DISCUSSION
Breast milk has a lot of essential nutrition required by babies during their early age of life. Maternal advocacy both physically and mentally is the key to successful breastfeeding. At Siriraj Hospital, not only obstetricians but also nurses can support and encourage the achievement of breastfeeding by early detection and correction of the abnormality of maternal nipples during antenatal
care. However, the success of breastfeeding depends on many factors beyond the maternal breast anatomy such as fetal tongue tie, breastfeeding position, areolar elasticity, maternal and fetal stress, parity, delivery mode, duration of labor and labor medications.13,14 The main objective of this study was to demonstrate the average length of nipple as a baseline data for Thai pregnant women. The result showed that nipple length and width as well as areola width were not different between both sides. The length and width of nipple did not increase in relation to the gestational age. This differs from areola width which significantly increased in association with gestational age. The difference may be caused by distinct tissue composition between nipples and areolas. The nipple consists of mainly dense connective tissue and lactiferous ducts surrounded by smooth muscle which is not altered by gestational age. Whereas underneath the areola contains fat, lobules and alveoli to keep the colostrums, so the areola can be expanded. In this study, the nipple length was found to be a strong predictor to determine the successful achievement of breastfeeding. Our data revealed that mothers with nipple length of 0.7 cm or more on at least one side could achieve a breastfeeding success rate of 4.38 times greater than those with shorter nipple. Therefore, the length of 0.7 cm may be reasonably used as a cut off point for normal nipple length in the Thai population. Interestingly, we found that the areolar width had significantly increased with gestational age. This could be explained by breast tissue enlargement and congestion as a result of rising progesterone and estrogen level during pregnancy. The influence of wider areolar on breastfeeding success should be further explored in future study. Theoretically, areolar elasticity as well as areolar width are essential for a teat formation and fundamental for the neonate’s ability to latch onto the breast. The elasticity of the areola can be simply tested by placing the thumb above the nipple and the index finger below the nipple then applying the steady pressure between both fingers.15 Ankyloglossia or tongue tie is one of the neonatal risk factors that cause poor latch on.16 It is characterized by the abnormal insertion of the lingual frenulum due to short and thick frenulum and resulting in impeding tongue protrusion. This study also showed a statistically insignificant yet promising result for improvement of breastfeeding success rate in tongue-tied neonate who undergo frenulotomy as shown by previous studies.