Most babies are born about 40 weeks after the first day of their mother's last menstrual period. But about 10 percent of babies arrive sooner. A baby born more than three weeks before his or her due date is considered premature.
Premature babies have less time to fully develop and mature in the womb. As a result, they're often at increased risk of medical and developmental problems. One of the biggest problems facing premature infants is underdeveloped lungs.
Your doctor may try to delay your baby's birth if you go into labor earlier than around 34 weeks into your pregnancy (preterm labor). Even a few extra days in the womb can give your baby's lungs a chance to become more mature. But sometimes, in spite of every effort, your baby may be born early.
Fortunately, the outlook for premature infants has improved dramatically in recent years. Great advances have been made in the care of premature infants, and even babies born as early as 23 weeks now have a good chance of survival.
Signs and symptoms
It's usually best for a baby to stay in the womb as close as possible to full term. Recognizing the signs of premature labor may help you prevent your baby from being born too soon. The following signs and symptoms can occur as early as four months before your due date:
- Regular contractions of your uterus. At first, contractions seem like a tightening in your abdomen that you can feel with your fingertips.
- Light vaginal spotting or bleeding.
- Menstrual-type or abdominal cramps.
- Low, dull back pain.
- Watery discharge from your vagina. This may be amniotic fluid, the protective liquid that surrounds your baby in the womb. If so, it's a sign that the membranes around your baby have ruptured.
- A feeling of pressure in your pelvis, as if your baby is pressing down.
- If you suspect you're in premature labor but haven't had a watery discharge, drink two or three glasses of water and lie down on your left side. This helps improve circulation to your uterus.
About half of women who go into premature labor do so for unknown reasons. Or, you may have a medical condition that contributes to early labor. These conditions may include:
- A rupture of your bag of waters (amniotic sac). Normally, these membranes that surround your baby rupture during labor or just before labor begins. But sometimes they may rupture weeks or even months before your due date, for no apparent reason. In that case, there's a high risk that your labor will begin within a few days. You and your baby are also at increased risk of infection.
- Certain infections. These include infections of your uterus, cervix or urinary tract.
- Weak cervix. A cervix that opens (dilates) without contractions (incompetent cervix). In a normal pregnancy, your cervix dilates in response to uterine contractions. But if your cervix is weak, it may open just from the pressure on your uterus caused by your progressing pregnancy. The cervix may have been weakened by a previous pregnancy or during a previous surgery involving the cervix, such as a dilation and curettage (D and C) or a biopsy. Other factors that may weaken your cervix include carrying more than one fetus or having too much amniotic fluid (hydramnios).
- Certain chronic diseases. These include high blood pressure, diabetes, kidney disease and hypothyroidism.
- Uterine abnormalities. These include an abnormally shaped uterus or a benign tumor (fibroid) of the uterus.
- A previous premature delivery. Women who have had a premature delivery are at higher risk of going into premature labor again. For many women, though, early labor happens only once.
- Substance abuse. These include smoking, alcohol use, or misuse of other drugs.
- Malnutrition. Women who are undernourished or anemic are more likely to give birth prematurely.
- Other conditions. A fetus with congenital defects or production of an overabundance of amniotic fluid also can contribute to early labor.
When to seek medical advice
Good prenatal care includes regular visits to your doctor throughout your pregnancy to check on both your health and your baby's health. If you're at risk of premature labor, being in weekly contact with your doctor or another member of his or her staff and carefully monitoring your own signs and symptoms can be especially helpful.
If you develop any signs or symptoms of early labor, such as bleeding with cramps and pain, a watery discharge from your vagina, or more than five or six contractions an hour, call your doctor or hospital right away. It's a good idea to keep these phone numbers handy so that you can find them quickly.
Screening and diagnosis
If your doctor suspects premature labor, he or she will check to see if your cervix has begun to dilate and whether the fetal membranes have ruptured. In some cases, a monitor may be used to measure the duration and spacing of your contractions. Monitoring the length of your cervix with ultrasound imaging may be done. In addition, sampling of the cervical canal for the presence of fetal fibronectin, a glue-like tissue lost with labor, also may help guide your treatment.
If it turns out that you're in premature labor, you and your doctor will need to decide whether to try to stop your labor. Considerations include your baby's well-being, as well as your own, along with the risks and benefits of each option.
Premature labor may create complications for you, for your baby or for both of you:
By itself, premature labor won't put you at any physical risk unless it's the result of another problem, such as a uterine infection. But all treatments used to delay delivery carry some risks.
Medications that halt uterine contractions often cause fluid to collect in the mother's lungs. This causes breathing difficulties and can pose a risk for both you and your baby. Other side effects depend on the medication used to stop labor. Some medications can lead to fatigue and muscle weakness. Others may cause a rapid heart beat, blood sugar abnormalities or stomach ulcers.
You and your doctor will need to consider your own risk if medications are used to stop labor, as well as the risks to your baby if he or she is born too soon.
If your baby is premature, how well he or she will thrive depends largely on the baby's gestational age at birth. Risks are greatest for the babies born most prematurely — those born between 23 and 26 weeks gestation.
About a third of these smallest survivors, who weigh less than 2 pounds at birth, will have serious medical problems such as cerebral palsy, fluid accumulation in the brain (hydrocephalus), seizures, lasting neurologic problems or developmental delays. Another third will have some less-serious chronic problems, such as mild cerebral palsy, the need to wear glasses and have ongoing eye care, or more mild developmental delays.
Other babies born at 23 to 25 weeks do very well at first and may show no signs of problems when they go home from the hospital. But as childhood progresses, many of these children display some difficulties related to their premature birth. In particular, they may not perform as well in school as other children their age.
Very premature babies are also at risk of other conditions:
- Bleeding in the brain (intracranial hemorrhage). If this occurs, it's usually in the first week to 10 days of life. The more severe the bleeding, the greater the likelihood that the child will develop serious problems, including developmental delays, seizures, learning disabilities and fluid accumulation in the brain.
- Retinal problems. Another complication seen in the youngest and most vulnerable premature babies is retinopathy of prematurity (ROP), an abnormal growth of blood vessels in the retina, the light-sensitive inner lining of the eye. ROP probably occurs because the vascular system in the baby's eye hasn't fully developed. Many cases of ROP disappear on their own, but sometimes the condition leads to scarring. The most serious cases may be treated with cryotherapy, a procedure in which an extremely cold instrument is used to help prevent the baby's retina from becoming detached. Sometimes lasers are used in a similar manner to treat ROP.
- Intestinal problems. Some preemies are also at risk of a potentially severe intestinal problem known as necrotizing enterocolitis (NEC). In the most serious cases, this condition can be life-threatening. Infants who have milder cases of NEC need to be fed intravenously and given antibiotics for 1 or 2 weeks.
- Sudden infant death syndrome (SIDS). Premature babies are at increased risk of SIDS, a mysterious condition that claims the lives of about 2,500 infants each year.
But not all preemies have medical or developmental problems. By 28 to 30 weeks, the risk of these complications is much lower. And for babies born between 32 and 35 weeks, most medical problems are short-term and may even have resolved by the time the baby comes home from the hospital.
Treatments related to premature birth may focus on women in preterm labor, on babies still in the womb, or on newborns in hospital neonatal (newborn) intensive care units (NICUs). These may include:
If you're experiencing preterm labor, your treatment depends on how far along you are in your pregnancy and how far your labor has progressed. Sometimes bed rest and extra fluids are enough to stop premature contractions. In other situations, your doctor may recommend certain medications. These may include some medications originally used for treating asthma, such as terbutaline (Brethaire, Brethine, Bricanyl) and ritodrine (Yutopar). These medications relax smooth muscles, including those of the uterus. Magnesium sulfate is a muscle relaxant that is given intravenously.
Medications that block the calcium channels in muscle cells can sometimes stop contractions. So can drugs that block the production of substances that stimulate uterine contractions (prostaglandins), such as ibuprofen (Advil, Motrin, others) or indomethacin (Indocin).
Medications often stop labor only for a brief period of time. They are best used to delay labor long enough to accomplish other goals, such as transferring the mother to a facility better equipped to handle premature delivery or allowing other medications to have a beneficial effect on the baby.
Although rare, preterm delivery may result from weakness of the connective tissue of the cervix with minimal pressure from uterine contractions. If this occurs, a surgical procedure known as cervical cerclage may be an option. Using strong thread, an obstetrician stitches around the cervix to close it. The thread is removed in the last month of pregnancy.
For babies in the womb
If your labor can't be stopped, you may receive medications to help prepare your baby for birth. Corticosteroids such as betamethasone can help make your baby's lungs more mature in as short a time as 24 to 48 hours.
Hospital NICUs are designed to provide care for premature babies and full-term babies who develop problems after birth. If your premature baby spends time in an NICU, he or she will receive round-the-clock intensive care from doctors, nurses and respiratory therapists specially trained to care for newborns with medical problems.
In an NICU, your baby will probably be kept in an incubator, an enclosed plastic bassinet that is kept warm so your baby can maintain normal body temperature. Because preemies have immature skin and very little body fat, they often need extra help to stay warm.
At first your baby will likely receive fluids and nutrients — known as total parenteral nutrition (TPN) — through an intravenous catheter, and later start milk feedings through a tube that has been passed through his or her nose. Like many premature infants, your baby may not yet have developed a sucking reflex or may be too weak to suck. When your baby is stronger, you'll likely be able to feed him or her by breast-feeding or with a bottle. The antibodies in breast milk are especially important for premature infants.
Sensors may be taped to your baby's body to monitor blood pressure, heart rate, breathing and temperature. Caregivers may also use ventilators to help your baby breathe. This high-tech equipment may seem overwhelming at first, but it's all designed to help your baby.
In a hospital neonatal (newborn) intensive care unit, babies are often first watched unclothed on a warmer bed. Later your baby will probably be kept in an incubator, an enclosed plastic bassinet.
As the parent, you play an important role in your baby's life, even though he or she is in the NICU. Your baby's caregivers will help you learn how to touch and eventually hold your baby in ways that are calming and not overstimulating. Talking or singing softly to your baby, or just providing quiet company, will give great support and comfort. When your baby is ready to eat on his or her own, the nurses will help you learn how to feed your child.
Babies are ready to go home when they no longer have medical problems that require continuous hospital care, when their body temperature is stable and when they can nurse well enough to gain weight. Your baby need not reach a specific weight or age before going home.
Before you take your baby home, your doctor will provide guidelines on how to care for him or her. Ask questions about any care issues or concerns.
Preemies are more susceptible than other newborns to serious infections, and their illnesses progress more quickly. That's why it's important that they be examined often. A follow-up visit will likely be scheduled soon after you take your baby home so that your doctor can examine the baby and answer any of your new or ongoing questions.
Some research suggests that hydroxyprogesterone caproate, a synthetic progestin hormone, may prevent premature labor in women at high risk. Although this treatment has been shown effective in preventing a recurrence of premature labor, more research is needed to confirm this approach before such treatment is widely accepted and used. The risks and complications of this treatment aren't known.
Previous experimentation with hormone treatment to prevent premature birth occurred with the use of diethylstilbestrol to prevent miscarriage. This treatment has proven ineffective, and caused reproductive problems in daughters of women who used it. These risks didn't become apparent until more than a decade after treatment was carried out.
Caring for a premature infant can be a great challenge. You'll face many challenges that don't exist for women who have delivered a full-term baby. Like many parents, you may have tremendous anxiety about your baby's health and the long-term effects of early birth. You may also feel angry, guilty or depressed.
All of these feelings are normal, and you'll likely find they change from day to day. Sometimes you may also experience the anxiety and sadness of postpartum depression — the result of sudden changes in your hormones after pregnancy. You may also find it hard to establish milk production if your baby is too small or too sick to breast-feed at first.
In addition, you may need more time to recover physically than you might think. This, combined with your desire to be at the hospital caring for your baby if he or she is in a neonatal intensive care unit, can lead to a great deal of fatigue.
Some of these suggestions may help during this difficult time:
- Learn everything you can about your baby's condition. In addition to talking to your doctor and your baby's caregivers, read books on premature birth and look for information on the Internet.
- Take care of yourself. Get as much rest as you can and eat a healthy diet. You'll feel stronger and better able to care for your baby.
- Seek good listeners for support. Talk to your partner or spouse, your friends, family or your baby's caregivers. If you're interested, your nursing staff or social worker may be able to suggest a support group in your area. Many parents find it particularly helpful to talk to other parents who are caring for a preemie.
- Accept help from others. Allow friends and family to help you. They can care for your other children, prepare food, clean the house or run errands. This helps you save your energy for your baby.
- Keep a journal. Record the details of your baby's progress as well as your own thoughts and feelings. Include pictures of your baby, so you can see how much he or she is changing. Photos will also help you feel close when your baby is still in the NICU.
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