Health Awareness blog

Preterm birth is refers to birth of premature infants the birth of a baby which is less than 37 weeks gestational. Premature birth is among the main cause of mortality in many countries. It is estimated that preterm birth rates range from 5% in developed countries and up to 25% in developing countries. In the US, for the year 2006, the preterm birth rate is 12.8% which is 36% increase since 1980s. Specifically, it is responsible for 85% of all neonatal illness and death. The complications of preterm birth can be either short or long term. Prematurity is complex and it is not straightforward issues. In this part, the discussion will concentrate on prematurity. The complications of prematurity will be discussed later in the next article.

            When dealing with premature birth, the major concern is about saving the child’s life.  Upon delivery, we would not think about the possible long term complications unless the baby shows sign of life or good outcome. Just for the sake of this discussion, I have two questions to ask all of us here. First, do the life is worth to be saved?  Second, will the child has a good future ahead, or will the child live cripple and cause burden to care takers and society? Financially, it cause so much to save one 500 grammar but it has no value if the child end up with severe cerebral palsy and need ventilator support at home. Won’t it be better to spend the many on someone that has better future in front of them?

There are various causes contribute to prematurity. The importance of knowing the causes of premature is to arrange a strategy to reduce the premature birth. This is a very challenging proposition while the patients still at the health care setting. Low rates of preterm deliveries are mainly associated with successful education to the patient to identify regular and frequent uterine contraction so they can alert the medical staff to do early intervention. Treatment can be initiated if cervical changes can be identified.

I like to divide causes of prematurity into 3 main factors; (i) maternal causes (ii) fetal causes and (iii) placental causes. Maternal causes include maternal chronic medical illness, history of preterm delivery, preeclampsia, abnormal anatomy of uterus, cervical incompetence or polyhydramnios. Some modifiable risk factors include drug use or infection such as group B streptococcus, urinary tract infections, vaginal infections. Then, fetal causes are referring to abnormality of the fetus or fetal behavior indicates that the intrauterine environment is not healthy. Multiple gestations like twins or triplets also can increase the risk of premature delivery. Finally, placental causes include placenta praevia, abruptio placenta, premature rupture of membranes and abnormal or decreased function of uterus.

By using above information, we can identify some modifiable causes like infection control and avoidance of alcohol. Smoking cessation is an effective way to prevent preterm birth. As for chronic medical illness or pre eclampsia, by controlling the illness at early stage, it may reduce the risk of preterm birth. This is one important management at health care setting where the doctors can handle the problems at the very beginning especially during antenatal follow up. This can reduce the incidence of preterm birth, hence the complications it may cause. Even though to reduce the premature birth is a demanding task, the most affordable effort is trying to delay it from happening. This is because the prognosis of premature infants improve by prolonged the gestation. As a general idea, the earlier the baby is born the shorter the gestational age, the more problem the baby will face and less likely he/she will develop normally. The spectrum of prematurity falls into 3 categories based on the gestational age and birth weight:           

            As the conclusion, it is important for the public to be aware of the risk factors of preterm birth so they can be avoided. Some risk factors are not modifiable, in this case, they have to be extra caution with their pregnancy. Early and frequent antenatal check-up will help to identify the possible problems and lead to a better outcome.

 REFERENCES:

1.      Steer, P. The epidemiology of preterm labor. BJOG: An International Journal of Obstetrics and Gynaecology, 2005, 112,1-3.

2.      Births: Final data for 2006,” National Vital Statistics Reports; 2006.Vol. 57, No. 7.

3.      McPhee, S.J. and Papadakis, M. A.  Current Medial Diagnosis & Treatment. Forty Eight Edition. 2009. McGraw Hill.

4.      Mattison, D.R., Wilson, S., Coussens,C. and Gilbert,D. (2003). The role of  Environmental Hazards in Premature Birth, Institute of Medicine of the National Academics, The National Academic Press, Washington, D.C.

5.      Oats, J. and Abraham, S.        Fundamentals of Obstrectics and Gynaecology . Eight edition. Spain. Elsevier Mosby; 2005.

6.      Beckmann, C.R.B., Ling, W.F., Smith, R.P., Barzansky,B.M., Herbert, W.N.P. and Laube, D.W.Obstetrics and Gynecology. Fifth edition. Philadelphia Lippincott Williams & Wilkins; 2002.

7.      Dambro., M.R. Griffith’s 5-minutes clinical consult. Philadelphia. Lippincott Williams & Wilkins; 2005.

Retinopathy of prematurity was previously known as ‘retrolental fibroplasia’ (RLF). Approximately 50,000 children worldwide are blind from ROP and the incidence is increasing at developing countries. It is caused by disorganized growth of retinal blood vessels and affects premature infants. It is found that prematurity was the main risk factor and also there is a significant association between gestational age, birth weight, oxygen therapy and blood transfusion. ROP consist of 5 stages (stage I to stage IV).

Stage I is the mild form of ROP, consist of mildly abnormal blood vessel growth. Majority of the child that develops stage I will eventually recovered and develop normal vision without any treatment. The disease usually resolves without further progression and the prognosis is good. Stage II consists of moderately abnormal blood vessels growth. This stage also has a good prognosis where usually no treatment is needed and the disease usually resolves on its own without become worsening in condition. The child will eventually develop normal vision.  Then, Stage III refers to severely abnormal blood vessel growth. The abnormal growth occurs toward the center of the eye instead of following the normal growth pattern along the surface of the retina. In terms of prognosis, some infants will improve without any treatment and eventually able to have normal vision like other kids. However, in some infants especially when he/she has a certain degree of stage III and ‘plus disease’, treatment is recommended to prevent retinal detachment. At this point, the treatment usually ensure good outcome. “Plus disease” means the blood vessels of the retina has become enlarged and twisted. These indicate the worsening of the ROP. For, Stage IV and stage V is already considered severe. Stage IV referred to partially detached retina. It occurs by the traction from the scar that produced by bleeding. In other words the abnormal vessels pull the retina away from the eye wall. Stage V is very severe defined by complete detached of retina. This is the end stage of the disease. The prognosis is poor, without treatment, the baby may have severe visual impairment. Blindness won’t be rare.

Risk factors for ROP are low birth weight, shortened gestation, exposure to prolong ventilation or oxygen and respiratory distress syndrome ROP affects over 20% of infants weighing less than 1500gram. Sepsis or infection at neonatal stage (in preemies) also may contribute to ROP. Furthermore, ROP is significantly associated with smaller, more immature and also sicker neonates.

There are some short term complications of ROP like retinal detachment,  blindness and low vision. The patient (when they grow up later) may also have myopia or hypermetropia. Myopia is short sightedness and far more common compared to hypermetropian or far sightedness.

Regardless the gestational age at birth, if ROP is going to occur, it will occur between 34 and 40 weeks after conception. That is why the newborn at risk should be sent for screening at this stage. The laser treatment is applied to the retina anterior to the vascular shunt that does not yet have a blood supply. The means of this treatment is to prevent retinal detachment. This is based on the idea abnormal vessels should be eliminated before they progress and lay down enough scar tissue that will cause traction of the wall of the eye. There are some other options of treatments include cryopexy, sclera buckle and vitrectomy.

References:

1.   Gilbert, C. Retinopathy of prematurity: A global perspective of the epidemics, population of babies at risk and implications for control. Early Human Development, 2008 February . 84 (2) : 77-8.

2.   Wheatley, CM., Dickson, JL., Mackey, DA., Craig JE. and Sale, MM. Retinopathy of prematurity: recent advances in our understanding. British Journal of Ophthalmology, 2002. 86:  696-700.

3.   Darlow,BA., Hutchinson, JL., Henderson-smart, DJ. Donoghue, DA,  Simpson, JM., Evans, NJ. Neonatal prenatal factors for severe retinopathy of prematurity of among very preterm infants of the Australian and New Zealand network. Pediatrics. 2005 April.  115 (4): 990-996.

4.      Karkhaneh, R,  Mousavi, SZ, Riazi-Esfahani, M, Ebrahimzadeh, SA., Roohipoor, R., Kadivar, M. Ghalichi, L, Mohammadi, SF. and Mansouri, MR. Incidence and risk factors of retinopathy prematurity in a tertiary eye hospital in Tehran. British Journal of Ophtalmology.  2008. 92: 1446-1449.

5.      Strobel, S,  Marks, S,  Smith,PK., El Habbal, MH. and Spitz, L. The great Ormond Street colour handbook of paediatrics and child health, London: Manson Publishing; 2007.

6.      Chye, JK.,  Lim, CT.,  Leong, HK. and Wong, PK. Retinopathy of prematurity in very low birth weight infants. Annals Academy  Medicine of  Singapore. 1999. 28: 193-198 .