

PARTICIPANTS

In total, 3 971 428 women aged 20-49 years, who participated in National Free Pre-Pregnancy Checkups Project from 2013 to 2016 and successfully got pregnant before 2017 in rural China.

RESULTS

A total of 101 700 (2·56 %) women were recorded having SA, with highest SA rate in women with severe anaemia (4·58 %). Compared with women with Hb of 110-149 g/l, the multivariable-adjusted OR for SA was 1·52 (95 % CI: 1·25, 1·86) for women with Hb < 70 g/l, 0·92 (0·84, 1·01) for 70-99 g/l, 0·80 (0·77, 0·83) for 100-109 g/l, 1·11 (1·08, 1·15) for 150-159 g/l, 1·12 (1·04, 1·20) for 160-169 g/l and 1·02 (0·93, 1·12) for ≥ 170 g/l, respectively. An approximate U-shaped curve for the risk of SA with Hb concentrations was observed when Hb concentrations less than 145 g/l, above which the association plateaued (Pnon-linear < 0·001).

CONCLUSIONS

Severe anaemia and high Hb concentration before pregnancy were associated with an increased risk of SA. Women with mild anaemia prior to pregnancy had lower risk of SA. Underlying mechanisms need to be further studied.

Impact of an integrated nutrition, health, water sanitation and hygiene, psychosocial care and support intervention package delivered during the pre- and peri-conception period and/or during pregnancy and early childhood on linear growth of infants in the first two years of life, birth outcomes and nutritional status of mothers: study protocol of a factorial, individually randomized controlled trial in India

Background

The period from conception to two years of life denotes a critical window of opportunity for promoting optimal growth and development of children. Poor nutrition and health in women of reproductive age and during pregnancy can negatively impact birth outcomes and subsequent infant survival, health and growth. Studies to improve birth outcomes and to achieve optimal growth and development in young children have usually tested the effect of standalone interventions in pregnancy and/or the postnatal period. It is not clearly known whether evidence-based interventions in the different domains such as health, nutrition, water sanitation and hygiene (WASH) and psychosocial care, when delivered together have a synergistic effect. Further, the effect of delivery of an intervention package in the pre and peri-conception period is not fully understood. This study was conceived with an aim to understand the impact of an integrated intervention package, delivered across the pre and peri-conception period, through pregnancy and till 24 months of child age on birth outcomes, growth and development in children.

Methods

An individually randomized controlled trial with factorial design is being conducted in urban and peri-urban low- to mid-socioeconomic neighbourhoods in South Delhi, India. 13,500 married women aged 18 to 30 years will be enrolled and randomized to receive either the pre and peri-conception intervention package or routine care (first randomization). Interventions will be delivered until women are confirmed to be pregnant or complete 18 months of follow up. Once pregnancy is confirmed, women are randomized again (second randomization) to receive either the intervention package for pregnancy and postnatal period or to routine care. Newborns will be followed up till 24 months of age. The interventions are delivered through different study teams. Outcome data are collected by an independent outcome ascertainment team.

Discussion

This study will demonstrate the improvement that can be achieved when key factors known to limit child growth and development are addressed together, throughout the continuum from pre and peri-conception until early childhood. The findings will increase our scientific understanding and provide guidance to nutrition programs in low- and middle-income settings.

Trial registration

Clinical Trial Registry – India #CTRI/2017/06/008908; Registered 23 June 2017, http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=19339&EncHid=&userName=society%20for%20applied%20studies

Effects of maternal diets on preterm birth and low birth weight: a systematic review

Current evidence indicates that maternal diets before and during pregnancy could influence rates of preterm birth, low birth weight (LBW) and small for gestational age (SGA) births. However, findings have been inconsistent. This review summarised evidence concerning the effects of maternal diets before and during pregnancy on preterm birth, LBW and SGA. Systematic electronic database searches were carried out using PubMed, Embase, Scopus and Cochrane library using the preferred reporting items for systematic reviews and meta-analyses guidelines. The review included forty eligible articles, comprising mostly of prospective cohort studies, with five randomised controlled trials. The dietary patterns during pregnancy associated with a lower risk of preterm birth were commonly characterised by high consumption of vegetables, fruits, whole grains, fish and dairy products. Those associated with a lower risk of SGA also had similar characteristics, including high consumption of vegetables, fruits, legumes, seafood/fish and milk products. Results from a limited number of studies suggested there was a beneficial effect on the risk of preterm birth of pre-pregnancy diet quality characterised by a high intake of fruits and proteins and less intake of added sugars, saturated fats and fast foods. The evidence was mixed for the relationship between maternal dietary patterns during pregnancy and LBW. These findings indicate that better maternal diet quality during pregnancy, characterised by a high intake of vegetables, fruits, whole grains, dairy products and protein diets, may have a synergistic effect on reducing the risk of preterm birth and SGA.

Association between parental body mass index and autism spectrum disorder: a systematic review and meta-analysis

Studies have examined the association between parental body mass index (BMI) and autism spectrum disorder (ASD) in offspring, with inconsistent results, especially regarding maternal obesity, overweight and underweight. Cochrane Library, EMBASE, PubMed and PsycINFO databases were searched up to March 2018 for relevant observational studies with no language restriction. Our literature search identified 13 eligible studies for meta-analysis (involving 943,293 children and 30,337 cases). For maternal BMI (13 studies), both maternal obesity [OR 1.41 (95% CI 1.19-1.67)] and maternal overweight [OR 1.16 (95% CI 1.05-1.27)] were significantly associated with ASD, while maternal underweight was not associated with ASD [OR 1.08 (95% CI 0.98-1.20)]. For paternal BMI (three studies), no association was found (paternal obesity: OR 1.28, 95% CI 0.94-1.74; overweight: OR 1.07, 95% CI 0.99-1.15; underweight: OR 1.12, 95% CI 0.87-1.44). Pooled estimates were robust in sensitivity analysis and subgroup analyses. Publication bias may exist for studies assessing maternal BMI and ASD risk, but the filled estimates were not altered. Relative to normal weight, maternal obesity and overweight were significantly associated with increased ASD risk, while maternal underweight was not associated with ASD. Although no association between paternal BMI and ASD was found, current evidence is limited (three studies). Future studies are warranted to address more confounding factors and to identify potential mediators of the association, but pre-pregnancy weight control is suggested.

Pre-pregnancy maternal obesity associates with endoplasmic reticulum stress in human umbilical vein endothelium

Obesity associates with the endoplasmic reticulum (ER) stress-induced endothelial dysfunction. Pregnant women with pre-pregnancy maternal obesity (PGMO) may transfer this potential risk to their offspring; however, whether ER stress occurs and associates with foetoplacental endothelial dysfunction in PGMO is unknown. We studied the l-arginine transport and nitric oxide (NO) synthesis in human umbilical vein endothelial cells (HUVECs) from women with PGMO or with a normal pre-pregnancy weight. We analysed the expression and activation of the ER stress sensors protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1α (IRE1α), and activating transcription factor 6 (ATF6). PGMO associated with lower endothelial NO synthase activity due to increased Thr⁴⁹⁵-inhibitor and decreased Ser¹¹⁷⁷-stimulator phosphorylation. However, higher expression and activity of the human cationic amino acid transporter 1 was found. PGMO caused activation of PERK and its downstream targets eukaryotic initiation factor 2 (eIF2α), C/EBP homologous protein 10 (CHOP), and tribbles-like protein 3 (TRB3). Increased IRE1α protein abundance (but not its phosphorylation or X-box binding protein 1-mRNA splicing) and increased c-Jun N-terminal kinase 1 phosphorylation was seen in PGMO. A preferential nuclear location of the activating transcription factor 6 (ATF6) was found in HUVECs from PGMO. All the changes seen in PGMO were blocked by TUDCA but unaltered by tunicamycin. Thus, PGMO may determine a state of ER stress via upregulation of the PERK-eIF2α-CHOP-TRB3 axis signalling in HUVECs. This phenomenon results in foetoplacental vascular endothelial dysfunction at birth.

Preconception Hb concentration and risk of preterm birth in over 2·7 million Chinese women aged 20-49 years: a population-based cohort study

Evidence on the association between maternal Hb concentration and preterm birth (PTB) risk is inconclusive. This paper aimed to explore whether women with anaemia or high Hb level before pregnancy would be at higher risk of PTB. We conducted a population-based cohort study with 2 722 274 women aged 20-49 years, who participated in National Free Pre-Pregnancy Checkups Project between 2013 and 2015 and delivered a singleton before 2016 in rural China. Logistic models were used to estimate OR and 95 % CI after adjusting for confounding variables. Restricted cubic spline models were applied to evaluate the dose-response relationships. A total of 192 819 (7·08 %) women had preterm deliveries. Compared with women with Hb of 110-149 g/l, the multivariable-adjusted OR for PTB was 1·19 (95 % CI 0·98, 1·44) for women with Hb<70 g/l, 1·01 (95 % CI 0·97, 1·03) for 70-99 g/l, 0·96 (95 % CI 0·95, 0·98) for 100-109 g/l, 1·04 (95 % CI 1·01, 1·06) for 150-159 g/l, 1·11 (95 % CI 1·05, 1·17) for 160-169 g/l and 1·19 (95 % CI 1·11, 1·27) for ≥170 g/l, respectively. The multivariable-adjusted OR for very PTB (VPTB) was 1·07 (95 % CI 1·03, 1·12) and 1·06 (95 % CI 1·01, 1·12) for women with Hb <110 and ≥150 g/l, compared with those with Hb of 110-149 g/l, respectively. Our study identified a U-shaped relationship between maternal preconception Hb concentration and PTB risk. Both preconception anaemia and high Hb level can significantly increase VPTB risk. Appropriate intervention for women with abnormal Hb levels before pregnancy is very necessary.

Maternal nicotine exposure has severe cross-generational effects on offspring behavior

Our previous studies showed that paternal nicotine exposure can lead to hyperactivity in the offspring. Nevertheless, the cross-generational effects of maternal and biparental nicotine exposure remain unclear. In this study, female and male mice were exposed respectively by nicotine before pregnancy. The maternal pre-pregnancy nicotine exposure led to depression-like behaviors in the F1 offspring. However, after biparental pre-pregnancy nicotine exposure, seventy percentage of the offspring exhibited a depressive phenotype while 20% were hyperactive, and the remaining exhibited no obvious abnormal behavior. The cross-generational effects appeared to be mediated via disruption of the balance between GSK3 and p-GKS3 by nicotine. These results suggested that pre-pregnancy nicotine exposure can induce alterations in the behavior of the offspring, and the cross-generational effects of maternal nicotine exposure were particularly serious.

Pre-pregnancy BMI, gestational weight gain and breast-feeding: a cohort study in China. Public Health Nutr. 2016; Dec 7. [Epub ahead of print]. [PMID: 27923421 DOI: 10.1017/S1368980016003165]

OBJECTIVE

The purpose of the present study was to examine the influence of maternal pre-pregnancy BMI and gestational weight gain (GWG) on initiation and duration of infant breast-feeding in a prospective birth cohort study.

DESIGN

Breast-feeding information was collected at 1, 3, 6 and 12 months postpartum. The association of pre-pregnancy BMI and GWG with delayed lactogenesis II and termination of exclusive breast-feeding was assessed with logistic regression analysis. The risk of early termination of any breast-feeding during the first year postpartum was assessed with Cox proportional hazards models.

SETTING

Urban city in China.

SUBJECTS

Women with infants from the Ma'anshan Birth Cohort Study (n 3196).

RESULTS

The median duration of any breast-feeding in this cohort was 7·0 months. Pre-pregnancy obese women had higher risks of delayed lactogenesis II (risk ratio=1·89; 95 % CI 1·04, 3·43) and early termination of any breast-feeding (hazard ratio=1·38; 95 % CI 1·09, 1·75) adjusted for potential maternal and infant confounders, when compared with normal-weight women. No differences in breast-feeding initiation or duration of exclusive breast-feeding according to pre-pregnancy BMI were found. Moreover, GWG was not associated with any poor breast-feeding outcomes.

CONCLUSIONS

The present study indicated that pre-pregnancy obesity increases the risks of delayed lactogenesis II and early termination of any breast-feeding in Chinese women.

A complex behavioural change intervention to reduce the risk of diabetes and prediabetes in the pre-conception period in Malaysia: study protocol for a randomised controlled trial

BACKGROUND

Over the past two decades, the population of Malaysia has grown rapidly and the prevalence of diabetes mellitus in Malaysia has dramatically increased, along with the frequency of obesity, hyperlipidaemia and hypertension. Early-life influences play an important role in the development of non-communicable diseases. Indeed, maternal lifestyle and conditions such as gestational diabetes mellitus or obesity can affect the risk of diabetes in the next generation. Lifestyle changes can help to prevent the development of type 2 diabetes mellitus. This is a protocol for an unblinded, community-based, randomised controlled trial in two arms to evaluate the efficacy of a complex behavioural change intervention, combining motivational interviewing provided by a community health promoter and access to a habit formation mobile application, among young Malaysian women and their spouses prior to pregnancy.

METHOD/DESIGN

Eligible subjects will be Malaysian women in the age group 20 to 39 years, who are nulliparous, not diagnosed with diabetes and own a smartphone. With an alpha-value of 0.05, a statistical power of 90 %, 264 subjects will need to complete the study. Subjects with their spouses will be randomised to either the intervention or the control arm for an 8-month period. The primary endpoint is change in waist circumference from baseline to end of intervention period and secondary endpoints are changes in anthropometric parameters, biochemical parameters, change in health literacy level, dietary habits, physical activity and stress level. Primary endpoint and the continuous secondary endpoints will be analysed in a linear regression model, whereas secondary endpoints on an ordinal scale will be analysed by using the chi-squared test. A multivariate linear model for the primary endpoint will be undertaken to account for potential confounders. This study has been approved by the Medical Research and Ethics Committee of the Ministry of Health Malaysia (protocol number: NMRR-14-904-21963) on 21 September 2015.

DISCUSSION

This study protocol describes the first community-based randomised controlled trial, to examine the efficacy of a complex intervention in improving the pre-pregnancy health of young Malaysian women and their spouses. Results from this trial will contribute to improve policy and practices regarding complex behavioural change interventions to prevent diabetes in the pre-conception period in Malaysia and other low- and middle-income country settings.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov (www.clinicaltrials.gov) on 30 November 2015, Identifier: NCT02617693 .

Metabolic syndrome in the non-pregnant state is associated with the development of preeclampsia

BACKGROUND

The aim of this study was to investigate the association between metabolic syndrome in the non-pregnant state and the development of preeclampsia.

METHODS

We enrolled 212,463 Korean women who had their first delivery between January, 2011 and December, 2012 and had undergone a national health screening examination through the National Health Insurance during the 1-2 years before their first delivery. Women who had hypertension in the non-pregnant state were excluded. The presence of metabolic syndrome was defined using the modified criteria published in National Cholesterol Education Program Adult Treatment Panel III criteria.

RESULTS

The prevalence of metabolic syndrome in non-pregnant state was 1.2%. Preeclampsia developed in 3.1% and its prevalence among women with and without metabolic syndrome was 7.3% and 3.0%, respectively. The pre-pregnancy prevalence of metabolic syndrome was higher in women who developed preeclampsia compared to that in those who had a normal pregnancy (1.1% vs. 2.8%; p<0.001). On multivariate regression analysis, women with metabolic syndrome had an increased risk of developing preeclampsia (odds ratio: 1.48; 95% CI: 1.26 to 1.74) compared to that in those without metabolic syndrome, after adjusting for age, family history of hypertension, smoking status, and pre-pregnancy body mass index. The risk of preeclampsia increased with a rise in the number of components of metabolic syndrome.

CONCLUSION

Metabolic syndrome in the non-pregnant state was associated with the development of preeclampsia. Further studies are needed to evaluate whether early intervention for metabolic syndrome before pregnancy can decrease the risk of developing preeclampsia.

Relative validity of a semi-quantitative, web-based FFQ used in the 'Snart Forældre' cohort - a Danish study of diet and fertility

OBJECTIVE

To assess the relative validity of a semi-quantitative, web-based FFQ completed by female pregnancy planners in the Danish 'Snart Forældre' study.

DESIGN

We validated a web-based FFQ based on the FFQ used in the Danish National Birth Cohort against a 4 d food diary (FD) and assessed the relative validity of intakes of foods and nutrients. We compared means and medians of intakes, and calculated Pearson correlation coefficients and de-attenuated coefficients to assess agreement between the two methods. We also calculated the proportion correctly classified based on the same or adjacent quintile of intake and the proportion of grossly misclassified (extreme quintiles).

SETTING

Participants (n 128) in the 'Snart Forældre' study who had completed the web-based FFQ were invited to participate in the validation study.

SUBJECTS

Participants in the 'Snart Forældre' study, in total ninety-seven women aged 20-42 years.

RESULTS

Reported intakes of dairy products, vegetables and potatoes were higher in the FFQ compared with the FD, whereas reported intakes of fruit, meat, sugar and beverages were lower in the FFQ than in the FD. Overall the de-attenuated correlation coefficients were acceptable, ranging from 0·33 for energy to 0·93 for vitamin D. The majority of the women were classified in the same or adjacent quintile and few women were misclassified (extreme quintiles).

CONCLUSION

The web-based FFQ performs well for ranking women of reproductive age according to high or low intake of foods and nutrients and, thus, provides a solid basis for investigating associations between diet and fertility.

Maternal obesity and energy intake as risk factors of pregnancy-induced hypertension among Iranian women

Pregnancy-induced hypertension is causing striking maternal, foetal and neonatal mortality and morbidity in the world. A case-control study was conducted on 113 women with gestational hypertension and 150 healthy pregnant women at Shahid Akbarabadi Hospital of obstetrics and gynaecology in south of Tehran. Women who were obese (OR 4.44; 95% CI 1.84-10.72) before pregnancy were more likely to develop gestational hypertension. Proportion of having excessive gestational weight gain was positively and significantly associated with development of gestational hypertension (OR 2.70; 95% CI 1.19-6.13). Furthermore, findings revealed that women who were in the highest quartile of mid-arm-circumference had a 3-fold increased risk of gestational hypertension compared to women in the lowest quartile (OR 8.93; 95% CI 2.16-36.93). We found that having been in the highest quartile of energy intake positively correlated with increased risk of gestational hypertension (OR 9.66; 95% CI 3.30-28.21). The results suggest pre-pregnancy obesity, excessive gestational weight gain, and increased intake of energy as potential risk factors of developing gestational hypertension.