High Maternal Body Mass Index in Early Pregnancy and Risks of Stillbirth and Infant Mortality-A Population-Based Sibling Study in Sweden

Grandmaternal body mass index in early pregnancy and risk of grandoffspring stillbirth: a nationwide, 3-generation cohort study

We investigated the association between maternal grandmaternal early pregnancy body mass index (BMI) and grandoffspring stillbirth risk in a Swedish population-based 3-generation cohort of 176 908 grandmothers (F0), 197 579 mothers (F1), and 316 459 grandoffspring (F2) born 1997-2016. There were 998 stillbirths (risk, 3.2 per 1000 births). Compared with grandmaternal BMI 18.5-24.9, adjusted relative risks (RRs) of grandoffspring stillbirth for BMIs of 25.0-29.9 and ≥30.0 were, respectively, 1.41 (95% CI, 1.15-1.72) and 1.62 (95% CI, 1.14-2.30). RRs for corresponding maternal (F1) BMI categories were, respectively, 1.32 (95% CI, 1.06-1.65) and 1.77 (95% CI, 1.39-2.25). Maternal BMI mediated only 19% of this relationship. Grandmaternal preeclampsia and maternal small-for-gestational age (SGA) birth were related to increased F2 stillbirth risk but did not mediate the association between grandmaternal BMI and grandoffspring stillbirth risk. To explore whether this association was explained by factors shared within families, we studied the relationship of maternal full sisters' BMI and stillbirth risk in 101 368 pregnancies. Stillbirth RRs for full sisters' BMI 25.0-29.9 and ≥30.0 compared with 18.5-24.9 were, respectively, 0.76 (95% CI, 0.51-1.13) and 0.88 (95% CI, 0.55-1.40). In conclusion, grandmaternal overweight and obesity were associated with grandoffspring stillbirth. This association is not fully explained by shared familial factors.

Factors associated with infant mortality in Nigeria: A scoping review

BACKGROUND

Infant mortality persists as a global public health concern, particularly in lower-middle-income countries (LIMCs) such as Nigeria. The risk of an infant dying before one year of age is estimated to be six times higher in Africa than in Europe. Nigeria recorded an infant mortality rate of 72.2 deaths per 1,000 live births in 2020, in contrast to the global estimate of 27.4 per 1,000 live births. Several studies have been undertaken to determine the factors influencing infant mortality.

OBJECTIVE

This scoping review sought to identify and summarise the breadth of evidence available on factors associated with infant mortality in Nigeria.

METHODS

This review followed the five-stage principles of Arksey and O'Malley's framework. Four electronic databases were searched with no limit to publication date or study type: Ovid MEDLINE, PubMed, CINAHL Complete, and Web of Science. Selected studies were imported into Endnote software and then exported to Rayyan software where duplicates were removed. Included articles were thematically analysed and synthesised using the socioecological model.

RESULTS

A total of 8,139 references were compiled and screened. Forty-eight articles were included in the final review. At the individual level, maternal- and child-related factors were revealed to influence infant mortality; socioeconomic and sociocultural factors at the interpersonal level; provision and utilisation of health services, health workforce, hospital resources and access to health services at the organisational level; housing/neighbourhood and environmental factors at the community level; and lastly, governmental factors were found to affect infant mortality at the public policy level.

CONCLUSION

Factors related to the individual, interpersonal, organisational, community and public policy levels were associated with infant mortality in Nigeria.

Maternal Prepregnancy Obesity Affects Foetal Growth, Birth Outcome, Mode of Delivery, and Miscarriage Rate in Austrian Women

The increasing obesity rates among women of reproductive age create a major obstetrical problem as obesity during pregnancy is associated with many complications, such as a higher rate of caesarean sections. This medical record-based study investigates the effects of maternal prepregnancy obesity on newborn parameters, birth mode, and miscarriage rate. The data of 15,404 singleton births that had taken place between 2009 and 2019 at the public Danube Hospital in Vienna were enrolled in the study. Newborn parameters are birth weight, birth length, head circumference, APGAR scores, as well as pH values of the arterial and venous umbilical cord blood. In addition, maternal age, height, body weight at the beginning and the end of pregnancy, and prepregnancy body mass index (BMI) (kg/m²) have been documented. The gestational week of birth, the mode of delivery, as well as the number of previous pregnancies and births, are included in the analyses. Birth length, birth weight, and head circumference of the newborn increase with increasing maternal BMI. Furthermore, with increasing maternal weight class, there tends to be a decrease in the pH value of the umbilical cord blood. Additionally, obese women have a history of more miscarriages, a higher rate of preterm birth, and a higher rate of emergency caesarean section than their normal-weight counterparts. Consequently, maternal obesity before and during pregnancy has far-reaching consequences for the mother, the child, and thus for the health care system.

Prolonged pregnancy and stillbirth among women with overweight or obesity - a population-based study in Sweden including 64,632 women

BACKGROUND

The proportion of overweight or obese pregnant women is increasing in many countries and babies born to a mother who is overweight or obese are at higher risk for complications. Our primary objective was to describe sociodemographic and obstetric factors across Body Mass Index (BMI) classifications, with secondary objective to investigate stillbirth and other pregnancy outcomes in relation to BMI classifications and gestational week.

METHODS

This population-based cohort study with data partly based on a cluster-randomized controlled trial includes 64,632 women with singleton pregnancy, giving birth from 28 weeks' gestation. The time period was January 2016 to 30 June 2018 (2.5 years). Women were divided into five groups according to BMI: below 18.5 underweight, 18.5-24.9 normal weight, 25.0-29.9 overweight, 30.0-34.9 obesity, 35.0 and above, severe obesity.

RESULTS

Data was obtained for 61,800 women. Women who were overweight/obese/severely obese had lower educational levels, were to a lesser extent employed, were more often multiparas, tobacco users and had maternal diseases to a higher extent than women with normal weight. From 40 weeks' gestation, overweight women had a double risk of stillbirth compared to women of normal weight (RR 2.06, CI 1.01-4.21); the risk increased to almost four times higher for obese women (RR 3.97, CI 1.6-9.7). Women who were obese or severely obese had a higher risk of almost all pregnancy outcomes, compared to women of normal weight, such as Apgar score < 7 at 5 min (RR1.54, CI 1.24-1.90), stillbirth (RR 2.16, CI 1.31-3.55), transfer to neonatal care (RR 1.38, CI 1.26-1.50), and instrumental delivery (RR 1.26, CI 1.21-1.31).

CONCLUSIONS

Women who were obese or severely obese had a higher risk of almost all adverse pregnancy outcomes and from gestational week 40, the risk of stillbirth was doubled. The findings indicate a need for national guidelines and individualized care to prevent and reduce negative pregnancy outcomes in overweight/obese women. Preventive methods including preconception care and public health policies are needed to reduce the number of women being overweight/obese when entering pregnancy.

Placental pathology associated with maternal age and maternal obesity in singleton pregnancy

OBJECTIVE

Maternal age, maternal obesity and neonatal sex dimorphism are known to affect pregnancy and neonatal outcome. However, the effects of these factors on specific placental pathology are less well-documented.

STUDY DESIGN

Clinical information, placental pathology and neonatal data from singleton delivery were collected at our hospital in March 2020 to October 2021 and correlation studies were performed.

RESULTS

A total 3,119 singleton placentas were examined between March 2020 and October 2021 in conjunction with clinical information and neonatal birth data. Advanced maternal age (>35) was significantly associated with a variety of pregnancy complications and placental pathology including preeclampsia/pregnancy induced hypertension (Pre/PIH), gestational diabetes mellitus (GDM2), intrauterine growth restriction (IUGR), and increased maternal body mass index (BMI) at delivery. Maternal obesity (BMI >30 at the time of delivery) was significantly associated with a variety of clinical features and placental pathology including PRE/PIH, GDM2 and decidual vasculopathy (mural arterial hypertrophy). No specific placental pathology was associated with neonatal sex except for more maternal inflammatory response (MIR, chronic deciduitis) in neonates of male sex.

CONCLUSION

Maternal age and maternal obesity were associated with not only clinical complications of pregnancy and neonatal birth weight but also specific placental pathology. Understanding the effects of maternal and environmental factors will help improve pregnancy outcome.

Male Rat Offspring Are More Impacted by Maternal Obesity Induced by Cafeteria Diet than Females-Additive Effect of Postweaning Diet

Maternal obesity increases the risk of health complications in offspring, but whether these effects are exacerbated by offspring exposure to unhealthy diets warrants further investigation. Female Sprague-Dawley rats were fed either standard chow (n = 15) or ‘cafeteria’ (Caf, n = 21) diets across pre-pregnancy, gestation, and lactation. Male and female offspring were weaned onto chow or Caf diet (2–3/sex/litter), forming four groups; behavioural and metabolic parameters were assessed. At weaning, offspring from Caf dams were smaller and lighter, but had more retroperitoneal (RP) fat, with a larger effect in males. Maternal Caf diet significantly increased relative expression of ACACA and Fasn in male and female weanling liver, but not CPT-1, SREBP and PGC1; PPARα was increased in males from Caf dams. Maternal obesity enhanced the impact of postweaning Caf exposure on adult body weight, RP fat, liver mass, and plasma leptin in males but not females. Offspring from Caf dams appeared to exhibit reduced anxiety-like behaviour on the elevated plus maze. Hepatic CPT-1 expression was reduced only in adult males from Caf fed dams. Post weaning Caf diet consumption did not alter liver gene expression in the adult offspring. Maternal obesity exacerbated the obesogenic phenotype produced by postweaning Caf diet in male, but not female offspring. Thus, the impact of maternal obesity on adiposity and liver gene expression appeared more marked in males. Our data underline the sex-specific detrimental effects of maternal obesity on offspring.

Determinants for Perinatal Mortality in South China: A Prospective Cohort Study

OBJECTIVE

To estimate the association of selected maternal and fetal characteristics with the risk of perinatal mortality in South China.

METHODS

A prospective cohort study was conducted from March 2013 to December 2019. The exposures of interest were maternal sociodemographic characteristics, lifestyle and habits during early pregnancy, and complications of pregnancy. Their effects on the development of perinatal death were analyzed in our study.

RESULTS

A total of 44,048 eligible pregnant women were included in the analysis. Of these, 596 fetuses were perinatal deaths (perinatal mortality was 13.5 per 1,000 births). After adjustment, maternal obesity, being employed, history of gestational hypertension, taking antidepressants during early pregnancy, history of gestational diabetes mellitus, gestational diabetes mellitus, infertility drug treatment and assisted reproductive techniques, history of neonatal death, preterm birth, and congenital malformations all significantly increased the risk of perinatal death. Ethnic minority, income > 5,000, multiparous women, and cesarean section associated with reduced risk of perinatal death.

CONCLUSION

Some factors of maternal sociodemographic characteristics, abnormal pregnancy history, lifestyle and habits during early pregnancy, and complications of pregnancy were associated with the risk of perinatal death.

Findings in Stillbirths Associated with Placental Disease

OBJECTIVE

Placental disease is a leading cause of stillbirth. Our purpose was to characterize stillbirths associated with placental disease.

STUDY DESIGN

The Stillbirth Collaborative Research Network conducted a prospective, case-control study of stillbirths and live births from 2006 to 2008. This analysis includes 512 stillbirths with cause of death assignment and a comparison group of live births. We compared exposures between women with stillbirth due to placental disease and those due to other causes as well as between women with term (≥ 37 weeks) stillbirth due to placental disease and term live births.

RESULTS

A total of 121 (23.6%) out of 512 stillbirths had a probable or possible cause of death due to placental disease by Initial Causes of Fetal Death. Characteristics were similar between stillbirths due to placental disease and other stillbirths. When comparing term live births to stillbirths due to placental disease, women with non-Hispanic black race, Hispanic ethnicity, lack of insurance, or who were born outside of the United States had higher odds of stillbirth due to placental disease. Nulliparity and antenatal bleeding also increased risk of stillbirth due to placental disease.

CONCLUSION

Multiple discrete exposures were associated with stillbirth caused by placental disease. The relationship between these factors and utility of surveillance warrants further study.

The Risks Associated With Obesity in Pregnancy

BACKGROUND

Approximately one-third of all women of childbearing age are overweight or obese. For these women, pregnancy is associated with increased risks for both mother and child.

METHODS

This review is based on pertinent publications retrieved by a selective search of PubMed, with special attention to current population-based cohort studies, systematic reviews, meta-analyses, and controlled trials.

RESULTS

Obesity in pregnancy is associated with unfavorable clinical outcomes for both mother and child. Many of the risks have been found to depend linearly on the body-mass index (BMI). The probability of conception declines linearly, starting from a BMI of 29 kg/m2, by 4% for each additional 1 kg/m2 of BMI (hazard ratio 0.96, 95% confidence interval: [0.91; 0.99]). A 10% increase of pregravid BMI increases the relative risk of gestational diabetes and that of preeclampsia by approximately 10% each. A 5 kg/m2 increase of BMI elevates the relative risk of intrauterine death to 1.24 [1.18; 1.30]. An estimated 11% of all neonatal deaths can be attributed to the consequences of maternal overweight and obesity. Nonetheless, in most randomized controlled trials, nutritional and lifestyle interventions did not bring about any clinically relevant reduction in the incidence of gestational diabetes and fetal macrosomia.

CONCLUSION

The risks associated with obesity in pregnancy cannot necessarily be influenced by intervention. Preventive measures aimed at normalizing body weight before a woman becomes pregnant are, therefore, all the more important.

Invited Commentary: The Causal Association Between Obesity and Stillbirth-Strengths and Limitations of the Consecutive-Pregnancies Approach

There has been a resurgence in analyses of consecutive pregnancies (or similarly, sibling designs) in perinatal and pediatric epidemiology. These approaches have attractive qualities for estimating associations with complex multifactorial exposures like obesity. In an article appearing in this issue of the Journal, Yu et al. (Am J Epidemiol. 2019;188(7):1328-1336) apply a consecutive-pregnancies approach to characterize the risk of stillbirth among women who develop obesity between pregnancies ("incident obesity"). Working within a causal framework and using parametric and nonparametric estimation techniques, the authors find an increase in stillbirth risk associated with incident obesity. Risk differences varied between 0.4 per 1,000 births (95% confidence interval (CI): 0.1, 0.7) and 6.9 per 1,000 births (95% CI: 3.7, 10.0), and risk ratios ranged from 1.12 (95% CI: 1.02, 1.23) to 2.99 (95% CI: 2.19, 4.08). The strengths of this approach include starting from a clearly defined causal estimand and exploring the sensitivity of parameter estimates to model selection. In this commentary, we put these findings in the broader context of research on obesity and birth outcomes and highlight concerns regarding the generalizability of results derived from within-family designs. We conclude that while causal inference is an important goal, in some instances focusing on formulation of a causal question drives results away from broad applicability.

Community-and proximate-level factors associated with perinatal mortality in Nigeria: evidence from a nationwide household survey

BACKGROUND

The perinatal mortality rate (PMR) in Nigeria rose by approximately 5% from 39 to 41 deaths per 1000 total births between 2008 and 2013, indicating a reversal in earlier gains. This study sought to identify factors associated with increased PMR.

METHODS

Nationally representative data including 31,121 pregnancies of 7 months or longer obtained from the 2013 Nigeria Demographic and Health Survey were used to investigate the community-, socio-economic-, proximate- and environmental-level factors related to perinatal mortality (PM). Generalized linear latent and mixed models with the logit link and binomial family that adjusted for clustering and sampling weights was employed for the analyses.

RESULTS

Babies born to obese women (adjusted odds ratio [aOR] = 1.46, 95% confidence interval [CI]: 1.13-1.89) and babies whose mothers perceived their body size after birth to be smaller than the average size (aOR = 1.92, 95% CI: 1.61-2.30) showed greater odds of PM. Babies delivered through caesarean section were more likely to die (aOR = 2.85, 95% CI: 2.02-4.02) than those born through vaginal delivery. Other factors that significantly increased PM included age of the women (≥40 years), living in rural areas, gender (being male) and a fourth or higher birth order with a birth interval ≤ 2 years.

CONCLUSIONS

Newborn and maternal care interventions are needed, especially for rural communities, that aim at counselling women that are obese. Promoting well-timed caesarean delivery, Kangaroo mother care of small-for-gestational-age babies, child spacing, timely referral for ailing babies and adequate medical check-up for older pregnant women may substantially reduce PM in Nigeria.

Retrospective analysis of risk factors for low 1-minute Apgar scores in term neonates

The current study was designed to investigate the perinatal risk factors for low 1-min Apgar scores in term neonates. We retrospectively analyzed the maternal and neonatal clinical data of 10,550 infants who were born through vaginal delivery from 37 weeks 0 days to 41 weeks 6 days of single gestation from January 2013 to July 2018. Because the 1-min Apgar score reflects neonatal status at birth, we analyzed the risk factors for low (score <7) 1-min Apgar scores through logistic regression. Among these 10,550 neonates, 339 (3.2%) had low (score <7) 1-min Apgar scores. Among them, 321 (94.7%) were admitted to the neonatology department for further observation or treatment. Multivariate analysis revealed that educational background, body mass index, gestational age, pathological obstetrics, longer duration of the second stage of labor, forceps delivery or vacuum extraction, neonatal weight, neonatal sex, and meconium-stained amniotic fluid were independent risk factors for 1-min Apgar scores <7. Neonates who had low 1-min Apgar scores were more frequently admitted to the neonatology department for further observation or treatment. Early detection of risk factors and timely intervention to address these factors may improve neonatal outcomes at birth and reduce the rate of admission to the neonatology department.

Investigating fetal growth restriction and perinatal risks in appropriate for gestational age infants: using cohort and within-sibling analyses

OBJECTIVE

Fetal growth restriction refers to fetuses that fail to reach their growth potential. Studies within siblings may be useful to disclose fetal growth restriction in appropriate for gestational age (AGA) infants. We analysed associations between birthweight percentiles and perinatal risks in AGA infants, using both population-based and within-sibling analyses.

DESIGN

Population-based cohort study.

SETTING AND SAMPLE

Using nation-wide Swedish registries (1987-2012), we identified 2 134 924 singleton AGA births (10th-90th birthweight percentile for gestational age), of whom 1 377 326 were full siblings.

METHODS

Unconditional Poisson regression was used for population analyses, and conditional (matched) Poisson regression for within-sibling analyses. We estimated associations between birthweight percentiles and stillbirth, neonatal mortality, and morbidity, using incidence rate ratios (IRRs) with 95% confidence intervals (CIs).

RESULTS

Stillbirth and neonatal mortality risks declined with increasing birthweight percentiles, but the declines were larger in within-sibling analyses. Compared with the reference group (40th to <60th percentile), IRRs (95% CIs) of stillbirth for the lowest and highest percentile groups (10th to <25th and 75th-90th percentiles, respectively) were 1.87 (1.72-2.03) to 0.76 (0.68-0.85) in population analysis and 2.60 (2.27-2.98) and 0.43 (0.36-0.50) in within-sibling analysis. Neonatal morbidity risks in term non-malformed infants with low birthweight percentiles were generally only increased in within-sibling analyses.

CONCLUSION

Using birthweight information from siblings may help to define fetal growth restriction in AGA infants.

TWEETABLE ABSTRACT

Size of siblings helps to detect growth-restricted infants with seemingly normal birthweights.

Contribution of maternal overweight and obesity to the occurrence of adverse pregnancy outcomes

AIMS

Maternal overweight and obesity in pregnancy are known to increase the risk of a range of complications and adverse pregnancy outcomes. This study estimates the population-level contribution of maternal overweight and obesity to adverse pregnancy outcomes.

METHODS

Data derived from the Australian Capital Territory (ACT) Maternal and Perinatal Data Collection were analysed. A total of 24 161 women who had a singleton birth in 2009-2015, with maternal weight and height information available, were included. In this study, the association between risk factors and outcomes was investigated using multilevel regression modelling. Based on model predictions under various hypothetical maternal weight scenarios, the number and proportion of adverse perinatal outcomes that could be potentially prevented were estimated.

RESULTS

Maternal overweight and obesity were associated with increased risks of gestational diabetes mellitus (GDM), pre-eclampsia, caesarean delivery, preterm birth (PTB), large for gestational age (LGA) and admission to the special care nursery or neonatal intensive care unit (SCN/NICU). The estimated proportions of adverse pregnancy outcomes attributable to overweight and obesity in pregnancy are 29.3% for GDM, 36.2% for pre-eclampsia, 15.5% for caesarean delivery, 21.6% for longer antenatal stay in hospital (≥2 days), 16.3% for extreme PTB, 25.2% for LGA and 6.5% for SCN/NICU admission.

CONCLUSIONS

Maternal overweight and obesity contribute to a large proportion of obstetric complications and adverse outcomes in the ACT. Effective intervention strategies to reduce the prevalence of overweight and obesity in pregnant women could have significant beneficial effects on pregnancy outcomes.

Understanding the consumption of folic acid during preconception, among Pakistani, Bangladeshi and white British mothers in Luton, UK: a qualitative study

Background

To review the similarities and differences in Pakistani, Bangladeshi and White British mothers health beliefs (attitudes, knowledge and perceptions) and health behaviour regarding their consumption of folic acid pre-conception, to reduce the risk of neural tube defects.

Methods

Our study used a descriptive qualitative research approach, implementing face-to-face focus group discussions with Pakistani, Bangladeshi or White British mothers (normal birth outcomes and mothers with poor birth outcomes) and semi-structured interviews or focus groups with service providers using semi-structured topic guides. This method is well suited for under researched areas where in-depth information is sought.

There were three sample groups:

Pakistani, Bangladeshi and White British mothers with normal birth outcomes (delivery after 37 weeks of gestation, in the preceding 6 to 24 months, weighing 2500 g and living within a specified postcode area in Luton, UK).

Pakistani Bangladeshi and white British bereaved mothers who had suffered a perinatal mortality (preceding 6 to 24 months, residing within a specificied postcode area).

Healthcare professionals working on the local maternity care pathway (i.e. services providing preconception, antenatal, antepartum and postpartum care).

Transcribed discussions were analysed using the Framework Analysis approach.

Results

The majority of mothers in this sample did not understand the benefits or optimal time to take folic acid pre-conception. Conversely, healthcare professionals believed the majority of women did consume folic acid, prior to conception.

Conclusions

There is a need to increase public health awareness of the optimal time and subsequent benefits for taking folic acid, to prevent neural tube defects.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1884-0) contains supplementary material, which is available to authorized users.

Promoting healthy lifestyle in fertility clinics; an Australian perspective

STUDY QUESTION

Are Australian fertility clinics adequately addressing unhealthy lifestyle in patients seeking fertility treatment?

SUMMARY ANSWER

This study has highlighted deficiencies in practices and education around managing patients with unhealthy lifestyle undergoing fertility treatment.

WHAT IS KNOWN ALREADY

The association between lifestyle and fertility is well documented, with obesity and smoking being of particular concern to fertility and pregnancy outcomes. Guidelines recommend that unhealthy lifestyle is addressed prior to conception, yet anecdotal experience suggests this is not being addressed. Lifestyle modification programmes can be effective in improving pregnancy rates and outcomes, however, recruitment to such programmes can be challenging.

STUDY DESIGN SIZE, DURATION

A cohort study of Australian fertility clinics’ attitudes and practices regarding lifestyle modification to augment reproductive treatment outcomes was conducted between August and October 2015.

PARTICIPANTS/MATERIALS, SETTING, METHOD

An online survey was administered to senior fertility nurses, from all registered fertility clinics in Australia. Data were collated and subjected to a univariate data analysis, where frequency tables were produced for each question. A separate qualitative analysis was undertaken of data from open ended questions.

MAIN RESULTS AND THE ROLE OF CHANCE

Fifty-three out of 85 potential respondents (62.4%), all from different clincis, completed the survey, with almost all acknowledging the importance of addressing unhealthy lifestyle before offering ART treatment. However, most clinics did not offer internal resources to assist with lifestyle modification. Whilst the promotion of healthy lifestyle was recognised as a key component of the role of a fertility nurse, participants did not feel that nurses were best equipped to provide lifestyle modification programmes, owing to a lack of resources and specific skills in this area. Suggested areas for improved practice included prioritising general health prior to offering treatment, and further utilising and upskilling nurses to assist with lifestyle modification programmes.

LIMITATIONS REASONS FOR CAUTION

The survey was completed by only one nurse from each clinic and as such may not be entirely representative of all clinic practices.

WIDER IMPLICATIONS OF THE FINDINGS

Fertility clinics are likely to see an increasing number of patients with unhealthy lifestyle, resulting in health concerns such as obesity. The results of this study provide an insight into how unhealthy lifestyle is currently being addressed in fertility clinics and suggested areas that could be targeted for improving practice and outcomes.

STUDY FUNDING/COMPETING INTERESTS

No conflict of interest to declare. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

TRIAL REGISTRATION NUMBER

NA

Maternal mortality in the indigenous and non-indigenous population in Pará: contribution to the surveillance of deaths

Abstract Objective: To analyze the occurrence of Maternal Mortality in general and in the indigenous population in the state of Pará. Method: A quantitative, analytical and retrospective study was performed, covering a historical series from 2005 to 2014. For the analysis of the results, non-parametric statistical tests, the Chi-square test and the G test were processed in the BioStat 5.0 software program. Results: A total of 884 maternal deaths were reported in the state of Pará, corresponding to a Mortality Rate of 60.7 per 100,000 live births for non-indigenous women and 135.8 per 100,000 live births for indigenous women. Oedema, proteinuria and hypertensive disorders in pregnancy, childbirth and puerperium corresponded to 30.5% (n = 270). Conclusion and Implications for the Practice: Maternal mortality remains a serious public health problem in the state of Pará, clearly demonstrating that indigenous pregnant women require greater care, since they showed higher Maternal Mortality Rates when compared to non-indigenous women.

Gestational diabetes mellitus and interpregnancy weight change: A population-based cohort study

BACKGROUND

Being overweight is an important risk factor for Gestational Diabetes Mellitus (GDM), but the underlying mechanisms are not understood. Weight change between pregnancies has been suggested to be an independent mechanism behind GDM. We assessed the risk for GDM in second pregnancy by change in Body Mass Index (BMI) from first to second pregnancy and whether BMI and gestational weight gain modified the risk.

METHODS AND FINDINGS

In this observational cohort, we included 24,198 mothers and their 2 first pregnancies in data from the Medical Birth Registry of Norway (2006-2014). Weight change, defined as prepregnant BMI in second pregnancy minus prepregnant BMI in first pregnancy, was divided into 6 categories by units BMI (kilo/square meter). Relative risk (RR) estimates were obtained by general linear models for the binary family and adjusted for maternal age at second delivery, country of birth, education, smoking in pregnancy, interpregnancy interval, and year of second birth. Analyses were stratified by BMI (first pregnancy) and gestational weight gain (second pregnancy). Compared to women with stable BMI (-1 to 1), women who gained weight between pregnancies had higher risk of GDM-gaining 1 to 2 units: adjusted RR 2.0 (95% CI 1.5 to 2.7), 2 to 4 units: RR 2.6 (2.0 to 3.5), and ≥4 units: RR 5.4 (4.0 to 7.4). Risk increased significantly both for women with BMI below and above 25 at first pregnancy, although it increased more for the former group. A limitation in our study was the limited data on BMI in 2 pregnancies.

CONCLUSIONS

The risk of GDM increased with increasing weight gain from first to second pregnancy, and more strongly among women with BMI < 25 in first pregnancy. Our results suggest weight change as a metabolic mechanism behind the increased risk of GDM, thus weight change should be acknowledged as an independent factor for screening GDM in clinical guidelines. Promoting healthy weight from preconception through the postpartum period should be a target.

Maternal Overweight and Obesity and Genital Anomalies in Male Offspring: A Population-Based Swedish Cohort Study

BACKGROUND

Overweight and obese pregnant women face higher risk of several critical birth outcomes, including an overall increased risk of congenital abnormalities. Only few studies have focused on associations between maternal overweight and the genital anomalies in boys, cryptorchidism and hypospadias, and results are inconclusive.

METHODS

We performed a population-based cohort study and assessed the associations between maternal body mass index (BMI) in early pregnancy and occurrence of cryptorchidism and hypospadias. All live-born singleton boys born in Sweden from 1992 to 2012 were included. From the Swedish Patient Register, information on cryptorchidism and hypospadias was available. Data were analysed using Cox proportional hazards regression adjusted for potential confounders. Mediation analyses were performed to estimate how much of the association between BMI and genital anomalies were mediated through obesity-related diseases.

RESULTS

Of the 1 055 705 live-born singleton boys born from 1992 to 2012, 6807 (6.4 per 1000) were diagnosed with hypospadias and 16 469 (15.6 per 1000) were diagnosed with cryptorchidism, of which 9768 (9.3 per 1000) underwent corrective surgery for cryptorchidism. We observed dose-response associations between maternal BMI and hypospadias and cryptorchidism. Boys of mothers with BMI ≥40.0 kg/m² had the highest adjusted hazard ratios for hypospadias (HR 1.35, 95% confidence interval [CI] 1.04, 1.76) and cryptorchidism (HR 1.25, 95% CI 1.00, 1.58). A substantial proportion of the associations between BMI and the genital anomalies were mediated through preeclampsia.

CONCLUSION

This large register-based study adds to the current literature and indicates that the occurrence of hypospadias and cryptorchidism increase with maternal overweight and obesity severity.

Optimal timing for elective caesarean delivery in a Chinese population: a large hospital-based retrospective cohort study in Shanghai

OBJECTIVE

To assess the relationship between the timing of antepartum elective caesarean delivery (CD) at term and perinatal outcomes in a Chinese population.

METHODS

We conducted a retrospective cohort study of mode of delivery at a large obstetric centre in Shanghai, China between 2007 and 2014. Eligibility criteria included: term nulliparous women with a singleton gestation undergoing antepartum elective CD.

RESULTS

There were 19 939 women delivered by antepartum CD without indications, with 5.9% performed at 37-37 6/7 weeks, 36.2% at 38-38 6/7 weeks, 38.4% at 39-39 6/7 weeks, 15.4% at 40-40 6/7 weeks, 4.0% at ≥41 weeks. As compared with births at 39-39 6/7 weeks, births at 37 weeks were associated with an increased odds of neonatal respiratory disease (adjusted odds ratian(aOR): 4.82; 95% CI 3.35 to 6.94), neonatal infection (aOR: 3.68; 95% CI 1.80 to 7.52), hypoglycaemia (aOR: 3.85; 95%CI 2.29 to 6.48), hyperbilirubinaemia (aOR: 3.50; 95%CI 2.12 to 5.68), neonatal intensive care admission (aOR: 3.73; 95% CI 2.84 to 4.89) and prolonged hospitalisation (aOR: 7.51; 95% CI 5.10 to 11.07). Births at 38 weeks, 40 weeks or ≥41 weeks were also associated with an increased odds of neonatal respiratory disease with corresponding aORs (95% CI) of 2.26 (1.71 to 3.00), 1.97 (1.33 to 2.94) and 2.91 (1.80 to 4.70), respectively.

CONCLUSION

For women undergoing elective CD, neonatal outcome data suggest that delivery at 39-39 6/7 complete weeks is optimal timing in a Chinese population.

Invited Commentary: Maternal Obesity and Impaired Fetal and Infant Survival-One More Piece Added to the Puzzle

The association between maternal obesity and increased risks of stillbirth and infant mortality is well documented, but it has often been questioned whether the association is driven by obesity per se or by unmeasured factors such as insulin resistance or genes. In this issue of the Journal, Lindam et al. (Am J Epidemiol. 2016;184(2):98-105) present results from a sibling case-control study which strongly support that these tragic outcomes are independent of genetic and early environmental risk factors shared within families. By sampling sisters from the Swedish Medical Birth Register, Lindam et al. compared the body mass indices (weight (kg)/height (m)(2)) of women who had stillbirths and infant deaths with those of their sisters or of population controls. Significant excess risks of both outcomes were observed in obese women (body mass index ≥30), and associations were strongest when sister controls were used. Although this careful analysis adds to the existing evidence of a causal relationship between maternal obesity and impaired fetal and infant survival, a biological pathway has not yet been established. Additionally, we are in urgent need of effective tools to reduce obesity in childbearing women and to identify and treat high-risk pregnancies.