Preterm and Postterm Labor and Birth The NICHD is currently conducting and sponsoring a number of clinical trials involving infants born prematurely. The Inst.i.tute"s Neonatal Research Network, established in 1986, strives to improve the care of and outcomes for infants, especially LBW and VLBW infants.
The Neonatal Research Network follows thousands of infants, through its 16 clinical centers throughout the country, to conduct clinical trials and observational studies for preventing and treating problems related to pregnancy, premature birth, and the newborn period. The Inst.i.tute"s Maternal-Fetal Medicine Unit Network also conducts clinical trials on these topics. Among the trials currently underway are: the BEAM (Beneficial Effects of Antenatal Magnesium Sulfate) trial, to try and prevent cerebral palsy; and the FOX (Fetal pulse OXimetry) trial, to learn more about the effects of cesarean delivery.
Section 56.3 Common Treatment to Delay Labor Decreases Preterm Infants" Risk for Cerebral Palsy From the National Inst.i.tutes of Health (NIH, www.nih.gov), August 27, 2008.
Preterm infants born to mothers receiving intravenous magnesium sulfate-a common treatment to delay labor-are less likely to develop cerebral palsy than are preterm infants whose mothers do not receive it, report researchers in a large National Inst.i.tutes of Health research network.
The study results appear in the August 28, 2008 New England New England Journal of Medicine Journal of Medicine.
"A third of all cases of cerebral palsy are a.s.sociated with preterm birth," said National Inst.i.tutes of Health (NIH) Director Elias A.
Zerhouni, MD. "This study shows a significant reduction in cerebral palsy among preterm infants whose mothers were given magnesium sulfate."
The researchers theorized that magnesium sulfate protects against cerebral palsy because it can stabilize blood vessels, protect against 453 Pregnancy and Birth Sourcebook, Third Edition damage from oxygen depletion, and protects against injury from swelling and inflammation.
Cerebral palsy refers to a group of neurological disorders affecting control of movement and posture and which limit activity. The brain may be injured or develop abnormally during pregnancy, birth, or in early childhood. The causes of cerebral palsy are not well understood.
The research was conducted by investigators in 20 partic.i.p.ating research centers of the Maternal Fetal Medicine Units Network of NIH"s Eunice Kennedy Shriver National Inst.i.tute of Child Health and Human Development (NICHD). The study"s first author was Dwight J. Rouse, MD, of the University of Alabama at Birmingham. Major funding was provided by NIH"s National Inst.i.tute of Neurological Disorders and Stroke (NINDS).
A 1995 study by NINDS researcher Karin Nelson, MD, and a researcher at the California Department of Health Services found that mothers of preterm infants who did not have cerebral palsy were more likely to have received magnesium sulfate than were mothers of infants who had cerebral palsy. Two larger randomized studies that subsequently were undertaken suggested that magnesium sulfate given to pregnant women delivering prematurely might protect their infants against cerebral palsy, but their results were inconclusive.
"Our study is the largest, most comprehensive effort to date that looked at using this inexpensive and commonly used treatment to reduce the occurrence of cerebral palsy after preterm birth," said Deborah Hirtz, MD, a pediatric neurologist at NINDS, and an author of the study. "Cerebral palsy can"t always be prevented, but the data from our study and its predecessors will help obstetricians make informed treatment decisions for the women under their care."
Women at the 20 partic.i.p.ating NICHD Maternal Fetal Medicine Unit Network sites were eligible to partic.i.p.ate. The women were from 24 to 31 weeks pregnant and at risk for preterm delivery. When the women went into labor, they were a.s.signed at random to receive intravenously a solution of either magnesium sulfate or a placebo. The women in the treatment group were given 6 grams of magnesium sulfate intravenously over 20 to 30 minutes, followed by 2 grams of magnesium sulfate every hour after that until either 12 hours had pa.s.sed, labor had subsided, or they had given birth. If the women in either group did not deliver within 12 hours, they were treated again if they went into labor by the 34th week of pregnancy.
For purposes of their statistical a.n.a.lysis, the researchers calculated the rates of moderate cerebral palsy, severe cerebral palsy, and death 454 Preterm and Postterm Labor and Birth among the infants in the study. The study authors did not include mild cerebral palsy in this calculation, as mild cerebral palsy will often disappear with time.
When the researchers considered only moderate and severe cerebral palsy together, cerebral palsy occurred less frequently in the magnesium sulfate group (1.9 percent) as compared to the placebo group (3.5 percent).
For their primary calculation, the researchers grouped the propor-tions of infants with moderate and severe cerebral palsy together with the proportion of infants who died. The researchers included the death rate in this primary calculation, because mortality among preterm infants is very high. The researchers found that a total of 11.3 percent of infants in the magnesium sulfate group had either moderate or severe cerebral palsy, or had died at birth or were stillborn. In contrast, a total of 11.7 percent of the infants in the placebo group had moderate to severe cerebral palsy or had died.
The proportion of deaths occurring in the magnesium sulfate group (9.5 percent) did not differ significantly from those in the placebo group (8.5 percent).
There was no difference in the average gestational age between the two groups of infants.
Cerebral palsy was diagnosed in 41 children from 942 magnesium sulfate-treated pregnancies, as compared to 74 children from 1,002 placebo-treated pregnancies. Of the children in the magnesium sulfate group, 2.2 percent had cerebral palsy cla.s.sified as mild, 1.5 percent as moderate, and 0.5 percent as severe. A higher proportion of children in the placebo group than in the magnesium sulfate group had cerebral palsy. Of the children in the placebo group, 3.7 percent had mild cases of cerebral palsy, 2.0 percent had moderate cases, and 1.6 percent had severe cases.
"This is a major advance," said Catherine Y. Spong, MD, Chief of NICHD"s Pregnancy and Perinatology Branch and an author of the study. "Our results show that obstetricians can use magnesium sulfate, which they have experience prescribing, to reduce the risk of a devastating condition, cerebral palsy, in preterm infants.
455.
Pregnancy and Birth Sourcebook, Third Edition Section 56.4 Overdue Pregnancy Reprinted with permission from "Pregnancy: What to Expect When You"re Past Your Due Date," April 2008, home/women/pregnancy/labor/143.html. Copyright 2008 American Academy of Family Physicians. All rights reserved.
When is a pregnancy considered overdue?
A pregnancy is usually completed in 38 to 42 weeks. "Post-term pregnancy," "prolonged pregnancy," and "post-date pregnancy" are all words used to describe a pregnancy that lasts beyond 42 weeks. About 5% of pregnancies are post-term.
How is my due date determined?
Your due date is estimated on the basis of the first day of your last period and on the size of your uterus (womb) early in your pregnancy.
An ultrasound (also called a sonogram) may also give your doctor information about how far along your pregnancy is.
A reliable way to know your due date is to count 40 weeks ahead from the first day of your last period. However, many women cannot remember the first day of their last period and are not exactly sure when they got pregnant. In addition, it"s usually hard to figure an accurate due date if you get pregnant soon after you stop taking birth control pills.
An early pelvic exam to measure the size of the uterus can be helpful. If you"re not sure about the date of your last period or your uterus is smaller or larger than expected, an early ultrasound exam is helpful.
What if my pregnancy goes one week past the due date?
If your pregnancy lasts one week or more past your expected due date, your doctor will usually begin checking your baby more closely.
Your doctor may check your baby"s heartbeat by using an electronic fetal monitor once or twice a week. In addition, an ultrasound exam 456 Preterm and Postterm Labor and Birth might be done to look at the amniotic fluid around your baby. Ultrasound can also be used to see how much your baby is moving. You should continue to feel your baby move throughout your pregnancy.
Decreased fetal movement may be a sign that you need to call your doctor.
In addition, your doctor may begin checking your cervix to see if it"s dilated and thinned. Your doctor may also recommend inducing (starting) labor.
What if my pregnancy goes two weeks past the due date?
Many doctors induce labor if a woman is two weeks past her due date. This is done to avoid complications, such as fetal distress or a baby that grows too large to deliver easily. Fetal distress occurs when the baby doesn"t get enough oxygen. Then the baby"s heart rate drops, and the baby can"t tolerate the stress of labor.
How will my doctor induce labor?
Labor can be induced in some women by using a medicine called oxytocin (brand name: Pitocin), which causes contractions to start.
Oxytocin is given through your veins. It usually starts to work in one to two hours.
Labor can also be induced in some women by "breaking the water," or rupturing the membrane that holds the amniotic fluid. This is not painful, but you may feel the fluid leak out when the membrane is broken.
457.
Part Six
Labor and Delivery
Chapter 57.
All about Labor and Delivery Prepare for Labor and Birth Once you reach the third trimester, you should talk to your doctor or midwife about labor and delivery. Learn your options for pain relief. Find out how to reach her if you go into labor. And ask her at what point in labor should you call.
Before you reach the last few weeks of pregnancy, you and your partner should visit the hospital or birthing center. Make sure you know how to get there, where to park, and where to check-in. Find out if you can preregister so that your insurance information is already in the computer when you arrive.
Signs of Labor Many women, especially with their first babies, think they are in labor when they"re not. This is called false labor. So don"t feel embarra.s.sed if you go to the hospital thinking you"re in labor, only to be sent home.
If you think labor has begun, you should call your doctor or midwife. They can decide if it"s time to go to the hospital or if you should be seen at the office first. Learn the signs of labor so you will know when the time has come.
From "Labor and Birth," by the Office of Women"s Health (www.womenshealth .gov), part of the U.S. Department of Health and Human Services, March 2007.
461.
Pregnancy and Birth Sourcebook, Third Edition Call your doctor if you experience any of the following: * You have contractions that come at regular and increasingly shorter intervals. Contractions should also become stronger over time.
* You have lower back pain that doesn"t go away. You might also feel premenstrual and crampy.
* Your water breaks (can be a large gush or a continuous trickle).
* You have a b.l.o.o.d.y (brownish or red-tinged) mucous discharge.
This is probably the mucous plug that blocks the cervix. Losing your mucous plug usually means your cervix is dilating (opening up) and becoming thinner and softer (effacing). Labor could start right away or may still be days away.
Choosing Where to Deliver Many women carefully choose the kind of environment in which to deliver their babies. You will need to contact your health insurance to find out what options are available. Not all companies will cover care given at a birth center and fewer will cover planned homebirths.
In general, women can choose to deliver at a hospital, birth center, or at home. Nowadays, most hospitals and birth centers offer birthing cla.s.ses like Lamaze and breastfeeding support.
Hospital Women with health problems, pregnancy complications, or those who are at risk for problems during labor and delivery should give birth in a hospital. Hospitals offer the most advanced medical equipment and highly trained doctors for pregnant women and their babies. In a hospital, doctors can do a cesarean section if you or your baby is in danger during labor. Women can get epidurals or many other pain relief options.
Only certain doctors and midwives have admitting privileges at each hospital. So before you choose your doctor or midwife learn about their affiliated hospital. When choosing a hospital you might consider: * Is it close to your home?
* Is an anesthesiologist at the hospital 24 hours a day?
* Do you like the feel of the labor and delivery rooms?
* Are private rooms available?
462.
All about Labor and Delivery * How many support people can you invite into the room with you?
* Does it have a neonatal intensive care unit (NICU) in case of serious problems with the baby?
* Can the baby stay in the room with you?
* Does it have an on-site birth center?
More and more hospitals are adding on-site birth centers. At these hospitals you can choose to deliver your baby in the comfortable, intimate setting of a birth center. If something goes wrong, you and your baby have the added security of already being in a hospital.
Birth Centers Healthy women who are at low risk for problems during pregnancy, labor, and delivery may choose to deliver at a birth or birthing center. Birth centers give women a "homey" environment in which to labor and give birth. They try to make labor and delivery a special, warm, family-focused process. Usually certified nurse-midwives, not obstetricians, deliver babies at birth centers.
Birth centers do not do any "routine" medical procedures. So, you will not automatically be hooked up to an intravenous (IV) line. Likewise, you won"t have an electronic fetal monitor around your belly the whole time. Instead, the midwife or nurse will check in on your baby from time to time with a handheld machine. Once the baby is born, all examinations and care will occur in your room. By doing away with most high-tech equipment and routine procedures, labor and birth remain a natural and personal process.
Women cannot receive epidurals at a birth center although some pain medicines may be available. If a cesarean section becomes necessary, women must be moved to a hospital for the procedure. Basic emergency care can be done on babies with problems while they are moved to a hospital.
Many birthing centers have showers or tubs in their rooms for laboring women. They also tend to have comforts of home like large beds and rocking chairs. In general, birth centers allow more people in the delivery room than do hospitals.
Birth centers can be inside of hospitals, affiliated with a hospital, or completely independent, separate facilities. If you are interested in delivering at a birth center, make sure it is accredited by the Commission for the Accreditation of Birth Centers. Accredited birth centers 463 Pregnancy and Birth Sourcebook, Third Edition must have affiliated doctors at a nearby hospital in case of problems with the mom or baby.
Homebirth Healthy pregnant women with no risk factors for complications during pregnancy, labor or delivery can consider a planned homebirth.
Some certified nurse midwives and physicians will deliver babies at home. If you are considering this choice you should ask your insurance company about their policy on homebirths. Some health insurance companies cover the cost of care for home births and others don"t.
Homebirths are common in many countries in Europe. But in the United States, planned homebirths are still a controversial issue. The American College of Obstetricians and Gynecologists (ACOG) is against homebirths. ACOG states that hospitals are the safest place to deliver a baby. In case of an emergency, says ACOG, a hospital"s equipment and highly trained physicians can provide the best care for a woman and her baby.
If you are considering a homebirth, you need to weigh the pros and cons. The main advantage is that you will be able to experience labor and delivery in the privacy and comfort of your own home. Since there will be no routine medical procedures, you will have control of your experience.
The main disadvantage of a homebirth is that in case of a problem, you and the baby will not have immediate hospital/medical care.
It will have to wait until you are transferred to the hospital. Plus, women who deliver at home have no options for pain relief.
To ensure your safety and that of your baby, you must have a highly trained and experienced midwife along with a fail-safe back-up plan.
You will need fast, reliable transportation to a hospital. If you live far away from a hospital, homebirth may not be the best choice. Your midwife must be experienced and have the necessary skills and supplies to start emergency care for you and your baby if need be. Your midwife should also have access to a physician 24 hours a day.
Managing the Pain Virtually all women worry about how they will cope with the pain of labor and delivery. Childbirth is different for everyone. So no one can predict how you will feel. The amount of pain a woman feels during labor depends partly on the size and position of her baby, the size of her pelvis, her emotions, and the strength of the contractions.
464.
All about Labor and Delivery Natural Pain Relief Many women choose to deliver their babies without using medicine for pain relief. Some of these women use other techniques to help them cope. Things women do to ease the pain include: * use breathing and relaxation techniques; * take warm showers or baths; * receive ma.s.sages; * have the supportive care or a loved one, nurse, or doula; * find comfortable positions while in labor (stand, crouch, sit, walk, etc.); * use a labor ball; or * listen to music.
Building a positive outlook on childbirth and managing fear may also help some women cope with the pain. It is important to realize that labor pain is not like pain due to illness or injury. Instead, it is caused by contractions of the uterus that are pushing your baby down and out of the birth ca.n.a.l. In other words, labor pain has a purpose.
Try the following to help you feel positive about childbirth: * Take a childbirth cla.s.s. Call the doctor, midwife, hospital, or birthing center for cla.s.s information.
* Get information from your doctor or midwife. Write down your questions and talk about them at your regular visits.
* Share your fears and emotions with friends, family, and your partner.
Waterbirthing More and more women in the United States are using water to find comfort during labor and delivery. In waterbirthing, laboring women get into a tub of water that is between 90 and 100 degrees. Some women get out of the tub to give birth. Others remain in the water for delivery.
The water helps women feel physically supported. It also keeps them warm and relaxed. This eases the pain of labor and delivery for many women. Plus, it is easier for laboring women to move and find comfortable positions in the water.
465.
Pregnancy and Birth Sourcebook, Third Edition Waterbirthing is relatively new in this country. So there is very little research on its benefits. Even so, some women say giving birth in the water is faster and easier. Plus, women may tear less severely and need fewer episiotomies in the water.
Waterbirthing may be gentler for your baby, too. It may ease the baby"s transition from the womb to the new world. The baby is born into an environment that is similar to the womb. Plus, the water dulls the lights, sound, and feel of the new world. Once the baby is born, it is brought to the surface of the water and wrapped in blankets.
Ask your doctor or midwife if you are a good candidate for waterbirthing. Water birth is not safe for women or babies who have health issues.
Medical Pain Relief While you"re in labor, your doctor, midwife, or nurse should ask if you need pain relief. It is her job to help you decide what option is the best for you. There are many different kinds of pain relief. Not all options are available at every hospital and birthing center. Plus your health history, allergies, and any problems with your pregnancy will make some options better than others.
Types of pain relief used for labor and delivery include the following.