Preterm labour and prematurity

Cervicovaginal microbiota and metabolome predict preterm birth risk in an ethnically diverse cohort

The syndrome of spontaneous preterm birth (sPTB) presents a challenge to mechanistic understanding, effective risk stratification, and clinical management. Individual associations between sPTB, self-reported ethnic ancestry, vaginal microbiota, metabolome, and innate immune response are known but not fully understood, and knowledge has yet to impact clinical practice. Here, we used multi–data type integration and composite statistical models to gain insight into sPTB risk by exploring the cervicovaginal environment of an ethnically heterogenous pregnant population (n = 346 women; n = 60 sPTB < 37 weeks’ gestation, including n = 27 sPTB < 34 weeks). Analysis of cervicovaginal samples (10–15⁺⁶ weeks) identified potentially novel interactions between risk of sPTB and microbiota, metabolite, and maternal host defense molecules. Statistical modeling identified a composite of metabolites (leucine, tyrosine, aspartate, lactate, betaine, acetate, and Ca²⁺) associated with risk of sPTB < 37 weeks (AUC 0.752). A combination of glucose, aspartate, Ca²⁺, Lactobacillus crispatus, and L. acidophilus relative abundance identified risk of early sPTB < 34 weeks (AUC 0.758), improved by stratification by ethnicity (AUC 0.835). Increased relative abundance of L. acidophilus appeared protective against sPTB < 34 weeks. By using cervicovaginal fluid samples, we demonstrate the potential of multi–data type integration for developing composite models toward understanding the contribution of the vaginal environment to risk of sPTB.

Pre-pregnancy BMI and weight gain: where is the tipping point for preterm birth?

BACKGROUND

Obesity in pregnant women is a major problem affecting both the mother and her offspring. Literature on the effect of obesity on preterm birth is inconsistent and few studies have investigated the influence of weight gain during pregnancy. This study examined the effect of maternal pre-pregnancy BMI and weight gain during pregnancy on preterm birth.

METHODS

Data from the Collaborative Perinatal Project (CPP) on 45,824 pregnant women with singleton, live-born infants with no sever congenital anomalies was analyzed. Primary outcome variables included preterm (< 37 weeks of gestation), categorized into spontaneous preterm with and without premature rupture of membrane (PROM) and indicated preterm. Maternal BMI was categorized into underweight (BMI < 18.50), normal weight (BMI =1 8.50 - 24.99), overweight (BMI = 25.00 - 29.99), and obese (BMI ≥ 30.00). Multinomial regression analysis was conducted and OR and 95% CI were calculated.

RESULTS

The rate of spontaneous preterm birth with PROM among overweight women decreased with increasing weight gain but increased among women who had excessive weight gain. Similarly, a U-shaped rate of spontaneous preterm birth with and without PROM was observed in obese women. Gaining less weight was protective of spontaneous preterm with and without PROM among overweight and obese women compared to normal weight women. Among underweight women, gaining < 7 kg or 9.5-12.7 kg was associated with increased odds of indicated preterm birth. Appreciable differences were also observed in the association between pre-pregnancy BMI, gestational weight gain and the subtypes of preterm births among African Americans and Caucasian Americans.

CONCLUSION

Reduced weight gain during pregnancy among overweight and obese women is associated with reduced spontaneous preterm birth with and without PROM. Health care professionals and public health workers should be aware of this risk and adhere to the 2009 IOM guideline that recommended reduced weight gain during pregnancy for obese and overweight women.

Histologic chorioamnionitis as a consideration in the management of newborns of febrile mothers

INTRODUCTION

Chorioamnionitis (CA) presents a risk for neonatal sepsis, but its diagnosis remains a challenge. Maternal fever is often used as a clinical predictor of infection, but may be affected by other factors. There is no consensus among neonatologists regarding the length of treatment of babies born to febrile mothers with negative blood culture, but whose placentas are positive for the presence of histologic CA (HCA).

OBJECTIVES

A prospective observational cohort study was conducted on term infants to determine the association of HCA with C-reactive protein (CRP) and elevated immature/total neutrophil (I/T) ratio and other perinatal factors.

METHODS

I/T ratio, CRP, blood culture and placental pathology were performed on 100 infants born to mothers with temperature ≥ 100.4 °F. Placental pathology performed on 100 control infants born to afebrile mothers.

RESULTS

There was a significant association between HCA and maternal fever (MF). The presence of elevated CRP was associated with HCA. There was no significant association between HCA and anesthesia, mode of delivery, nor elevated I/T ratio.

CONCLUSIONS

Maternal fever is associated with HCA. The HCA in conjunction with an elevated CRP can guide the duration of antimicrobial therapy in infants born to febrile mothers.

[Risk factors for pre-term birth in Londrina, Paraná State, Brazil]

The objective of this study was to identify risk factors associated with pre-term birth among live births in a hospital in Londrina, Paraná State, Brazil. Cases consisted of 328 pre-term births, and controls were 369 births with gestational age greater than 37 weeks. A multiple hierarchical logistic regression analysis was carried out. There was a significant correlation (p < 0.05) between pre-term birth and the following variables: socioeconomic status (slum residence); low age of head-of-family; maternal BMI < 19 or > 30 kg/m2; history of prematurity; history of assisted reproduction; mothers in a relationship for less than two years; maternal stress; weekly maternal alcohol consumption; insufficient prenatal care; gestational complications such as bleeding, genital tract infection, altered amniotic fluid volume, high blood pressure, and hospital admission; and twin pregnancy. Regular walks during pregnancy were a protective factor. Improved quality of prenatal care and the identification of the above factors during pregnancy may help reduce premature birth.