GDM: Medical Nutrition Therapy (2016)


Reyes E, Matinez N, Parra A, Castillo-Mora A, Ortega-Gonzalez C. Early intensive obstetric and medical nutrition care is associated with decreased prepregnancy obesity impact on perinatal outcomes. Gynecol Obstet Invest. 2012; 73: 75-81. 

PubMed ID: 21893947
Study Design:
Prospective Cohort Study
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To compare the gestational weight gain and adverse perinatal outcomes both maternal and in the newborn in urban Mexican women with pre-pregnancy overweight or obesity without any concomitant disease under an early intensive obstetric and nutrition program vs. women with pre-pregnancy normal weight under routine hospital prenatal care, attending a third-level medical institution.
Inclusion Criteria:
  • Women with uncomplicated pregnancy and up to 13 weeks gestation, who were attending for prenatal care from January 2007 to December 2008
  • Singleton pregnancy, without previous history of GDM or any other concomitant diseases
  • Planning to receive prenatal care and to have resolution of pregnancy at the same institution.
Exclusion Criteria:
Previous history of GDM, T2DM, pre-pregnancy hypertension, renal, immunologic or hepatic diseases. 
Description of Study Protocol:

Consecutive women attending for prenatal care between January 2007 and December 2008.

Historic cohort.


  • Both OW and OB women received nutrition assessment and intervention within two weeks after admission to prenatal care with a diet of 25kcal per kg of ideal body weight for gestational age never less than 1,500kcal, with 45-48% complex CHO, 20-21% protein and 30-32% lipids
  • In NW, nutrition assessment was not included with only specific information about maternal weight gain during pregnancy, however if excessive weight gain occurred, they were referred to an RD for assessment
  • In OW and OB, total energy intake was modified according to the progression of pregnancy at four-week intervals, but if excessive they were immediately scheduled for a new visit with the RD
  • Diet was assessed monthly with multiple-pass 24-hour recalls.

Statistical Analysis
Descriptive statistics, outcome frequencies, difference of proportions, one-way ANOVA with individual groups and multivariable logistic regression and odds ratio and 95% CI were calculated.

Data Collection Summary:

Timing of Measurements
First obstetric visit (up to 13 weeks pregnancy) and end of pregnancy.

Dependent Variables

  • Miscarriage: Loss of pregnancy before 20 weeks of pregnancy 
  • GDM
  • Premature rupture of membranes
  • Pre-term birth: Less than 37 weeds gestation
  • Gestational hypertension
  • Pre-eclampsia
  • Spontaneous labor
  • Cesarean delivery
  • Puerperium complications
  • Gestational age at delivery
  • Stillbirth, early neonatal death
  • Small for gestational age (SGA). Less than 10th percentile; or large for gestational age (LGA), over 90th percentile
  • Major congenital defects.

Independent Variables
Intensive obstetric care and medical-nutrition program for those whose pregestational BMI classified them as overweight (OW), 25.0kg/m2 to 29.9kg/m2; obese (OB), 30kg/m2 or more vs. routine hospital prenatal care for those of normal weight (NW), 18.5kg/m2 to 24.9kg/m2.

Control Variables

  • Monthly obstetric visits up to 30 weeks gestation, then biweekly to 36 weeks and then every week
  • Abdominal ultrasound each trimester
  • Weights at each visit and weight gain assessed.
Description of Actual Data Sample:
  • Initial N: 546 women
  • Attrition (final N): 546
  • Age: 27.03±8.5 years (normal weight), 30.5±7.3 years (overweight), 31.2±6.1 years (obese)
  • Ethnicity: Mexican
  • Other relevant demographics: NW women were younger than OW and OB, mainly primigravid and with fewer first-degree relatives with T2DM
  • Location: Mexico City, Mexico.
Summary of Results:


  • There was no between-group difference in gestational age at delivery or among their newborns' birth weights. 
  • Gestational weight gain was lower in OB women (6.1±4.4kg) compared to OW (9.5±5.1kg) and NW (10.3±5.4kg) women (P<0.001) without differences among the latter two groups. However, when analyzed according to the IOM recommendations, NW women had 31.3%, 51.7% and 17%; OW women had 14%, 50.3% and 35.7%; and OB women had 20.7%, 56.9% and 22.4% below, within and above, respectively, the IOM weight gain recommended
  • The percentage of women with a weight gain below recommended was greater in NW vs. OW (P=0.0001) and vs. OB (P=0.02) and the percentage of OW women with a weight gain above recommended was greater than in NW (P=0.0001) and OB women (P<0.01)
  • The incidence of GDM in the whole group was 10.6%; NW and OW women had a similar frequency of GDM, but lower than in OB women (P<0.001 and <0.01, respectively)
  • The incidence of of pre-eclampsia was significantly higher in OB than in NW (P<0.01)
  • The lack of spontaneous initiation of labor was the greatest in OB women compared to OW women (P<0.01) and NW (P<0.001)
  • There were more planned Cesarean sections in the OB than the NW (P< 0.0001) and OW (P=0.04)
  • There were no other significant between-group differences in any other maternal outcomes.
Author Conclusion:
Early intensive medical-nutrition prenatal care and adequate gestational weight gain may contribute to decreasing most maternal and newborn adverse outcomes associated with pre-pregnancy overweight or obesity.
Funding Source:
University/Hospital: Instituto Nacional de Perinatologia Isidoro Espinosa de los Reyes
Reviewer Comments:
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? Yes
  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? Yes
  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? Yes
3. Were study groups comparable? Yes
  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? Yes
  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? Yes
  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? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  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? No
  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? N/A
  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? Yes
  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? Yes
  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? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  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)? N/A
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
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