Determining the Effect of Gestational Diabetes Status on Breastfeeding Outcomes
Feeding newborns with breast milk immediately after birth increases the production of milk by stimulating the prolactin receptors in breast tissue; it also decreases the risk of hypoglycemia in newborn infants . The World Health Organization (WHO) (2001) proposed that, besides starting to breastfeed early, infants should be exclusively breastfed for the first six months, with continued breastfeeding up to two years and beyond. Supplementary food given in the early period can be the cause of various risks in newborn infants [1,2]. Research has shown that breastfeeding decreases the risk of type 2 diabetes, cardiovascular diseases, premenopausal breast cancer and ovarian cancer in mothers. It has also been found to protect newborn infants from obesity, diabetes, Crohn’s disease, lymphoma and atopic dermatitis [3-7]. However, the prevalence of breastfeeding could be affected by the gradually increasing prevalence of gestational diabetes mellitus (GDM) [1,8,10]. The American Diabetes Association (ADA) estimated that 18% of pregnancies in the world are affected by GDM . According to the Turkish Diabetes Foundation (2013), the incidence of GDM in Turkey is 3%. A study by Tarim (2009) reported that the incidence of GDM in Turkey varies from 1.4% to 13.5% .
Gestational diabetes is caused because some placental hormones (estrogen, cortisol, and human placental lactogen) can have a blocking effect on insulin, a condition called insulin resistance. As the placenta grows, more of these hormones are produced, and insulin resistance becomes greater. Normally, the pancreas is able to make additional insulin to overcome insulin resistance, but when the production of insulin is not enough to overcome the effect of the placental hormones, gestational diabetes results or there may be worsening of pregestational diabetes [3-6].
Although mothers with diabetes generally prefer to breastfeed, clinical studies have shown that breastfeeding can be affected by diabetes [12-18]. GDM is thought to delay lactogenesis stage 1 (characterised by the start of lactation) and stage 2 (characterised by the increase of milk production) . It also increases the risk of hypoglycaemia in newborn [1, 19, 20].
Materials and Methods
The data were analysed using SPSS version 11.5. The level of statistical significance was set at p<0.05. Independent sample t-tests and chi-square tests were applied to determine the differences between groups related to breastfeeding results infirst 24 hour and in the end of first week postpartum. Type of breastfeeding were evaluated according to the criteria of Labbok and Krasovec (Figure 1) , and results were compared with chi-square analysis.
Graph 1. Comparation of exclusively breastfeeding of mothers with and without GDM.
Mothers with GDM had an average age of 31.3±5.8, compared to 27.6±5.13 for mothers without GDM (p=0.000). The BMI was higher in mothers with GDM (p=0.000). The two groups had similar educational backgrounds; most were primary school graduates. There were no significant differences between the groups in terms of parity (p=0.066) and type of delivery (p=0.883) (Table 1).
Breastfeeding patterns during the first 24 hours
Nearly all (98.8%) the mothers with GDM and 100% of the mothers without GDM were breastfeeding at the end of the first week (p=0.499). In both groups, infants were generally breastfed at intervals of two hours (p=0.110). Among mothers with GDM, 35.9% continued to experience problems related to breastfeeding, compared to 23.5% among mothers without GDM (p=0.017). Insufficient milk secretion was continuing to be a problem in 65.6% of mothers with GDM (p=0.003). About a quarter (24.7%) of mothers with GDM felt a need to express milk (p=0.019). Half (50%) of the women with GDM felt the need to express milk due to insufficient milk secretion, and 34.8% of the women without GDM felt the need to express milk because their breasts were filled with milk (p=0.005). Significantly more mothers with GDM used supplementary food (p=0.000) (Table 4).
Type of breastfeeding at the end of the first week postpartum
Nearly seven out of 10 (68.8%) mothers with GDM and 85.3% of mothers without GDM were engaged in exclusive breastfeeding at the end of the first week postpartum (p=0.000) (Table 5).
Table 1. Introduction and obstetric characteristic of mothers (n=340).
Table 4. Comparison of breastfeeding results at the end of the first week postpartum (n=340).
A systematic study by Taylor et al. which examined 12 studies conducted between 1966 and 2003 on the relationship between breastfeeding and type 2 diabetes mellitus (DM), found that women with type 2 DM had lower rates of breastfeeding than those without DM . The delay in first breastfeeding among mothers with GDM was hypothesised to be caused by a delay in lactogenesis as a result of insufficient insulin connected to alveolar cell receptors. In addition, the authors suggested that mothers with GDM experience difficulties in early first breastfeeding due to the risk of hypoglycaemia in their infants. Despite the study was conducted at babyfriendly hospitals, supporting early breastfeeding by health professionals’ especially in infants of mothers with GDM should be reconsidered again in these hospitals [1-2].
More infants of mothers with GDM were deeply asleep when they were first held, compared to infants of mothers without GDM. Deep sleep in infants could be due to their susceptibility to hypoglycaemia as a result of high insulin level that is transported from mother to baby, although this hypothesis could not be tested because the hospitals did not take regular measurements of the infants’ blood glucose levels. Chertok et al. found that 9.5% of infants born to mothers with GDM had hypoglycaemia, and that 23.8% of the infants had blood glucoselevels at the border of hypoglycaemia . Karabayir, Atalay, Adal & Onal retrospectively examined the files of 82 children with full-term diabetic mothers (2% type 1 DM, 5% type 2 DM, 93% GDM) and hypoglycaemia was found in 35.4% of the infants . Hypoglycaemia increases their tendency to sleep, slows down infant’s neuromotor movements and can weaken their sucking reflex. Decreased sucking can inhibit the milk secretion reflex, which in turn can decrease lactation [1,21,27]. Having insufficient milk was a significant problem for women in both groups in fırst 24 hour postpartum. Insufficient milk was defined as having soft breast, not coming any milk when breast was pressed and crying baby after breastfeeding. Soltani et al. found that women with diabetes (type 1 DM, type 2 DM, GDM) experienced problems such as inability to start lactation, insufficient milk, infant’s refusal to suck and infant’s loss of weight . Studies examining the breastfeeding problems of GDM mothers are limited; nevertheless, they have shown that GDM mothers experience serious breastfeeding problems, which is consistent with our study findings.
While breastfeeding at two-hour intervals was common in both groups, breastfeeding at intervals longer than two hours was high among mothers with GDM. Among mothers with GDM, frequent breastfeeding is of great importance in reducing the hypoglycaemia risk of their infants and in starting and continuing lactation, which can be delayed by GDM.1 Youngwanichsetha and Phumdoung findings showed the significant association between neonatal hypoglycaemia and gestational diabetes .
Our study also found that mothers with GDM expressed milk mostly due to insufficient milk, whereas mothers without GDM expressed milk mostly because their infants did not want to breastfeed. Forster et al. had GDM pregnant undertake milk expression twice a day for at least 10 minutes from the 36th week of pregnancy until they came to the hospital to give birth. Mothers who did antenatal milk expression gave their infants less supplementary food and gave more breast milk alone during the first 24 hours. In addition, the rate of breastfeeding was higher within the period they remained at hospital. Thus, milk expression can positively affect breastfeeding results . In our research mothers with GDM used many other supplements besides breast milk during the first 24 hours compared to women without GDM. Forster et al. suggested that it would be beneficial to examine milk express and similar practices to decrease the rate of giving supplements to this new-born’s. The supplements given the most in both groups were water, water with sugar and cow’s milk . According to the TDHS 2008, among the infants less than two months old, 21.3% were given supplementary food, 4.1% were given other milk, yogurt and cheese and 18.3% were given other liquids.Our study findings are similar to these TDHS results .
Another important point, healthy mothers had a higher rate of exclusive breastfeeding than mothers with GDM. According to the TDHS 2003, the percentage of mothers who exclusively breastfed their infants less than six months old was 20.8%; this increased to 41.6% in the TDHS 2008 [26, 29]. It is possible that the rate of exclusive breastfeeding in both groups was higher in our study compared to the TDHS data because we evaluated breastfeeding results during the first 24 hours and conducted our study at baby-friendly hospitals. Hummel et al. also found that mothers with GDM breastfed less and had a shorter exclusive or partial breastfeeding time than healthy mothers. Among women with GDM, a delayed onset of lactation and giving newborns supplemental products can increase the risk of hypoglycaemia in their newborns . This, in turn, can negatively affect exclusive breastfeeding.Similar results were obtained for the average breastfeeding period in the first week postpartum of mothers with and without GDM. The average breastfeeding period for mothers with GDM increased at the end of the first week compared to the first 24 hours. This could be due to the infants’ improved neuromotor activity, the decreased hypoglycaemia risk among infants of mothers with GDM or the infants’ increased sucking strength. It could also be because the mother and infant had become used to each other and to breastfeeding.
Although breastfeeding was higher among women without GDM at the end of the first week postpartum, almost all the women participating in the study breastfed their infants. The TDHS 2008 reported that 98.5% of infants less than two months old were breastfed . Despite problems of lactation in mothers with GDM and the risk of hypoglycaemia in the early period, both groups had a high rate of breastfeeding in the first week postpartum. This could be because breastfeeding is a cultural practice in Turkey and the mothers receive good social support on breastfeeding. While there was a difference in the breastfeeding interval of infants of mothers with and without GDM during the first 24 hours, this difference disappeared at the end of the first week. In particular, breastfeeding at intervals longer than two hours among mothers with GDM decreased. The regulation of breastfeeding intervals at the end of the first week could stem from the decreased risk of hypoglycaemia in infants of mothers with GDM and from the infants’ strengthened sucking reflex. It could also be due to the increasing attachment between the mother and the infant, the breastfeeding behaviour becoming routine and a decreased intake of supplementary products.
But at the end of the first week, more GDM mothers were still experiencing breastfeeding problems. The problem of insufficient milk continued in women with GDM but decreased in women without GDM. This could stem from the delay of the lactogenesis 2 process in women with GDM, which is characterised by abundant milk secretion. Therewith parallel the most common reason for expressing milk in the end of first week in GDM mothers, was insufficient milk. This suggests that the delay in lactogenesis 1 in women with GDM also affected lactogenesis 2 .
Compared with the first 24 hours, there was a decrease in giving supplements among mothers without GDM. Continued use of supplementary liquids in the group with GDM could be caused by a delay in lactogenesis 2, stemming from GDM and insufficient milk. In a study by Soltani et al. 14.9% of women with DM gave supplements at the first breastfeeding; this increased to 19.1% at the end of the first week . This increase in giving supplements shows that breastfeeding problems in women with DM gradually increased. In our study, giving supplements among women with GDM was similar in two measurement. At the end of the first week, a higher proportion of healthy mother’s breastfed their infants with only mother’s milk compared to mothers with GDM. These results suggest that nurses should support and improve exclusively breastfeeding in GDM mothers.
Declaration of Conflicting Interests
The authors received no financial support for this study.
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