In many countries, primary care practitioners care for healthy mothers who do not have any recognized risk factors for poor pregnancy outcomes, while high-risk mothers are referred to subspecialist care. In spite of careful screening and diligent pregnancy care, poor outcomes such as fetal or neonatal death, hypertension, placental abruption or previa, preterm delivery, low birth weight and complications of labor continue to occur in apparently low-risk mothers. Van Rijn and colleagues examined the ability of maternal serum alpha-fetoprotein (MSAFP) and serum human chorionic gonadotropin (hCG) levels to predict poor outcome in apparently low-risk mothers.

Using data from more than 7,000 mothers screened for neural tube defects, Down syndrome, or both, they identified 145 (2.4 percent) patients with elevated MSAFP, elevated maternal serum hCG levels, or both. These women were significantly more likely than other pregnant women to have pre-existing risk factors for poor pregnancy outcome (43 to 23 percent, respectively). Women with elevated MSAFP or maternal serum hCG had a threefold increased risk in adverse pregnancy outcome compared with mothers with normal levels. If both indicators were elevated, the risk was increased five-fold compared with mothers with normal levels. When the data were analyzed to account for pre-existing risk, abnormal MSAFP or maternal serum hCG levels predicted risk of adverse outcome only in mothers without previous risk factors. Women who had elevated levels of the indicators but no recognized risk factors had a 3.8 times higher risk of adverse pregnancy outcome compared with women in the same risk category who had normal serum markers. One quarter of low-risk women who had only elevated MSAFP had adverse outcomes. Adverse outcomes occurred in 41 percent of low-risk mothers with only hCG elevation. When both indicators were elevated, 69 percent of mothers had poor pregnancy outcomes.

The authors conclude that elevations of MSAFP or hCG in mothers at no apparent risk of adverse pregnancy outcome are significant indicators. Up to 10 percent of apparently low-risk mothers could qualify for this category. These mothers should now be regarded as being at significant risk of adverse outcomes of pregnancy and merit intensified obstetric surveillance.