Tuesday 20th September, 2005
Presenters:
Associate Professor Paul Haber and Christine Stephens, Nurse Manager Drug Health, RPAH.
This seminar gave us an overview of the Drugs in Pregnancy Service (DIPS*) at RPA Hospital, covering issues around drug use in pregnancy, followed by some case histories to illustrate approaches to various management dilemmas. Christine Stephens outlined the general approach DIPS used over time, stressing the change to a family unit focus that happened after their 1994 review. 'DIPS' aims to build relationships between the patient, her family and the various service providers before the baby is born, and they to try to be as inclusive as possible in their approach to team management. Early intervention is of prime importance. They also aim to build up supports for the family that are needed in the baby's first two years of life, and stress the value of having health care providers involved who are committed for the long-term. Liaison is done with GPs, Redfern Aboriginal Medical Service, family support units, DOCS, Benevolent Society, Early Childhood Centres and other relevant groups from as early in the pregnancy as possible. As well as this focus on the multi-disciplinary approach to pregnancy and post natal care, 'DIPS' tries to foster inter-agency collaboration between such groups, being very aware of the difficulties inherent in inter-agency communication. Comprehensive discharge plans with clear assignment of responsibilities and GP attendance at case conferences are examples of two methods used to achieve this.
DIPS do a comprehensive assessment of the family unit, and explore the psycho-social circumstances of extended family members and whether any family members also have drug dependency problems. As well as making sure appropriate supports are in place, DIPS will also ensure a family is not over-serviced, as this can be a hindrance to a family developing independent coping skills. DIPS are pro-active with regards to child protection case planning, always being upfront and willing to assist families in making the necessary changes. They aim to identify potential risks, eg finding out about safe storage of take-away methadone. They provide a lot of education about what to expect post discharge. As an example Christine outlined the importance of explaining to parents the changes that take place in babies who have been on morphine and are relatively settled, and become less settled when the morphine is ceased. In this scenario it is important to teach parents settling techniques before they are discharged and give them information about the spectrum of normal newborn behaviour.
DIPS aim to get women to attend a minimum of 5 antenatal visits as research has shown this to be the minimum number of visits needed to positively influence outcomes. They provide alcohol and other drug assessments and treatments including provision of inpatient withdrawal programmes and provide beds for women with intractable pregnancy-related vomiting. They do a lot of their ante-natal care on a one-on-one basis as their patient population tend not to go to parenting classes. They address nutritional and dental issues, social, lifestyle and pregnancy related issues, ever with a family-centred approach. 38% of their patients are of Aboriginal and Torres Strait Islander background, are often on a temporary Centrelink benefit and most are not alone, with partners, friends and relatives usually around. There are 20% of referrals which come from "out of area", most coming from the ante-natal clinic, GPs and other clients.
Presentations of women with untreated drug dependency into labour ward are now only 4.2%, a vast improvement, we were told, from the early 90s. DIPS staff have learnt that it is important not to just have one mode of operation but to be flexible and cut down barriers to access as much as possible.
The principle drugs of concern used by patients at this service are heroin, benzodiazepines, cocaine and alcohol. It was noted that alcohol is often less likely to be acknowledged by the patient to be a problem. Paul Haber told us that there is no evidence that light and infrequent drinking causes foetal harm, and outlined the NHMRC guidelines that suggest women consider not drinking at all whilst pregnant or otherwise limit intake to 1 or 2 drinks once or twice a week. Heavy drinking in pregnancy is clearly linked with the development of the foetal alcohol syndrome, where alcohol kills the cells that should form the midline structures in the brain and the face. It was acknowledged that many women with alcohol dependency are never seen at all by drug and alcohol services.
The effects of some other drugs in pregnancy were outlined. Because cannabis is usually used with tobacco it is not easy to look at its effects in isolation. Tobacco is known to increase the chance of low birth weight babies and decrease the length and head circumference of newborns (also can cause microcephaly). A Canadian study (Fried, 2000) was quoted in which heavy use in the mother was associated with adverse long-term effects on the offspring. These involved subtle changes in some finer points of global functioning but not intelligence. Tobacco use, on the other hand, was shown to be associated with lower IQ in a dose dependent manner in the same review of outcomes, some going for up to mid-teenage years.
Use of hydroponic cannabis (assuming it is stronger) was said to be more harmful to the foetus than 'bush' THC. Some believe the opposite to be the case as higher THC concentrations, if associated with less raw cannabis use, may limit exposure to other more dangerous burnt products in the smoking process (personal communication G. Chesher, retired associate professor of pharmacology, Sydney University).
The increased risk of SIDS among babies born to mothers who smoke is thought to be related to tobacco use rather than cannabis. Some women now 'cook' with cannabis to avoid using it with nicotine (eg. 'cannabis/hash cookies'). There was discussion about contradictory information that cannabis can cause nausea as well as treat it at different times. Because of the lack of evidence surrounding foetal safety and cannabis use in the mother, as with most other drugs, we should advise women not to use cannabis during pregnancy.
Cocaine use in pregnancy was also discussed and in this case there is no doubt of the deleterious effects to both mother and foetus. It is associated with maternal hypertension and increased chances of miscarriage, stillbirth and placental abruption. Babies are often born small for their gestational age and neonates experience a significant withdrawal syndrome. It is now recommended that all neonates born to mothers who have used cocaine have a scan done to detect cerebral infarcts, as there is a significantly increased risk of this occurring. Cocaine is harmful throughout all stages of pregnancy and many perinatal deaths are associated with maternal cocaine use.
There was a brief discussion of ecstasy use in pregnancy and Prof. Haber told us that the risks to the foetus were comparable to amphetamines. It was stated that about one third of "ecstasy" tablets have no psychoactive component, one third have a variable quantity of MDMA and one third contain other psychoactive drugs. This should be born in mind when monitoring the pregnancy of women who give a history of ecstasy use, although the strength may be more reliable in some circles.
Four interesting case histories were discussed to help guide us in our management of common scenarios. The first case involved a woman on methadone maintenance with intractable vomiting. Firstly it was recommended that she be advised not to have a methadone dose on an empty stomach and not to run or exercise straight after a dose. Both prochlorperazine (Stemetil) and metoclopramide (Maxalon) tablets or injection can be used, the former being also available in suppository form. The role of ondansetron (Zofran) is increasing, with obstetricians using it as a second line agent, especially as buccal �wafer�. It is not suitable for long-term use and is quite costly with a potential for side effects in pregnancy.
A change between formulations may help some women (Biodone sugar-free versus the syrup). In women on high dose methadone (and some others who are sensitive) split dosing (half morning and night) may be helpful. Take-away methadone may be increased for the period of vomiting so women can sip their doses at home.
A second case history also looked at the problem of pregnancy related vomiting, this time associated with weight loss. It was pointed out that many women lose weight in the first trimester of pregnancy and that this in itself is not a concern. What is important is to assess the fundal height to check that the nutritional status of the mother has not affected the well being of the foetus. The woman may need detailed information about nutrition and diet. Most antenatal clinics now only do a baseline weight of the mother at first presentation, as it is the fundal height that reflects intrauterine growth, and frequent maternal weighing may cause unnecessary worry.
The third case history brought up the issue of buprenorphine use in pregnancy. Whilst it is a �category C� drug, it was pointed out that so is methadone. There is limited local research into the effects of buprenorphine in pregnancy and on neonates. However, worldwide there are now greater than 250 published cases of buprenorphine use in pregnancy and most have reported safe outcomes. Currently pregnant women are advised to transfer over to methadone maintenance treatment, and this should ideally occur as an in-patient. There was much audience debate about this issue, but it was generally agreed that it is wise to get a second opinion if considering prescribing buprenorphine to a pregnant woman. If a woman is unable to take methadone, then the outcome following buprenorphine treatment is likely to be much better than having no prescribed treatment. Christine touched on the similarities and differences between babies experiencing neonatal abstinence syndrome according to whether their mother was on methadone or buprenorphine. The duration of total treatment time with morphine is much the same for babies coming from either situation, though indications are that for buprenorphine there are fewer needing morphine and for shorter periods. It was also emphasised that not all babies of mothers on MMT or buprenorphine require morphine, and that the chances of a baby developing NAS are not strongly dose-related.
The final case history promoted a discussion about child protection issues. In this particular case, a mother on MMT was found to have morphine metabolites in her urine at 3 weeks post-partum. Her baby was healthy and had not required any morphine post delivery. The importance of setting up frequent reviews with this patient was emphasised. A urinary drug screen result in isolation is not so much a reason to notify DOCS, but is certainly an indication to see the patient more often and explore what is happening in her life. Relevant issues to explore include whether the procurement of drugs is impacting on the family's finances, and whether drug use interferes with the mother's ability to attend to the needs of her newborn. We should ask about who else cares for the baby, and who else comes to the house. Do any drug dealers visit the house, or does the mother take her baby with her to procure drugs? Is she in a stable relationship or does she have several partners? We were reminded of the fact that two-thirds of deaths of babies occur in households where there are significant problems with drug and alcohol use, so we must always satisfy ourselves with regard to the safety of children.
Written by Jenny James, Daruk AMS (edited by Andrew Byrne).
*Note that the hospital DIPS has now been renamed the Perinatal and Family Drug Health Service (PFDHS).
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