Preterm is defined by World Health Organization (WHO) as babies born alive before 37 completed weeks of gestation or fewer than 259 days of gestation since the first day of a woman’s last menstrual period (LMP). Normally, a pregnancy lasts about 40 weeks.

Premature babies, especially those born very early, often have complicated medical problems. Typically, complications of prematurity vary. But the earlier your baby is born, the higher the risk of complications.

Depending on how early a baby is born, he or she may be:

-Late preterm, born between 34 and 36 completed weeks of pregnancy
-Moderately preterm, born between 32 and 34 weeks of pregnancy
-Very preterm, born at less than 32 weeks of pregnancy
-Extremely preterm, born at or before 25 weeks of pregnancy

Most premature births occur in the late preterm stage.

Symptoms

Various methods for detection of gestational age-

Early ultrasound scan: estimation of fetal crown-rump length, biparietal diameter / femur length between gestational ages 6 – 18 weeks.
Fundal Height: distance from pubis symphysis to fundus.
Last menstrual period: women’s recall of the date of the first day of her last menstrual period.
Newborn examination: validated scores using external +/or neurological examination.
Best obstetric estimate: uses an algorithm to estimate gestational age based on best information available, commonly used in high-income settings.

Signs of preterm labor-

In most cases, preterm labor begins unexpectedly and the cause is unknown. Like regular labor, signs of early labor are:

Change in vaginal discharge (a significant increase in the amount of discharge or leaking fluid or bleeding from the vagina).
Contractions (the abdomen tightens like a fist) every 10 minutes or more often.
Pelvic pressure—the feeling that the baby is pushing down.
Low, dull backache.
Cramps that feel like a menstrual period.
Abdominal cramps with or without diarrhea.

Risk factors for premature birth

Some reasons for premature birth remain unknown. However, there are a few maternal risk factors, including:

High blood pressure
Diabetes
Severe illness
Smoking
Twin or multiple pregnancy
Previous premature birth.

Diagnosis

To date, there is no single test or sequence of assessment measures to accurately predict preterm birth. Clinical, biophysical, and biochemical tests that can be used as predictors for preterm birth are:

Clinical predictors- Identification of clinical risk factors, symptoms like pelvic pressure, increased vaginal discharge/changed in vaginal discharge, backache, and menstrual-like cramps.

Biophysical predictors: Uterine contraction monitoring during pregnancy- Uterine contractions can be detected through maternal self-perception, and by medical personnel and by electronic monitoring.

Cervical Examination: Manual examination for cervical dilatation, effacement, consistency, position, and station of the presenting part can be determined by manual examination. Cervical dilatation and effacement have been related to an increased risk of preterm birth.

Sonographic evaluation: A decreased cervical length as measured by endovaginal ultrasound examination has also been related to an increased risk of preterm birth.

Fetal fibronectin; in the vaginal discharge may be measured. The presence of this protein is linked to preterm birth.

Tests for Preterm/ premature baby may include:

Cardio-respiratory monitoring: baby’s breathing and heart rate are monitored on a continuous basis.

Fluid input and output is monitored in determining fluid requirements in very low birth weight babies.

Blood tests: to know about complete blood count, white blood cell (WBC) count, blood type and antibody testing (Coombs test), serum sodium, potassium, calcium, glucose and bilirubin levels in baby’s blood.

Echocardiogram: This test is an ultrasound of the heart to check for problems with structure and function of baby’s heart.

Ultrasound scan: Ultrasound scans may be done to check the brain for bleeding or fluid buildup or to examine the abdominal organs for problems in the gastrointestinal tract, liver or kidneys.

Eye examination: An ophthalmologist (eye doctor) may examine baby’s eyes and vision to check for problems with the retina (retinopathy of prematurity).

If baby develops any complications, other specialized testing may be needed.

Treatment

Intensive care for your premature baby

The neonatal intensive care unit (NICU) or special care nursery provides round-the-clock care for your premature baby.

Supportive care

Specialized supportive care for your baby may include:

Being placed in an incubator. Your baby will probably stay in an enclosed plastic bassinet (incubator) that’s kept warm to help your baby maintain normal body temperature. Later on, NICU staff may show you a particular way to hold your baby — known as “kangaroo” care — with direct skin-to-skin contact.

Monitoring of your baby’s vital signs. Sensors may be taped to your baby’s body to monitor blood pressure, heart rate, breathing and temperature. A ventilator may be used to help your baby breathe.

Having a feeding tube. At first your baby may receive fluids and nutrients through an intravenous (IV) tube. Breast milk may be given later through a tube passed through your baby’s nose and into his or her stomach (nasogastric, or NG, tube). When your baby is strong enough to suck, breast-feeding or bottle-feeding is often possible.

Replenishing fluids. Your baby needs a certain amount of fluids each day, depending upon his or her age and medical conditions. The NICU team will closely monitor fluids, sodium and potassium levels to make sure that your baby’s fluid levels stay on target. If fluids are needed, they’ll be delivered through an IV line.

Spending time under bilirubin lights. To treat infant jaundice, your baby may be placed under a set of lights — known as bilirubin lights — for a period of time. The lights help your baby’s system break down excess bilirubin, which builds up because the liver can’t process it all. While under the bilirubin lights, your baby will wear a protective eye mask to rest more comfortably.

Receiving a blood transfusion. Your preterm baby may need a blood transfusion to raise blood volume — especially if your baby has had several blood samples drawn for various tests.

Medications

Medications may be given to your baby to promote maturing and to stimulate normal functioning of the lungs, heart and circulation.

Surgery

Sometimes surgery is necessary to treat a number of conditions associated with prematurity.

Taking your baby home

Your baby is ready to go home when he or she:

Can breathe without support
Can maintain a stable body temperature
Can breast- or bottle-feed
Is gaining weight steadily
Is free of infection

Reference:

www.who.int/topics/preterm_birth