Postpartum diabetes mellitus among patients with early gestational diabetes: A systematic review and meta-analysis

AIMS

It is unclear whether patients diagnosed with early gestational diabetes mellitus (GDM) (<24 weeks) are at higher risk of diabetes mellitus (DM) in the postpartum period compared to those with standard GDM (diagnosed ≥24 weeks). This study assessed if rate of DM diagnosed postpartum differs among patients with early versus standard GDM.

METHODS

PubMed, EMBASE, WHO ICTRP, Clinicaltrials.gov and Cochrane Central Register of Controlled Trials were searched from inception to March 2023. Randomized controlled trials or observational studies that assessed rate of postpartum DM among patients with early GDM were included. Primary outcome was rate of DM diagnosed postpartum. Secondary outcomes were postpartum visit attendance, completion and results of postpartum oral glucose tolerance testing, and glycated hemoglobin (HbA1c) levels.

RESULTS

Of 5682 studies screened, 11 met inclusion criteria (N = 1573 early GDM vs. N = 3340 standard GDM). Patients with early GDM had mean age of 30.2-37.0 years and mean body mass index (BMI) of 24.4-35.6 kg/m2, while the standard group had a mean age of 28.9-32.8 years and mean BMI of 23.6-36.0 kg/m2. Most studies evaluated postpartum glucose tolerance at 5-12 weeks, though one followed patients up to six years postpartum. Overall, patients with early GDM were more likely to be diagnosed with DM postpartum than those with standard GDM (12.8 % vs. 6.1 %, RR 1.89, 95 % CI 1.10-3.24). Impaired glucose tolerance was also higher in patients with early GDM (24.7 % vs. 13.0 %, RR 1.84, 95 % CI 1.32-2.57).

CONCLUSIONS

Rate of DM diagnosed postpartum was higher in patients with early GDM compared to standard GDM.

Lifestyle modifications in the development of diabetes mellitus and metabolic syndrome in Chinese women who had gestational diabetes mellitus: a randomized interventional trial

OBJECTIVES

To study whether lifestyle intervention can reduce the development of type II diabetes mellitus (DM) and metabolic syndrome (MS) among Chinese women who had gestational diabetes mellitus (GDM).

METHODS

A prospective randomized controlled interventional trial of 450 women who had GDM and impaired glucose tolerance (IGT) postpartum. Advice on diet and exercise was given to the intervention group and reinforced in each follow-up visit. Women in both arms were followed for 36 months. Blood pressure and anthropometry were measured at each visit and blood tests were repeated.

RESULTS

Fewer women in the intervention group developed DM (15 versus 19 %) but this was not statistically significant, and there was a lower incidence of DM among women over 40 years old. No difference was found in fasting glucose, insulin and homeostasis model assessment (HOMA) index. Both systolic and diastolic blood pressures, and triglyceride level, were lower but the significance was inconsistent among visits. BMI and percentage body fat were also significantly lower in the later visits. There was no difference in waist-hip ratio and basal metabolic rate.

CONCLUSIONS

Our results demonstrate a trend towards lower incidence of type II DM within 3 years postpartum in GDM women given lifestyle advice, which also potentially offers protection against development of MS, in terms of lower blood pressure and triglyceride level. Women over 40 years old are more likely to benefit. Future studies should address ways to maximize compliance to lifestyle intervention as its potential benefits can be undermined by challenges of motherhood.

Population health significance of gestational diabetes

OBJECTIVE

Women who have had gestational diabetes mellitus (GDM) have a high risk of subsequently developing diabetes. However, the contribution of GDM toward the total population of people with diabetes, or its population health impact, has not been examined. Therefore, the aim of this study is to determine the population health significance of GDM by estimating the proportion of cases of diabetes in women that would have been preceded by a pregnancy complicated by GDM.

RESEARCH DESIGN AND METHODS

A MEDLINE search was conducted to identify controlled follow-up studies of women with GDM. Meta-analysis of these studies, using the Mantel-Haenszel method for pooling relative risks (RRs), provided an overall RR for the development of diabetes in women with GDM versus control women who had been pregnant without GDM. Recent large studies examining the prevalence of GDM were also reviewed. This enabled the calculation of the population-attributable risk (PAR) for these populations. In this case, the PAR represents the proportion of cases of diabetes among parous women that were associated with previous GDM.

RESULTS

From six controlled follow-up studies, the overall RR for developing diabetes after GDM was calculated to be 6.0 (95% CI 4.1-8.8). Applying this to the studies of GDM prevalence, the PAR for GDM ranged from 0.10 to 0.31 (i.e., 10-31% of parous women with diabetes would have experienced a GDM pregnancy earlier).

CONCLUSIONS

In some populations, women who have had GDM comprise a substantial proportion of subjects who ultimately develop diabetes. Effective measures to prevent women with GDM from progressing to frank diabetes could therefore have a significant population health impact.

Obstetric profiles and pregnancy outcomes of immigrant women in New South Wales, 1990-1992

This study examined the obstetric profiles and pregnancy outcomes of immigrant women in New South Wales (NSW). The source of data was the NSW Midwives Data Collection. The characteristics of 64,922 immigrant women were compared with 189,357 Australian-born non-Aboriginal women who delivered babies between 1990-1992 in NSW. The study demonstrated that immigrant women were older, generally had less private health insurance coverage and fewer teenage pregnancies. Immigrant women showed lower rates of essential hypertension, but higher rates of hepatitis B and gestational diabetes. While induced labour was conducted less frequently among immigrant women, episiotomy, instrumental delivery and Caesarean section were performed more frequently among this group. The incidence of postpartum complications was higher among immigrant women. Differences were assessed among women from European, Asian, Middle Eastern, American, New Zealand/Oceania and African backgrounds. For example, the higher rates of hepatitis B, gestational diabetes, episiotomy, instrumental delivery, Caesarean section, postpartum haemorrhage, third degree tear and puerperal infection among Asian-born women were of concern. By contrast, pregnancies among Middle Eastern-born women were associated with fewer complications in spite of their high parity and high percentage of teenage pregnancies. Infants of immigrant mothers were more likely to be resuscitated and/or admitted to special care nursery/neonatal intensive care unit. These findings in immigrant women in NSW suggested the need for culturally appropriate obstetric services, clinical practice reviews, and the greater involvement of general practitioners in obstetric care.