Although advances in technology and knowledge are helping increasingly premature babies survive, they still face many healthcare challenges in their young lives. — Filepic
Preterm babies are defined as those born alive before 37 completed weeks of pregnancy.
Their birth is either spontaneous or iatrogenic.
The latter is the result of planned induction of labour or Caesarean section for maternal or foetal reasons.
Preterm births are sub-categorised based on gestational age:
- Extremely preterm – less than 28 completed weeks of pregnancy
- Very preterm – 28 to less than 32 completed weeks, and
- Moderate to late preterm – 32 to 37 completed weeks.
Globally, an estimated 13.4 million babies were born prematurely, i.e. more than one in 10 babies, in 2020.
About 900,000 died in 2019 from the complications of preterm birth, and many had lifetime disabilities of varying severity.
The more preterm the birth is, the greater the likelihood of complications, disability and death.
The 2020 Malaysian Neonatal Registry recorded 319,867 babies from 46 public hospitals nationwide.
A total of 10.7% were delivered preterm, with more then three quarters (77.6%) being late preterm (34 to 37 completed weeks of pregnancy).
The Registry was set up to study the outcome of sick babies admitted to neonatal intensive care units (NICUs) around the country.
A total of 20,033 babies fulfilled the study criteria for the Registry, of which 18,208 (90.9%) were inborn (i.e. in the hospital), while 1,825 (9.1%) were outborn (i.e. outside the hospital).
Of these babies, 3,524 (17.6%) were born below 32 weeks of gestational age and 3,768 (18.8%) had birth weights of 1,500 grammes and below.
Risk factors
There are various clinical practice guidelines (CPGs) worldwide for the prevention and management of preterm births.
These CPGs are intended for healthcare professionals, particularly doctors.
In a review of 37 such guidelines published April (2024) in the International Journal of Gynaecology and Obstetrics, there was strong consensus on the following risk factors of preterm births:
- Previous preterm birth
- Premature pre-labour rupture of membranes (PPROM) or mid-trimester pregnancy loss
- Cervical surgery/excision
- Low pre-pregnancy weight
- Congenital uterine anomalies
- Smoking during pregnancy, and
- Maternal age of less than 18 years old or more than 35 years old.
There was moderate consensus of the following risk factors:
- Multiple dilatation and curettage procedures after 13 weeks’ gestation
- High pre-pregnancy weight, and
- An inter-pregnancy interval of less than 12 months.
Meanwhile, there was weak consensus on the risk factors of previous use of cerclage (i.e. a cervical stitch used to prevent a weak cervix from opening too early during pregnancy), maternal in-utero diethylstilbestrol exposure, and previous full dilatation caesarean section.
Prevention
In the same review, there were recommendations for the prevention of preterm births in both the general and high-risk obstetric population.
The positive recommendations for the prevention of preterm births in the general obstetric population were:
- Stop smoking
- Screen for and treat asymptomatic bacteriuria (i.e. bacteria in the urine that doesn’t cause any symptoms) at the first antenatal visit
- Treat symptomatic bacterial vaginosis and other lower genital tract infections
- Give vaginal progesterone to asymptomatic women with a short cervix without a history of preterm birth
- Treat with cervical cerclage if the woman’s cervical length is very short (less than 10 millimetres) or her cervix is dilated prior to 24 weeks gestation, and
- Consider the use of a cervical pessary in women with a short cervix and no history of preterm birth.
The negative recommendations were:
- Do not screen for asymptomatic bacterial vaginosis in an unselected population
- Do not treat asymptomatic bacterial vaginosis in women without risk factors for preterm birth
- Do not use cervical cerclage as a firstline treatment in asymptomatic women with a short cervix without a history of preterm birth, PPROM or mid-trimester loss, and
- No monitoring of cervical length after cerclage.
There was no consensus on:
- The use of specialised preterm birth clinics or intensive antenatal prevention programmes
- The use of intramuscular 17-hydroxyprogesterone in women without a history of preterm birth
- The use of probiotics to treat bacterial vaginosis to prevent preterm birth
- Supplementation with omega-3 fatty acids to reduce risk of preterm birth, and
- Preferred cerclage techniques.
Meanwhile, the positive recommendations for the prevention of preterm births in the high-risk obstetric population were:
- Screen for and treat asymptomatic or symptomatic bacterial vaginosis in women at increased risk of preterm birth
- Give progesterone therapy to women with a history of spontaneous preterm birth
- Recommend cerclage for women with a history of preterm birth, PPROM or mid-trimester pregnancy loss due to cervical insufficiency, and a mid-trimester short cervix
- Recommend cerclage for women with a short cervix and previous cervical trauma
- Recommend elective cervical cerclage in women with a history of more than three extreme preterm births or second trimester pregnancy losses due to cervical insufficiency, and
- Recommend abdominal cerclage (either laparoscopic or open) in women with a history of trachelectomy or of cervical insufficiency and previous unsuccessful vaginal cervical cerclage.
There were negative recommendations for any form of activity restriction, bed rest or pelvic rest in women at risk of preterm birth.
There was also no consensus on:
- Recommending cervical pessary for women with a short cervix and a history of spontaneous preterm birth or mid-trimester loss
- Recommending elective cerclage in women with risk factors for preterm birth other than a history of spontaneous preterm birth or pregnancy loss due to cervical insufficiency, and
- Recommending cerclage in women with a previous preterm birth and a short cervix.
There was limited discussion in all the reviewed CPGs on the prediction of preterm birth in asymptomatic women, particularly those who are not at high risk of this occurrence.
Highlighting preemies
The World Health Organization (WHO) launched its guidelines on recommendations for the care of preterm or low birthweight babies on Nov 17, 2022.
The guidelines were based on new evidence that can improve the care of preterm or low birth weight babies.
There are 25 recommendations that “substantially expand the ‘what’, ‘where’ and ‘how’ for improving the survival, health and well-being of preterm and low birth weight babies. This includes kangaroo mother care and involving families in the care of their babies right from the time of birth.”
Although CPGs are intended for healthcare professionals, particularly doctors, they should be of interest to all pregnant women receiving healthcare, so that they can better understand and/or discuss them with their doctor, in the event the need arises.
World Prematurity Day has been commemorated annually on Nov 17 since 2011.
Its objective is to raise global awareness of the challenges and burdens of premature birth, which is the leading cause of death in children under five years.
Although advances in technology and research in the past few decades have contributed tremendously to improvements in diagnosis, prevention and provision of care, premature births continue to pose healthcare challenges.
Everyone, from parents, potential parents to governmental agencies at all levels, can play a role in raising awareness and providing appropriate care to one of the most vulnerable, i.e. those who will or have been born before their time.
Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email starhealth@thestar.com.my. The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
