Extreme maternal underweight and feto-infant morbidity outcomes: a population-based study

Impact of maternal underweight on obstetric and neonatal prognosis: A retrospective study

INTRODUCTION

Maternal underweight (BMI < 18.5) is an uncommon situation with potentially serious obstetric consequences, though data in the literature are scarce.

OBJECTIVE

To compare the obstetrical prognosis of patients with normal BMI and BMI < 18.5.

STUDY DESIGN

We performed a retrospective study in France (Normandy).

RESULTS

We included 14,246 patients between January 2011 and November 2017, among whom 12,648 (88.8 %) had normal BMI, 1269 were considered mild underweight (17 ≤ BMI < 18.5 kg/m²) and 329 (2.3 %) were considered severe to moderate underweight (BMI < 17 kg/m²). The risk of preterm birth was all the greater as the thinness was severe (ORa: 1.34 [1.12-1.60] and ORa 1.77 [1.31-2.34]) and the risk of intrauterine growth retardation also increased with severe thinness (ORa: 1.63 [1.35-1.96] and ORa 2.28 [1.69-3.07]). The risk of a caesarean section or scheduled labour was no different. Neonatal parameters were comparable between the groups.

CONCLUSION

Our study confirms an increased risk of preterm delivery and intrauterine growth retardation with increased thinness after adjusting for confounding factors. This link had only been shown previously in 2 studies Neither the type of prematurity (induced or spontaneous) nor the severity of prematurity is influenced by the severity of thinness; however, the low prevalence of thinness limits the power of these data. It would be interesting to study the medico-economic relevance of a policy of close maternal-foetal surveillance in this target population.

Maternal body weight trajectories across the life course and risk of preterm delivery

We examined the association between life course body weight percentile trajectories and risk for preterm delivery (PTD). Data about women's weight at birth, age 18, and before pregnancy were obtained by retrospective self-report in a cohort of 1410 black women in metropolitan Detroit. Growth mixture models were used to categorize women with similar weight percentile trajectories across these time points. Log-Poisson models were used to examine the association between the trajectory groups and PTD. Four trajectory groups with different beginning and endpoints of their weight percentiles (high-high, high-low, low-high and low-low) best fit the data. The groups with the highest prevalence of PTD were those that started low (low-high, 21%; low-low, 18%). The low-high group had a higher prevalence of PTD than the high-high trajectory group in unadjusted models (prevalence ratio=1.49 [95% confidence interval (CI) 1.11, 2.00]). The association became not significant after adjusting for maternal age at delivery, income, diabetes and hypertension. When compared with the high-high trajectory group, the low-low trajectory seemed to also have a higher prevalence of PTD after adjusting for maternal age at delivery, income, diabetes and hypertension (prevalence ratio=1.35 [95% CI 1.00, 1.83]). Results suggest that a woman's risk for PTD is influenced by her body weight trajectory across the life course.

The relationship between selected socioeconomic factors and thinness among Polish school-aged children and adolescents

The analysis was performed on a database including 17,427 records of subjects aged 7-18 years, randomly sampled from a population of Polish students. Thinness was determined using international cut-off points, defined to pass through body mass index of 18.5 kg/m² at the age of 18. The weighted prevalence of thinness and odds ratios with 95% confidence interval were estimated for gender, birth weight, level of schooling and school location, gross domestic product (GDP) per inhabitant, family income and maternal education. Body height was analysed according to body mass and birth weight categories. The prevalence of thinness was higher among children with low birth weight and among girls. The prevalence of thinness decreased with increasing GDP per inhabitant. In analysis by level of schooling: primary-middle-secondary, prevalence of thinness decreased among boys and increased among girls. Thin students were significantly shorter than other students, and thin girls less likely participated in physical education.

CONCLUSION

Gender and socioeconomic factors are important determinants of thinness among Polish children and adolescents. Public health strategies should address family eating practices to prevent negative effects of weight deficit, especially among girls/children from low GDP regions. What is Known: • Socioeconomic factors and gender influence weight status of children and adolescents. What is New: • The first time the prevalence and determinants of thinness based on data from a nationally representative, weighted sample of Polish children aged 7-18 years were presented. • The analysis shows how gender and socioeconomics determinants influence the prevalence of thinness among children and adolescent in post-transformation country and can be used to international comparisons.

Preconception care: nutritional risks and interventions

INTRODUCTION

There is increasingly a double burden of under-nutrition and obesity in women of reproductive age. Preconception underweight or overweight, short stature and micronutrient deficiencies all contribute to excess maternal and fetal complications during pregnancy.

METHODS

A systematic review and meta-analysis of the evidence was conducted to ascertain the possible impact of preconception care for adolescents, women and couples of reproductive age on maternal, newborn and child health (MNCH) outcomes. A comprehensive strategy was used to search electronic reference libraries, and both observational and clinical controlled trials were included. Cross-referencing and a separate search strategy for each preconception risk and intervention ensured wider study capture.

RESULTS

Maternal pre-pregnancy weight is a significant factor in the preconception period with underweight contributing to a 32% higher risk of preterm birth, and obesity more than doubling the risk for preeclampsia, gestational diabetes. Overweight women are more likely to undergo a Cesarean delivery, and their newborns have higher chances of being born with a neural tube or congenital heart defect. Among nutrition-specific interventions, preconception folic acid supplementation has the strongest evidence of effect, preventing 69% of recurrent neural tube defects. Multiple micronutrient supplementation shows promise to reduce the rates of congenital anomalies and risk of preeclampsia. Although over 40% of women worldwide are anemic in the preconception period, only one study has shown a risk for low birth weight.

CONCLUSION

All women, but especially those who become pregnant in adolescence or have closely-spaced pregnancies (inter-pregnancy interval less than six months), require nutritional assessment and appropriate intervention in the preconception period with an emphasis on optimizing maternal body mass index and micronutrient reserves. Increasing coverage of nutrition-specific and nutrition-sensitive strategies (such as food fortification; integration of nutrition initiatives with other maternal and child health interventions; and community based platforms) is necessary among adolescent girls and women of reproductive age. The effectiveness of interventions will need to be simultaneously monitored, and form the basis for the development of improved delivery strategies and new nutritional interventions.

Inter-pregnancy weight change impacts placental weight and is associated with the risk of adverse pregnancy outcomes in the second pregnancy

BACKGROUND

The inter-pregnancy period is considered a teachable moment when women are receptive to weight- management guidance aimed at optimising pregnancy outcome in subsequent pregnancies. In population based studies inter-pregnancy weight change is associated with several adverse pregnancy outcomes but the impact on placental size is unknown.

METHODS

The association between inter-pregnancy weight change and the primary risk of adverse pregnancy outcomes in the second pregnancy was investigated in 12,740 women with first two consecutive deliveries at a single hospital using logistic regression.

RESULTS

Compared with women who were weight stable, weight loss (>1BMI unit) between pregnancies was associated with an increased risk of spontaneous preterm delivery, low placental weight and small for gestational age (SGA) birth, while weight gain (>3BMI units) increased the risk of pre-eclampsia, gestational hypertension, emergency caesarean section, placental oversize and large for gestational age (LGA) birth at the second pregnancy. The relationship between weight gain and pre-eclampsia risk was evident in women who were overweight at first pregnancy only (BMI ≥25 units), while that between weight loss and preterm delivery was confined to women with a healthy weight at first pregnancy (BMI <25 units). In contrast, the association between weight loss and SGA was independent of first pregnancy BMI. A higher percentage of women who were obese at first pregnancy were likely to experience a large weight gain (P < 0.01) or weight loss (P < 0.001) between consecutive pregnancies compared with the normal BMI reference group.

CONCLUSION

Inter-pregnancy weight change in either direction increases the risk of a number of contrasting pregnancy complications, including extremes of placental weight. The placenta may lie on the causal pathway between BMI change and the risk of LGA or SGA birth.

Genetic analysis of low BMI phenotype in the Utah Population Database

The low body mass index (BMI) phenotype of less than 18.5 has been linked to medical and psychological morbidity as well as increased mortality risk. Although genetic factors have been shown to influence BMI across the entire BMI, the contribution of genetic factors to the low BMI phenotype is unclear. We hypothesized genetic factors would contribute to risk of a low BMI phenotype. To test this hypothesis, we conducted a genealogy data analysis using height and weight measurements from driver's license data from the Utah Population Data Base. The Genealogical Index of Familiality (GIF) test and relative risk in relatives were used to examine evidence for excess relatedness among individuals with the low BMI phenotype. The overall GIF test for excess relatedness in the low BMI phenotype showed a significant excess over expected (GIF 4.47 for all cases versus 4.10 for controls, overall empirical p-value<0.001). The significant excess relatedness was still observed when close relationships were ignored, supporting a specific genetic contribution rather than only a family environmental effect. This study supports a specific genetic contribution in the risk for the low BMI phenotype. Better understanding of the genetic contribution to low BMI holds promise for weight regulation and potentially for novel strategies in the treatment of leanness and obesity.

Maternal pre-pregnancy underweight and fetal growth in relation to institute of medicine recommendations for gestational weight gain

PURPOSE

Maternal nutritional status is one of the most important factors of fetal growth and development. Consequently, the currently increasing prevalence of underweight women worldwide has come in the focus of interest of perinatal medicine. The aim of the study was to assess the effect of low pre-pregnancy body mass index (BMI) on fetal growth.

MATERIALS AND METHODS

Data on 4678 pregnant women and their neonates were retrospectively analyzed. Pre-pregnancy BMI of study women was categorized according to the WHO standards. Fetal growth was assessed by birth weight and birth length, birth weight for gestational age, and ponderal index.

RESULTS

Study group included 351 (7.6%) women with pregestational BMI<18.5kg/m(2), while all women with pregestational BMI 18.5-25kg/m(2) (n=3688; 78.8%) served as a control group. The mean birth weight and birth length of neonates born to underweight mothers were by 167g and 0.8cm lower in comparison with the neonates born to mothers of normal nutritional status, respectively (P<0.001 both). The prevalence of small for gestational age (SGA) births was twofold that found in the control group of mothers of normal nutritional status (9.7% vs. 4.9%; P<0.001). The inappropriately low gestational weight gain additionally increased the rate of SGA infants in the group of mothers with low pre-pregnancy BMI (21.4% vs. 10.4%; P=0.02). Pre-pregnancy BMI category did not influence neonatal growth symmetry.

CONCLUSION

Low maternal pregestational BMI is associated with fetal growth assessment. Improvement of the maternal nutritional status before pregnancy can increase the likelihood of perinatal outcome.

Abnormal maternal body mass index and obstetric and neonatal outcome

OBJECTIVE

The objective of this study is to examine the effects of abnormal maternal body mass index (BMI), either underweight or severe or morbid obesity (BMI >35), on obstetrical and neonatal outcomes.

METHODS

A three-year period (2.007-2.009) observational retrospective study was carried out in Granada (Spain). Women were categorized by first ten weeks of pregnancy BMI, according to World Health Organization (WHO) into three groups: underweight (<18.5), normal (20-24.9), and severe or morbid obese (>35). Obstetrical and neonatal outcomes were evaluated using normal group as reference after suitable adjustments for confounding factors.

RESULTS

3.016 patients out of 12.781 single births were included. Maternal BMI classified 168 women (5.5 %) as underweight, 2.597 (86.1%) as normal, and 251 (8.3%) as severe or morbidly obese. As compared to normal women, underweight women were younger, and class II or III obese showed higher parity and higher incidence of hypertension disorders and Diabetes Mellitus. After controlling for these confounders, underweight women showed increased adjusted risk of oligohydramnios and low birth weight babies, and severe or morbidly obese women had an increased adjusted risk of Streptococcus Group B colonization, induction of labour, elective and emergency cesarean section, fetal macrosomia, fetal acidosis at birth, and perinatal mortality.

CONCLUSIONS

Severe or morbid obesity were associated with an increased risk of adverse perinatal outcome and mortality and should be managed as high-risk pregnancies.

[Prognosis criteria for the management of the infertile couple]

Advanced maternal age, obesity and cigarette smoking are associated with decreased fertility, adverse Assisted Reproductive Technologies (ART) outcomes and fetal and neonatal complications. IVF failures increase dramatically in women aged between 42-43 years. Advanced paternal age is associated with fetal and neonatal adverse outcomes. However, it remains uncertain that advanced paternal age could impair IVF results. Obesity (Body mass index more than 30 kg/m(2)) is associated with lower fecundity, pregnancy complications and adverse ART results. The rate of complications is increasing with higher BMI. Cigarette smoking is associated with longer time to conceive and decreased IVF results. In case of infertility associated with obesity or cigarette smoking, physicians have to inform their patient about the benefits of smoking cessation and weight loss. However, maternal age had to be considered as the main prognosis factor before delaying ART because of dietary or smoking cessation program.