Data collection
abortions
A general information questionnaire obtained demographic and midwifery history data at visit one. The questionnaire consisted of two parts: the first was demographic information include age, education, occupation, height, and weight. The second part of midwifery history information include gestational age according to the first day of the last menstrual period (LMP), gestational age according to the first-trimester ultrasound, number of abortions, number of deliveries, and history of curettage.