This site is intended for health professionals only

At the heart of general practice since 1960

Are GPs too wary of birth defects?

There is nothing national newspapers like better than sensational headlines about use of drugs in pregnancy, but last week's media storm had a different flavour from the usual.

There is nothing national newspapers like better than sensational headlines about use of drugs in pregnancy, but last week's media storm had a different flavour from the usual.

By Daniel Cressey

This time, the focus was not on the risks of birth defects or premature delivery, but the dangers of women missing out on the treatment they need.The RCGP's Dr Jim Kennedy told the BBC: 'Women are being denied use of drugs for everything from headaches and depression to infections.'

He later rushed to downplay his comments as media interest soared, but behind the gaudy headlines lies an earnest debate over where the balance of risks and benefit lies.

With a raft of recent studies on the potential dangers of drugs as disparate as paracetamol, paroxetine and metronidazole (see box below), some doctors are adamant no amount of caution can be too great.

Professor Jim Thornton, professor of obstetrics and gynaecology at the University of Nottingham, said: 'You cannot be too cautious about prescribing in pregnancy. With epilepsy we are cautious ­ anticonvulsants are known to be teratogenic to some extent so it's right to try very hard to get women off them. Diabetes: you get them off oral drugs and on to insulin.'

Dr Patrick O'Brien, a spokesperson for the Royal College of Obstetrics and Gynaecology, also urged greater caution. 'Overall I'd say: have a higher threshold for prescribing any medication in pregnancy, especially in the first 12 weeks.'

Dr Brian Crichton, honorary lecturer in therapeutics and pharmacology at the University of Warwick, advised GPs to avoid using some drugs, such as paroxetine, in women of child-bearing age. 'It's difficult to look at changing medication in patients with depression. The bottom line is to try and not get into that position,' he said.

But Dr Kennedy is not alone in wondering if such a level of vigilance is either practical or desirable. Dr Anthony Brzezicki, prescribing lead for central Croydon PCT, Surrey, said: It's difficult to ask every woman of child- bearing age every time we see them ­ that's not realistic.'

Mr Malcolm Griffiths, clinical director of obstetrics and gynaecology at Luton and Dunstable Hospital NHS Trust, warned: 'An overcautious approach is understandable but it does sometimes compromise care. There is a lack of clarity about some drugs, or groups of drugs.'

He cited the example of NSAIDs prescribed for severe pelvic pain in pregnancy, adding: 'All the books say they are contra-indicated ­ but the evidence against NSAIDs is rather weak.'

Dr Harry Yoxall, secretary of Somerset LMC, said: 'It's a red light; if they're pregnant we don't prescribe. We have been a bit overcautious.'

Drug safety experts warn the real problem is an information vacuum, with drug companies unwilling to carry out trials on pregnant women and often applying blanket warnings on the use of their drugs in pregnancy.

Professor Tony Avery, head of the division of primary care at the University of Nottingham, said: 'People have rightly been worried about prescribing in pregnancy since thalidomide.

'For obvious reasons drug companies have been reluctant to include pregnant women in clinical trials. Over time this has led to a significant lack of research on the effects of even relatively common drugs.'

Professor Saad Shakir, head of the Drug Safety Research Unit in Southampton and a part-time GP, said the lack of evidence was the core of the problem.

'There is a small amount of available information. There's a need to study the potential effect of medicines in pregnant women. We need more data to assess the risk-benefit balance on the basis of evidence rather than on the basis of suspicion.'


A year of pregnancy scares

  • January 2005 ­ researchers link paracetamol administered late in pregnancy to childhood asthma.
  • Canadian study finds oral steroids increase risk of infant hypertension.
  • October 2005 ­ GSK study links paroxetine in pregnancy to birth defects, particularly cardiac malformations.
  • December 2005 ­ researchers find oral hypoglycaemic drugs raise risk of adverse pregnancy outcomes.
  • January 2006 ­ study links metronidazole to preterm birth.

Rate this article 

Click to rate

  • 1 star out of 5
  • 2 stars out of 5
  • 3 stars out of 5
  • 4 stars out of 5
  • 5 stars out of 5

0 out of 5 stars

Have your say