Smoking in Dutch pregnant women and birth weight

Asthma as a disruption in iron homeostasis

Over several decades, asthma has evolved from being recognized as a single disease to include a diverse group of phenotypes with dissimilar natural histories, pathophysiologies, responses to treatment, and distinctive molecular pathways. With the application of Occam's razor to asthma, it is proposed that there is one cause underlying the numerous phenotypes of this disease and that the responsible molecular pathway is a deficiency of iron in the lung tissues. This deficiency can be either absolute (e.g. asthma in the neonate and during both pregnancy and menstruation) or functional (e.g. asthma associated with infections, smoking, and obesity). Comparable associations between asthma co-morbidity (e.g. eczema, urticaria, restless leg syndrome, and pulmonary hypertension) with iron deficiency support such a shared mechanistic pathway. Therapies directed at asthma demonstrate a capacity to impact iron homeostasis, further strengthening the relationship. Finally, pathophysiologic events producing asthma, including inflammation, increases in Th2 cells, and muscle contraction, can correlate with iron availability. Recognition of a potential association between asthma and an absolute and/or functional iron deficiency suggests specific therapeutic interventions including inhaled iron.

Perinatal outcomes and unconventional natural gas operations in Southwest Pennsylvania

Unconventional gas drilling (UGD) has enabled extraordinarily rapid growth in the extraction of natural gas. Despite frequently expressed public concern, human health studies have not kept pace. We investigated the association of proximity to UGD in the Marcellus Shale formation and perinatal outcomes in a retrospective cohort study of 15,451 live births in Southwest Pennsylvania from 2007–2010. Mothers were categorized into exposure quartiles based on inverse distance weighted (IDW) well count; least exposed mothers (first quartile) had an IDW well count less than 0.87 wells per mile, while the most exposed (fourth quartile) had 6.00 wells or greater per mile. Multivariate linear (birth weight) or logistical (small for gestational age (SGA) and prematurity) regression analyses, accounting for differences in maternal and child risk factors, were performed. There was no significant association of proximity and density of UGD with prematurity. Comparison of the most to least exposed, however, revealed lower birth weight (3323 ± 558 vs 3344 ± 544 g) and a higher incidence of SGA (6.5 vs 4.8%, respectively; odds ratio: 1.34; 95% confidence interval: 1.10–1.63). While the clinical significance of the differences in birth weight among the exposure groups is unclear, the present findings further emphasize the need for larger studies, in regio-specific fashion, with more precise characterization of exposure over an extended period of time to evaluate the potential public health significance of UGD.

Vitamin C supplementation ameliorates the adverse effects of nicotine on placental hemodynamics and histology in nonhuman primates

OBJECTIVE

We previously demonstrated that prenatal nicotine exposure decreases neonatal pulmonary function in nonhuman primates, and maternal vitamin C supplementation attenuates these deleterious effects. However, the effect of nicotine on placental perfusion and development is not fully understood. This study utilizes noninvasive imaging techniques and histological analysis in a nonhuman primate model to test the hypothesis that prenatal nicotine exposure adversely effects placental hemodynamics and development but is ameliorated by vitamin C.

STUDY DESIGN

Time-mated macaques (n = 27) were divided into 4 treatment groups: control (n = 5), nicotine only (n = 4), vitamin C only (n = 9), and nicotine plus vitamin C (n = 9). Nicotine animals received 2 mg/kg per day of nicotine bitartrate (approximately 0.7 mg/kg per day free nicotine levels in pregnant human smokers) from days 26 to 160 (term, 168 days). Vitamin C groups received ascorbic acid at 50, 100, or 250 mg/kg per day with or without nicotine. All underwent placental dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) at 135-140 days and Doppler ultrasound at 155 days to measure uterine artery and umbilical vein velocimetry and diameter to calculate uterine artery volume blood flow and placental volume blood flow. Animals were delivered by cesarean delivery at 160 days. A novel DCE-MRI protocol was utilized to calculate placental perfusion from maternal spiral arteries. Placental tissue was processed for histopathology.

RESULTS

Placental volume blood flow was significantly reduced in nicotine-only animals compared with controls and nicotine plus vitamin C groups (P = .03). Maternal placental blood flow was not different between experimental groups by DCE-MRI, ranging from 0.75 to 1.94 mL/mL per minute (P = .93). Placental histology showed increased numbers of villous cytotrophoblast cell islands (P < .05) and increased syncytiotrophoblast sprouting (P < .001) in nicotine-only animals, which was mitigated by vitamin C.

CONCLUSION

Prenatal nicotine exposure significantly decreased fetal blood supply via reduced placental volume blood flow, which corresponded with placental histological findings previously associated with cigarette smoking. Vitamin C supplementation mitigated the harmful effects of prenatal nicotine exposure on placental hemodynamics and development, suggesting that its use may limit some of the adverse effects associated with smoking during pregnancy.

Care of Drug-Addicted Pregnant Women: Current Concepts and Future Strategies – an Overview

This review focuses on drug use during pregnancy and the perinatal period, a constellation that is seen more often. Drug use in pregnant women poses an increased risk for adverse health outcomes both for the mother and child. Care is often complicated by social and environmental factors, as well as psychiatric comorbidities. It is, therefore, very important to provide drug-using pregnant women with optimal ante-, peri- and post-natal care. Health professionals should approach them in a nonjudgmental and supportive way, and provide them with the same care and attention as nondrug-using women. Adequate care requires interdisciplinary teams. Ideally, healthcare providers should be specialized in the care of drug-using pregnant women.

Maternal homocysteine and related B vitamins as risk factors for low birthweight

OBJECTIVE

We designed a large prospective study to explore the relationship between maternal homocysteine concentrations and related B vitamins and birthweight.

STUDY DESIGN

Blood was sampled from pregnant women at 30-34 weeks of gestation and their newborn infants (n = 366).

RESULTS

Concentrations of all analytes were higher in umbilical cord compared with maternal samples. Birthweight was related negatively to maternal homocysteine (r = -0.12) but not related to maternal cobalamin, methylmalonic acid, and folate (r = 0.02, r = 0.06, and r = 0.04, respectively). Regression analysis revealed smoking (beta = -313; 95% confidence interval [CI], -479 to -149), gestational age (beta = 150; 95% CI, 118-182), female sex (beta = -146; 95% CI, -256 to -35), and parity (beta = 104; 95% CI, 37-171) as strong determinants of birthweight. Maternal homocysteine, cobalamin, methylmalonic acid, and folate were not determinants of birthweight in multivariate analysis.

CONCLUSION

Maternal homocysteine and B vitamins are not related to birthweight in a multivariate model that was adjusted for potential confounders.

Smoking during pregnancy and postpartum: smoking rates and intention to quit smoking or resume after pregnancy

BACKGROUND

A substantial number of women smoke while pregnant. The majority of those who quit return to smoking within 12 months. The aim of this study is to estimate smoking rates and to measure the urge to smoke and the motivation to change smoking behavior among women who recently delivered.

METHODS

Data presented stem from two studies. Study 1 is an epidemiological survey investigating the health of neonates. Study 2 presents screening data of an efficacy trial for a smoking cessation and relapse prevention intervention. Participants were recruited on maternity wards within 7 days after delivery.

RESULTS

Five hundred fifty-three (29.1%) women were never smokers, 145 (7.6%) were former smokers, 492 (25.9%) abstained during pregnancy, and 712 (37.4%) smoked throughout pregnancy. Of the smokers, 69% did not intend to quit smoking within the next 6 months. Of the women who quit during pregnancy, 80% did not want to resume smoking within the next 6 months or after weaning.

CONCLUSIONS

Smoking and relapse rates indicate a need for increased efforts to reduce smoking during pregnancy and postpartum. Reported intention to quit or resume does not reflect the high number of relapses. Indicators for relapse need to be found.

Fetal behavior in smoking compared to non-smoking pregnant women

OBJECTIVE

To determine the effects of maternal smoking on fetal spontaneous behavior and auditory processing.

METHODS

38 fetuses of smoking (n=18) and non-smoking (n=20) mothers, stratified by gestational age (<37, >or=37 weeks GA), were examined at least 1h following smoking. Observations included spontaneous fetal heart rate (FHR; 20 min) and body movements (20 min) followed by a 2 min audiotape of the mother reading a story while FHR and body movements were recorded.

RESULTS

There were no differences in spontaneous behaviors; full-term fetuses showed a FHR acceleration and body movement during the mother's voice. A FHR response following voice offset was limited to fetuses less than 37 weeks GA of non-smoking mothers.

CONCLUSION

Fetuses less than 37 weeks GA of mothers who smoke throughout pregnancy have a delayed onset of response to the maternal voice, a subtle difference which may have implications for later language development for prematurely born infants which needs further investigation.

Management of women who use drugs during pregnancy

Substance abuse in pregnancy is associated with significant maternal and fetal morbidity. The complication for care is that the mother is the cause of the problem that potentially harms not only herself but also her unborn child. The abuse is further complicated by the associated legal, social and environmental problems. The aim for the obstetrician is to provide a non-judgemental, supportive environment to minimise the risk, not only during pregnancy and the neonatal period, but also in the long term. To achieve this, caregivers need to be multidisciplinary and tolerant of the mother's problem. The aim of antenatal care is to reduce risk, which does not mean that the mother must abstain from drug use. The aim is to keep her within the care system and encourage her to take responsibility for her situation. No-one should be turned away or denied help as, ultimately, this is harmful to the mother and her baby. To provide this care, the obstetrician needs support from midwives, addiction counsellors, social workers, neonatologists, health visitors and general practitioners. Whereas the healthcare structure in the UK lends itself to this approach, this is not the case in other parts of the world. However, programmes of comprehensive antenatal care do not universally improve the health of the mother and the outcome of her pregnancy. The specifics of the care provided are probably less important than the quality of the care given and the degree of engagement of the individual. This chapter outlines the problems and potential solutions with reference to the service in Leeds in the UK.

Mental health during pregnancy: a study comparing Asian, Caucasian and Native Hawaiian women

OBJECTIVE

This study examines perinatal mental health issues, ethnic differences, and comorbidity among pregnant women in Hawaii.

METHODS

Eighty-four participants were recruited from women, ages 18-35, seeking prenatal care on Oahu. They were interviewed at their initial prenatal visit about substance use, depression, and anxiety.

RESULTS

Sixty-one percent of women screened positive for at least one mental health issue. Thirteen percent of all pregnant women reported drinking during pregnancy with 5% reporting problem drinking, 15% reported smoking cigarettes on a regular basis, 5% of pregnant women had probable depression, and 13% of pregnant women had probable anxiety. Significant ethnic differences were found in cigarette smoking, with the highest rate among Native Hawaiian women (35%). Native Hawaiian women were also more likely to binge drink.

CONCLUSION

Given the high rates of potential mental health issues in our sample, our findings highlight the importance of screening and treatment for mental health issues early in pregnancy in Hawaii.

Association of DNA adducts and genotypes with birth weight

The relationships between DNA adducts and birth weight and between birth weight and genetic polymorphisms of metabolic genotypes were studied using DNA from the children part of placental samples. The samples were collected in the districts of Teplice and Prachatice and in the city of Prague. DNA adducts were analyzed by (32)P-postlabeling in a total of 199 subjects, genetic polymorphisms in 1013 subjects. GSTM1, GSTP1, GSTT1, CYP1A1*2A, and CYP1A1*2C genotypes were determined for each subject. The level of DNA adducts was not correlated with birth weight in any group (N=199), including that from the polluted district of Teplice (N=90). Birth weight was significantly decreased by smoking, ETS and alleles of CYP1A1*2C. The risk of low birth weight and prematurity was significantly increased by genotypes of GSTM1 and CYP1A1*2C and the combination GSTM1+CYP1A1*2A. Genotypes are primarily effect modifiers, whose effect incorporates the effect of environmental factors. This means that in the future, the impact of air pollution on children's health should be studied together with their genetic polymorphisms.

Paternal occupational exposure to radiofrequency electromagnetic fields and risk of adverse pregnancy outcome

BACKGROUND

During the last decades, public concern that radiofrequency radiation (RFR) may be related to adverse reproductive outcomes has been emerging. Our objective was to assess associations between paternal occupational exposure to RFR and adverse pregnancy outcomes including birth defects using population-based data from Norway.

METHODS

Data on reproductive outcomes derived from the Medical Birth Registry of Norway were linked with data on paternal occupation derived from the general population censuses. An expert panel categorized occupations according to exposure. Using logistic regression, we analyzed 24 categories of birth defects as well as other adverse outcomes.

RESULTS

In the offspring of fathers most likely to have been exposed, increased risk was observed for preterm birth (odds ratio (OR): 1.08, 95% confidence interval (CI): 1.03, 1.15). In this group we also observed a decreased risk of cleft lip (OR: 0.63, 95% CI: 0.41, 0.97). In the medium exposed group, we observed increased risk for a category of "other defects" (OR: 2.40, 95% CI: 1.22, 4.70), and a decreased risk for a category of "other syndromes" (OR: 0.75, 95% CI: 0.56, 0.99) and upper gastrointestinal defects (OR: 0.61, 95% CI: 0.40, 0.93).

CONCLUSION

The study is partly reassuring for occupationally exposed fathers.

Ambient air pollution and pregnancy outcomes: a review of the literature

Over the last decade or so, a large number of studies have investigated the possible adverse effects of ambient air pollution on birth outcomes. We reviewed these studies, which were identified by a systematic search of the main scientific databases. Virtually all reviewed studies were population based, with information on exposure to air pollution derived from routine monitoring sources. Overall, there is evidence implicating air pollution in adverse effects on different birth outcomes, but the strength of the evidence differs between outcomes. The evidence is sufficient to infer a causal relationship between particulate air pollution and respiratory deaths in the postneonatal period. For air pollution and birth weight the evidence suggests causality, but further studies are needed to confirm an effect and its size and to clarify the most vulnerable period of pregnancy and the role of different pollutants. For preterm births and intrauterine growth retardation (IUGR) the evidence as yet is insufficient to infer causality, but the available evidence justifies further studies. Molecular epidemiologic studies suggest possible biologic mechanisms for the effect on birth weight, premature birth, and IUGR and support the view that the relation between pollution and these birth outcomes is genuine. For birth defects, the evidence base so far is insufficient to draw conclusions. In terms of exposure to specific pollutants, particulates seem the most important for infant deaths, and the effect on IUGR seems linked to polycyclic aromatic hydrocarbons, but the existing evidence does not allow precise identification of the different pollutants or the timing of exposure that can result in adverse pregnancy outcomes.

Does maternal smoking influence leptin levels in term, appropriate-for-gestational-age newborns?

OBJECTIVES

Leptin, a hormone produced in adipose tissue and the placenta, is correlated with neonatal growth. The aim of this study was to investigate the effect of maternal smoking during pregnancy on cord blood leptin concentrations in term, appropriate-for-gestational-age infants.

METHODS

Two groups of term, appropriate-for-gestational-age newborns were selected: 19 infants of smoking mothers and 91 infants of non-smoking mothers. Neonatal anthropometric measurements were taken and leptin levels were measured by radioimmunoassay.

RESULTS

Leptin concentrations were similar (p=0.915) between the groups. Leptin levels correlated only with ponderal index (p < 0.01) and gestational age of the newborns (p < 0.05).

CONCLUSIONS

This study indicates that maternal smoking during pregnancy does not affect cord blood leptin levels in term, appropriate-for-gestational-age infants.

Housing conditions, perceived stress, smoking, and alcohol: determinants of fetal growth in Northwest Russia

BACKGROUND

Social determinants of health have become important in countries of the former Soviet Union during the time of transition.

AIM

This article estimates the influence of living conditions, smoking, alcohol, and maternal stress on fetal growth indices in an urban Russian setting.

METHODS

All pregnant women registered at antenatal care centres in Severodvinsk (Northwest Russia) and their infants comprised the study base (n = 1399). Multivariate linear regression analysis was applied to quantify the effects of the studied factors on birth weight and the ponderal index (PI) adjusted for maternal education, age, occupation, marital status, parity, pre-pregnancy weight, paternal employment, gestational age, and others.

RESULTS

Infants of smoking mothers were 126 g lighter compared with non-smokers [95% confidence interval (CI): -198; -54]. On average, birth weight decreased 27 g per cigarette smoked during pregnancy. Living in shared apartments, living in crowded housing situations, and perceived stress were associated significantly with birth weight loss: -89 g (95% CI: -153; -25), -82 g (95% CI: -136; -28), and -61 g (95% CI: -116; -7), respectively. A positive association between maternal alcohol consumption and birth weight was found. Living with parents was associated positively with both birthweight and PI. Infants whose fathers consumed more than 100 ml of absolute alcohol per week were thinner at birth compared with those of non-drinking and moderate drinking fathers.

CONCLUSIONS

Poor housing conditions, maternal stress, smoking, and alcohol consumption are independent determinants of fetal growth in Northwest Russia.

Risk factors for low birth weight: a review

Low birth weight (LBW) is one of the main predictors of infant mortality. The global incidence of LBW is around 17%, although estimates vary from 19% in the developing countries (countries where it is an important public health problem) to 5-7% in the developed countries. The incidence in Spain in the decade 1980-1989 was about 5.7%. LBW is generally associated with situations in which uterine malnutrition is produced due to alterations in placental circulation. There are many known risk factors, the most important of which are socio-economic factors, medical risks before or during gestation and maternal lifestyles. However, although interventions exist to prevent many of these factors before and during pregnancy, the incidence of LBW has not decreased.

Drugs of abuse in pregnancy

Care for the drug-using pregnant woman is being increasingly recognized as part of the obstetrician's role. There is great potential for improvement in provision of services for this group of women, partly because traditionally our antenatal clinics have not been perceived as being conducive to disclosure regarding drug use, but also because hard data and, indeed, randomized controlled trials on the subject, are scarce.From the little evidence available, and from our own experience in this area, we have attempted to outline the main problems encountered in the antenatal, intrapartum and postnatal periods with each of the main drugs of abuse and the management thereof. It is important to note that we include cigarette smoking and alcohol, probably the most commonly used drugs in pregnancy, and recognize that the picture is wider than the stereotypical emaciated intravenous heroin addict. Where possible, evidence from trial data is included, but much of the what is quoted is descriptive from personal experience from ourselves and others working in the field.

Toxic and essential elements in placentas of Swedish women

OBJECTIVES

To evaluate interactions between toxic and essential elements in the mother-fetus relationship and possible predictors of trace element concentrations in placenta and cord blood.

DESIGN AND METHODS

A group of 106 Swedish women was investigated for concentrations of cadmium, lead, and several essential elements in placenta as well as cadmium, lead, zinc, and selenium in venous blood collected at gestational week (gw) 36 and umbilical cord blood. Relations between these elements and maternal and child's characteristics were examined.

RESULTS

The concentrations of cadmium in placenta ranged from 10 to 170 nmol/kg, with the median value (Md) being 46 nmol/kg. Cord blood cadmium (Md of 0.19 nmol/L) was only about 10% of that in maternal blood. Smokers had significantly higher cadmium concentrations in blood (p < 0.001) and placenta (p = 0.001) than non-smokers. The median placental concentration of lead was 26 nmol/kg (range 0-630 nmol/kg). The lead levels in cord blood (Md of 54 nmol/L) were almost the same as in maternal blood. Statistically significant negative associations were found between cord blood lead, on one hand, and child's weight, length, and head circumference, on the other. The placental levels (medians and ranges) of the essential elements (micromol/kg) were 160 (120-280) for zinc, 2.4 (2.0-3.3) for selenium, 15 (10-20) for copper, 0.084 (0.02-0.32) for cobalt, 0.055 (0.03-0.12) for molybdenum, and 1.2 (0. 65-5.1) for manganese, respectively. Several of the essential elements in placenta correlated significantly with each other. Multiparous mothers had significantly lower concentrations of zinc (p = 0.002) and selenium (p = 0.049) in serum as well as zinc (p = 0. 001) and calcium (p = 0.004) in placenta than nulliparous ones. Also, cord blood zinc decreased with parity.

CONCLUSIONS

The results showed that lead, but not cadmium crossed easily the placental barrier. There were no negative effects of cadmium on the zinc status. Cord blood lead, on the other hand, was a negative predictor of child's birth weight, length and head circumference, indicating that lead might have negative influence on growth in children even at very low exposure levels. There was a depletion of maternal stores of essential elements with increasing parity.