• alpha-fetoprotein;
  • free beta-human chorionic gonadotrophin;
  • inhibin A;
  • maternal serum markers;
  • pregnancy-associated plasma protein A;
  • pregnancy complications;
  • unconjugated estriol

Key content

  • Screening for Down syndrome is available in the first or second trimester.
  • In the absence of aneuploidy and structural anomalies, abnormal maternal serum levels of first and second trimester markers are associated with adverse obstetric outcome.
  • As the number of markers increases and their value becomes more extreme the likelihood of adverse obstetric outcome increases.
  • Although many of the associations between maternal serum markers for adverse maternity outcome are statistically significant, the positive predictive value for individual outcomes are too low for them to be clinically useful as screening tests.
  • Potential management strategies for care of women with abnormal serum markers are yet to be established.
  • Pregnancies complicated by pre-eclampsia, fetal growth restriction, pre-term delivery, fetal demise and spontaneous miscarriage have been associated with abnormal deviations in either one or several components of these markers.

Learning objectives

  • To review the relationship between abnormal first and second trimester maternal markers and adverse obstetric outcomes.

Ethical issues

  • Despite evidence of increased pregnancy complications with unexplained abnormal quadruple screen, the optimal method to manage them is unclear.
  • The cost of screening and emotional anxiety caused to patients must be outweighed by the benefits of early detection and the ability to reduce the overall risk.
  • It is a great dilemma for obstetricians on how to proceed when confronted with an unexplained abnormal serum screen.