Substance abuse during pregnancy: effect on pregnancy outcomes.

OBJECTIVE: To determine the contribution of drug use to maternal and perinatal complications, controlling for social confounders. STUDY DESIGN: This is a retrospective cohort study of 247 drug-using women and 741 controls over a 4-year period from 1997 to 2000. Cases were identified from the drug dependency register. Three controls for each woman with substance abuse were selected from the delivery suite records, with calliper matching by year of delivery (any control patient who delivered within 6 months before or after the date of delivery of a drug-using woman was considered as a potential match) and district of residence (post code). The primary outcomes of interest were preterm birth, abruption, pre-eclampsia, intrauterine growth restriction and low birth weight. RESULTS: There were statistically significantly more preterm births amongst drug-using women (relative risk (RR) 2.5, 95% confidence interval (CI) 1.6-3.8), with preterm births complicating 25% of births amongst drug users. The incidence of low birth weight was 30.8% amongst drug-using women compared to 8% in control women (RR 3.6, CI 2.4-5.4), and the incidence of growth restriction was 25%, significantly higher than the control group (RR 3.82, CI 2.4-6.1). The risk of abruption was also higher (RR 2.74, CI 1.1-7.0). Of note is the extremely low incidence of pre-eclampsia among drug users, even after controlling for the confounder effects of parity and smoking. CONCLUSIONS: Despite multidisciplinary co-ordinated antenatal care, women with substance abuse during pregnancy are at significant risk of adverse obstetric and perinatal outcome, controlling for social confounders. A limitation of the study is that the sample size was not large enough to clearly assess individual drugs. This is the first study to highlight low incidence of pre-eclampsia among drug users over and above the effect of smoking. Further research is needed to elucidate the underlying biological reason for the lack of pre-eclampsia in women with substance abuse during pregnancy.

Outcome predictors in pregnant opiate and polydrug users.

A retrospective case note study of 93 women was performed in order to assess the effect of maternal factors on neonatal outcome in a group of women attending a specialist clinic for pregnant drug users. There were no significant differences in outcome for chaotic drug users compared with non-chaotic drug users, or for cocaine users compared with non-cocaine using drug users. Women who reduced their methadone dose during pregnancy delivered babies of significantly higher birth weight than those whose methadone dose remained the same or increased (median 3027 g, range 1780-3629 g vs 2645 g, range 580-3720 g). Women who abused benzodiazepines during pregnancy produced babies of significantly lower birth weight than those women who did not use benzodiazepines (median 2100 g, range 580-3520 g vs 2767 g, range 1530-3720 g). The results of this study give healthcare staff evidence to use in encouraging drug-using women to avoid benzodiazepines during pregnancy and to reduce their methadone dosage. The treatment received from a specialist clinic may mitigate against some of the other recognised effects of drug use during pregnancy.

A survey of the management of neonatal opiate withdrawal in England and Wales.

UNLABELLED: This report details the results of a survey of 213 maternity units in England and Wales concerning the use of neonatal opiate withdrawal (NOW) charts and the drug therapy management of babies born to drug using mothers. There was a response rate of 89.6%. NOW charts were used in 36.6% of units. There were eight different charts in use in which over 35 different signs of NOW were recorded, ranging from 10 to 22 on individual charts. Nine different drugs were used to manage NOW, with chlorpromazine most commonly used. CONCLUSION: Drug misuse increasing in women of childbearing age and the management of the drug affected neonate varies widely, with inconsistent policies on determining the presence of NOW and how to treat it.

Maternity services for drug misusers in England and Wales: a national survey.

A postal questionnaire was sent to the 213 National Health Service maternity units in England and Wales to identify their current involvement with drug misusers. The response rate was 89.5%. Data indicated that only 29% had formal links with their local drug agency. Child protection case conferences were automatically convened in 52%, and 57% routinely admitted babies to high dependency areas. Twenty-seven per cent of the units did not offer hepatitis B screening to pregnant women, and 32% did not offer hepatitis B prophylaxis to babies whose mothers were infected. Local Health purchasing authorities should ensure that their providers are offering appropriate services to pregnant drug misusers in order to encourage such women to seek help without fear of discrimination. Liaison between health care agencies should be encouraged and areas with low levels of drug misuse should receive help with formulating policies, and training, from units with more experience.