Association of Obesity With Maternal and Cord Blood Penicillin Levels in Women With Group B Streptococcus Colonization

OBJECTIVE

To compare maternal and cord blood penicillin concentrations in women with and without obesity who are receiving intrapartum group B streptococcus (GBS) prophylaxis.

METHODS

We performed a prospective cohort study of term women receiving intrapartum penicillin prophylaxis for GBS colonization (determined by antenatal rectovaginal culture). The following outcomes were compared between obese (body mass index [BMI] 35 or higher at delivery) and nonobese (BMI less than 30 at delivery) groups: penicillin concentration in maternal blood (after two penicillin doses) and umbilical cord blood, GBS rectovaginal colonization status on admission and after two completed doses, and neonatal GBS colonization (using a postnatal ear swab). Fifty-five women were needed to detect a 0.75 SD difference in cord blood penicillin concentrations.

RESULTS

Fifty-five women were enrolled and had all specimens collected; 49 had complete data for analysis (obese n=25, nonobese n=24). There was no difference in the median maternal penicillin concentration between groups (obese 4.2 micrograms/mL vs nonobese 4.0 micrograms/mL, P=.58). There was, however, a 60% lower median cord blood penicillin concentration in the obese compared with the nonobese group (2.7 micrograms/mL vs 6.7 micrograms/mL, respectively, P<.01), with no significant difference in time from last penicillin dose to delivery (obese 2.9 hours vs nonobese 1.7 hours, P=.07). The difference in cord blood concentrations remained significant after adjustment for nulliparity, hypertensive disorders, and time from last penicillin dose to delivery. Only 59.6% of women tested positive for GBS by rectovaginal culture on admission (obese 60.9% vs nonobese 58.3%, P=.86).

CONCLUSION

The median cord blood penicillin concentration was 60% lower in neonates born to women with obesity compared with those born to women without obesity. However, all concentrations exceeded the minimum inhibitory concentration. Maternal penicillin levels were not significantly different between groups. More than 40% of women who previously tested positive for GBS by antenatal culture tested negative for GBS on admission for delivery.

Neighborhood Violent Crime and Perceived Stress in Pregnancy

Stress has been shown to adversely affect pregnancy outcomes. Neighborhood crime rates may serve as one publicly available social determinant of health for pregnancy studies that use registry or electronic health record datasets in which individual-level stress data are not available. We sought to determine whether neighborhood violent crime incidents were associated with measured perceived stress in a largely minority, urban pregnancy cohort. We performed a secondary analysis of the 1309 Philadelphia residents participating in the Motherhood and Microbiome cohort (n = 2000) with both neighborhood violent crime and Cohen's Perceived Stress Scale (PSS-14) data. Generalized linear mixed models accounting for confounding variables and geographic clustering demonstrated that, regardless of race, women with the highest quartile of neighborhood violent crime had significantly elevated odds of high stress compared to women with lower crime. We also found that Black women were more likely to have both the highest quartile of neighborhood violent crime and high stress than non-Black women. Overall, this study demonstrates that neighborhood violent crime is associated with perceived stress in pregnancy. Given disparate exposure to crime and prenatal stress by race, future work is warranted to determine whether urban neighborhood violence and/or stress reduction strategies would improve birth outcome racial disparities.

SARS-CoV-2 seroprevalence among parturient women in Philadelphia

Limited data are available for pregnant women affected by SARS-CoV-2. Serological tests are critically important for determining SARS-CoV-2 exposures within both individuals and populations. We validated a SARS-CoV-2 spike receptor binding domain serological test using 834 pre-pandemic samples and 31 samples from COVID-19 recovered donors. We then completed SARS-CoV-2 serological testing of 1,293 parturient women at two centers in Philadelphia from April 4 to June 3, 2020. We found 80/1,293 (6.2%) of parturient women possessed IgG and/or IgM SARS-CoV-2-specific antibodies. We found race/ethnicity differences in seroprevalence rates, with higher rates in Black/non-Hispanic and Hispanic/Latino women. Of the 72 seropositive women who also received nasopharyngeal polymerase chain reaction testing during pregnancy, 46 (64%) were positive. Continued serologic surveillance among pregnant women may inform perinatal clinical practices and can potentially be used to estimate exposure to SARS-CoV-2 within the community.

Cervical length change as a predictor of preterm birth in symptomatic patients

BACKGROUND

Distinguishing between true and false preterm labor remains a challenge. The shortening in cervical length throughout a gestation has been theorized to be a possible predictor of spontaneous preterm birth. Although there are some studies evaluating cervical length shortening as a predictor of spontaneous preterm birth, it is not known whether the shortening in cervical length from an asymptomatic to symptomatic state, when a patient presents with preterm labor symptoms, is predictive of spontaneous preterm birth.

OBJECTIVE

This study aimed to determine the utility of cervical length shortening from an asymptomatic time point (anatomic ultrasound) to when a patient presents with preterm labor symptoms as a predictor of spontaneous preterm birth.

STUDY DESIGN

A prospective cohort study was performed to evaluate the use of transvaginal cervical length assessment in symptomatic women in predicting spontaneous preterm birth from January 2013 to March 2015. Women with singleton gestations who presented to our institution between 22 0/7 weeks and 33 6/7 weeks of gestation with preterm labor symptoms were included in the overall cohort. This was a planned secondary analysis to evaluate the shortening in cervical length from an asymptomatic state (anatomic ultrasound) to a symptomatic state as a predictor of preterm birth. For this analysis, inclusion criteria were known delivery status, cervical length screening performed at anatomic ultrasound, and a valid cervical length measurement at the time of preterm labor symptoms. Women with preterm rupture of membranes, cervical dilation of >2 cm, or moderate to severe bleeding were excluded. Cervical length shortening was defined as a decrease in cervical length of >10 mm from anatomic ultrasound to the time of presentation with preterm labor symptoms. The outcome evaluated was spontaneous preterm birth before 37 weeks of gestation. Chi-square test and receiver operating characteristic curves were used to evaluate the data. Multivariable logistic regression was used to calculate the odds. Test characteristics of cervical length shortening of >10 mm were determined.

RESULTS

A total of 549 women were included in the original cohort, and 277 women were included in this secondary analysis. The overall rate of spontaneous preterm birth was 8.3%. There were 52 women (19%) with cervical length shortening of >10 mm. The rate of spontaneous preterm birth was significantly higher for those with cervical length shortening of >10 mm than those with cervical length shortening of ≤10 mm (21.2% vs 5.3%; P=.001). This higher risk of spontaneous preterm birth remained after adjusting for confounders including maternal age and previous spontaneous preterm birth (adjusted odds ratio, 4.71; 95% confidence interval, 1.84-12.09). Using cervical length shortening of >10 mm as a screening test had a sensitivity of 47.8%, a specificity of 83.9%, a positive predictive value of 21.2%, and a negative predictive value of 94.7%.

CONCLUSION

In women presenting with preterm labor symptoms, a cervical length that is >10 mm shorter from anatomic ultrasound is associated with an increased risk of spontaneous preterm birth.

SARS-CoV-2 Seroprevalence Among Parturient Women

Limited data are available for pregnant women affected by SARS-CoV-2. Serological tests are critically important to determine exposure and immunity to SARS-CoV-2 within both individuals and populations. We completed SARS-CoV-2 serological testing of 1,293 parturient women at two centers in Philadelphia from April 4 to June 3, 2020. We tested 834 pre-pandemic samples collected in 2019 and 15 samples from COVID-19 recovered donors to validate our assay, which has a ~1% false positive rate. We found 80/1,293 (6.2%) of parturient women possessed IgG and/or IgM SARS-CoV-2-specific antibodies. We found race/ethnicity differences in seroprevalence rates, with higher rates in Black/non-Hispanic and Hispanic/Latino women. Of the 72 seropositive women who also received nasopharyngeal polymerase chain reaction testing during pregnancy, 46 (64%) were positive. Continued serologic surveillance among pregnant women may inform perinatal clinical practices and can potentially be used to estimate seroprevalence within the community.

Cervicovaginal microbial communities deficient in Lactobacillus species are associated with second trimester short cervix

BACKGROUND

The cervix functions as a barrier to ascending pathogens in pregnancy. Short cervical length and lack of cervicovaginal Lactobacillus species are risk factors for spontaneous preterm birth; however, whether they interact to increase risk remains unknown.

OBJECTIVE

We sought to examine the relationship between cervicovaginal microbiota and short cervix as well as their combined impact on spontaneous preterm birth risk.

STUDY DESIGN

This was a secondary analysis of a prospective nested, case-control pregnancy study. Cervical swabs were collected between 16 and 20 weeks of gestation. Cervical length was measured per standard clinical care during a clinically indicated ultrasound at approximately 20 weeks of gestation. Cervicovaginal microbiota were analyzed with 16S ribosomal RNA gene sequencing and classified into community state types among 67 cases of spontaneous preterm birth, 47 cases of medically indicated preterm birth, and 358 cases of term births. Logistic regression was used to model associations of community state type IV, a community characterized by a paucity of Lactobacillus species and a wide array of anaerobic bacteria, and short cervix (<25 mm) as well as to model the association of a combination of short cervix and community state type IV with the odds of spontaneous preterm birth.

RESULTS

Among the 472 women in the data set, there were 38 with short cervix (8.1%) and 177 with community state type IV (37.5%). Short cervix was associated with spontaneous preterm birth (adjusted odds ratio, 15.59; 95% confidence interval, 6.77-35.92). Women with community state type IV had higher odds of short cervix (adjusted odds ratio, 2.17; 95% confidence interval, 1.04-4.53) as well as spontaneous preterm birth (adjusted odds ratio, 1.97; 95% confidence interval, 1.06-3.65). While the interaction of community state type IV and short cervix was not significant (P = .771), women with both short cervix and community state type IV (n = 20) had higher odds of spontaneous preterm birth compared with women with both normal cervical length and community state types I, II, III, or V (n = 277) (adjusted odds ratio, 21.8; 95% confidence interval, 6.78-70.2).

CONCLUSION

Community state type IV, characterized by a diverse set of strict and facultative anaerobes and a paucity of Lactobacillus species, is associated with increased odds of short cervix. Women with both community state type IV and short cervix have higher odds of spontaneous preterm birth than women with either factor alone. Determining the cascade of events leading to premature cervical shortening, including dysbiosis, may be critical in preventing spontaneous preterm birth.

The stepwise assembly of the neonatal virome is modulated by breastfeeding

The gut of healthy human neonates is usually devoid of viruses at birth, but quickly becomes colonized, in some cases leading to gastrointestinal disorders^1–4. Here we report that viral community assembly in neonates takes place in distinct steps. Fluorescent staining of virus-like particles purified from infant meconium/early stool samples show few or no particles, but by one month of life particle numbers achieve 10⁹ per gram, and these numbers appear to persist through life^5–7. We investigated the origin of these viral populations using shotgun metagenomic sequencing of viral-enriched preparations and whole microbial communities, and followed up with targeted microbiological analyses. Results indicate that, early after birth, pioneer bacteria colonize the infant gut, and by one month prophage induced from these bacteria provide the predominant population of virus-like particles. By four months of life, identifiable viruses that replicate in human cells become more prominent. Multiple human viruses were more abundant in stool samples from babies exclusively fed formula versus those fed partially or fully on breast milk, paralleling reports that breast milk can be protective against viral infections^8–10. Phage populations also differed associated with breastfeeding. Evidently colonization of the infant gut is stepwise, first mainly by temperate bacteriophages induced from pioneer bacteria, and later by viruses that replicate in human cells, with the second phase modulated by breastfeeding.

Maternal stress, low cervicovaginal β-defensin, and spontaneous preterm birth

Background

Spontaneous preterm birth (sPTB) is a major contributor to infant mortality and its etiology remains poorly understood. Host immunity and maternal stress may play a role in the pathogenesis of sPTB but mechanisms are poorly delineated. Antimicrobial proteins in the cervicovaginal space, such as beta defensins, modulate immune responses to bacteria and have been shown to modulate the risk of sPTB from non-optimal microbiota. While stress is known to induce immunological changes, no study has examined the interplay between maternal stress and the immune response in association with sPTB.

Objectives

Our objectives were to determine whether psychosocial stress was associated with a mediator of the immune system in the cervicovaginal space, beta defensin-2, and to examine the combined impact of high stress and low cervicovaginal beta defensin-2 levels on the odds of sPTB.

Study Design

From the Motherhood & Microbiome cohort study (n=2000), we performed a secondary, nested case-control study, frequency matched by race/ethnicity, of 519 pregnant women (110 sPTB and 409 term). Stress and cervicovaginal beta defensin-2 levels were measured at 16-20 weeks of gestation. Stress was dichotomized at a score of 30 on Cohen's Perceived Stress Scale (PSS-14). We measured cervicovaginal beta defensin-2 levels with ELISA and dichotomized at the median. We modeled associations of high stress and low cervicovaginal beta defensin-2 levels using multivariable logistic regression. We also compared the proportion of women with high stress and low cervicovaginal beta defensin-2 levels among women with spontaneous preterm and term births using Chi-Square tests. We modeled adjusted associations of stress and cervicovaginal beta defensin-2 levels with odds of sPTB using logistic regression.

Results

The majority of the study population was non-Hispanic black (72.8%), insured by Medicaid (51.1%), and had a PSS-14 score < 30 (80.2%). High stress was associated with reduced adjusted odds of low beta defensin-2 levels (aOR 0.63, 95% CI: 0.38 -0.99). In a model adjusted for race and smoking, both high stress (aOR 1.72, 95% CI: 1.03-2.90) and low beta defensin-2 (aOR 1.58, 95% CI: 1.004-2.49) were associated with increased odds of sPTB. We then built a model of the four possible combinations of low and high stress and low and high beta defensin-2 levels with the odds of sPTB. Women with either high stress (aOR 1.37, 95% CI: 0.68 - 2.78) or low beta defensin-2 (aOR 1.40, 95% CI: 0.83-2.34), had slightly elevated but not significantly increased odds of sPTB compared to women with neither exposure. However, women with both high stress and low beta defensin-2 had significantly elevated odds of sPTB compared to women with neither exposure (aOR 3.16, 95 % CI: 1.46 - 6.84).

Conclusion

High perceived stress and low cervicovaginal beta defensin-2 levels are associated with higher odds of sPTB, and when present concurrently, they result in the highest odds of sPTB in a largely non-Hispanic black cohort. Our findings warrant further work to examine social determinants of health and the host cervicovaginal immune responses that may modulate the pathogenesis of sPTB.

The Metabolomic Signature of the Placenta in Spontaneous Preterm Birth

The placenta is metabolically active and supports the growth of the fetus. We hypothesize that deficits in the capacity of the placenta to maintain bioenergetic and metabolic stability during pregnancy may result in spontaneous preterm birth (SPTB). To explore this hypothesis, we performed a nested cased control study of metabolomic signatures in placentas from women with SPTB (<36 weeks gestation) compared to normal pregnancies (≥38 weeks gestation). To control for the effects of gestational age on placenta metabolism, we also studied a subset of metabolites in non-laboring preterm and term Rhesus monkeys. Comprehensive quantification of metabolites demonstrated a significant elevation in the levels of amino acids, prostaglandins, sphingolipids, lysolipids, and acylcarnitines in SPTB placenta compared to term placenta. Additional quantification of placental acylcarnitines by tandem mass spectrometry confirmed the significant elevation in SPTB human, with no significant differences between midgestation and term placenta in Rhesus macaque. Fatty acid oxidation as measured by the flux of ³H-palmitate in SPTB placenta was lower than term. Collectively, significant and biologically relevant alterations in the placenta metabolome were identified in SPTB placenta. Altered acylcarnitine levels and fatty acid oxidation suggest that disruption in normal substrate metabolism is associated with SPTB.

Importance of Early Diagnosis in Peripartum Cardiomyopathy

Peripartum cardiomyopathy (PPCM) can lead to long-term systolic dysfunction, especially among black women. Hypertensive disorders of pregnancy (HDP) are the strongest risk factor for PPCM, but controversy remains on whether HDP predict a favorable outcome. Women with HDP are also often diagnosed with PPCM earlier than those without HDP. Our objective is to determine recovery of systolic function in patients with PPCM stratified by HDP, timing of diagnosis, and race. We conducted a retrospective cohort study of 220 patients (55% black) diagnosed with PPCM. Patients with PPCM and HDP were diagnosed earlier postpartum than patients without HDP (P=0.013), an effect that was most pronounced in nonblack patients. Rates of left ventricular ejection fraction (LVEF) recovery were similar among PPCM patients with and without HDP (68.4% versus 62.6%, P=0.425). In contrast, patients with PPCM diagnosed after 1-month postpartum had lower rates of LVEF recovery than patients diagnosed <1-month postpartum (53.7% versus 69.9%, P=0.035). LVEF at time of diagnosis is a strong predictor of LVEF recovery, and patients with PPCM diagnosed after 1-month postpartum had lower baseline LVEF compared to patients presenting earlier (P=0.041). The presence of HDP does not correlate with LVEF recovery in our racially diverse PPCM cohort. In contrast, early diagnosis portends a favorable outcome. Early diagnosis is associated with higher LVEF at presentation, likely explaining the improved outcomes in these women. These findings underscore the need for early monitoring and diagnosis, especially in at-risk and underserved populations.

Damaging Variants in Proangiogenic Genes Impair Growth in Fetuses with Cardiac Defects

OBJECTIVE

To determine the impact of damaging genetic variation in proangiogenic pathways on placental function, complications of pregnancy, fetal growth, and clinical outcomes in pregnancies with fetal congenital heart defect.

STUDY DESIGN

Families delivering a baby with a congenital heart defect requiring surgical repair in infancy were recruited. The placenta and neonate were weighed and measured. Hemodynamic variables were recorded from a third trimester (36.4 ± 1.7 weeks) fetal echocardiogram. Exome sequencing was performed on the probands (N = 133) and consented parents (114 parent-child trios, and 15 parent-child duos) and the GeneVetter analysis tool used to identify damaging coding sequence variants in 163 genes associated with the positive regulation of angiogenesis (PRA) (GO:0045766).

RESULTS

In total, 117 damaging variants were identified in PRA genes in 133 congenital heart defect probands with 73 subjects having at least 1 variant. Presence of a damaging PRA variant was associated with increased umbilical artery pulsatility index (mean 1.11 with variant vs 1.00 without; P = .01). The presence of a damaging PRA variant was also associated with lower neonatal length and head circumference for age z score at birth (mean -0.44 and -0.47 with variant vs 0.23 and -0.05 without; P = .01 and .04, respectively). During median 3.1 years (IQR 2.0-4.1 years) of follow-up, deaths occurred in 2 of 60 (3.3%) subjects with no PRA variant and in 9 of 73 (12.3%) subjects with 1 or more PRA variants (P = .06).

CONCLUSIONS

Damaging variants in proangiogenic genes may impact placental function and are associated with impaired fetal growth in pregnancies involving a fetus with congenital heart defect.

Racial disparities in preterm birth in USA: a biosensor of physical and social environmental exposures

Race is a social construct that involves a person’s self-assigned, and externally-perceived, group membership. Group membership can determine much about Americans’ lives and health. Complex health disorders such as cardiovascular disease, asthma, and obesity disproportionately affect Non-Hispanic black Americans. An individual’s risk of any of these disorders encompasses both genetic predisposition and environmental stimuli. We propose that environmental stressors may be large contributors to differences in preterm birth rates in the United States between racial groups. Environmental exposures differ by race due to ongoing residential, educational and economic racial segregation as well as discrimination. Characterizing and mitigating environmental factors that contribute to differential preterm risk could identify women at risk, prevent some preterm births, and reduce perinatal health disparities.

The tracking of lipopolysaccharide through the feto-maternal compartment and the involvement of maternal TLR4 in inflammation-induced fetal brain injury

Problem

Exposure to intrauterine inflammation (IUI) has been shown to induce fetal brain injury and increase the risk of acquiring a neurobehavioral disorder. The trafficking of the inflammatory mediator, lipopolysaccharide (LPS), in the pregnant female reproductive tract in the setting of IUI and the precise mechanisms by which inflammation induces fetal brain injury are not fully understood.

Method of study

FITC‐labeled LPS was utilized to induce IUI on E15, tissues were collected, and fluorescence was visualized via the Spectrum IVIS. Embryo transfer was utilized to create divergent maternal and fetal genotypes. Wild‐type (WT) embryos were transferred into TLR4−/− pseudopregnant dams (TLR4−/−_mat/WT_fet). On E15, TLR4−/−_mat/WT_fet dams or their WT controls (WT_mat/WT_fet) received an intrauterine injection of LPS or phosphate‐buffered saline (PBS). Endotoxin and IL‐6 levels were assessed in amniotic fluid, and cytokine expression was measured via QPCR.

Results

Lipopolysaccharide trafficked to the uterus, fetal membranes, placenta, and the fetus and was undetectable in other tissues. Endotoxin was present in the amniotic fluid of all animals exposed to LPS. However, the immune response was blunted in TLR4−/−_mat/WT_fet compared with WT controls.

Conclusion

Intrauterine administered LPS is capable of accessing the entire feto‐placental unit with or without a functional maternal TLR4. Thus, bacteria or bacterial byproducts in the uterus may negatively impact fetal development regardless of the maternal genotype or endotoxin response. Despite the blunted immune response in the TLR4‐deficient dams, an inflammatory response is still ignited in the amniotic cavity and may negatively impact the fetus.

IL‐6 protein expression in the amniotic fluid of WTmat/WTfet and TLR4‐/‐mat/WTfet Pregnant females were treated with an intrauterine dose of LPS (250 μg) or PBS on E15. LPS injection resulted in significantly increased IL‐6 protein in WT animals (*, P = 0.0017) compared to controls. LPS did not significantly elevate IL‐6 levels in the TLR4‐/‐mat/WTfet animals. The WTmat/WTfet dams had a significantly higher immune response compared to their TLR4‐/‐mat/WTfet counterparts (#, P = 0.015).