Sir- We would like to compliment Drs Bosio et al¹ for the first reported prospective screening study for drug abuse in an Irish obstetric population. We would disagree, however, with the deduction that "drug abuse is not a serious problem among Dublin's pregnant population." 43 cases of neonatal drug withdrawal were identified at our hospital between July 1996 and June 1997 and these babies had significant impact on facilities and staffing levels in our neonatal ICU. 

We recently anonymously screened the urine of 131 women who booked consecutively for antenatal care at the Coombe Women's Hospital, using a one-step immunoassay technique (Accusign; PBM, Princeton, New Jersey, USA). Further biochemical analysis of the samples was not performed. 5 samples tested positive for amphetamines; 2 for opiates and none for cocaine, yielding an overall detection rate of approximately 5%. Urine was not tested for other substances, e.g. methadone, cannabis, benzodiazepines or alcohol and therefore, our prevalence of "hard drugs" was approximately 3.8%. Again, this must be an underestimate of the true figure because of the limitations also cited in the author's paper. 

Surely we must give serious consideration to antenatal screening for drugs of abuse. As we know, drug history is unreliable, there is a significance prevalence of the condition, women are accustomed to providing urine samples regularly at antenatal visits and we have tests that are sensitive and specific and can provide immediate results. Diagnosis and early recognition of maternal drug abuse improves perinatal outcome by intensifying antenatal care² and maternal treatment programmes are cost effective.³ Obviously, we would advocate proper structuring of perinatal facilities in Ireland for women who abuse drugs before screening could be implemented. 

In developed countries, it is accepted that in the public interest car drivers should be tested for alcohol excess. In sport, random drug testing is widely accepted. In many countries, the abuse of certain drugs is illegal. The individual rights of the woman must be considered but the impact of drug abuse during pregnancy on the newborn may be profound. We report our findings because we would like to provoke a debate as to whether screening for recreational drug abuse should be introduced universally in the maternity services in the interests of both our patients? 

Bridgette Byrne, Amanda Cotter, Eleanor Molloy, Michael Turner,
Coombe Womens Hospital,
Dublin 8.

References

1. Bosio P, Keenan E, Gleeson R, et al. The prevalence of chemical substance and alcohol abuse in an obstetric population in Dublin. IMJ 1997;90(4):149-50. 
2. MacGregor SN, Keith LG, Bachichia JA, Chasnoff IJ. Cocaine abuse during pregnancy: correlation between prenatal care and perinatal outcome. Obstet Gynecol 1989;74:882-5. 
3. Phibb CS, Bateman DA, Schwartz RM. The neonatal costs of maternal cocaine use. JAMA 1991;266:1521- 26.