RESUMEN
PURPOSE: To explore the contribution of maternal and fetal parameters in predicting the time interval between diagnosis and development of adverse events leading to delivery in singleton pregnancies complicated with fetal microsomia. METHODS: Prospective study on singleton pregnancies referred to a tertiary center because of suspicion of fetal smallness in the third trimester. The study cohort included cases with fetal abdominal circumference (AC) ≤ 10th centile or estimated fetal weight ≤ 10th centile or umbilical artery pulsatitlity index ≥ 90th centile. Development of pre-eclampsia, fetal demise, and fetal deterioration diagnosed by fetal Doppler studies or fetal heart rate monitoring and leading to delivery were considered as adverse events. Maternal demographics, obstetric history, blood pressure, serum PLGF, and fetal Doppler studies were explored as predictors of the time interval between the first visit to the clinic and the diagnosis of complications. RESULTS: In 59 women, the median incubation period from presentation to the clinic to an adverse event was 6, 2 weeks, whereas half of the pregnancies (52.5%) did not develop any adverse event. PLGF was the strongest predictor of adverse events. Both PLGF in raw values and PLGF MOM had equally good predictive ability (AUC 0.82 and 0.78 respectively). Optimal cut-off points were 177.7 pg/ml for PLGF raw values (sensitivity 83% and specificity 66.7%) and 0.277 MoM (sensitivity 76% and specificity 86.7%). On multiple Cox regression analysis, maternal systolic blood pressure, PLGF, fetal increased umbilical artery PI, and reduced CP ratio were independently associated with adverse events. Half of the pregnancies with low PLGF and only one in ten with high PLGF were delivered within two weeks after the initial visit. CONCLUSION: Half of the pregnancies carrying a small fetus in the third trimester will not develop maternal or fetal complications. PLGF is a strong predictor of adverse events that can be used to customize antenatal care.
