In order to prevent early excessive weight loss in newborns identification of significant risk factors is crucial. If we identify significant risk factors, then we can figure out how and when to prevent early excess weight loss and hopefully also improve long term exclusive breastfeeding. These risk factors may change from country to country. To the best of our knowledge, this is the most extensive study in Turkey that has investigated risk factors for early weight loss in breastfed and term newborns. cesarean section (CS), primiparity, gestational age, maternal age and female gender were the significant risk factors found in the study.
WHO has stated that no robust evidence existed for ideal CS rate. The rate in our study was quite high (15). In Turkey CS rates has increased five folds during the period of 1993–2013 (16). The latest CS rate of 2018 was 52% (17). In literature, there were studies that had smaller number of cases to identify CS delivery as a barrier for breastfeeding (18, 19). Due to the size of this study group and high ratio of CS, the results obtained in this study are clear of the effects of other risk factors. Late skin to skin, post-operative pain and IV fluid administration may be associated with lower success rates in exclusive breastfeeding following CS (20, 21).
According to our findings neonatal weight loss rate was statistically significant for maternal age above 35 years. This is parallel with previous findings from various studies (19, 22). However, many research analyses the combined effect of maternal age and parity (23, 24). Due to our study’s large data, it was possible to identify maternal age as an independent risk factor from parity. Delayed childbearing can be a barrier for breastfeeding and galactagogue use can be an alternative method of lactation support (25).
Being primiparous was another prominent risk factor of our study. This finding is especially valuable as it has been eminent in a study where maternal age was also evaluated. The rate of weight loss > 7% was 61.2% among babies born as the first child of the family. This may be related maternal inexperience and anxiety (4, 23). Such anxieties may have detrimental effect on successful breastfeeding (26). Multiparas show earlier start of breastfeeding which may be associated with previous experience (27).
In our study, over 64% of the early term babies (37 weeks 0 days- 38 weeks and 6 days) lost more than 7% of their birth weight whereas the percentage of excessive weight loss for term babies were around 51% (Tables 4 and 5). This notable difference may be due to increased mortality and hospital stay, difficulty in regulating blood glucose, increased respiratory morbidities and newborn intensive care admissions (28, 29). The sleepiness and reduced ability to effectively latch on is a major problem of early term babies. Even if some early term infants may seem to latch on properly, they may not be able to transfer adequate amount of breastmilk. They require additional attention as breastfeeding support (10).
Findings about gender as a risk factor for early weight loss is controversial. In one study where risk factors for early lactation problems among primiparous mothers were investigated, being boy was observed as a risk factor. The reasons of this finding were explained as; sex-specific differences in infant suckling maturation, gender-based differential behaviours in mothers or the observed association may be because of chance (30). In another study, where 414 newborns were evaluated for the risk factors over 8% weight loss, gender difference was not found to be significant (19). In our study, being a girl was a risk for early weight loss. According to WHO, child growth velocity based on weight, for the first 7 days of life boys’ weight increment was found 21gr/day whereas girls had 14 gr/day average regardless of birth weight (31). Obviously, there are physiological differences between genders in terms of early weight loss and gain. Further prospective studies that investigate the effect of gender on infant weight loss after birth are needed.
The study has some limitations. Information on the management of maternal gestational diabetes mellitus, maternal increased insulin resistance and maternal hypothyroidism was not gathered. The study group consisted majorly of women who were administered anaesthesia, general or epidural. This may have limited the expression of the group of mothers that received no anaesthesia. Birth weight of newborns were mostly above 3000 grams.