The PRIDE Study (PRIDE: PRegnancy and Infant DEvelopment) is a large prospective cohort study that aims at including at least 100,000 pregnant women in early pregnancy to study a broad range of research questions pertaining to maternal and child health, preconception, prenatal, and perinatal care, and adverse developmental effects in offspring. At the first prenatal care visit, women are asked to fill out web-based questionnaires at baseline, during gestational weeks 17 and 34, and 2 and 6 months after pregnancy, as well as biannually throughout childhood. In addition, a food frequency questionnaire and a paternal questionnaire are administered at baseline and pharmacy and obstetric records are obtained. For subgroups of participants, blood and saliva samples for genetic and biochemical analyses are being collected as well. The data collection for the PRIDE Study started in July 2011 in the region of Nijmegen and was gradually being expanded to encompass all of the Netherlands in the beginning of 2016.
The PRIDE Study is a prospective cohort study, in which pregnant women and their children will be followed over a long period of time. Ideally, we will follow the children into puberty. Using this design, we will be able to identify factors during pregnancy that may influence maternal and child health. In addition, a broad range of research questions can be answered using data from the PRIDE Study.
Data collection of the PRIDE Study is primarily being conducted using Web-based questionnaires. Studies have shown that this method of data collection delivers information that is comparable or even better compared with information gathered through the traditional paper-based questionnaires. Furthermore, specific questions can be asked to specific groups of participants based on certain characteristics.
The participants will receive an invitation to fill out different questionnaires by email. In these questionnaires, information on many items is collected, including the pregnancy and pregnancy complications, general health and medication use, lifestyle factors, and occupational exposures. If a participant does not have access to the Internet or prefers to participate using paper-based questionnaires, this option is offered to her. The participants are invited to fill out five questionnaires during and shortly after pregnancy, which all have their own themes. However, the questions in those questionnaires are not limited to the themes:
- Questionnaire 1: Maternal health, at baseline (after first prenatal care visit, usually at gestational weeks 8-12).
This questionnaire mainly focuses on maternal health, but also on exposures in the periconceptional period (3 months before conception until date of filling out the questionnaire).
- Food Frequency Questionnaire (FFQ). At the end of questionnaire 1, the women are asked to fill out an FFQ. This FFQ focuses on food intake in the last month.
- Questionnaire 2: Occupation and living conditions, gestational week 17.
This questionnaire mainly focuses on occupational exposures, living conditions, and exposures in the last part of the first trimester and the beginning of the second trimester.
- Questionnaire 3: Health care and well-being, gestational week 34.
This questionnaire mainly focuses on prenatal health care and expectations of child bearing and parenthood. Furthermore, exposures in the remainder of the second trimester and the beginning of the third trimester are assessed.
- Questionnaire 4: Delivery and infant health, 2 months after the estimated date of delivery.
This questionnaire mainly focuses on the delivery, experiences, and infant health in the first months of life.
- Questionnaire 5: Maternal and child health, 6 months after the estimated date of delivery.
In this questionnaire, the health of the mother and her child are of primary interest, but other items, such as breast feeding, and various exposures, are assessed as well.
- In the second phase of the PRIDE Study, biannual questionnaires are administered throughout childhood, focusing on exposures and child health.
Furthermore, at baseline, the prospective father is asked to fill out a questionnaire about his health and exposures in the preconceptional period.
In addition to the questionnaires, data will be collected using other methods as well. If the participant gives consent, her questionnaire data is linked with data from the Netherlands Perinatal Registry (www.perinatreg.nl), her pharmacy, and her midwife, obstetrician and/or general practitioner. Also, medical records are requested when the child is diagnosed with a birth defect. Therefore, detailed medical information concerning the mother and het child is available.
In mid-pregnancy, saliva samples are being collected to measure cortisol levels. These will be used as a biomarker for maternal stress, which is one of the priority exposures of the PRIDE Study.
Finally, blood samples are being collected for a subgroup of women in the first trimester. In these samples, genetic variations and levels of certain substances that probably influence maternal and/or child health will be assessed.
We have defined two main objectives for the PRIDE Study:
1. To identify factors to which women may be exposed during pregnancy that potentially affect the health of the future mother or her unborn child at any point in life.
2. To evaluate specific aspects of preconceptional, prenatal and perinatal care in the Netherlands.
In light of these objectives, numerous research questions have been formulated for the PRIDE Study. In addition, a list of priority exposures and outcomes was formulated to guide the data collection phase.
Van Gelder MMHJ, Bretveld RW, Roukema J, Steenhoek M, van Drongelen J, Spaanderman MEA, van Rumpt D, Zielhuis GA, Verhaak CM, Roeleveld N. Rationale and design of the PRegnancy and Infant DEvelopment (PRIDE) Study. Paediatric and Perinatal Epidemiology 2013;27(1):34-43. Abstract PDF