In our study, we aimed to investigate factors associated with postpartum DM screening in women with GDM. We found that only 20.6% of the women with GDM performed the postpartum DM screening. We also found that older age, GDMA2, vacuum assisted delivery, and recommendation for screening during the postpartum visit were all associated with increased rates of actually performing the postpartum DM screening test.
GDM is a well-known risk factor for diabetes further in life. However, the rate of the postpartum DM screening remains much lower than desired among women with GDM. This screening test is essential for identifying women at risk for overt diabetes and to reduce the harmful effects of a hyperglycemic state on their general health and its consequences on future morbidity. Identifying the factors influencing these low rates is crucial and may aid in raising the awareness and rates of postpartum DM screening.
Overall, only 20.6% of women with GDM preformed a DM screening test postpartum. This is a lower rate than previously reported, with rates ranging from 23-58% in different studies (5, 14–18). The lower rate of screening in our study can be attributed to a number of factors. In our hospital, there is a high prevalence of patients with poor prenatal care, which can be associated with poor compliance. Additionally, less than 60% of the women discharged from the maternity unit were given a recommendation for postpartum DM screening. Only half of the women in our study attended a postpartum visit at the gynaecologist office, and only 10% of them were given a recommendation for screening, which is a much lower rate than previously described (25).
Our findings show that the odds of postpartum DM testing increased with increasing maternal age, a similar findings were shown in a 2010 study by Lawrence et al. (4). We also found that vacuum assisted delivery was associated with higher rates of postpartum DM screening. A possible explanation for this finding is that a more distressing delivery may increase the likelihood for better postpartum follow-up. This finding is in opposed to previous study which compared screening rates of women with and without GDM associated complications, and did not find a difference in screening rates between the two groups (19). On the other hand, caesarean section was not found to be significantly associated with increasing postpartum DM screening. It is possible that a caesarean section is considered a more routine mode of delivery especially if elective, while vacuum delivery is considered as a more traumatic occurrence.
Hunt et al. found that women who were diagnosed with GDMA2 and required insulin during their pregnancy also failed to return for postpartum glucose testing (5). In our study we found the opposite. A diagnosis of GDMA2 was significantly associated with higher rates of postpartum DM testing, similar to findings of several other studies (22-25). One explanation could be that the use of insulin therapy during pregnancy may lead to greater awareness of diabetes and to higher rates of compliance with postpartum DM screening recommendations. Moreover, setup of treating patients with GDM may have major influence on the compliance for screening after labour. Since in the Negev most of the women with GDMA2 are treated in hospital setup and are accompanied with multi-disciplinary team during pregnancy, we expect more awareness for the future risk of developing diabetes and higher percent of completing screening.
In our study, the recommendation for screening at discharge had no effect on rates of postpartum DM screening. However, like Tovar et al. found in their study, recommendation for screening during a postpartum visit was positively and significantly associated with postpartum DM testing (12). This finding highlights the impact of the primary gynaecologist on patient education and compliance. Increasing referrals for postpartum screening by primary physicians, will likely increase the rates of completing postpartum DM screening. Medical workers should make an effort to increase awareness to the importance of postpartum DM screening, which may ultimately result in improved DM screening.
Our study’s strength is in the fact that our medical center is the only tertiary medical center in the south of Israel, and most patients receive all their in-patient management at SUMC, therefore represents unselected data. Another strength is the fact that all the medical information about inpatient and outpatient visits and tests is available through computerized medical records. We also have the advantage of having a heterogenic population in the Negev reducing the risk of selection bias.
Our study is not without limitations. It is a retrospective study, and as such, there is a possibility of recall bias as well as missing data. There is also a possibility of the presence of confounding variables, which we attempted to control for using multivariable logistic regression models.
In conclusion, among women with GDM, screening during the postpartum period offers a window of opportunity for early identification of DM. The rates of screening are low and need to increase. The low rates may be attributed to a lack of patient compliance but also to the relatively low rates of postpartum screening recommendations by medical staff. We found that women with older age, vacuum extraction delivery, GDMA2 and those who received a recommendation for screening during the postpartum visit were more likely to perform postpartum DM testing. Further studies should be conducted and different interventions should be evaluated in order to increase the postpartum DM screening rates.