A new customised placental weight standard redefines the relationship between maternal obesity and extremes of placental size and is more closely associated with pregnancy complications than an existing population standard

Sociodemographic factor associations with maternal and placental outcomes: A cluster and partial least squares regression analysis

INTRODUCTION

Maternal social disadvantage adversely affects maternal and offspring health, with limited research on placental outcomes. Therefore, we examined maternal sociodemographic factor associations with placental and birth outcomes in general (Lifeways Cross-Generation Cohort) and at-risk (PEARS Study of mothers with overweight or obesity) populations of pregnant women.

METHODS

TwoStep cluster analysis profiled Lifeways mothers (n = 250) based on their age, parity, marital status, household income, private healthcare insurance, homeowner status, and education. Differences in placental and birth outcomes (untrimmed placental weight (PW), birthweight (BW) and BW:PW ratio) between clusters were assessed using one-way ANOVA and chi-square tests. Partial least squares regression analysed individual effects of sociodemographic factors on placental and birth outcomes in Lifeways and PEARS mothers (n = 461).

RESULTS

Clusters were classified as "Married Homeowners" (n = 140, 56 %), "Highest Income" (n = 58, 23.2 %) and "Renters" (n = 52, 20.8 %) in the Lifeways Cohort. Renters were younger, more likely to smoke, have a means-tested medical card and more pro-inflammatory diets compared to other clusters (p < 0.01). Compared to Married Homeowners, renters' offspring had lower BW (-259.26 g, p < 0.01), shorter birth length (-1.31 cm, p < 0.01) and smaller head circumference (-0.59 cm, p = 0.02). PLS regression analyses identified nulliparity as having the greatest negative effect on PW (Lifeways and PEARS) while being a homeowner had the greatest positive effect on PW (Lifeways).

CONCLUSION

Certain combinations of sociodemographic factors (particularly homeownership) were associated with less favourable lifestyle factors, and with birth, but not placental outcomes. When explored individually, parity contributed to the prediction of placental and birth outcomes in both cohorts of pregnant women.

Defining poor growth and stillbirth risk in pregnancy for infants of mothers with overweight and obesity

BACKGROUND

Mothers who are obese carry heavier fetuses and have lower rates of small for gestational age (<10th birthweight centile) infants. However, their infants may be growth-restricted (with an increased risk of stillbirth) at a higher birthweight centile compared with infants from healthy-weight women.

OBJECTIVE

This study aimed to quantify the birthweight centile at which the risk of stillbirth in infants born to obese women equaled that of <10th-centile infants born to healthy-weight women, and clarify the relationship between maternal body mass index, infant size, and stillbirth.

STUDY DESIGN

We conducted a retrospective cohort study on all infants born in Victoria, Australia, from 2009 to 2019 (754,946 cases for analysis). We applied uncustomized birthweight centiles to all infants, and stratified the maternal cohort by body mass index (<20 kg/m2, 20-25 kg/m2, 25-30 kg/m2, 30-35 kg/m2, 35-40 kg/m2, ≥40 kg/m2). For each body mass index category, we assessed proportions of infants born <10th centile and <3rd centile, stillbirth rates among infants of all sizes, and small for gestational age infants. We calculated the stillbirth rate (per 1000) and relative risk (risk of stillbirth if born <10th centile vs >10th centile) for healthy-weight women (body mass index, 20-25 kg/m2). We then determined the birthweight centile for infants born to mothers within other body mass index categories that equaled that rate or risk.

RESULTS

Stillbirth rates increased with increasing maternal body mass index. Infants classified as small for gestational age (<10th centile) from mothers with high body mass index had a higher risk of stillbirth (relative risk, 3.15; 95% confidence interval, 2.22-4.47; for mothers with body mass index ≥40 kg/m2 vs healthy-weight mothers [body mass index, 20-25 kg/m2]). The stillbirth rate (stillborn infants per 1000 births) among <10th-centile infants born to healthy-weight mothers was 7.5 per 1000. The same stillbirth rate was observed at higher birthweight centiles for infants of women with higher body mass index (<18th centile for those with a body mass index of 25-30 kg/m2, <25th centile for body mass index of 30-35 kg/m2, <31st centile for body mass index of 35-40 kg/m2, <41st centile for body mass index of ≥40 kg/m2). The relative risk of stillbirth among small for gestational age infants of healthy-weight mothers was 5.46 (95% confidence interval, 4.65-6.40). The birthweight centile with a comparable relative risk of stillbirth increased with increasing body mass index (<16th centile for women with body mass index of 25-30 kg/m2, <19th centile for body mass index of 30-35 kg/m2, <28th centile for body mass index of 35-40 kg/m2, <30th centile for body mass index ≥40 kg/m2).

CONCLUSION

Obesity affects the relationship between infant size and perinatal mortality. The stillbirth risk observed in <10th-centile infants from healthy-weight mothers occurs at higher birthweight centiles with overweight or obese mothers. Clinicians should be aware that the same infant risk exists at a higher birthweight centile for women with higher body mass index.

Placental pathology findings amongst extremely preterm perinatal deaths in Aotearoa New Zealand

INTRODUCTION

Women of South Asian ethnicity are overrepresented in adverse pregnancy outcomes across high-income countries, including placental dysfunction and antepartum haemorrhage. As the burden of mortality is highest for extremely preterm infants, we aimed to identify any differences in placental pathology among perinatal deaths from 20⁺⁰ to 27⁺⁶ weeks gestation between South Asian, Māori and New Zealand (NZ) European women in Aotearoa NZ, with a focus on women of South Asian ethnicity.

METHODS

Placental pathology reports and clinical data from perinatal deaths between 2008 and 2017 were provided by the NZ Perinatal and Maternal Mortality Review Committee, blinded and analysed by an experienced perinatal pathologist using the Amsterdam Placental Workshop Group Consensus Statement criteria. South Asian ethnicity was classified as Indian, Fijian Indian, South African Indian, Sri Lankan, Pakistani and Bangladeshi.

RESULTS

886 of 1571 placental pathology reports met the inclusion criteria. Women of South Asian ethnicity were significantly more likely to show features of histologic chorioamnionitis (aOR 1.87, 95%CI 1.19-2.94) and chorionic vasculitis (aOR 1.92, 95%CI 1.13-3.29), than NZ European and Māori women respectively. 13 of 15 (87%) of South Asian mothers with a diabetic disorder were identified with chorioamnionitis, compared to 1 in 5 (20%) of Māori and 5 in 12 (41%) of NZ European women. Cord hyper-coiling was also more common among South Asian pregnancies, compared to NZ European (aOR 1.98, 95%CI 1.10-3.56).

DISCUSSION

Differences in placental pathology by ethnicity were observed among extremely preterm perinatal deaths. Underlying metabolic disorders and an associated pro-inflammatory environment may play an important role in the causal pathway leading to these deaths in women of South Asian ethnicity.

The importance of nutrition in pregnancy and lactation: lifelong consequences

Most women in the United States do not meet the recommendations for healthful nutrition and weight before and during pregnancy. Women and providers often ask what a healthy diet for a pregnant woman should look like. The message should be “eat better, not more.” This can be achieved by basing diet on a variety of nutrient-dense, whole foods, including fruits, vegetables, legumes, whole grains, healthy fats with omega-3 fatty acids that include nuts and seeds, and fish, in place of poorer quality highly processed foods. Such a diet embodies nutritional density and is less likely to be accompanied by excessive energy intake than the standard American diet consisting of increased intakes of processed foods, fatty red meat, and sweetened foods and beverages. Women who report “prudent” or “health-conscious” eating patterns before and/or during pregnancy may have fewer pregnancy complications and adverse child health outcomes. Comprehensive nutritional supplementation (multiple micronutrients plus balanced protein energy) among women with inadequate nutrition has been associated with improved birth outcomes, including decreased rates of low birthweight. A diet that severely restricts any macronutrient class should be avoided, specifically the ketogenic diet that lacks carbohydrates, the Paleo diet because of dairy restriction, and any diet characterized by excess saturated fats. User-friendly tools to facilitate a quick evaluation of dietary patterns with clear guidance on how to address dietary inadequacies and embedded support from trained healthcare providers are urgently needed.

Recent evidence has shown that although excessive gestational weight gain predicts adverse perinatal outcomes among women with normal weight, the degree of prepregnancy obesity predicts adverse perinatal outcomes to a greater degree than gestational weight gain among women with obesity. Furthermore, low body mass index and insufficient gestational weight gain are associated with poor perinatal outcomes. Observational data have shown that first-trimester gain is the strongest predictor of adverse outcomes. Interventions beginning in early pregnancy or preconception are needed to prevent downstream complications for mothers and their children. For neonates, human milk provides personalized nutrition and is associated with short- and long-term health benefits for infants and mothers. Eating a healthy diet is a way for lactating mothers to support optimal health for themselves and their infants.