EAL

GDM: Weight Management (2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To study energy requirements in pregnancy.

Inclusion Criteria:

Had one child whom she breastfed
Intended to breastfeed current infant
Not employed outside the home
Neither obese nor lean
No unusual dietary preferences

Exclusion Criteria:

Excluded if not included above.

Description of Study Protocol:

Recruitment

Longitudinal studies started 4 - 5 years prior on healthy pregnant women living in different environments. Women were living in or near Glasgow, Scotland.

Design: Cohort Study

Blinding Used (if applicable): not applicable

Intervention (if applicable): food intake measured by the use of the individual weighed inventory technique

Statistical Analysis:

Statistical analysis not described.

Data Collection Summary:

Timing of Measurements

The first group of women (n=21) collected data every 6 wk for 5 consecutive days including the weekend starting between 6-10 wk gestation. The second group (n=23 collected data for 5 consecutive days every 4 weeks and the third group (n=23) collected data for 3 consecutive days every 2 wks.

Dependent Variables

Food intake was assessed by the weighed individual inventory technique (each subject weighed or measuring foods before eating and any left over after eating) and the foods and amounts recorded on records.
Dietitian visited subjects at home to explain the routine and revisited the following day to assure accuracy of data collection and returned on alternate days to check the dietary record.
Energy and nutrient content of food records were calculated
BMR determined during different stages of pregnant

Independent Variables

Pregnancy stages

Control Variables

None mentioned

Description of Actual Data Sample:

Initial N: 67 women

Attrition (final N): 67

Age: mean age 28 years for all groups

Ethnicity: not mentioned

Other relevant demographics:

Anthropometrics: differences between groups not statistically analyzed

Location: Glasgow, Scotland

Summary of Results:

Other Findings:

Energy intake was similar for the 3 groups of women, so data was pooled.

The increase in energy intake was slow and gradual from the very early stages of pregnancy up to about the last 3-4 wk.

Between the early and late stages of pregnancy, daily intake increased by no more than 100 kcal/d (mean of 50 kcal/d) The rise was more rapid in the last 3-4 wk of pregnancy to 300 kcal/d with a mean of 150 kcal/d.

There was a decrease in BMR between ~15 and 20 wk gestation and a rise ~25 wk.

Author Conclusion:

A normal pregnant woman living in an industrialized country does not require an extra intake of food equivalent to the theoretical energy cost of pregnancy. The real requirements seem to be no more than about 50-100 kcal/d for the first 34-38 wk, and about 200-300 kcal/d for the final few wk

Funding Source:

Not-for-profit

Reviewer Comments:

The average weight gain was 24 to 27 pounds. The women averaged ~5’4” and 128 to 138 lbs before pregnancy.

A limitation of this study was that there was no monitoring or evaluation of physical activity during pregnancy.

Some of the details of the study (methods and results) were documented in other articles. Statistical analysis not described.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		???
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	???
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	???
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	Yes
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		No
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	No
	8.2.	Were correct statistical tests used and assumptions of test not violated?	???
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	No
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	???
	8.6.	Was clinical significance as well as statistical significance reported?	No
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes