The length of birth of a baby can describe linear growth during the womb. If the baby is born with a short body length, it shows a disturbance during the womb which usually shows the condition of malnutrition (chronic nutrition) suffered by the mother (Par'i, 2017). Babies to have a short birth length if the birth length is <48 cm. (Ministry of Health, 2013). Maternal nutritional status factors that affect baby's birth length are <150 cm maternal height, body mass index before pregnancy <18.5, protein consumption <100 AKG, and maternal weight gain during pregnancy <9.1 kg (Irawati & Salimar, 2014).

The length of the short-term baby is a risk factor for stunting. (Trihono, Tjandrarini, Irawati, Utami, & Nurlinawati, 2015). Short-term birth length results are 1.56 times stunting, so if not handled properly, babies with short birth lengths this will stunting and impact stunting across generations. (Rahmadi, 2017; Trihono et al., 2015). Stunting is a condition of a person's height that is shorter than the 2005 standard WHO-MGRS (Multicentre Growth Reference Study)

According to the WHO (World Health Organization) in 2016, in the world there are around 155 million children under 5 years of age who are stunted (Organization, 2016) Stunting is said to be a health problem in the community if the prevalence of under-five children is above 20%. In 2013 compared to several other Southeast Asian countries, the prevalence of stunting children in Indonesia (37.2%) was highest when compared to Myanmar (35%), Vietnam (23%), Malaysia (17%), Thailand (16%) and Singapore (4%) (RI, 2016).

The prevalence of stunting children in Indonesia is 30.8%, compared to 2013 (37.2%) and in 2010 (35.6%), there has been a decrease in the prevalence of stunting. In Central Java Province the prevalence of stunting was 31.2% (Indonesia, 2018). One of the districts with the highest number of stunting toddlers in Central Java is a priority for the intervention of stunting children, namely Brebes Regency with a number of stunting children, around 69,201 children under five (Poverty, 2017).

Mothers during pregnancy need additional complete protein as the main ingredient for the formation of body cells for the fetus. The quality and quantity of good protein intake can function as Insulin Growth Factor 1 (IGF-1) which is a mediator of growth hormone and bone matrix formation. Mothers consuming <100% AKG protein will affect 1.1-2.7 birth lengths (Trihono et al, 2015).

The right solution is needed to prevent the occurrence of a short baby birth length, which starts from the time of pregnancy so as not to give birth to a short baby. Based on the description above, the purpose of this study is "Proving serum protein levels in the mother that affect the short birth length of the baby".

In this study, short babies were born to most mothers with normal height. There is no difference in birth length between mothers with normal and abnormal height (Yustiana & Nuryanto, 2014). Most of the mothers in this study experienced normal body weight gain of 34 respondents (70.8%). When pregnant all nutrients are needed more, but protein and mineral intake such as iron and calcium are often less consumed which also play a role in fetal bone formation while in the womb (Arisman, 2010; Trihono et al., 2015).

The average arm circumference of respondents in the case group and the control group was included in the normal category (≥23.5 cm), which was 81.23% of respondents. When the size of the arm circumference for pregnant women is used as chronic energy deficiency screening to detect the risk of mothers giving birth to short babies and low birth weight (LBW) (Par'i, 2017).

The hemoglobin levels of the respondents in this study were mostly in the normal category (≥11 g / dl) which was 64.58%. But in the case group more mothers with hemoglobin were less than normal than the control group, which was 45.8%. So short babies born to most mothers with hemoglobin are less normal or anemia. Anemia is a condition where the hemoglobin level in the blood is below normal. Hemoglobin plays a role in transporting oxygen throughout the body (Destarina, 2018). Anemia can cause stunted growth and development of the fetus through impaired nutrient supply and utero placenta oxygenation. This can increase maternal delivery of IUGR (intra-uterine growth retardation), infants born with anemia, and preterm labor (Yustiana & Nuryanto, 2014).

In this study most of the respondents did not have a history of infectious diseases during pregnancy which was 81.25%. Only about 18.75% of respondents have a history of infectious diseases during pregnancy. If during pregnancy the mother does not suffer from an infectious disease, nutritional status can be better and the adequacy of maternal nutrition during pregnancy can be monitored through weight gain during pregnancy, an assessment that can be done to estimate the rate of fetal growth (Arisman, 2010).

Based on the results of the chi square test in this study, there was no significant relationship between serum protein levels in mothers with a short birth length event with a value of p = 0.380 and not a risk factor for short birth length infants with OR = 2.000 (95% CI = 0.623-6,421). Odd ratio of maternal serum protein level was 2.000, which means that mothers with low serum protein levels had a 2.000 times greater risk of giving birth to babies with short birth lengths compared to mothers with normal serum protein levels. There is no correlation between maternal protein consumption during pregnancy and the length of birth of the baby (Setyawati, Barida, & Irawati, 2016).

The results that are not statistically significant in this study can be attributed to different sources of protein intake between each mother and thus have different effects on fetal linear growth. In general, the quality of animal protein intake is better than vegetable protein. Intake of animal protein has advantages such as a more complete amino acid composition, containing iron that is easily absorbed and digestibility of animal protein intake better than vegetable protein intake (Oktaviani, Pratiwi, & Rahmadi, 2018; Setyawati et al., 2016). But the type of animal protein intake is a food that is difficult to reach for some people who have low income because of the high price (Ernawati, Rosamalina, & Permanasari, 2013).

Low serum protein levels in the mother were not proven to be the effect of the birth length of the short baby and were not statistically significant (p = 0.380). Odd ratio of maternal serum protein level was 2,000 (95% CI = 0.623-6,421) which means that mothers with low serum protein levels had a 2,000 times greater risk of giving birth to babies with short birth lengths compared to mothers with normal serum protein levels.