Objective. To identify pregnancy worries in women by assessing the intensity of these worries and how they change over the course of pregnancy, as well as their relations with sociodemographic and clinical variables. Design. Longitudinal study using a postal questionnaire. Setting. University hospital in Madrid. Population. 285 pregnant women. Method. Women were asked about their pregnancy-specific worries in their first trimester (mean gestational age 14.4 weeks) and third trimester (mean gestational age 34.3 weeks). Main Outcome Measures. The women completed a questionnaire that included sociodemographic information and the Cambridge Worry Scale. Results. Pregnancy worries were significantly reduced during the third trimester. The main concern throughout gestation was worry about fetal health. Multiparity and pregnancy planning protected women from pregnancy worries, whereas having had a miscarriage had a negative effect. A younger age and being employed contributed to greater socioeconomic worries. Conclusions. Worries related to the health of the fetus are universal across different nationalities. A first pregnancy, unplanned pregnancy, and previous miscarriage are risk factors that influence the intensity of a woman's worries. To improve the health and quality of life of pregnant women, a holistic approach to their care should include evaluation of their worries and appropriate intervention in particular groups considered at risk.