Preterm birth

Abstract

The birth of a preterm infant correlates significant with health associated conditions for the newborn, next to emotional and economic costs for families and communities. The global impact of prematurity is reflected through the fifteen million preterm births that are recorded every year and the 1.1 million newborns who died do to preterm birth complications. The preterm birth rate has staidly decreased in the last 10 years, being estimated as lower than 10% for Romania but it remains the global leading cause of neonatal and childhood mortality.

Knowing the risk factors could help prevent the consequences related to it.

 

Tablet of Contents:

1. Introduction

2. Discussions

3. Conclusions

 

1. Introduction

Preterm birth constitutes the main cause of neonatal mortality and morbidity, having an increasing rate in the last decades [1]. World Health Organization (WHO) defined premature birth or preterm birth as the birth occurring after 20 weeks and before 37 weeks of gestation [2].

The birth of a preterm infant correlates significant with health associated conditions for the newborn, next to emotional and economic costs for families and communities. It is appreciated that annually 965000 deaths in the neonatal period and 125000 deaths of children aged one are due to prematurity [3].

Preterm infants are categorized in different degrees by gestational age or birth weight. According to gestational age (GA) the classification of premature babies includes: Late Preterm birth (LPT)- GA between 34 and 37 weeks, Very Preterm birth (VPT)-GA less than 32 weeks and Extremely Preterm birth (EPT)-GA at or below 28 weeks. According to birth weight preterm infants can present: Low Birth Weight (LBW)-BW less than 2500g, Very Low Birth Weight-BW less than 1500g, Extremely Low Birth Weight (ELBW)-BW less than 1000g [1].

The WHO and partners analyzed in 2010 data from national registries, studies report and reproductive health surveys to estimate the incidence of preterm birth over the last 20 years.

From the analysis of data corresponding to 185 countries they obtained an average global incidence of prematurity of 11,1%, with the highest rate of 18% in sub-Saharan Africa. For Romania, the estimated rate of prematurity is about 9% [4]. Regarding the epidemiology of preterm birth, there are several factors that increase woman’s risk on experiencing a preterm birth such as history of preterm birth [5, 6], anemia [7, 8], high catecholamine levels in the maternal urine [9], tobacco consumption [10, 11], premature rupture of membranes (PROM) [12, 13], high blood pressure (HBP) [14], vaginal bleeding [12], inter-gestational intervals ≤1 year [12], urinary tract infection (UTI) [12, 15, 16], lack of prenatal care [13], inadequate prenatal care [13, 17], maternal age less than 20 years [17], maternal age over 35 years [16,18], oligohydramnios [15], history of induced abortion [19, 20], twin pregnancy [6, 13, 15], advanced maternal age [15]. Within the obstetrical factors that can lead to preterm birth are encountered: placental abruption, placenta praevia, preeclampsia, congenital anomalies, shortened cervix, oligo-polyhydramnios and chorio-amnionitis [1].

 

2. Discussions

The global impact of prematurity is reflected through the fifteen million preterm births that are recorded every year and the 1.1 million newborns who died do to preterm birth complications. The preterm birth rate has staidly decreased in the last 10 years, being estimated as lower than 10% for Romania [1].

A retrospective study was conducted in the University Emergency Hospital of Bucharest for a period of three years (from January 2014 to December 2016) to determine the incidence of preterm births and to report the main maternal, fetal and obstetrical conditions related to prematurity. They also tried to evaluate the occurrence of short-term complications according to gestational age and birth weight. During the study in the Department of Obstetrics and Gynecology of the University Emergency Hospital of Bucharest 12.987 births were registered. The incidence of prematurity was 10%, with 1 405 preterm births and low births weight infants. The percentage corresponds with data reported in specialized literature. The most frequent short-term complications encountered in preterm infants were: pronounced jaundice, hypoxia, tachypnea, hypoglycemia/hypocalcemia, respiratory distress, anemia, sepsis, necrotizing enterocolitis, necessity of intensive care, hemorrhagic disease of the newborn, retinopathy, hyaline membrane disease, convulsions, intraventricular hemorrhages, cerebral hemorrhages, cerebral edema, acute cardio respiratory failure, intravascular disseminated coagulation and decease [1].

Preterm birth remains the global leading cause of neonatal and childhood mortality; prevention in case of existing risk factors and appropriate pregnancy follow-up could help prevent the consequences related to it [1]. In case of twin pregnancy, which has a higher incidence of premature rupture of membranes and premature birth compared to singletons, the Delayed Interval Delivery (DID) has been described. DID is a condition that appears in multiple pregnancies when one or more fetuses are delivered vaginal and the remaining fetuses are retained in the uterus until a higher gestational age. The Polizu Department of “Alessandrescu-Rusescu” National Institute for Mother and Child Health presented three cases of patients with dichorionic twin pregnancies obtained by in vitro fertilization who were admitted to the hospital for uterine contractions or preterm premature rupture of membranes.

Despite the tocolytic treatment, the contractions did not cease leading to the delivery of the first fetus. The contractions stopped and the second twin was left in utero along with the placenta of the first one. The vaginal birth of the second twin took place at 26, 31 and respectively 28 weeks of gestation [21]. DID is associated with multiple risks, especially to the mother. The most important are chorioamnionitis, which may lead to fetal loss and maternal sepsis, disseminated intravascular coagulopathy from the retained placenta, abruption placenta [22]. Natheless, with a good management, the remained fetus can obtain a real chance to life. In the table below, we can see that in the three cases that were mentioned all the newborns had a good evolution [21].

 

Table 3. Neonatal outcomes

 

	Patient 1	Patient 2	Patient 3
Birth weight	1100 g	1660 g	1130 g
Duration of admission	78 days	35 days	35 days
Weight    at    hospital discharge	2640 g	2100 g	2340 g
Clinical condition at discharge	Good	Good	Good

The impact of abnormal adherent placenta, another risk factor for preterm birth, can be reduced significantly with prenatal diagnosis and appropriate pregnancy surveillance.

Ultrasonographic detection is based on some typical aspects (placental gaps and loss of the clear retroplacental space) that guide suspicion anchored by the clinical context [23].

Another prevention measurements for preterm birth are progesterone supplementation, sonographic measurement of cervical length in women with a history of preterm birth, cerclage, administration of low-dose aspirin, acute tocolytic therapy, appropriate interpregnancy intervals (at least 12 months and not longer than 60 months), surgical correction of the uterine malformations, prevention and reduction of multifetal gestations, regular antenatal and during pregnancy screening for eventual infections, reduction of occupational fatogue and weight loss before pregnancy in obese women [24]. The ideal timing of delivery is the key for an ulterior better evolution; for pregnancies between 25 to 32 weeks gestation, each day gained in utero may improve survival by up to 1% to 2% [21].

 

3. Conclusions

•    Preterm birth constitutes the main cause of neonatal mortality and morbidity

•    For Romania, the estimated rate of prematurity is about 9%

•    Regarding the epidemiology of preterm birth, there are several factors that increase woman’s risk on experiencing a preterm birth

•    Knowing the risk factors could help prevent the consequences related to it.

•    In case of twin pregnancy, the Delayed Interval Delivery (DID) has been described as a method of prevention of preterm birth of the remaining fetuses, after the vaginal delivery of the first fetus

•    DID is associated with multiple risks, especially to the mother. Natheless, with a good management, the remained fetus can obtain a real chance to life. In the table below, we can see that in the three cases that were mentioned all the newborns had a good evolution

•    The impact of abnormal adherent placenta can be reduced significantly with prenatal diagnosis and appropriate pregnancy surveillance.

 

The Authors:

MIHAI Ana-Maria [1]

SPATARU Hristina Gina [1]

SUCIU Nicolae [1] [2]

[1] “Alessandrescu-Rusescu” National Institute for Mother and Child Health, Polizu Department, Bucharest (ROMANIA).

[2] “Carol Davila” University of Medicine and Pharmacy, Bucharest (ROMANIA).

 

Contributo selezionato da Filodiritto tra quelli pubblicati nei Proceedings “4th Congress of the Romanian Society for Minimal Invasive Surgery in Ginecology – Annual Days of the National Institute for Mother and Child Health Alessandrescu-Rusescu - 2018”

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Contribution selected by Filodiritto among those published in the Proceedings “4th Congress of the Romanian Society for Minimal Invasive Surgery in Ginecology – Annual Days of the National Institute for Mother and Child Health Alessandrescu-Rusescu - 2018”

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