Teratogenic potential of cocaine

Socioeconomic characteristics of women with substance use disorder during pregnancy and neonatal outcomes in their newborns: A national registry study from the Czech Republic

BACKGROUND

Maternal substance use can pose a risk to the fetal health. We studied the background characteristics of women with substance use disorders (SUDs) and selected neonatal outcomes in their children.

MATERIAL AND METHODS

A database-linkage study was performed. The sample consisted of pregnant women with a SUD during pregnancy (ICD-10 diagnosis F10-F19 except F17, n = 1710), women not diagnosed with a SUD (n = 1,511,310) in Czechia in 2000-2014, and their children. The monitored neonatal outcomes were gestational age, birth weight, preterm birth, and small-for-gestational age (SGA). Binary logistic regression adjusted for age, marital status, education, concurrent substance use, and prenatal care was performed.

RESULTS

Women with illicit SUDs were younger, more often unmarried, with a lower level of education, a higher abortion rate, a higher smoking rate, and lower compliance to prenatal care than women with a SUD related to alcohol, or sedatives and hypnotics (SH). Women with a SUD had worse socioeconomic situations, poorer pregnancy care, and worse neonatal outcomes than women without a SUD. After adjustment, we found no difference in SGA between the illicit SUD groups and the alcohol and the SH groups. The newborns from all SUD groups had a higher risk of SGA when compared to women without a SUD. However after adjustment, the difference remained significant just in the alcohol group (OR = 1.9, 95 % CI = 1.4-2.6).

CONCLUSION

Mother's SUD during pregnancy increased risk of fetal growth restriction as measured by SGA. The role of maternal socioeconomic and lifestyle factors for the risk of SGA was substantial.

Substance use in pregnancy: The medical challenge

Substance use contributes significantly to the global burden of disease. Growing numbers of women use nicotine, alcohol, and illicit substances. Women are the most vulnerable to problematic substance use in their reproductive years. The first 1000 days of life, starting at conception, have been established as a critical window of time for long-term health and development. Substance use in pregnancy is associated with negative pregnancy and child health outcomes. The impact of antenatal substance use on these outcomes needs to be considered within a challenging and complex context. This review provides an overview of the current literature on the impact of substances on pregnancy and child outcomes as well as the evidence and guidelines on screening and interventions for women using substances during pregnancy.

Illicit substance use in pregnancy - a review

Illicit substance use is not uncommon in women of childbearing age. The direct effects of illicit substance use on the mother, pregnancy and the fetus are not well understood, in contrast to the indirect effects of social disadvantage and intercurrent medical and psychiatric illness, which are well documented. We have undertaken a review of the current literature regarding the effects of illicit substance use in pregnancy and include a suggested approach to identification and management of at-risk women.

Prenatal cocaine administration increases glutathione and alpha-tocopherol oxidation in fetal rat brain

Recent findings suggest that prenatal cocaine exposure results in significant attenuation of uterine and placental blood flow. The extent of blood flow reduction to fetuses positively correlates with reductions in glial-derived neurotrophic factor (GDNF) and dopamine (DA). However, whether such changes in uterine blood flow are sufficient to induce oxidative stress have yet to be determined. In the following experiments, the impact of prenatal cocaine exposure on fetal brain levels of the endogenous antioxidant glutathione (GSH and its oxidized form GSSG) or the exogenous antioxidant alpha-tocopherol (alpha-T and its oxidized quinone form) was investigated. It was hypothesized that cocaine exposure would result in greater oxidation of both GSH and alpha-T. Results indicated that a single injection of cocaine to a drug-naive pregnant dam results in significant (-16.38%) reductions in the levels of GSH. GSSG can be either raised or reduced as a result of fetal uterine position: fetuses at the ovarian extremes show significant increases in GSSG in response to cocaine (+64.73%), whereas cervically situated fetuses show decreased GSSG (-47.91%). Additionally, cocaine significantly decreased the levels of alpha-T (-15.9%) and increased the levels of its oxidative product alpha-Tquinone (alpha-Tq, +34.05%). Levels of alpha-T were not affected by fetal uterine position. These data collectively suggest that cocaine exposure increases the utilization of both endogenous and exogenous anti-oxidants in the fetal rat brain. Along with previous studies, these data support the hypothesis that cocaine-induced vasoconstriction results in oxidative stress in the gestating fetus.

Prenatal cocaine exposure induces an attenuation of uterine blood flow in the rat

We have previously demonstrated that maternal cocaine injections result in a gradient of fetal brain cocaine levels that decrease as a function of the fetuses' proximity to the ovaries at embryonic (E) day 15. Our prior data suggest that cocaine-induced vasoconstriction may (1) limit cocaine's entry into the brain and (2) cause damage to DA neurons through injury associated with hypoxia or ischemia of the utero-placental junction. Therefore, using the microsphere technique (labeled with Ru(103)), the following study sought to determine whether the previously observed pattern of cocaine distribution among fetuses in the uterus were due to position-specific reductions in uterine or placental blood flow. On day 15, a single subcutaneous injection of 30 mg/kg cocaine HCl was administered to each rat. Thirty minutes after the cocaine injection, reference blood samples were drawn from the ventral tail artery. Uterine segments and placentae were removed and subjected to gamma counting. While results regarding placental blood flow were equivocal, cocaine significantly reduced average uterine blood flow by 54.6%. In addition, as one moves more proximal to the ovaries, cocaine progressively attenuates blood flow in uterine tissue segments. These data support the hypothesis that the pattern of drug distribution and subsequent brain alterations from prenatal cocaine exposure in our previous reports are likely due to differences in uterine blood flow.

Fetal effects of cocaine: an updated meta-analysis

BACKGROUND

A very large number of women in the reproductive age group consume cocaine, leading to grave concerns regarding the long term health of millions of children after in utero exposure. The results of controlled studies have been contradictory, leading to confusion, and, possible, misinformation and misperception of teratogenic risk.

OBJECTIVE

To systematically review available data on pregnancy outcome when the mother consumed cocaine.

METHODS

A meta-analysis of all epidemiologic studies based on a priori criteria was conducted. Comparisons of adverse events in subgroups of exposed vs. unexposed children were performed. Analyses were based on several exposure groups: mainly cocaine, cocaine plus polydrug, polydrug but no cocaine, and drug free.

RESULTS

Thirty three studies met our inclusion criteria. For all end points of interest (rates of major malformations, low birth weight, prematurity, placental abruption, premature rupture of membrane [PROM], and mean birth weight, length and head circumference), cocaine-exposed infants had higher risks than children of women not exposed to any drug. However, most of these adverse effects were nullified when cocaine exposed children were compared to children exposed to polydrug but no cocaine. Only the risk of placental abruption and premature rupture of membranes were statistically associated with cocaine use itself.

CONCLUSIONS

Many of the perinatal adverse effects commonly attributed to cocaine may be caused by the multiple confounders that can occur in a cocaine using mother. Only the risk for placental abruption and PROM could be statistically related to cocaine. For other adverse effects, additional studies will be needed to ensure adequate statistical power.

The impact of prenatal drug exposure on the neonate

Several social or recreational drugs singly or together have demonstrated effects on the fetus and neonate, with those effects extending into adulthood. The use of recreational drugs during pregnancy remains a major health problem, with adverse effects including higher rates of fetal distress and demise, lower Apgar scores, growth retardation, and adverse neurodevelopmental outcome. Ethanol has the most profound effects, with physical stigmata of the drug seen in one third of exposed infants. In children without the affected physical appearance, profound neurodevelopmental sequelae have been demonstrated. Other drugs, such as cocaine, heroin, amphetamines, and nicotine, have been associated with impaired fetal growth and acute withdrawal during the neonatal period. Subsequently, these infants and children have an increased risk for altered neurodevelopment and long-term health status. Long-term follow-up and assessment are essential. The risk of neonatal withdrawal or abstinence syndrome is greatest with narcotic drugs but has been found to occur in neonates following exposure to cocaine, nicotine, and amphetamines. Early treatment with tincture of opium, paregoric, or phenobarbital is crucial. Assessment of the overall health status of the infant should include growth parameters, signs and symptoms of infection (especially hepatitis, syphilis, and immunodeficiency viruses), and neurobehavioral function. Such assessments should not be limited to the newborn period, as neurodevelopmental sequelae may not be manifest until later in infancy and childhood. In addition, evaluation of the social milieu is warranted because of the increased risk for neglect and abuse of drug-exposed infants and children. Early intervention, maternal drug rehabilitation treatment, and parenting classes are frequently prescribed, but their efficacy is variable. Further investigations should study the potential benefits of these recommendations.