Short and long IPI after live birth, but not after pregnancy termination, showed increased odds for PTB.

Objective To examine the relationship between maternal characteristics, serum biomarkers, and preterm birth (PTB) by spontaneous and medically-indicated subtypes. Design Population-based cohort. Setting California, United States of America. Population From a total population of 1,004,039 live singleton births in 2009 and 2010, 841,665 pregnancies with linked birth certificate and hospital discharge records were included. Methods Characteristics were compared for term and preterm deliveries by PTB subtype using logistic regression and odds ratios adjusted for maternal characteristics and obstetric factors present in final stepwise models (adjORs) and 95% confidence intervals (CIs). First and second trimester serum marker levels were analyzed in a subset of 125,202 pregnancies with available first and second trimester serum biomarker results. Main Outcome Measure PTB by subtype. Results In fully adjusted models, ten characteristics and three serum biomarkers were associated with increased risk in each PTB subtype (Black race/ethnicity, preexisting hypertension with and without preeclampsia, gestational hypertension with preeclampsia, preexisting diabetes, anemia, previous PTB, one or ≥ two previous cesarean section(s), interpregnancy interval ≥ 60 months, low first trimester pregnancy-associated plasma protein A, high second trimester alpha-fetoprotein, and high second trimester dimeric inhibin A). These risks occurred in 51.6 to 86.2% of all pregnancies ending in PTB depending on subtype. The highest risk observed was for medically-indicated PTB < 32 weeks in women with preexisting hypertension and preeclampsia (adjOR 89.7, 27.3 – 111.2). Conclusions Our findings suggest a shared etiology across PTB subtypes. These commonalities point to targets for further study and exploration of risk reduction strategies.

Objective To investigate the distribution of known factors for preterm birth (PTB) by severity of maternal underweight; to investigate the risk adjusted relationship between severity of underweight and PTB and to assess if the relationship differed by gestational age. Design Retrospective cohort study. Setting State of California, USA. Methods Maternally linked hospital and birth certificate records of 950,356 California deliveries in 2007–2010 were analyzed. Singleton live births of women whose pre-pregnancy body mass index (BMI) was underweight (<18.5 kg/m2) or normal (18.50–24.99 kg/m2) were analyzed. Underweight BMI was further categorized as: severe (<16.00), moderate (16.00–16.99) or mild (17.00–18.49). PTB was grouped as 22–27, 28–31, 32–36 or <37 weeks (compared with 37–41 weeks). Adjusted multivariable Poisson regression modeling was used to estimate relative risk for PTB. Main outcome measures Risk of PTB. Results 72,686 (7.6%) women were underweight. Increasing severity of underweight was associated with increasing percent PTB: 7.8% (n=4421) in mild, 9.0% (n=1001) in moderate and 10.2% (475) in severe underweight. The adjusted relative risk of PTB also significantly increased: aRR=1.22 (95%CI: 1.19–1.26) in mild, aRR=1.41 (95%CI: 1.32–1.50) in moderate and aRR=1.61 (95%CI: 1.47–1.76) in severe underweight. These findings were similar in spontaneous PTB, medically indicated PTB, and the gestational age groupings. Conclusion Increasing severity of maternal pre-pregnancy underweight BMI was associated with increasing risk adjusted PTB at <37 weeks. This increasing risk was of similar magnitude in spontaneous and medically indicated births and in preterm delivery at 28–31 and at 32–36 weeks of gestation.

Elevated PAPP-A, elevated MS-AFP and prior CDs are associated with MAP among women with previa.

Objective To determine whether pregnancies resulting in early preterm birth (< 30 weeks) were more likely than term pregnancies to have elevated mid-trimester tumor necrosis factor alpha (TNF-α) levels co-occurring with lipid patterns suggestive of hyperlipidemia. Study Design Patterns were examined using stored non-fasted serum samples from 108 California and 734 Iowa singleton pregnancies collected as part of statewide prenatal screening. The frequency of elevated mid-pregnancy serum TNF-α levels and lipid patterns suggestive of hyperlipidemia (e.g. elevated total cholesterol (TC), low-density-lipoproteins (LDLs), or triglycerides (TGs), decreased high-density lipoproteins (HDLs)) (considered independently and by co-occurrence) were compared in pregnancies resulting in early preterm birth to those resulting in term birth using logistic regression models. Results While no differences between preterm and term pregnancies were evident when TNF-α or target lipid abnormalities occurred in isolation, early preterm pregnancies were two to four times more likely than term pregnancies to have elevated TNF-α levels co-occurring with indicators of hyperlipidemia (37.5% versus 13.9% in the California sample (adjusted OR 4.0, 95% CI 1.1 – 16.3) and 26.3% versus 14.9% in the Iowa sample (adjusted OR 2.7, 95% CI 1.1 – 6.3)). Observed differences were not explicable to any maternal or infant characteristics. Conclusion Pregnancies resulting in early preterm birth were more likely than term pregnancies to have elevated mid-pregnancy TNF-α levels co-occurring with lipid patterns suggestive of hyperlipidemia. Patterns offer clues for further study of the signaling of early parturition in preterm birth.