Browsing by Author "Allshouse, Amanda"

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    High early pregnancy body mass index is associated with alterations in first- and second-trimester angiogenic biomarkers
    (Elsevier, 2022) Beck, Celeste; Allshouse, Amanda; Silver, Robert M.; Grobman, William A.; Simhan, Hyagriv; Haas, David; Reddy, Uma M.; Blue, Nathan R.; Obstetrics and Gynecology, School of Medicine
    Background: Obesity is associated with various placenta-mediated adverse pregnancy outcomes, including preeclampsia, preterm birth, and stillbirth. Mechanisms linking obesity with placental dysfunction are not completely understood. Objective: This study aimed to examine the relationship between early pregnancy body mass index and placental angiogenic biomarkers soluble fms-like tyrosine kinase-1, placental growth factor, and the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio. Study design: We conducted secondary analyses of an existing substudy within a multisite, prospective observational cohort study of nulliparous pregnant women in the United States. First- and second-trimester maternal blood samples, first-trimester body mass index, and demographic, lifestyle, and pregnancy outcomes data were collected. Soluble fms-like tyrosine kinase-1 and placental growth factor concentrations were measured at 6 to 13 and 16 to 22 weeks of gestation for women (cases) who experienced one of several adverse pregnancy outcomes (delivery at <37 weeks of gestation, preeclampsia or eclampsia, birthweight for gestational age <5th percentile, or stillbirth) and for those who had none of those outcomes (controls). We used multivariable mixed-effects linear regression models to estimate the association of body mass index with angiogenic biomarkers at both time points. We evaluated mean change between first- and second-trimester biomarker concentrations using multivariable linear regression models. Lastly, we used logistic regression models to estimate the risk of a high second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio, using clinically established cutoffs for risk prediction. Results: Angiogenic biomarker and early pregnancy body mass index data were available for 2363 women (1467 with adverse pregnancy outcomes and 896 controls). High early pregnancy body mass index was associated with consistently lower soluble fms-like tyrosine kinase-1 concentrations across the first and second trimesters of pregnancy. We found lower first-trimester placental growth factor concentrations in the group with class II or III obesity (P<.001) and lower second-trimester placental growth factor concentrations among groups who were overweight, with class I obesity, and class II or III obesity (P<.001). For every unit increase in early pregnancy body mass index, there was a -4.4 pg/mL (95% confidence interval, -3.6 to -5.2) smaller mean increase in placental growth factor concentrations between the first and second trimesters of pregnancy. These differences resulted in significantly lower mean first-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios among groups who were overweight, with class I obesity, and class II or III obesity (P<.05) and in a significantly higher second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio among the group with class II or III obesity (P<.001), compared with the group with normal body mass index. Each unit of increase in body mass index was associated with a 0.5 (95% confidence interval, 0.3-0.7) greater mean increase in the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio between the first and second trimesters of pregnancy. In stratified analyses, associations between body mass index and angiogenic biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor were similar in nonadverse pregnancy outcome and adverse pregnancy outcome subgroups, whereas associations between body mass index and the soluble fms-like tyrosine kinase-1-to-placental growth factor ratio were attenuated in the subgroups. Participants in the group with class II or III obesity were 3.13 (95% confidence interval, 1.15-8.49) times more likely than participants with normal weight to have a second-trimester ratio of ≥38 in univariate analysis. Conclusion: High early pregnancy body mass index was associated with lower soluble fms-like tyrosine kinase-1 and placental growth factor concentrations across early pregnancy. Maternal body mass was inversely associated with first-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios and positively associated with second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratios, driven by a diminished rise in placental growth factor between the first and second trimesters of pregnancy. Women with class II or III obesity have an increased risk of a high second-trimester soluble fms-like tyrosine kinase-1-to-placental growth factor ratio associated with placental dysfunction.
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    Prospective Evaluation of Placental Abruption in Nulliparous Women
    (Taylor & Francis, 2022) Lueth, Amir; Blue, Nathan; Silver, Robert M.; Allshouse, Amanda; Hoffman, Matthew; Grobman, William A.; Simhan, Hyagriv N.; Reddy, Uma; Haas, David M.; Obstetrics and Gynecology, School of Medicine
    Introduction: Because most data on placental abruption are derived from retrospective studies, multiple sources of bias may have affected the results. Thus, we aimed to characterize risk factors and outcomes for placental abruption in a large prospective cohort of nulliparous women. Methods: This was a secondary analysis of women enrolled in the Nulliparous Pregnancy Outcomes Study Monitoring-to-be (nuMom2b) study, a prospective observational cohort. Participants were recruited in their first trimester of pregnancy from 8 sites and had 4 study visits, including at delivery. Placental abruption was defined by confirmed clinical criteria. The primary analysis was restricted to abruption identified antepartum and intrapartum. As a secondary analysis, we examined antepartum and intrapartum abruptions separately. We compared risk factors (maternal demographic and clinical characteristics) and outcomes in women with and without placental abruption using univariable and multivariable analyses as appropriate. Results: 9450 women were included in the primary analysis. Abruption was identified in 0.66% (n = 62), of which 35 (56%) were antepartum and 27 (44%) intrapartum. For women with abruption, the mean gestational age at delivery was 35.6 ± 4.4 weeks and 38.8 ± 2.2 weeks for women without abruption. Gravidity was associated with abruption (OR 3.1, 95% CI: 1.6-6.0). In univariate analysis, abruption was associated with cesarean delivery (OR 3.7, 95% CI: 2.2-6.0), blood transfusion (OR 3.8, 95% CI: 1.4-10.7), PPROM (OR 9.0, 95% CI: 5.4-15.1), preterm birth (OR 8.5, 95% CI: 5.1-14.2), SGA (OR 4.0, 95% CI: 2.3-6.95), RDS (OR 5.5, 95% CI: 2.6-11.2), IVH 20.2 (OR 20.2, 95% CI: 5.9-68.8) and ROP (OR 12.2, 95% CI: 2.8-52.6). However, after adjustment for confounders including gestational age, abruption was only associated with increased odds of cesarean delivery and blood transfusion. Results were similar when restricted to antepartum and intrapartum abruptions. Conclusion: Abruption was identified in <1% of nulliparous women. However, few maternal risk factors were identified. Neonatal morbidities were associated with an abruption and were primarily driven by gestational age due to preterm birth.