INTRODUCTION

Fetal macrosomia is defined as a birth weight of 4,000 g or more or, in some settings, a weight greater than 4,500 g; although clinical behaviors should be taken from 4,000 g^1,2. Fetal macrosomia is known to be associated with several maternal and perinatal complications, including infection, postpartum hemorrhage, prolonged labor, high-grade perineal tears, cesarean delivery, anesthetic accidents and thromboembolic events³. According to the American College of Obstetricians and Gynecology (ACOG), macroeconomic fetuses are at increased risk of perinatal asphyxia, meconium aspiration, clavicle fracture, brachial plexus injury and shoulder dystocia⁴.

Although its prevalence varies among different races and ethnic groups, it affects approximately 6-10% of all newborns^1,3. A study carried out by the World Health Organization in 2014 and 2015 reports that in the South American region, 7.6% of all newborns were born macrosomic⁵. Likewise, a study published in Peru in 2017 found that the global prevalence of macrosomia was 5.3%, which is a relatively lower percentage than that found worldwide, however, it carries with it many morbid conditions already explained previously.

Maternal insulin is known to be the main hormone responsible for intrauterine fetal growth. During pregnancy, irregular maternal postprandial blood glucose levels and excessive insulin secretion, especially in the second and third trimesters, can cause fetal macrosomia⁷. The study of hyperglycemia and adverse pregnancy outcome (HAPO) identified a consistent relationship between maternal glucose and birth weight gain⁸. A systematic review by Falavigne et al.⁹reported that treatment of gestational diabetes mellitus (GDM) was effective in reducing rates of macrosomia, pre-eclampsia and shoulder dystocia. Therefore, the risk of fetal macrosomia should be considered during prenatal care for pregnant women with pre-gestational or gestational diabetes mellitus. Other factors are related to the incidence of fetal macrosomia, such as the lipid profile, mainly triglycerides, and HDL cholesterol levels^10,11. As well as maternal obesity, which is related to higher birth weight. However, most studies exploring these relationships were done in other countries, and these relationships need to be explored in populations such as ours. Therefore, the objective of this study was to identify the maternal characteristics associated with the diagnosis of fetal macrosomia at the Sergio E. Bernales Hospital (HNSEB in Spanish) from January to December 2018.

METHODS

An observational, analytical, retrospective, case-control study was conducted. The population was composed of postpartum women with macrosomic newborns. A case-control formula with 95% confidence level, 80% power and odds ratio of 2.02 was considered for the sample size. The sample size consisted of 133 cases (postpartum with macrosomic infants) and 399 controls (postpartum with non-macrosomic infants). The postpartum women whose medical controls during gestation and delivery were performed at the Hospital Sergio E. Bernales during the study period were included. The exclusion criteria were having medical records with illegible handwriting and incomplete information.

The following variables were considered: mother's age, child's sex, gestational diabetes, pre-pregnancy, post-term pregnancy. To collect the information, the Teaching and Research Support Office of the Sergio Bernales Hospital was asked for the corresponding authorization, subsequently, it was coordinated with the Bureau of Statistics to have access to medical records.

The numbers of clinical records were located in the hospitalization record book of the gynecology service of the Sergio E. Bernales Hospital in 2018. Later, an electronic database was created, in the Microsoft Excel 2016 program, to select us according to the sampling technique. The data collection technique was documentation. A datasheet was designed for the collection. A sample of 133 cases of newborns with macrosomia was taken from a population of 4,363 postpartum women from January to December 2010 at the Sergio Bernales Hospital. All patients were included in this study and met the inclusion and exclusion criteria.

To look for the association between variables we found the ORs with their respective 95% confidence intervals, using logistic regression, a p-value was considered as significant if it was less than 0.05. The research project was authorized by the Sergio E. Bernales National Hospital and the Ricardo Palma University.

RESULTS

Of the total sample evaluated, it was observed that concerning the age variable, its mean was 27.01 years with a standard deviation of 6.74, with a predominance of the age group in patients under 35 years of age with 83.3%. Also, it can be seen that multiparous pregnant women predominated with 64.8% of the total. Concerning the sex of the newborn, the female sex predominated with 51.1%, the mean age was 27.01± 6.74 years and the average BMI was 26.23 ± 4.52 Kg/m2. The next variable studied was gestational age, with a predominance of full-term pregnant women (90.0%), Also, it can be seen that in the culmination of gestation variable, predominates cesarean with 50.2%. This and other characteristics can be seen intable 1.

According to the bivariate analysis, the risk factors associated with fetal macrosomia were maternal age, sex of the newborn, low weight gain, excessive weight gain, post-term pregnancy, pregestational diabetes, and gestational diabetes. The respective OR and p-values can be seen intable 2.

Intable 3it can be seen that, when the multivariate analysis is performed, the variables of the sex of the newborn, excessive weight gain, post-term pregnancy, and gestational diabetes were those that had a statistically significant association, while the age of the mother and excess BMI were not statistically significant.

DISCUSSION

Macrosomia is an obstetric complication. Previous reports have shown that macrosomic newborns are at increased risk of developing hypertension, obesity and type 2 diabetes mellitus in adulthood⁵. In a study, conducted by Ismael, in Ica in 2016 he found a prevalence of 5% in fetal macrosomia¹². In Mexico, an incidence of 5.4% was reported in 2016¹³. While Quiroz¹⁴, in our country, at María Auxiliadora Hospital, found an incidence of 9.83% in the same year. These values are similar to those found in the present study.

Maternal age over 35 years in women who had a son or daughter with fetal macrosomia had about twice the risk of developing fetal macrosomia, statistically significant results only in the bivariate analysis, but not in the multivariate. In a study conducted in Turkey, they reported that women over the age of 35 years had 1.5 times higher risk of developing fetal macrosomia, which was also significant; in both studies, the values are very similar.¹⁵

In a study conducted by Cordova with a case-control design at the Naval Medical Center in 2017, it was found that 63% of the macrosomic newborns were male, with an OR of 2.02 and a p-value = 0.027¹⁶; for us, the male newborn had a similar, slightly better OR, with a statistically significant relationship with fetal macrosomia, indicating that male gender acts as a risk factor for the presentation of fetal macrosomia. Excessive weight gain was found in more than half of women with a child who had fetal macrosomia, with a risk of almost double that of developing this disease; this relationship was maintained when the multivariate analysis was done. These results are consistent with the study conducted at San Jose Hospital in 2017 by Alva, in which this factor had an OR of 1.42 and a significant p-value, which would be a risk factor for macrosomia¹⁷

Post-term gestational age represented a risk factor for fetal macrosomia in bivariate and multivariate analysis. This result is similar to that found in a study carried out by Leda in the country of Paraguay, where it was found that post-term pregnancy presented an OR of 14.7 times more risk of developing macrosomia with a p less than 0.001, being statistically significant¹⁹. Also, an excess BMI was a risk factor for fetal macrosomia, which however did not maintain this association in the multivariate analysis. This result contrasts with that found in a study conducted in the neonatal department of San Jose Hospital in 2017 by Alva, who found that BMI was present in 60.7% of cases of fetal macrosomia and had an OR 1.97 times greater risk of developing macrosomia and a statistically significant P value²⁰. Another study at Vitarte Hospital conducted between January and July 2018 by Arroyo found an OR of 7.22 times the risk of developing fetal macrosomia, with a statistically significant p¹⁷.

The presence of pregestational diabetes did not represent a risk factor for fetal macrosomia, a result analogous to the study conducted at the Guillermo Diaz de la Vega Regional Hospital during January 2016 and February 2018 by Midward, which found an OR greater than 1 and a p=5,754; corroborating that there is no significant correlation between this maternal pathology and newborn macrosomia²⁰. However, the presence of gestational diabetes was a risk factor for fetal macrosomia in the bi and multivariate analysis. This is consistent with the findings of a study carried out at the Naval Medical Center by Verastegui in 2014, which found an OR of 2.5 and a p=0.027, which is statistically significant. This could be explained by the fact that children of diabetic mothers suffer an anabolic effect due to fetal hyperinsulinism⁸.

The limitations of the present study are the non-measurement of socio-demographic variables and laboratory values such as fasting glucose, hyperinsulinemia or hypertriglyceridemia. However, the results presented allow us to design interventions to prevent this pathology in our environment.

CONCLUSIONS

In the population studied, the sex of the newborn, the presence of gestational diabetes, excessive weight gain and post-term pregnancy were risk factors for macrosomia in the newborn.