Smoking Exposure in Early Pregnancy and Adverse Pregnancy Outcomes: Usefulness of Urinary Tobacco-Specific Nitrosamine Metabolite 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol Levels

Assessing tobacco smoke exposure in pregnancy from self-report, urinary cotinine and NNAL: a validation study using the New Hampshire Birth Cohort Study

OBJECTIVES

Accurate assessment of tobacco smoke exposure is key to evaluate its effects. We sought to validate and establish cut-offs for self-reported smoking and secondhand smoke (SHS) exposure during pregnancy using urinary cotinine and 4-(methylnitrosamino)-1-(-3-pyridyl)-1-butanol (NNAL) in a large contemporary prospective study from the USA, with lower smoking prevalence than has previously been evaluated.

DESIGN

Prospective birth cohort.

SETTING

Pregnancy clinics in New Hampshire and Vermont, USA.

PARTICIPANTS

1396 women enrolled in the New Hampshire Birth Cohort Study with self-reported smoking, urinary cotinine, NNAL and pregnancy outcomes.

PRIMARY AND SECONDARY OUTCOME MEASURES

Cut-offs for urinary cotinine and NNAL concentrations were estimated from logistic regression models using Youden's method to predict SHS and active smoking. Cotinine and NNAL were each used as the exposure in separate multifactorial models for pregnancy outcomes.

RESULTS

Self-reported maternal smoking was: 72% non-smokers, 5.7% ex-smokers, 6.4% SHS exposure, 6.2% currently smoked, 10% unreported. Cotinine and NNAL levels were low and highly intercorrelated (r=0.91). Geometric mean cotinine, NNAL were 0.99 ng/mL, 0.05 pmol/mL, respectively. Cotinine cut-offs for SHS, current smoking were 1.2 ng/mL and 1.8 ng/mL (area under curve (AUC) 95% CI: 0.52 (0.47 to 0.57), 0.90 (0.85 to 0.94)). NNAL cut-off for current smoking was 0.09 pmol/mL (AUC=0.82 (95% CI 0.77 to 0.87)). Using cotinine and NNAL cut-offs combined gave similar AUC to cotinine alone, 0.87 (95% CI 0.82 to 0.91). Cotinine and NNAL gave almost identical effect estimates when modelling pregnancy outcomes.

CONCLUSIONS

In this population, we observed high concordance between self-complete questionnaire smoking data and urinary cotinine and NNAL. With respect to biomarkers, either cotinine or NNAL can be used as a measure of tobacco smoke exposure overall but only cotinine can be used to detect SHS.

Effects of active and/or passive smoking during pregnancy and the postpartum period

INTRODUCTION

Tobacco smoking may cause adverse effects during pregnancy and postpartum. The aim of this study was to evaluate several repercussions of active and/or passive smoking by the mother at home, during pregnancy, at delivery, as well as for the newborn baby and breastfeeding, including the effect of quitting smoking in the first trimester of pregnancy.

METHODS

A prospective longitudinal study was carried out with a sample of 800 pregnant women. Four evaluations were made: first and third trimester of pregnancy, and 2 and 6/8 months postpartum. Sociodemographic, obstetric, health and tobacco consumption details were collected, with biochemical tests being performed to confirm the self-reported abstinence.

RESULTS

Being an active and passive smoker predicted suffering complications in pregnancy (OR 2.50; 95% CI; 1.42-4.35) and delivery (OR 3.10; 95% CI; 1.75-5.51), and also tended not to breastfeed (OR 2.44; 95% CI; 1.35-4.42). Being an active smoker predicted complications at childbirth (OR 5.58; 95% CI; 2.64-7.77), for the baby (OR 3.77; 95% CI; 1.53-9.36) and not breastfeeding at 2 (OR 25.73; 95% CI; 11.95-55.40), and 6/8 months postpartum (OR 6.61; 95% CI; 3.21-13.58). Being a passive smoker reduces the intend to breastfeed (OR 1.81; 95% CI; 1.11-2.95), and the practice of breastfeeding at 2 months postpartum (OR 1.94; 95% CI; 1.11-3.37). Women who quit smoking are less likely to suffer complications in pregnancy and childbirth, and are more likely to attend antenatal and breastfeeding classes, and to have babies with higher birth weight.

CONCLUSIONS

Active and passive tobacco consumption has significant implications during pregnancy and postpartum period. Smoking cessation at the beginning of pregnancy reverses much of these effects.

Effects of Tobacco Consumption and Anxiety or Depression during Pregnancy on Maternal and Neonatal Health

This study analyzed the possible interaction effects between tobacco consumption and anxiety or depression during pregnancy on maternal and neonatal health. We recruited a sample of 807 pregnant Spanish women from public healthcare services. Women completed a questionnaire on sociodemographic variables, health status and tobacco consumption (continuous, quitting or no consumption) in the first and third trimester of pregnancy and at 2 months postpartum, and self-reported measures of anxiety and depression in the first trimester. Abstinence of tobacco consumption was verified through biochemical measurements. Interaction effects between tobacco consumption and anxiety were found for delivery (p < 0.001), neonatal health complications (p = 0.026) and gestational age at birth (p = 0.029). Interaction effects between tobacco consumption and depression were found for pregnancy (p = 0.032), delivery complications (p < 0.001) and weeks of gestation at birth (p = 0.031). This study suggests that there are different kinds of interaction effects between tobacco consumption and anxiety or depression. Smokers with high anxiety presented more delivery complications compared to quitters and non-smokers with high anxiety. There is a cumulative effect of anxiety on the effects of tobacco consumption on maternal health. The results highlighted the beneficial impact of quitting smoking during pregnancy to reduce the risk of suffering anxiety, depression and health complications.

[Effects of active and/or passive smoking during pregnancy and the postpartum period]

INTRODUCTION

Tobacco smoking may cause adverse effects during pregnancy and postpartum. The aim of this study was to evaluate several repercussions of active and/or passive smoking by the mother at home, during pregnancy, at delivery, as well as for the new born baby and breastfeeding, including the effect of quitting smoking in the first trimester of pregnancy.

METHODS

A prospective longitudinal study was carried out with a sample of 800 pregnant women. Four evaluations were made: first and third trimester of pregnancy, and 2 and 6/8 months postpartum. Sociodemographic, obstetric, health and tobacco consumption information was collected, with biochemical tests being performed to confirm the self-reported abstinence.

RESULTS

Being an active and passive smoker predicted suffering complications in pregnancy (OR 2.50; 95% CI; 1.42-4.35) and delivery (OR 3.10; 95% CI; 1.75-5.51), and also intend not to breastfeed (OR 2.44; 95% CI; 1.35-4.42). Being an active smoker predicted complications at childbirth (OR 5.58; 95% CI; 2.64-7.77), for the baby (OR 3.77; 95% CI; 1.53-9.36) and not breastfeeding at 2 (OR 25.73; 95% CI; 11.95-55.40), and 6/8 months postpartum (OR 6.61; 95% CI; 3.21-13.58). Being a passive smoker reduces the intention to breastfeed (OR 1.81; 95% CI; 1.11-2.95), and the practice of breastfeeding at 2 months postpartum (OR 1.94; 95% CI; 1.11-3.37). Women who quit smoking are less likely to suffer complications in pregnancy and childbirth, and are more likely to attend antenatal and breastfeeding classes, and to have babies with higher birth weight.

CONCLUSIONS

Active and passive tobacco consumption has significant implications during pregnancy and postpartum period. Smoking cessation at the beginning of pregnancy reverses much of these effects.

Impact of a prenatal episode and diagnosis in women with serious mental illnesses on neonatal complications (prematurity, low birth weight, and hospitalization in neonatal intensive care units)

Pregnancy in women with mental disorders is increasingly common. The aim of this study was to determine, in women with severe mental illnesses, whether a prenatal episode was related to neonatal complications and if a specific disorder was associated with a higher risk. A population of infants and their mothers (n = 1439) jointly admitted to psychiatric Mother-Baby Units in France and Belgium (2001-2010) was assessed respectively for prematurity, low birth weight (LBW), hospitalization in neonatal intensive care units (NICUs), and maternal mental health during pregnancy. Logistic regression was used to explore the association between neonatal complications and a prenatal episode of mental illness and if the presence of a specific disorder was related to a higher risk, taking into account maternal socio-demographic characteristics, pregnancy data, and antenatal exposure to psychotropic drugs. Among the children, 145 (10.2%) were premature, 226 (15.8%) had a LBW, and 348 (24.3%) have been hospitalized in neonatology. The presence of an episode of mental illness during pregnancy was linked to LBW (OR = 2.21 [1.44-3.38]; p = 0.003) and NICU hospitalizations (OR = 1.53 [1.06-2.19], p = 0.002). Among diagnoses, the presence of a severe substance use disorder in these women was related to LBW (OR = 2.96 [1.49-5.85]; p = 0.002) and NICU (OR = 2.88 [1.56-5.29]; p = 0.04). Our results underline the importance of systematic and early detection of psychiatric symptoms and substance use disorders during pregnancy in preventing neonatal complications in women with serious mental illness.