Introduction:

The high incidence of intrauterine growth restriction is a public health problem; in this pathology, newborns present weight below the 10th percentile, this implies an increase in morbidity in the short term (complications due to hypoxia) and long term (pathologies typical of Fetal Programming) as well as the cost of health services. L-arginine at different doses has been used for some pathologies such as preeclampsia with controversial results. Authors have mentioned that the joint administration of l-citrulline can increase the efficacy of l-arginine. A stunted fetus is a challenge for the fetal physician; due to the complexity of the follow-up, but above all to determine the moment for the termination of the pregnancy. Finding some treatment to promote weight gain would improve the short- and long-term expectations of these infants.

General objective To determine the efficacy of L-arginine + L-Citrulline (3 / 2g) every 24 hours, in fetuses with a decrease in their growth curve in the third trimester of pregnancy.

Material and methods Clinical trial, parallel, controlled, randomized simple, Double blind. Two groups of pregnant women will be carried out in the third trimester; fetus with a decrease in its growth curve, percentile> 10 and <25 for gestation age, they will be given an informed consent letter and they will be randomized (double blind), they will proceed to give intervention (L-arginine + Citrin (3 / 2 g) every 24 hours Vs placebo), a follow-up will be carried out every two weeks, where the weight and growth curve will be calculated in percentile, until the resolution of the pregnancy and data will be taken from the perinatal results in both groups.

Statistic analysis Medics of central tendency will be calculated and Chi squared will be applied for qualitative variables, T of student for qualitative variables and it is considered P <0.005.

50 patients with a pregnancy of more than 26 weeks of gestation, 25 with intervention and 25 control will be included; in which the fetus is between 10 and 25th percentile . It will be carried out in the obstetric service of the old civil hospital, with a double-blind randomization.

Evaluations will be carried out every two weeks where the fetal weight, umbilical artery Doppler, middle cerebral artery, venous duct, uterine arteries, amniotic fluid, placenta will be evaluated.

The assessment will be made until birth, from where the birth weight, height, Apgar, Capurro score, characteristics and placental weight, approximate bleeding will be collected.

Inclusion Criteria:

• Pregnancy with a single fetus
• Patient over 18 years of age
• Patient under 35 years of age
• Pregnancy greater than 25 weeks' gestation confirmed by first trimester ultrasound or reliable last period
• Fetus with decrease or flattening of its growth curve by ultrasound (P> 10 and <25)
• Apparently healthy fetus
• Fetus without Doppler alterations in any of its blood vessels (Venous Ductus, Cerebral Artery medial, Umbilical Artery .

Exclusion Criteria:

• Fetus diagnosed with a malformation
• Fetus diagnosed with a syndrome or chromosomopathy
• Fetus below the 10th percentile for gestational age by ultrasound
• Mother with Type 1, Type 2 or Gestational Diabetes mellitus.
• Chronic maternal hypertension
• Preeclampsia with data of severity or early onset
• Aspirin intake (100-150 mg a day from the first trimester of pregnancy)
• Fetus with a poor ultrasonographic window for evaluation.
• Mother with BMI <18.5 prior to pregnancy
• Maternal BMI> 30
• Known allergy to treatment
• Non-reassuring fetal state.
• Abnormal placental insertion.
• Patient with renal insufficiency, LUPUS or Antiphospholipid syndrome

single pregnancy in third trimester with fetus between the 10th to 25th percentile

we don´t know who receives the intervention and who receives the placebo