| dc.description.abstract | A small proportion of women develop complications during the preterm period of pregnancy (the period before 37 weeks of gestation). An increase in blood pressure (hypertension) in combination with organ failure is one of these complications, also known as HELLP syndrome or preeclampsia. In some pregnancies, this increase in blood pressure goes hand in hand with a growth restriction of the fetus due to placental insufficiency. A high blood pressure (with or without accompanying organ failure) can be dangerous for mother whereas placental insufficiency can result in chronic brain damage of the fetus or even stillbirth. Consequently, health of both mother and child is sometimes best served by medically-induced preterm labor.
To inform couples about the risks for the newborn of medically-induced preterm labor (such as serious breathing problems or dying due to prematurity) versus the chance of stillbirth when continuing pregnancy, risk estimates of these undesirable pregnancy outcomes are required. Such estimates can be made using prediction models, mathematical models containing information about the mother, fetus and current course of pregnancy. Using these risk estimates, couples together with their healthcare professionals can come to a decision on medical management. The aim of this research project was to summarize all available prediction models on adverse outcomes of the fetus or newborn for women dealing with complications of an high blood pressure in the preterm period of pregnancy.
To this end, a systematic search of medical literature was performed. After model identification, the quality of the models and their robustness when using the models in external patient populations (for instance, patients with the same medical problem in another hospital or country) was studied using standardized tools and checklists by two independent researchers. Information on the performance of the prediction models was studied, which can be expressed using statistical formulas.
This literature search identified 8 studies describing 16 prediction models. None of the models were tested outside of the original study population. This is cumbersome as models tend to predict best in the population in which they were developed. Most models included ultrasonography measurements to calculate the risks of stillbirth or complications after birth, such as serious illness or death of the newborn. The methods used to create the prediction models were not in line with current standards for this type of research. Furthermore, most studies lacked important information on how the prediction models were created and how well they can predict the outcome of interest.
This research project has four main conclusions. First, 8 studies reporting on 16 prediction models were identified and none of these models were tested outside the original study population. Second, the methods used to develop the models are not in line with current standards. Third, important information about the predictive performance of the models was lacking in most publications. Consequently and fourth, none of the prediction models described in this research project are suitable for clinical use. | |
