Correction of first trimester biochemical aneuploidy screening markers for smoking status: influence of gestational age, maternal ethnicity and cigarette dosage

Serum pregnancy-associated plasma protein A levels in the first, second and third trimester of pregnancy: relation to newborn anthropometric parameters and maternal tobacco smoking

INTRODUCTION

The purpose of this study was to evaluate the associations of the first, second and third trimester serum pregnancy-associated plasma protein A (PAPP-A) concentrations with neonatal anthropometric parameters. The effect of tobacco smoking during pregnancy on PAPP-A level was also studied.

MATERIAL AND METHODS

One hundred and fifty healthy pregnant women were divided into smoking and tobacco-abstinent groups. Serum PAPP-A level was measured with the KRYPTOR rapid random-access immunoassay analyzer. The relationship between PAPP-A and newborn related outcome as well as markers of estimated intensity of cigarette smoking was evaluated by univariate and multivariate linear regression.

RESULTS

Pregnancy-associated plasma protein A concentration was positively correlated with birth weight in the first (β = 31.6; p < 0.001), second (β = 10.6; p < 0.05), and third (β = 4.6; p < 0.001) trimester of gestation. A significant association between PAPP-A and birth body length and head circumference in the second (β = 0.02; p < 0.05) and third trimester (β = 0.01; p < 0.01) was also found. The serum PAPP-A levels were significantly lower in the smoking than in the tobacco-abstinent group in each trimester of pregnancy (p < 0.001). The largest impact of the number of cigarettes smoked per day on PAPP-A level was found in the second (β = -1.2; p = 0.004) and third trimester (β = -2.6; p = 0.001).

CONCLUSIONS

Maternal serum PAPP-A levels during gestation might be significant predictors for birth weight. Increased PAPP-A concentrations in the second and third trimester appeared to also be predictive for newborn body length and head circumference. Smoking alters maternal PAPP-A levels in all trimesters, with the greatest impact related to the number of cigarettes smoked per day.

Hepcidin and Iron Metabolism in Pregnancy: Correlation with Smoking and Birth Weight and Length

To estimate the effect of tobacco smoking on iron homeostasis and the possible association between hepcidin and the neonatal birth weight and length, concentrations of serum hepcidin and selected iron markers were measured in 81 healthy pregnant women (41 smokers and 40 nonsmokers). The smoking mothers had significantly lower concentrations of serum hepcidin (p < 0.001), iron (p < 0.001), and hemoglobin (p < 0.05), but higher erythropoietin (p < 0.05) levels compared with non-smoking pregnant women. Logistic regression analysis showed the highest negative impact of the number of cigarettes smoked per day (β = -0.46; p < 0.01) and positive impact of ferritin level (β = 0.47; p < 0.001) on serum hepcidin concentration. The birth weight and the body length of smoking mothers' infants were significantly lower than in tobacco abstinent group (p < 0.001). In multiple regression analysis, birth body weight (β = 0.56; p < 0.001) and length (β = 0.50; p < 0.001) were significantly related to maternal hepcidin values. Tobacco smoking affected hepcidin level in serum of pregnant women in a dose-dependent manner. Low concentrations of iron and hemoglobin in maternal serum coexisting with high level of erythropoietin suggest that smoking could lead to subclinical iron deficiency and chronic hypoxia not only in mothers but also in fetus. Low serum hepcidin concentration in smoking pregnant women might be associated with lower fetal birth weight and length.

Evaluation of the impact of maternal smoking on ultrasound and endocrinological markers of first trimester placentation

OBJECTIVES

To study the effect of maternal smoking on 2D ultrasound measurements and maternal serum (MS) levels of endocrinologic markers of placentation.

STUDY DESIGN

Prospective population-based cohort study of 32 smokers and 96 non-smoking controls with a normal pregnancy outcome.

MAIN OUTCOME MEASURES

Placental thickness and 2D-volume and MS levels of pregnancy-associated plasma protein A (PAPP-A) and free-beta human chorionic gonadotrophin (fβhCG) at 11-13(+6)weeks of gestation and mid-trimester MS α-fetoprotein (AFP), unconjugated estriol (uE3) and inhibin A levels.

RESULTS

The MS levels of fβhCG and PAPP-A were significantly (P < 0.01 and P < 0.001, respectively) lower in the serum and the level of inhibin A significantly (P < 0.001) higher in the smokers than in controls. There was no significant difference for the MSAFP, MSuE3 placental thickness, basal plate surface and volume between the groups.

CONCLUSION

The placental morphological alterations secondary to maternal smoking are mainly at the level of the villous trophoblast and are not associated with changes in the placental size or utero-placental interface during the first trimester of pregnancy.

Accuracy of self-reported smoking status in first trimester aneuploidy screening

OBJECTIVES

To review the accuracy of self-reporting of smoking status in our first trimester screening population and to assess the levels of pregnancy-associated plasma protein-A (PAPP-A) and free-β human chorionic gonadotropin (free-hCGβ) in women who were classified for smoking status by serum cotinine concentrations and self-reporting.

METHODS

Cotinine concentration was determined in the stored serum 696 self-reported smokers and 442 self-reported non-smokers. PAPP-A and free-hCGβ multiples of the medians (MoMs) determined at screening were reverted to uncorrected for self-reported smoking status.

RESULTS

A total of 21.7% of those self-reporting as non-smokers had increased serum cotinine concentrations (using a cut-off of 13.7 ng/mL), indicating a positive smoking status. This under-reporting meant that serum PAPP-A and free-hCGβ MoMs were greater reduced in smokers classified by cotinine levels (17.2% and 9.7%) than in those classified by self-reporting (14.6% and 2.8%). Women who were classified as smokers at conception but had stopped at some time afterwards did not have significantly reduced marker MoMs to non-smokers.

CONCLUSIONS

Self-reporting results in under-representation of smoking in our population, resulting in a significant bias and inflated screen-positive rates.