Part 33 (2/2)

Further references are available on the book's website at16.Substance abuse during pregnancy Clinical evaluation 297.

Cocaine abuse during pregnancy 311.

Treatment of substance use during Use of hallucinogens during pregnancy 302.

pregnancy 319.

Alternatives to traditional treatment Opiate abuse during pregnancy 321.

for substance dependence during Inhalant (organic solvent) abuse pregnancy 303.

during pregnancy 324.

Specific social and illicit substances Tobacco use in pregnancy 326.

used during pregnancy 304.

Phencyclidine use in pregnancy 328.

Amphetamine abuse during Use of Ts and blues in pregnancy 329.

pregnancy 307.

Polydrug use during pregnancy 330.

Cannabinoid use during pregnancy 309.

Key references 331.

Pregnant substance abusers are frequently (>50 percent) unmarried, have no prenatal care, or began using prenatal care late in pregnancy, and are dependent upon public health care resources. The substances most frequently used during pregnancy include: alcohol, cocaine, heroin, methamphetamine, and tobacco. Alcohol use with tobacco is frequently part of a polydrug use, but a small percentage of women use only alcohol. Typically, pregnant substance abusers are dependent on public a.s.sistance for medical care (s.l.u.tsker et al et al., 1993). Use of mood-altering chemicals without medical supervision is widely prevalent in the USA today. According to some sources (Rouse, 1996), prevalence is as high as 7090 percent of the population and women between 15 and 40 years of age use such substances and often conceive while using them (Finnegan, 1994). There are substantial health risks for pregnant women and their unborn children because of social and illicit substance use during gestation. The most critical period for the induction of congenital anomalies is the first trimester (specifically the first 58 days postconception) (see Chapter 1, Introduction to drugs in pregnancy). Importantly, most women do not know that they are pregnant during early gestation. Their usual life style practices are thus superimposed on the critical period of pregnancy, embryogenesis. Fetal development in the second and third trimesters of pregnancy is also a time of great vulnerability, and continued substance use during this period also carries the risk of atypical development (i.e., some congenital anomalies, but mainly growth r.e.t.a.r.dation). Virtually every substance of abuse for which there is information crosses the placenta (Box 16.1) (Little and Vanbeveren, 1996).

Clinical evaluation 297.

Box 16.1 Substances of abuse that are known to cross the placenta placenta Alcohol Heroin Methadone Amphetamine Inhalants (toluene) Methamphetamine Barbiturate LSD (lysergic acid Morphine Benzodiazepines diethylamide) PCP (phencyclidine) Cocaine Marijuana Tobacco (nicotine) Codeine Mescaline Ts and Blues (pentazocine) From Little and VanBeveren, 1996.

CLINICAL EVALUATION.

Medicolegal considerations Physician knowledge of patient use of social and illicit substances during pregnancy places certain legal obligations on the care providers. The intake interview and medical history-taking process should be sufficiently thorough to discover information regarding the use of potentially dangerous substances. Upon discovery of an exposure, the important second step is to determine timing of exposures during pregnancy, and the nature and extent of the social or illicit substance use. If the exposure actually occurred during gestation, the obstetrician needs to know as much as possible about the teratogenic and toxic potentials of the substance or combinations of substances. The physician may have his or her own resources for researching the topic or may refer the patient to a specialist. Medicolegally, the physician must disclose fully to the patient medically known risks that are posed by maternal substance abuse. This disclosure should also be doc.u.mented in the medical record in a clear and concise manner. It is extremely important that the physician emphasizes to the patient that the use of social or illicit substances is totally contraindicated during the course of pregnancy.

These are not theoretical concerns because we have a.s.sisted in the defense of physicians sued for adverse pregnancy outcomes caused by substance abuse, despite the physician's appropriate counseling that the patient chose to ignore. The riskbenefit ratio for substance abuse during pregnancy is easily explained to be increased risk with no benefit. The patient consultation, particularly this aspect, must be doc.u.mented in the medical record to show that the risk was recognized and patient appropriately advised. Patients have been asked to initial or sign counseling notes regarding substance abuse during pregnancy to acknowledge that they received and understood counseling. The sections that follow doc.u.ment the maternal and fetal medical risks for specific substances including: alcohol, amphetamine, cocaine, heroin, inhalants, lysergic acid diethylamide (LSD), marijuana, methadone, mushrooms, methamphetamine, morphine, phencyclidine (PCP), tobacco, and T's and blues.

Patient consultation Pregnant women usually admit to some use of a substance, but rarely do they admit that they have a 'problem' with social or illicit substance. Once some substance use is admit-298 Substance abuse during pregnancy ted, two tandem approaches to the history-taking process are suggested. Differences in substance use between weekdays and weekends are important to ascertain, because it is common for the user's pattern of use to differ greatly between these two time periods. The patient should describe her daily activities, including any substances used, from awaken-ing to going to sleep at night on a normal weekday. Weekend activities and substance use should be a.s.sessed similarly. The second approach is to ask about substance use in particular. The patient should be asked when she begins drinking or using drugs during the course of a day and the duration of such use. For example, does the patient use the substance as an 'eye-opener' in the morning (Sokol et al et al., 1989) and is it what she uses to go to sleep. The patient should be asked to disclose how much of the substance is used in an average day and approximately how much would be consumed in an hour. Combined with information about the weekly pattern (weekend versus weekday), a semiquant.i.ta-tive estimate of the amount and frequency of substance use can be made.

Alcohol use during pregnancy is well studied and crude risks of fetal alcohol syndrome can actually be made by estimating the average daily dose. With other less well-researched substances used during pregnancy, daily dose information can be used only to a.s.sess the severity of maternal addiction. Very serious dependencies are, of course, a.s.sociated with more severe adverse effects. At the outset, the physician should explain to the patient that the purpose of obtaining this personal and private information is to better manage the pregnancy, i.e., to give medical care more suited to the patient's specific needs. The patient should also be rea.s.sured that this information is Table 16.1 Table 16.1 Summary of embryo-fetal effects of social and illicit substance use during pregnancy Summary of embryo-fetal effects of social and illicit substance use during pregnancy Substance FGR.

Congenital Withdrawal Perinatal Doc.u.mented anomalies syndrome morbidity syndrome Alcohol +.

Amphetamines +.

Barbituates +.

Benzodiazepines ?(+).

Cocaine +.

Codeine +.

Heroin +.

Inhalants +.

LSD.

Marijuana +.

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