Integrating multiple lines of evidence to assess the effects of maternal BMI on pregnancy and perinatal outcomes

BACKGROUND

Higher maternal pre-pregnancy body mass index (BMI) is associated with adverse pregnancy and perinatal outcomes. However, whether these associations are causal remains unclear.

METHODS

We explored the relation of maternal pre-/early-pregnancy BMI with 20 pregnancy and perinatal outcomes by integrating evidence from three different approaches (i.e. multivariable regression, Mendelian randomisation, and paternal negative control analyses), including data from over 400,000 women.

RESULTS

All three analytical approaches supported associations of higher maternal BMI with lower odds of maternal anaemia, delivering a small-for-gestational-age baby and initiating breastfeeding, but higher odds of hypertensive disorders of pregnancy, gestational hypertension, preeclampsia, gestational diabetes, pre-labour membrane rupture, induction of labour, caesarean section, large-for-gestational age, high birthweight, low Apgar score at 1 min, and neonatal intensive care unit admission. For example, higher maternal BMI was associated with higher risk of gestational hypertension in multivariable regression (OR = 1.67; 95% CI = 1.63, 1.70 per standard unit in BMI) and Mendelian randomisation (OR = 1.59; 95% CI = 1.38, 1.83), which was not seen for paternal BMI (OR = 1.01; 95% CI = 0.98, 1.04). Findings did not support a relation between maternal BMI and perinatal depression. For other outcomes, evidence was inconclusive due to inconsistencies across the applied approaches or substantial imprecision in effect estimates from Mendelian randomisation.

CONCLUSIONS

Our findings support a causal role for maternal pre-/early-pregnancy BMI on 14 out of 20 adverse pregnancy and perinatal outcomes. Pre-conception interventions to support women maintaining a healthy BMI may reduce the burden of obstetric and neonatal complications.

FUNDING

Medical Research Council, British Heart Foundation, European Research Council, National Institutes of Health, National Institute for Health Research, Research Council of Norway, Wellcome Trust.

Maternal educational attainment in pregnancy and epigenome-wide DNA methylation changes in the offspring from birth until adolescence

Maternal educational attainment (MEA) shapes offspring health through multiple potential pathways. Differential DNA methylation may provide a mechanistic understanding of these long-term associations. We aimed to quantify the associations of MEA with offspring DNA methylation levels at birth, in childhood and in adolescence. Using 37 studies from high-income countries, we performed meta-analysis of epigenome-wide association studies (EWAS) to quantify the associations of completed years of MEA at the time of pregnancy with offspring DNA methylation levels at birth (n = 9 881), in childhood (n = 2 017), and adolescence (n = 2 740), adjusting for relevant covariates. MEA was found to be associated with DNA methylation at 473 cytosine-phosphate-guanine sites at birth, one in childhood, and four in adolescence. We observed enrichment for findings from previous EWAS on maternal folate, vitamin-B12 concentrations, maternal smoking, and pre-pregnancy BMI. The associations were directionally consistent with MEA being inversely associated with behaviours including smoking and BMI. Our findings form a bridge between socio-economic factors and biology and highlight potential pathways underlying effects of maternal education. The results broaden our understanding of bio-social associations linked to differential DNA methylation in multiple early stages of life. The data generated also offers an important resource to help a more precise understanding of the social determinants of health.

Analysis of DNA methylation at birth and in childhood reveals changes associated with season of birth and latitude

BACKGROUND

Seasonal variations in environmental exposures at birth or during gestation are associated with numerous adult traits and health outcomes later in life. Whether DNA methylation (DNAm) plays a role in the molecular mechanisms underlying the associations between birth season and lifelong phenotypes remains unclear.

METHODS

We carried out epigenome-wide meta-analyses within the Pregnancy And Childhood Epigenetic Consortium to identify associations of DNAm with birth season, both at differentially methylated probes (DMPs) and regions (DMRs). Associations were examined at two time points: at birth (21 cohorts, N = 9358) and in children aged 1-11 years (12 cohorts, N = 3610). We conducted meta-analyses to assess the impact of latitude on birth season-specific associations at both time points.

RESULTS

We identified associations between birth season and DNAm (False Discovery Rate-adjusted p values < 0.05) at two CpGs at birth (winter-born) and four in the childhood (summer-born) analyses when compared to children born in autumn. Furthermore, we identified twenty-six differentially methylated regions (DMR) at birth (winter-born: 8, spring-born: 15, summer-born: 3) and thirty-two in childhood (winter-born: 12, spring and summer: 10 each) meta-analyses with few overlapping DMRs between the birth seasons or the two time points. The DMRs were associated with genes of known functions in tumorigenesis, psychiatric/neurological disorders, inflammation, or immunity, amongst others. Latitude-stratified meta-analyses [higher (≥ 50°N), lower (< 50°N, northern hemisphere only)] revealed differences in associations between birth season and DNAm by birth latitude. DMR analysis implicated genes with previously reported links to schizophrenia (LAX1), skin disorders (PSORS1C, LTB4R), and airway inflammation including asthma (LTB4R), present only at birth in the higher latitudes (≥ 50°N).

CONCLUSIONS

In this large epigenome-wide meta-analysis study, we provide evidence for (i) associations between DNAm and season of birth that are unique for the seasons of the year (temporal effect) and (ii) latitude-dependent variations in the seasonal associations (spatial effect). DNAm could play a role in the molecular mechanisms underlying the effect of birth season on adult health outcomes.

The effect of maternal BMI, smoking and alcohol on congenital heart diseases: a Mendelian randomisation study

BACKGROUND

Congenital heart diseases (CHDs) remain a significant cause of infant morbidity and mortality. Epidemiological studies have explored maternal risk factors for offspring CHDs, but few have used genetic epidemiology methods to improve causal inference.

METHODS

Three birth cohorts, including 65,510 mother/offspring pairs (N = 562 CHD cases) were included. We used Mendelian randomisation (MR) analyses to explore the effects of genetically predicted maternal body mass index (BMI), smoking and alcohol on offspring CHDs. We generated genetic risk scores (GRS) using summary data from large-scale genome-wide association studies (GWAS) and validated the strength and relevance of the genetic instrument for exposure levels during pregnancy. Logistic regression was used to estimate the odds ratio (OR) of CHD per 1 standard deviation (SD) higher GRS. Results for the three cohorts were combined using random-effects meta-analyses. We performed several sensitivity analyses including multivariable MR to check the robustness of our findings.

RESULTS

The GRSs associated with the exposures during pregnancy in all three cohorts. The associations of the GRS for maternal BMI with offspring CHD (pooled OR (95% confidence interval) per 1SD higher GRS: 0.95 (0.88, 1.03)), lifetime smoking (pooled OR: 1.01 (0.93, 1.09)) and alcoholic drinks per week (pooled OR: 1.06 (0.98, 1.15)) were close to the null. Sensitivity analyses yielded similar results.

CONCLUSIONS

Our results do not provide robust evidence of an effect of maternal BMI, smoking or alcohol on offspring CHDs. However, results were imprecise. Our findings need to be replicated, and highlight the need for more and larger studies with maternal and offspring genotype and offspring CHD data.

Lost to follow-up in the Norwegian mother, father and child cohort study

BACKGROUND

The aim of pregnancy cohorts was to understand causes and development of health and disease throughout the life course. A major challenge in cohort studies is to avoid selection bias from loss to follow-up.

OBJECTIVE

The aim of this study was to describe what characterises drop out from the Norwegian Mother, Father and Child Cohort Study (MoBa), and provide a resource to inform the interpretation of results from analysis of cohort data.

METHODS

We estimated loss to follow-up in subsets of participants that responded to questionnaire waves in MoBa through an eight-year period and described characteristics of participants who responded to follow-ups. Within each wave of questionnaires, we estimated two exposure-outcome associations: the relationship between maternal smoking during pregnancy and offspring birthweight, and between educational level and pre-pregnancy body mass index (BMI). We explored the use of inverse probability weighting to correct the bias due to loss to follow-up.

RESULTS

Participants who continued to respond were older, higher educated, less likely to smoke and had lower BMI. We observed a decline in participation of current smokers from 22.3% to 17.5%, and participants who reported an unplanned pregnancy dropped from 19.2% to 16.4%. There was a gradual decline in the inverse relationship between maternal smoking during pregnancy and offspring birthweight with increasing follow-up information, indicating that selection bias due to drop out resulted in lower effect estimates. For the relationship between parental educational level and BMI, the inverse association increased with amount of follow-up information, indicating that the selection bias resulted in higher effect estimates. Inverse probability weighting did not completely correct the estimates for bias due to loss to follow-up.

CONCLUSIONS

Participants who remain cohort members are different from subjects who drop out. Users of large cohorts should be aware of selective loss to follow-up and consider imputation or weighting to account for loss to follow-up when analysing questionnaire responses.

Early life growth and associations with lung function and bronchial hyperresponsiveness at 11-years of age

Low birthweight and being born small-for-gestational age (SGA) are linked to asthma and impaired lung function. Particularly, poor intrauterine growth followed by rapid catch-up growth during childhood may predispose for respiratory disease. Bronchial hyperresponsiveness (BHR) is an essential feature of asthma, but how foetal and early childhood growth are associated with BHR is less studied. Our hypothesis was that children born SGA or with accelerated early life growth have increased BHR and altered lung function at 11-years of age. We studied the associations between SGA and early childhood growth with lung function and BHR at 11-years of age in a subgroup of 468 children from the Norwegian Mother, Father and Child Cohort Study (MoBa), and included data from the Medical Birth Registry of Norway (MBRN). Weight at 6 months of age was positively associated with forced vital capacity (adjusted Beta: 0.121; 95% Confidence interval: 0.023, 0.219) and negatively associated with the ratio of forced expiratory flow in first second/forced vital capacity (-0.204; -0.317, -0.091) at 11-years of age. Similar patterns were found for weight at 36 months and for change in weight from birth to 6 months of age. SGA or other various variables of early childhood growth were not associated with BHR at 11-years of age. Early life growth was associated with an obstructive lung function pattern, but not with BHR in 11-year old children. Foetal growth restriction or weight gain during early childhood do not seem to be important risk factors for subsequent BHR in children.

Airway symptoms and atopy in young children prescribed asthma medications: A large-scale cohort study

Diagnosing asthma and deciding treatment are difficult in young children. An inappropriate and too high prescription rate of inhaled corticosteroids (ICS) is suggested, but how airway symptoms are associated with prescriptions of asthma medication is less known. We studied how strongly wheeze, lower respiratory tract infections (LRTI), and atopic diseases are associated with dispensing of asthma medications during early childhood. We used data from the Norwegian Mother and Child Cohort Study and the Norwegian Prescription Database at four age-intervals (0-6, 6-18, 18-36 months, and 3-7 years). Primary outcomes were dispensed asthma medications (no medication, short-acting β-2 agonist, or ICS). Relative risks (RRs) and average attributable fractions (AAFs) were estimated. Both wheeze and LRTI were positively associated with both medication groups (0-6 months: no data on wheeze). The RRs and AAFs were higher for wheeze than LRTI. For ICS, the AAFs (95% CI) for wheeze vs LRTI were: 6 to 18 months: 69.2 (67.2, 71.2)% vs 10.4 (9.0, 11.8)%, 18 to 36 months: 33.0 (30.5, 35.5)% vs 10.0 (8.0, 12.0)%, and 3 to 7 years: 33.7 (31.0, 36.5)% vs 1.2 (0.5, 1.9)%. Except at 3 to 7 years of age, the AAFs were lower for atopic diseases than for LRTI and wheeze. Atopic diseases modified the associations between wheeze and ICS at 18 to 36 months and between LRTI or wheeze and ICS at 3 to 7 years. In conclusion, both wheeze and LRTI were associated with prescriptions of asthma medications in young children, with the strongest associations seen for wheeze. Atopic diseases contributed to these associations only in the oldest age groups.

Health outcomes of asymptomatic HIV-infected pregnant women initiating antiretroviral therapy at different baseline CD4 counts in Ethiopia

OBJECTIVE

To compare health outcomes following initiation of antiretroviral therapy (ART) for asymptomatic HIV-infected pregnant women at different CD4 levels.

METHODS

We analyzed data from 706 asymptomatic HIV-infected Ethiopian women initiating ART during pregnancy between February 2012 and October 2016. The outcomes evaluated were CD4 gain, CD4 normalization (CD4 count ≥750cells/mm3) and occurrence of HIV-related clinical events after twelve months of treatment.

RESULT

On average, CD4 count (cells/mm3) increased from 391 (95% CI: 372-409) at baseline to 523 (95% CI: 495-551) after twelve months of treatment. Rate of CD4 gain was higher among women with baseline CD4 between 350 and 499 compared to CD4 ≥500 (207 versus 6, p<0.001). But women with baseline CD4 between 350 and 499 could not catch up with women with CD4 ≥500. Women with baseline CD4 ≥500 had significantly higher likelihood of achieving CD4 normalization as compared to those with CD4 between 350 and 499 (AOR=0.32, 95% CI: 0.13-0.76). No strong evidence of differential risk in the occurrence of HIV-related clinical events.

CONCLUSION

Starting ART for asymptomatic HIV-infected women with CD4 count ≥500cells/mm3 was beneficial to preserve or recover immunity after 12 months of treatment in a resource limited setting.

Early HIV Infections Among Men Who Have Sex with Men in Five Cities in the United States

We tested blood samples from men who have sex with men (MSM) to detect early HIV infection. Early HIV included both acute (infected past 30 days) and recent (estimated recency past 240 days). Acute infections were defined as screen immunoassay (IA) negative/NAAT-positive or IA-positive/Multispot-negative/NAAT-positive. Recent infections were defined as avidity index cutoff <30 % on an avidity-based IA and, (1) not reporting antiretroviral therapy use or, (2) HIV RNA >150 copies/mL. Of 937 samples, 26 % (244) were HIV-infected and of these 5 % (12) were early. Of early infections, 2 were acute and 10 recent; most (8/12) were among black MSM. Early infection was associated with last partner of black race [adjusted relative risk (ARR) = 4.6, confidence intervals (CI) 1.2-17.3], receptive anal sex at last sex (ARR = 4.3, CI 1.2-15.0), and daily Internet use to meet partners/friends (ARR = 3.3, CI 1.1-9.7). Expanding prevention and treatment for black MSM will be necessary for reducing incidence in the United States.

A profile of an HIV-and child-specific programme in New Orleans, Louisiana, USA

Since the beginning of the AIDS epidemic, 4.3 million children under 15 years of age have been infected with HIV worldwide; in the year 2000 alone, the World Health Organization estimates that 600,000 children became HIV-infected. Ancillary services offer the potential to improve access to and retention in primary care through removal of barriers to care. Globally, ancillary services may actually represent a significant proportion of all care delivered to HIV-infected children, particularly in the absence of expensive antiretroviral treatments. The purpose of this non-concurrent cohort study was to describe a population of HIV-infected children receiving ancillary services from an HIV- and family-specific ancillary service programme in New Orleans, Louisiana, USA. Forty-two HIV-infected children ages newborn to 13 years were included in the study. The majority were between one and five years of age (50.0%), male (54.8%), African-American (88.1%), and perinatally infected (97.6%). Services were well utilized; delivery decreased with age and increased with severity of clinical disease. Improved retention, prescription of antiretroviral treatment and HIV-related emergency room utilization were associated with ancillary service receipt. Ancillary services delivered by an HIV- and family-specific programme assist HIV-infected children to receive improved medical care. Ancillary services are a valuable adjunct to primary care, particularly in the complex care of the HIV-infected children from historically underserved populations.

Association between ancillary services and clinical and behavioral outcomes among HIV-infected women

The purpose of this study was to evaluate the association between ancillary services, including case management, and clinical and behavioral outcomes for human immunodeficiency virus (HIV)-infected women. Data were obtained from databases systematically maintained by Family Advocacy, Care and Education Services (FACES) and the HIV Outpatient Program (HOP) in New Orleans. HIV-infected women receiving primary care from HOP and ancillary services from FACES between January 1, 1997 and December 31, 1998 were eligible. Data were analyzed using generalized estimating equations (GEE) with STATA software. The majority of women included in the study were African American (86.7%), infected heterosexually (78.8%), and had absolute CD4 counts greater than 200 (58.6%). After adjusting for age, time, entry time into HOP, pregnancy, CD4 count, substance abuse status, and social and clinical stressors, receipt of more than four combined case manager contacts or ancillary services per month was significantly associated with being prescribed a protease inhibitor, improved adherence and retention in primary care, and enrolling on a research protocol. Receiving more than one transportation service per month was significantly associated with improved adherence, improved retention, one or more emergency room visits per month, and one or more hospitalizations per month. Receiving more than one contact with case managers per month was associated with improved retention in primary care. Findings suggest that receipt of case management and ancillary services is associated with improvements in multiple outcomes for HIV-infected women. A client-centered approach to providing ancillary services appears to be effective in improving behavioral and utilization characteristics in this population of low-income, high-risk women.

Obstetric outcome of 904 pregnancies after intracytoplasmic sperm injection

The obstetric data of 904 consecutive pregnancies obtained after intracytoplasmic sperm injection (ICSI) using ejaculated spermatozoa (group I), epididymal spermatozoa (group II), testicular spermatozoa (group III) and after the replacement of frozen-thawed embryos (group IV) are described. In all, there were 785 pregnancies in group I, 37 pregnancies in group II, 30 pregnancies in group III and 52 pregnancies in group IV. A total of 24 pregnancies (2.5%) have so far been lost to follow-up. The incidence of pregnancy loss, i.e. subclinical pregnancies, clinical abortions and ectopic pregnancies were highest in group IV (61.4%). Early pregnancy loss in groups I, II and III were 21.9, 37.8 and 33.3% respectively. Prenatal diagnosis was performed in 64.4% of the clinical pregnancies: amniocentesis in 48.2% and chorionic villus sampling in 16.2%. The karyotypes were normal in 97.6% of the prenatal diagnoses and there were 1.2% de novo and 1.2% inherited chromosome aberrations. Pregnancy complications such as prematurity and low birthweight were related to pregnancy multiplicity. Perinatal mortality occurred in 15 babies (17.1 per thousand), including nine intrauterine fetal deaths after 25 weeks of gestation and six cases of mortality during the first 7 days after birth. There is no evidence that the technique of ICSI using sperm cells of different origins yielded a higher obstetric risk.

Obstetric outcome of 424 pregnancies after intracytoplasmic sperm injection

An evaluation of the outcome of pregnancies resulting from intracytoplasmic sperm injection for severe male factor infertility was conducted by analysing the data obtained from the patients and/or their obstetrician/gynaecologist on standardized questionnaires. The data from 424 pregnancies between April 1991 and September 1994 were analysed. Early pregnancy loss before 16 weeks occurred in 99 cases (23.3%), including 48 clinical abortions (11.3%), 47 subclinical pregnancies (11.1%) and four ectopic pregnancies (0.9%). Vanishing twins and triplets, which could be regarded as early embryonic wastage, were found in 36 cases (8.5%). One pregnancy was interrupted at week 15 of gestation because of anhydramnios, and four pregnancies (0.9%) ended in spontaneous late abortions before 26 weeks. A total of 320 pregnancies (75.5%) resulted in the birth of at least one child; 222 of these (69.3%) were singletons, 93 were twins (29.1%) and five were triplets (1.6%). The problems of prematurity and low birthweight were especially related to the multiplicity of pregnancies. Furthermore, from among the total of 423 babies born, we have observed three cases of stillbirth and five cases of neonatal mortality. The perinatal mortality rate was therefore 18.9 per 1000 births. The results of this study show that the obstetric outcome of these pregnancies was similar to that obtained after conventional in-vitro fertilization and other assisted reproduction techniques.

Employee recognition: a key to motivation

Productivity--why it's low and how to enhance it--is on everyone's mind these days. A major component of productivity is employee satisfaction. If an employee is dissatisfied, feels unappreciated or under-compensated, that employee will not perform to the best of his or her ability. How is the personnel administrator to address this pressing problem? One answer that emerges is employee recognition programs. In many cases, properly run recognition programs can boost awareness of the organization, build employee pride, raise morale and, ultimately, increase productivity. As some of our respondents observed, higher salary is not the best answer. While a larger paycheck is always appreciated, everyone's pride is boosted by a public demonstration of appreciation.