Protocol - Serial Pregnancy Weight - Weights Measured During Gestation
Serial measures of weight either (1) abstracted from health care (prenatal) records, or (2) measured prospectively for the duration of gestation. Data collected entail (1) weights measured at all prenatal visits; (2) dates of all prenatal visits; (3) reported pre-pregnancy weight; (4) reported or measured height; and (5) gestational age at every prenatal visit and at delivery. If the opportunity exists to collect the information prospectively as part of the research protocol, this is preferred.
Weights Measured during Gestation (Research Protocol)
Gestational ages, date of initial examination, and pre-pregnancy weight are abstracted from medical records (also described in the protocol, Weights Abstracted from Prenatal Charts). Weight in pregnancy is measured at prenatal or research visits using a research protocol (see Measured Weight). Height can be collected by self-report (see Self-reported Height) or, preferably, by measurement in the 1st trimester (see Standing Height).
Most obstetric practices and prenatal clinics use a standardized form to chart prenatal course. The American Congress of Obstetricians and Gynecologists (ACOG, formerly the American College of Obstetricians and Gynecologists) has an Antenatal Record form that is periodically upgraded and available for its members. There are others, such as the POPRAS (Problem Oriented Perinatal Risk Assessment System) or Hollister Maternal/Newborn Record System forms, which are also in common use. All of the standardized forms have places or spaces to report information on gestational age, pre-pregnancy weight, and dates of examination, and these can be abstracted. For women carrying a singleton fetus, the expected schedule of prenatal visits suggested by ACOG is monthly through the 7th month (28 weeks), every 2-3 weeks through the 9th month (36 weeks), and weekly thereafter until delivery. The gestational age at delivery can be found in the labor and delivery chart.
An example of the relevant section of the ACOG Antenatal Record Form B (Initial Physical Exam) which charts date of exam, pre-pregnancy weight, and height:
An example of the relevant section of the ACOG Antenatal Record Form C which contains the date of the woman’s last menstrual period (LMP) and estimated due date(s) (EDD) for establishing (or correcting) gestational age at each prenatal visit:
Gestational age (written with both weeks and days, e.g., 39 weeks and 0 days or 39 + 0) is calculated using the best obstetrical EDD based on the following formula:
Gestational Age = (280 - (EDD - Reference Date))/ 7
Personnel and Training Required
For the aspects of the measures requiring chart review, the abstracter should be trained in medical terminology and records review; for measuring weights, the examiner should be trained as for Measured Weight.
Paper-and-pencil (for chart review) and/or digital scale or beam balance scale.
|Specialized requirements for biospecimen collection||No|
|Average time of greater than 15 minutes in an unaffected individual||No|
Mode of Administration
Physical measurement and/or medical record abstraction
Women who have had a pregnancy (20 weeks or longer) or are currently pregnant.
Weight and weight gain in pregnancy are associated with adverse pregnancy outcomes, including risk for low and high birth weight (i.e., small-for-gestational [SGA] and large-for-gestational age [LGA] newborns); risk for preeclampsia and gestational diabetes; and risk for cesarean delivery. Maternal weight gain below recommended is associated with a lower birth weight. Maternal weight gain in excess of recommendations is associated with a high birth weight and, especially among those women who were normal weight before pregnancy, has also been independently associated with risk of overweight and obesity in the offspring.
|caDSR Common Data Elements (CDE)||Person Measured Serial Pregnancy Weight Gain Weight Value||5021307||CDE Browser|
Total Weight Gain in Pregnancy, Rates of Weight Gain
Process and Review
The Expert Review Panel #1 reviewed the measures in the Anthropometrics, Diabetes, Physical Activity and Physical Fitness, and Nutrition and Dietary Supplements domains.
Guidance from the ERP includes:
a. Added a new measure
b. New Data Dictionary
Protocol Name from Source
American Congress of Obstetricians and Gynecologists (ACOG) Antenatal Form B and C
American Congress of Obstetricians and Gynecologists (http://www.acog.org/).
Institute of Medicine, Committee to Reexamine IOM Pregnancy Weight Guidelines. (2009). Weight gain during pregnancy: Reexamining the guidelines. K. M. Rasmussen & A. L. Yaktine (Eds.). Washington, DC: National Academy Press.
Rasmussen, K. M., Catalano, P. M., & Yaktine, A. L. (2009). New guidelines for weight gain during pregnancy: what obstetrician/gynecologists should know. Current Opinion in Obstetrics and Gynecology, 21, 521-526.
|Variable Name||Variable ID||Variable Description||dbGaP Mapping|
|PX021702020100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702110100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702030100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702040100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702050100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702060100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702070100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702080100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702090100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702100100||What is the date of today's prenatal examination?||Variable Mapping|
|PX021702020200||What is the patient's gestational age at more||N/A|
|PX021702110200||What is the patient's gestational age at more||N/A|
|PX021702030200||What is the patient's gestational age at more||N/A|
|PX021702040200||What is the patient's gestational age at more||N/A|
|PX021702050200||What is the patient's gestational age at more||N/A|
|PX021702060200||What is the patient's gestational age at more||N/A|
|PX021702070200||What is the patient's gestational age at more||N/A|
|PX021702080200||What is the patient's gestational age at more||N/A|
|PX021702090200||What is the patient's gestational age at more||N/A|
|PX021702100200||What is the patient's gestational age at more||N/A|
|PX021702020300||What is the patient's height at today's more||N/A|
|PX021702110300||What is the patient's height at today's more||N/A|
|PX021702030300||What is the patient's height at today's more||N/A|
|PX021702040300||What is the patient's height at today's more||N/A|
|PX021702050300||What is the patient's height at today's more||N/A|
|PX021702060300||What is the patient's height at today's more||N/A|
|PX021702070300||What is the patient's height at today's more||N/A|
|PX021702080300||What is the patient's height at today's more||N/A|
|PX021702090300||What is the patient's height at today's more||N/A|
|PX021702100300||What is the patient's height at today's more||N/A|
|PX021702010100||What is the date of initial examination||N/A|
|PX021702010200||What is the patient's height measured at more||Variable Mapping|
|PX021702010300||What is the patient's weight measured at more||Variable Mapping|
|PX021702020400||What is the patient's weight at today's more||N/A|
|PX021702110400||What is the patient's weight at today's more||N/A|
|PX021702030400||What is the patient's weight at today's more||N/A|
|PX021702040400||What is the patient's weight at today's more||N/A|
|PX021702050400||What is the patient's weight at today's more||N/A|
|PX021702060400||What is the patient's weight at today's more||N/A|
|PX021702070400||What is the patient's weight at today's more||N/A|
|PX021702080400||What is the patient's weight at today's more||N/A|
|PX021702090400||What is the patient's weight at today's more||N/A|
|PX021702100400||What is the patient's weight at today's more||N/A|
Serial Pregnancy Weight Gain
October 1, 2015
Serial changes in weight of the participant during the course of pregnancy for the most recent pregnancy.
Serial weights are used to assess patterns of weight gain over various periods, such as trimesters, and rates of weight gain, especially in the last two trimesters. Rates of weight gain are the only weight gain measures that are not dependent on a recalled or self-reported pre-pregnancy weight. Gestational weight gain and rates are generally interpreted based on a woman’s pre-pregnancy body mass index (BMI, kg/m2).
Anthropometrics, weight, body mass index, BMI, gestation, ACOG