Fetal Effects

Outcomes of pregnancy in women using illegal drugs and in women who smoke cigarettes

OBJECTIVE

To compare obstetric outcomes in women using illegal drugs with women who smoke cigarettes.

DESIGN

Retrospective cohort study.

SETTING

Aberdeen, UK.

POPULATION

All deliveries in Aberdeen in women using illegal drugs and women who smoked cigarettes during 1997-2007.

MATERIAL AND METHODS

The women who used illegal drugs were identified from a database of affected pregnant women in Aberdeen. The Aberdeen Maternity and Neonatal Databank was used to identify women who smoke cigarettes and to obtain pregnancy outcome information. Sociodemographic characteristics, maternal and perinatal outcomes were compared using chi-squared test, independent sample t-test and logistic regression analysis.

MAIN OUTCOME MEASURES

Preterm delivery, low birthweight (standardized birthweight score <-2) and admission to the neonatal unit.

RESULTS

Of the 561 illegal drug users, 96% were also cigarette smokers. Compared with women who smoke cigarettes with no reported illegal drug use, they were significantly more likely to have a preterm delivery [adjusted odds ratio (aOR) 1.6 (95% confidence interval (CI) 1.3-2.1)], low birthweight baby [aOR 1.9 (95%CI 1.4-2.6)], baby admitted to the neonatal unit [aOR 13.3 (95%CI 10.9-16.3)], deep vein thrombosis [aOR (95%CI 8.8-50.8)] and antepartum hemorrhage [aOR (95%CI 1.2-2.1)]. They were less likely to be at the extremes of age, or to develop pregnancy-induced hypertension [aOR 0.3 (95%CI 0.2-0.4)].

CONCLUSION

Illegal drug use in pregnancy appears to increase the risk of adverse outcomes, over and above that related to cigarette smoking, but appears to be associated with lower prevalence of gestational hypertension.

Neonatal neurobehavior effects following buprenorphine versus methadone exposure

AIM

To determine the effects of in utero exposure to methadone or buprenorphine on infant neurobehavior.

DESIGN

Three sites from the Maternal Opioid Treatment: Human Experimental Research (MOTHER) study, a double-blind, double-dummy, randomized clinical trial participated in this substudy.

SETTING

Medical Centers that provided comprehensive maternal care to opioid-dependent pregnant women in Baltimore, MD, Providence, RI and Vienna, Austria.

PARTICIPANTS

Thirty-nine full-term infants.

MEASUREMENTS

The Neonatal Intensive Care Unit (NICU) Network Neurobehavioral Scale (NNNS) was administered to a subgroup of infants on postpartum days 3, 5, 7, 10, 14-15 and 28-30.

FINDINGS

While neurobehavior improved for both medication conditions over time, infants exposed in utero to buprenorphine exhibited fewer stress-abstinence signs (P < 0.001), were less excitable (P < 0.001) and less over-aroused (P < 0.01), exhibited less hypertonia (P < 0.007), had better self-regulation (P < 0.04) and required less handling (P < 0.001) to maintain a quiet alert state relative to in utero methadone-exposed infants. Infants who were older when they began morphine treatment for withdrawal had higher self-regulation scores (P < 0.01), and demonstrated the least amount of excitability (P < 0.02) and hypertonia (P < 0.02) on average. Quality of movement was correlated negatively with peak NAS score (P < 0.01), number of days treated with morphine for NAS (P < 0.01) and total amount of morphine received (P < 0.03). Excitability scores were related positively to total morphine dose (P < 0.03).

CONCLUSION

While neurobehavior improves during the first month of postnatal life for in utero agonist medication-exposed neonates, buprenorphine exposure results in superior neurobehavioral scores and less severe withdrawal than does methadone exposure.

Longitudinal study of maternal report of sleep problems in children with prenatal exposure to cocaine and other drugs

Sleep data were collected by maternal report in a prospective longitudinal follow up of cocaine-exposed and unexposed children. There were 139 participants: 23 with no prenatal drug exposure, 55 exposed to cocaine alone or in combination with other drugs, and 61 exposed to drugs other than cocaine. Characteristics differed between exposure groups including birth size, caretaker changes, maternal socioeconomic status, and postnatal drug use. Compared to those with no drug exposure, children with prenatal drug exposure other than cocaine experienced greater sleep problems (p = .026). Prenatal nicotine exposure was a unique predictor of sleep problems (p = .048). Early sleep problems predicted later sleep problems (all ps < .01). Together, these preliminary findings suggest possible neurotoxic sleep effects that persist over time. Larger studies, however, need to be conducted that better control for potential postnatal confounding factors.

Pattern of alcohol consumption during pregnancy and risk for low birth weight

PURPOSE

The effects of moderate alcohol drinking on low birth weight are not clear, and conflicting results have been reported. We assessed the influence of different patterns of alcohol drinking during pregnancy on low birth weight.

METHODS

A case-control study was carried out at the University of Cantabria Hospital, Spain, from 1998 to 2002. Cases (n = 552) were mothers delivering a single newborn weighing less than 2500 g. Controls (n = 1451) were selected from a random sample of all delivering women. Information was obtained from personal interview, clinical charts, and prenatal care records. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated. Adjustment for potential confounders was made by means of logistic regression.

RESULTS

Alcohol consumption of less than 6 g/day decreased the risk for low birth weight (adjusted OR = 0.64; 95% CI, 0.46-0.88). A similar result was obtained for moderate drinkers (<12 g/day) on weekends only. The opposite relationship was observed between alcohol consumption on weekdays of 12 g/day or greater (adjusted OR = 2.67; 95% CI, 1.39-5.12), not observed in those drinking on weekends only. The interaction between alcohol consumption and tobacco smoking was analyzed. Weekday drinkers of 12 g/day or greater showed an increased risk in smokers. Alcohol consumption on weekends only in nonsmokers was inversely related. The influence of alcohol was greater for small-for-gestational-age (SGA) than non-SGA babies.

CONCLUSIONS

Alcohol consumption of 12 g/day or greater increased the risk for low birth weight, whereas lower consumption during weekends showed the opposite effect (mainly in nonsmokers).

Prenatal alcohol and drug exposures in adoption

Prenatal alcohol and drug exposures are a significant concern in many domestic and international adoptions. This article addresses the following substance exposures for children: alcohol, opiates, tobacco, marijuana, cocaine, and methamphetamines. For each substance, we review the teratogenicity of the exposure and identify the spectrum of neurodevelopmental issues that can present in children exposed to this substance. Diagnosis of the spectrum of fetal alcohol outcomes is also discussed. When possible, we provide country-specific statistics on exposure risks for adopted children.

Altered cocaine-induced behavioral sensitization in adult mice exposed to cocaine in utero

Behavioral sensitization induced by psychostimulants is characterized by increased locomotion and stereotypy and may reflect aspects of neuronal adaptations underlying drug addiction in humans. To study the developmental contributions to addictive behaviors, we measured behavioral responses in adult offspring to a cocaine sensitization paradigm following prenatal cocaine exposure. Pregnant Swiss-Webster (SW) mice were injected twice daily from embryonic days 8 to 17 (E8-E17, inclusive) with cocaine (20 or 40 mg/kg/day; COC20 and COC40, respectively), or saline vehicle (SAL and SPF40) subcutaneously (s.c.). A nutritional control group of dams were 'pair-fed' with COC40 dams (SPF40). P120 male offspring from each prenatal treatment group were assigned to a behavioral sensitization group and injected with cocaine (15 mg/kg) or saline intraperitoneally (i.p.) every other day for seven doses. Locomotor activity and stereotypy were measured during habituation, cocaine initiation, and following a cocaine challenge 21 days after the last initiation injection. As expected, animals demonstrated significantly more locomotion and stereotypic behavior following acute and recurrent injection of cocaine compared to saline-injected animals. However, for each prenatal treatment group, cocaine-sensitized animals showed unique temporal profiles for the increase in locomotor sensitization and stereotypy over the course of the sensitization protocol. Two features that distinguished the altered behavioral progression of prenatally cocaine-exposed animals (COC40) from control (SAL) animals included blunted augmentation of locomotion and enhanced patterns of stereotypic behavior. These findings provide evidence that the behavioral activating effects of cocaine in adult animals are altered following exposure to cocaine in utero.

Neurologic complications of substance abuse

In addition to overdose, withdrawal, and addictive behavior, licit and illicit drugs produce a wide range of neurologic complications. Trauma results from intoxication and from violence related to a drug's illegality. Infection, including AIDS, is most often a consequence of parenteral use. Seizures can be secondary to either toxicity or withdrawal. Stroke can be ischemic or hemorrhagic. Persistent cognitive dysfunction affects alcoholics and probably users of other drugs as well. Teratogenicity is better documented for ethanol and tobacco than for illicit drugs. Other complications of recreational drug use include peripheral neuropathy, myelopathy, parkinsonism, leukoencephalopathy, optic atrophy, and cerebellar ataxia.

Drug abuse's smallest victims: in utero drug exposure

The social and economic impact of drug use on our global population continues to increase leaving no geographical, social or cultural group untouched. The National Institute on Drug Abuse (NIDA), in one of the few large surveys of maternal abuse, found that 5.5% of mothers reported taking an illicit substance during gestation. These figures certainly are underestimates due to the stigma of drug use during pregnancy and the accompanying legal, ethical and economic issues. Although drugs of choice and routes of administration vary by country, exposure of our most valuable resource, our children, to the developmental effects of drugs is an enormous problem. In utero drug exposure can have a severe impact not only on the development of the fetus, but also on the child during later stages of life. More than 75% of infants exposed to drugs have major medical problems as compared to 27% of unexposed infants. The cost of treating drug-affected infants was twice the cost of non-affected infants. Obstetrical complications including placental insufficiency, miscarriage, intrauterine death, and increased incidence of infectious and sexually-transmitted diseases are higher in the drug-abusing mother. Treatment for pregnant addicts should be a high priority for our governments. Increased awareness and improvement in our understanding of drug abuse in the medical, legal and social realms will enable us to reduce the barriers to treatment for this important population.Accurate identification of in utero drug exposure has important implications for the care of the mother and child, but can raise difficult legal issues. Society discourages prenatal care with the infliction of harsh criminal penalties. Maternal drug use during pregnancy can be monitored with urine, sweat, oral fluid and/or hair testing. Detection of in utero drug exposure has traditionally been accomplished through urine testing; however, the window of detection is short, reflecting drug use for only a few days before delivery. Monitoring exposure through testing of alternative matrices, such as neonatal meconium and hair, offers advantages including non-invasive collection and detection earlier in gestation. There are many unresolved issues in monitoring in utero drug exposure that urgently require research. These can be divided into research to definitively differentiate drug exposed and non-drug-exposed fetuses, determine the most efficient methods to routinely monitor women's drug use, and determine how these drug test results relate to neonatal and maternal outcomes. Research in this area is difficult and expensive to perform, but necessary to assess accurately drug effects on the fetus. By increasing our understanding of the physiological, biochemical and behavioral effects of gestational drug exposure, we may ultimately provide solutions for better drug prevention, treatment and a reduction in the number of drug-exposed children.

The opioid contract

Opioid contracts are widely used but not well studied. Despite the widespread use of the opioid contract or agreement, there is no standard approach. Some studies have found both considerable variability between opioid contracts as well as consistent core themes. While an opioid contract may be an appealing tool for obtaining informed consent, providing education, or otherwise overcoming some of the problems associated with chronic opioid therapy for noncancer pain, its efficacy is not well established. This article will consider many of the significant factors that impact clinicians and patients using a contract or agreement for chronic opioid therapy.

Characteristics of preterm delivery and low birthweight among 113,994 infants in Alberta: 1994-1996

This study examined the impact of infant and maternal factors on preterm delivery and low birthweight (LBW) in Alberta between January 1, 1994 and December 31, 1996. Data on 113,994 births were collected from vital statistics registration birth data. Logistic regression models for preterm and LBW delivery suggested the key risk factors were multiple and still birth (odds ratios > 22.0). Other characteristics included female gender, birth defects, nulliparous women, maternal age 35 and greater, unmarried, history of abortion, maternal smoking, maternal street drug use, and having less than 4 prenatal visits (odds ratios 0.86-2.54). Interactions between smoking and alcohol, and smoking and parity were noted. Efforts to improve the currently low rates (8.2%) of smoking cessation during pregnancy are required. Social, economic and medical factors associated with delayed childbearing and birth outcomes should be investigated.

Methods to identify and characterize developmental neurotoxicity for human health risk assessment. III: pharmacokinetic and pharmacodynamic considerations

We review pharmacokinetic and pharmacodynamic factors that should be considered in the design and interpretation of developmental neurotoxicity studies. Toxicologic effects on the developing nervous system depend on the delivered dose, exposure duration, and developmental stage at which exposure occurred. Several pharmacokinetic processes (absorption, distribution, metabolism, and excretion) govern chemical disposition within the dam and the nervous system of the offspring. In addition, unique physical features such as the presence or absence of a placental barrier and the gradual development of the blood--brain barrier influence chemical disposition and thus modulate developmental neurotoxicity. Neonatal exposure may depend on maternal pharmacokinetic processes and transfer of the xenobiotic through the milk, although direct exposure may occur through other routes (e.g., inhalation). Measurement of the xenobiotic in milk and evaluation of biomarkers of exposure or effect following exposure can confirm or characterize neonatal exposure. Physiologically based pharmacokinetic and pharmacodynamic models that incorporate these and other determinants can estimate tissue dose and biologic response following in utero or neonatal exposure. These models can characterize dose--response relationships and improve extrapolation of results from animal studies to humans. In addition, pharmacologic data allow an experimenter to determine whether exposure to the test chemical is adequate, whether exposure occurs during critical periods of nervous system development, whether route and duration of exposure are appropriate, and whether developmental neurotoxicity can be differentiated from direct actions of the xenobiotic.

The opioid contract in the management of chronic pain

Although the "opioid contract" is widely used in the administration of chronic opioid therapy, its use has not been well defined and there are few guidelines for developing or revising such tools. We reviewed opioid contracts from 39 major academic pain centers and analyzed every statement for its core meaning. These statements were grouped into general categories and then into specific statement groups. Substantial diversity in the content of the 39 contracts was found. Statements could be grouped into 12 general categories, 43 statements groups, and 125 individual statements. Each of the 39 contracts reviewed contained 22.5% +/- 10.9% of the entire list of 125 statements and 32.6% +/- 11.2% of the 43 statement categories. Contract length averaged less than 3 pages (range: 1 to 1 mean 2.2). We describe frequent and infrequent themes that may be well suited for inclusion in any given contract. While there are many significant issues related to the usage of a formal contract in chronic opioid therapy, there was substantial consistency among the contracts in their universal attempts to improve care through dissemination of information, facilitate a mutually agreed-upon course, or enhance compliance. This study serves as an initial step in considering the risk and benefits of an opioid contract as well as its ideal content and presentation.

Transplacental cocaine exposure. 2: Effects of cocaine dose and gestational timing

We have utilized a mouse model of transplacental cocaine exposure to investigate the effects of cocaine dose and gestational timing in altering brain and body growth and postnatal behavior in exposed offspring. Pregnant dams were injected with cocaine HCl at 40 mg/kg/day (COC 40) or 20 mg/kg/day (COC 20), or 10 mg/kg/day (COC 10) SC from embryonic day (E) 8 to E17, or cocaine HCl at 40 mg/kg/day SC from E8 to E13 (COC Early) or from E13 to E17 (COC Late) divided in two daily doses. COC 40 and COC Late dams, as well as dams in nutritionally paired control groups (injected with saline vehicle and pair-fed with the COC dams: SPF 40, SPF 20, SPF 10), demonstrated less weight gain than SAL controls (injected with saline vehicle and allowed access to food ad lib). The surrogate fostered offspring of COC 40 and SPF 40 dams demonstrated brain and body growth retardation [on postnatal day (P) 1 and P9] when compared to pups born to SAL dams. Offspring of COC Late, SPF 20, and SPF 10 dams demonstrated brain and body growth retardation on P1 when compared to pups born to SAL dams. Pups from all groups were tested for first-order Pavlovian conditioning on P9, or for the ability to ignore redundant information in a blocking paradigm on P50. Only COC 40 mice (i.e., offspring born to COC 40 dams) were unable to acquire an aversion to an odor previously paired with shock on P9. When compared with SAL controls, COC 40 mice (and to a less significant extent SPF 40 mice) demonstrated a persistent behavioral deficit in the blocking paradigm on P50, which may reflect alterations in selective attention. Correlation analyses indicated that the dose and gestational timing of transplacental cocaine exposure, and varying degrees of malnutrition, had effects on blocking performance, with greater prenatal cocaine exposure and increased prenatal malnutrition resulting in more significant behavioral impairments. A path regression analysis demonstrated independent and significant effects of prenatal cocaine as well as prenatal malnutrition in contributing to impaired performance in the blocking paradigm. As suggested by the clinical literature, our preclinical data support a model whereby the dose and duration of prenatal cocaine exposure have direct effects on offspring brain and body growth and on behavioral performance.

Pharmacology of drug transfer across the placenta

The effect of drugs in the fetus can be thought of in terms of the dose-response based on a knowledge of the general principles by which drug is transferred from the mother to the fetus. Fetal drug concentration, which determines the fetal response, is a function of the maternal concentration, the placental permeability, the fetal drug clearance, and differences in protein binding and ionization between the maternal and fetal plasma.

Birth outcome from a prospective, matched study of prenatal crack/cocaine use: I. Interactive and dose effects on health and growth

OBJECTIVE

This prospective, longitudinal project was designed to determine the effects of prenatal cocaine use on the pregnancy outcomes of women from a historically understudied rural public health population.

METHODOLOGY

We interviewed over 2500 women prenatally, identified 154 cocaine users, and matched 154 controls on race, parity, socioeconomic status, and location of prenatal care (that related to level of pregnancy risk). Drug testing was required at enrollment and at delivery; detailed demographic, psychosocial, and drug histories were taken at each available trimester and follow-up visit. After birth, neonatal nurse practitioners, blinded to maternal history of drug use, examined infants to assess gestational age and take growth measurements. Medical charts were reviewed and the Hobel Risk Scale was completed.

RESULTS

Compared with controls, the cocaine users had significantly higher Hobel Prenatal and Total Risk Scores and more preterm infants (28 vs 14), but not a significantly greater number of fetal deaths (3 vs 1). After controlling for the effects of marijuana, alcohol, and tobacco use, the following results remained. There was no difference in gestational age, Ponderal Index, birth weight, or length between infants born to cocaine users and controls. There was a significant interaction effect such that infant head and chest circumference were smaller in cocaine users who also smoked tobacco. Significant correlation coefficients demonstrated the effects of the amount of drug usage on fetal growth during each trimester of pregnancy. The average cocaine use per day for trimesters one and three and for the entire pregnancy was negatively related to birth length. The mean amounts used in trimesters two and three were negatively related to head circumference. Amounts of tobacco and alcohol use in pregnancy were also inversely related to fetal growth measures. When the effects of marijuana, alcohol, and tobacco were partialed out, there continued to be a negative relationship between the amount of cocaine used in the third trimester and infant length and head circumference.

CONCLUSIONS

The observed decrement in fetal growth, especially head circumference, among cocaine-exposed neonates raises concerns about later growth and development. Follow-up of these infants will reveal if these disadvantages continue. These early results also emphasize the importance of considering amount and time of drug exposure as well as the interactive effects of drug exposure and other risk variables.

Cognitive and behavioral deficits associated with parental alcohol use

OBJECTIVE

To review and synthesize the scientific literature on cognitive and behavioral deficits associated with parental alcohol use and to highlight areas for future attention.

METHOD

Studies of children of alcoholic parents (generally fathers) and of children prenatally exposed to alcohol were reviewed, focusing on cognitive and behavioral findings. Relevant animal studies were also reviewed.

RESULTS

Large numbers of children may be affected by parental alcohol use. Prenatal alcohol exposure is frequently associated with specific cognitive and behavioral deficits. Children of alcoholic fathers also can present with difficulties in learning, language, and temperament. Similarities in the deficits of these two groups were noted.

CONCLUSIONS

The problems associated with parental alcohol use merit much more clinical and research attention. Current clinical approaches often fail to recognize the diagnostic and therapeutic significance of this history, and subgroups of alcohol-affected children may confound research studies of other problems. Subtle deficits in learning, language, and self-regulation may be the most developmentally devastating and the least likely to be identified and addressed effectively. This is an important area in which to combine behavior genetic and environmental approaches to understanding development.

Perinatal and neonatal issues of substance abuse

Substance abuse during pregnancy can be teratogenic for the fetus and can cause decreased growth parameters in the newborn infant. Short-term and long-term neurobehavioral problems have been documented also in babies born to substance-abusing mothers. The problem of substance abuse during pregnancy and its effects on the fetus is unique in medicine in that it is 100% preventable. Physicians will need to take an active role in leading society to take action in preventing substance abuse during pregnancy, and emphasis on this action should occur long before the woman becomes pregnant. Until medical schools and residency programs take responsibility for teaching the importance of preventing substance abuse and of identifying the substance-abuser, drug and alcohol use will continue to exact its tragic toll on future generations.

Cocaine babies: a result of multiple teratogenic influences

The history of cocaine use is reviewed. Cocaine teratogenesis has only recently been studied, and initial human studies had serious methodological flaws. These flaws included ascertainment bias, publication bias (studies finding cocaine effects have been more likely to be presented or published), and overemphasis on the perinatal period. Comparison with alcohol teratogenesis shows that alcohol is a more potent teratogen, which, however, produces major and specific effects (fetal alcohol syndrome) in less than 10% of offspring with heavy alcohol exposure during pregnancy. Nonspecific minor congenital anomalies or fetal alcohol effects are seen in a larger number. Personal experience with two groups of children exposed to cocaine in utero is reviewed. Insurance patients gained weight, took vitamins, and generally, their children did well in spite of cocaine use. Indigent patients were usually unmarried and often "street people," probably used more cocaine, generally used other drugs as well, often did not gain weight during pregnancy, and were much more likely to have children with problems. Surveys show that most cocaine users also use alcohol, often simultaneously. Those who use both agents are more likely to have troubled backgrounds and antisocial behavior and to drop out of treatment programs than those who use only alcohol. Cocaethylene or ethylbenzoylecgonine is formed in the liver when cocaine and alcohol are simultaneously ingested. It is a potent stimulant and dopamine uptake blocker that is more toxic to myocardial cells than is cocaine. Good nutrition is now known to be very important in preventing congenital anomalies and fetal death. A multihit model of neurologic handicap, which stresses the importance of a good postnatal environment, is briefly outlined.(ABSTRACT TRUNCATED AT 250 WORDS)