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

Abstract

IntroductionThe 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 methodsOne 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.ResultsPregnancy-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).ConclusionsMaternal 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.

Does Active Smoking Influence the Second Trimester Biochemical Markers Concentrations?

“…Thus, the multiple of median (MoM) is a conventional measurement unit that reflects how far the value of a measured parameter (NT or biochemical markers) is from the median value expected for the same gestational age. Because studies showed that some other factors (behavioral or diseases) influence the median value, it is obvious that it is necessary to correct the MoM according to the presence of these factors [4][5][6][7]. So, the corrected multiple of median (MoMc) represents the MoM value adjusted for the presence of interfering factors (mode of conception, presence of diabetes, smoker status, ethnicity, etc).…”

“…The deviation of a measured value from the median is expressed in multiple of medians (MoM) and is used to calculate a relative risk for aneuploidy. Because it was proved that other parameters (mode of conceiving, smoking, ethnicity, diabetes, etc) interfere with the level of biochemical markers, it is mandatory to correct the MoM according to mentioned parameters [4][5][6][7]. Thus a corrected MoM (MoMc) is calculated for each biochemical marker considering interfering parameters.…”

The effect of active and passive maternal smoking before and during pregnancy on neonatal weight at birth

“…The birthweight of children born to active smokers during pregnancy has been es-timated to be 150-250 g lower as compared to pregnant non-smokers. Also, the risk for LBW has been reported [20][21][22][23]. The correlation between active maternal smoking and neonatal birthweight depends on the number of cigarettes a day and is visible even for the lowest amount of tobacco in active smokers [6,24].…”

The Effect of Chemical Compounds from Cigarettes Smoke on First Trimester Biochemical Markers

“…Obviously, such an effect is also observed in pregnant women who smoke [4,5]. Since some of blood biochemical parameters influenced by inhalation of chemical compounds released by smoking are used to assess the risk of fetal aneuploidy, it is imperative to quantify the degree of alteration and to develop algorithms to counterbalance this effect [6][7][8][9].…”

“…Since the MoM value directly contributes to the evaluation of the risk, any alteration of values by behavioral, environmental or morphologic factors could negatively influence the accuracy of the screening test [6][7][8][9]. As a result, mathematical strategies were developed to correct the influence of these disturbing factors.…”