Pregnancy and Birth Sourcebook Part 31

Preventing and Treating Rh Disease of the Newborn In generations past, Rh incompatibility was a very serious problem. Fortunately, significant medical advances have been made to help prevent complications from Rh incompatibility and to treat any newborn affected by Rh disease.

Today, when a woman with the potential to develop Rh incompatibility is pregnant, doctors administer a series of two Rh immune-globulin shots during her first pregnancy. The first shot is given around the 28th week of pregnancy and the second within 72 hours after giving birth. Rh immune-globulin acts like a vaccine, preventing the mother's body from producing any potentially dangerous Rh antibodies that can cause serious complications in the newborn or complicate any future pregnancies.

A dose of Rh immune-globulin may also be given if a woman has a miscarriage, an amniocentesis, or any bleeding during pregnancy.

If a doctor determines that a woman has already developed Rh antibodies, then the pregnancy will be closely monitored to make sure that those levels are not too high. In rare cases, if the incompatibility 400 Rh Incompatibility is severe and the baby is in danger, a series of special blood transfusions (called exchange transfusions) can be performed either while the baby is still in the uterus or after delivery.

Exchange transfusions replace the baby's blood with RBCs that are Rh-negative. This procedure stabilizes the baby's level of red blood cells and minimizes further damage caused by circulating Rh antibodies already present in the baby's bloodstream.

Because of the success rate of the Rh immune-globulin shots, exchange transfusions are needed in fewer than 1% of Rh-incompatible pregnancies in the United States today.

If Rh Disease Is Not Prevented Rh incompatibility rarely causes complications in a first pregnancy and does not affect the health of the mother. But Rh antibodies that develop during subsequent pregnancies can be potentially dangerous to mother and child. Rh disease can result in severe anemia, jaundice, brain damage, and heart failure in a newborn. In extreme cases, it can cause the death of the fetus because too many RBCs have been destroyed.

If you're not sure what your Rh factor is and think you're pregnant, it's important to start regular prenatal care as soon as possible- including blood-type testing. With early detection and treatment of Rh incompatibility, you can focus on more important things-like welcoming a new, healthy baby into your household.

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Chapter 50.

Umbilical Cord Abnormalities The umbilical cord is a narrow tube-like structure that connects the fetus (developing baby) to the placenta (afterbirth). The cord is sometimes called the baby's "supply line" because it carries the baby's blood back and forth, between the baby and the placenta. It delivers nutrients and oxygen to the baby and removes the baby's waste products.

The umbilical cord begins to form at five weeks after conception.

It becomes progressively longer until 28 weeks of pregnancy, reaching an average length of 22 to 24 inches.1 As the cord gets longer, it generally coils around itself. The cord contains three blood vessels: two arteries and one vein.

* The vein carries oxygen and nutrients from the placenta (which connects to the mother's blood supply) to the baby.

* The two arteries transport waste from the baby to the placenta (where waste is transferred to the mother's blood and disposed of by her kidneys).

A gelatin-like tissue called Wharton's jelly cus.h.i.+ons and protects these blood vessels.

A number of abnormalities can affect the umbilical cord. The cord may be too long or too short. It may connect improperly to the placenta "Umbilical Cord Abnormalities," 2008 March of Dimes Birth Defects Foundation. All rights reserved. For additional information, contact the March of Dimes at their website www.marchofdimes.com.

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Pregnancy and Birth Sourcebook, Third Edition or become knotted or compressed. Cord abnormalities can lead to problems during pregnancy or during labor and delivery.

In some cases, cord abnormalities are discovered before delivery during an ultrasound. However, they usually are not discovered until after delivery when the cord is examined directly. The following are the most frequent cord abnormalities and their possible effects on mother and baby.

What is single umbilical artery?

About 1 percent of singleton and about 5 percent of multiple pregnancies (twins, triplets, or more) have an umbilical cord that contains only two blood vessels, instead of the normal three. In these cases, one artery is missing.2 The cause of this abnormality, called single umbilical artery, is unknown.

Studies suggest that babies with single umbilical artery have an increased risk for birth defects, including heart, central nervous system and urinary-tract defects, and chromosomal abnormalities.2,3 A woman whose baby is diagnosed with single umbilical artery during a routine ultrasound may be offered certain prenatal tests to diagnose or rule out birth defects. These tests may include a detailed ultrasound, amniocentesis (to check for chromosomal abnormalities) and in some cases, echocardiography (a special type of ultrasound to evaluate the fetal heart). The provider also may recommend that the baby have an ultrasound after birth.

What is umbilical cord prolapse?

Umbilical cord prolapse occurs when the cord slips into the v.a.g.i.n.a after the membranes (bag of waters) have ruptured, before the baby descends into the birth ca.n.a.l. This complication affects about 1 in 300 births.1 The baby can put pressure on the cord as he pa.s.ses through the cervix and v.a.g.i.n.a during labor and delivery. Pressure on the cord reduces or cuts off blood flow from the placenta to the baby, decreasing the baby's oxygen supply. Umbilical cord prolapse can result in stillbirth unless the baby is delivered promptly, usually by cesarean section.

If the woman's membranes rupture and she feels something in her v.a.g.i.n.a, she should go to the hospital immediately or, in the United States, call 911. A health care provider may suspect umbilical cord prolapse if the fetus develops heart rate abnormalities after the membranes have ruptured. The provider can confirm a cord prolapse by doing a pelvic examination. Cord prolapse is an emergency. Pressure on the cord must be relieved immediately by lifting the presenting 404 Umbilical Cord Abnormalities fetal part away from the cord while preparing the woman for prompt cesarean delivery.

The risk of umbilical cord prolapse increases if: * the baby is in a breech (foot-first) position; * the woman is in preterm labor; * the umbilical cord is too long; * there is too much amniotic fluid; * the provider ruptures the membranes to start or speed up labor; * the woman is delivering twins v.a.g.i.n.ally. The second twin is more commonly affected.

What is vasa previa?

Vasa previa occurs when one or more blood vessels from the umbilical cord or placenta cross the cervix underneath the baby. The blood vessels, unprotected by the Wharton's jelly in the umbilical cord or the tissue in the placenta, sometimes tear when the cervix dilates or the membranes rupture. This can result in life-threatening bleeding in the baby. Even if the blood vessels do not tear, the baby may suffer from lack of oxygen due to pressure on the blood vessels. Vasa previa occurs in 1 in 2,500 births.4 When vasa previa is diagnosed unexpectedly at delivery, more than half of affected babies are stillborn.4 However, when vasa previa is diagnosed by ultrasound earlier in pregnancy, fetal deaths generally can be prevented by delivering the baby by cesarean section at about 35 weeks of gestation.4 Pregnant women with vasa previa sometimes have painless v.a.g.i.n.al bleeding in the second or third trimester. A pregnant woman who experiences v.a.g.i.n.al bleeding should always report it to her health care provider so that the cause can be determined and any necessary steps taken to protect the baby.

A pregnant woman may be at increased risk for vasa previa if she: * has a velamentous insertion of the cord (the umbilical cord inserts abnormally into the fetal membranes, instead of the center of the placenta); * has placenta previa (a low-lying placenta that covers part or all of the cervix) or certain other placental abnormalities; * is expecting more than one baby.

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Pregnancy and Birth Sourcebook, Third Edition What is a nuchal cord?

About 25 percent of babies are born with a nuchal cord (the umbilical cord wrapped around the baby's neck).1 A nuchal cord, also called nuchal loops, rarely causes any problems. Babies with a nuchal cord are generally healthy.

Sometimes fetal monitoring shows heart rate abnormalities during labor and delivery in babies with a nuchal cord. This may reflect pressure on the cord. However, the pressure is rarely serious enough to cause death or any lasting problems, although occasionally a cesarean delivery may be needed.

Less frequently, the umbilical cord becomes wrapped around other parts of the baby's body, such as a foot or hand. Generally, this doesn't harm the baby.

What are umbilical cord knots?

About 1 percent of babies are born with one or more knots in the umbilical cord.1 Some knots form during delivery when a baby with a nuchal cord is pulled through the loop. Others form during pregnancy when the baby moves around. Knots occur most often when the umbilical cord is too long and in identical-twin pregnancies. Identical twins share a single amniotic sac, and the babies' cords can become entangled.

As long as the knot remains loose, it generally does not harm the baby. However, sometimes the knot or knots can be pulled tight, cutting off the baby's oxygen supply. Cord knots result in miscarriage or stillbirth in 5 percent of cases.1 During labor and delivery, a tightening knot can cause the baby to have heart rate abnormalities that are detected by fetal monitoring. In some cases, a cesarean delivery may be necessary.

What is an umbilical cord cyst?

Umbilical cord cysts are outpockets in the cord. They are found in about 3 percent of pregnancies.2 There are true and false cysts: * True cysts are lined with cells and generally contain remnants of early embryonic structures.

* False cysts are fluid-filled sacs that can be related to a swelling of the Wharton's jelly.

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Umbilical Cord Abnormalities Studies suggest that both types of cysts are sometimes a.s.sociated with birth defects, including chromosomal abnormalities and kidney and abdominal defects.2 When a cord cyst is found during an ultrasound, the provider may recommend additional tests, such as amniocentesis and a detailed ultrasound, to diagnose or rule out birth defects.

Does the March of Dimes support research on umbilical cord abnormalities?

The March of Dimes continues to support research aimed at preventing umbilical cord abnormalities and the complications they cause. One grantee is studying the development of blood vessels in the umbilical cord for insight into the causes of single umbilical artery and other cord abnormalities. The goals of this study are to: * develop a better understanding of the causes of birth defects; * develop treatments to help prevent oxygen deprivation before and during delivery, which may contribute to cerebral palsy and other forms of brain damage.

References Cruikshank, D.W. Breech, Other Malpresentations, and Umbilical Cord Complications, in: Scott, J.R., et al. (eds.), Danforth's Obstetrics and Gynecology, Danforth's Obstetrics and Gynecology, 9th Edition. Philadelphia, Lippincott Williams and Wilkins, 2003, pages 381395. 9th Edition. Philadelphia, Lippincott Williams and Wilkins, 2003, pages 381395.

Morgan, B.L.G. and Ross, M.G. Umbilical Cord Complications.

emedicine.com, March 1, 2006.

Gossett, D.R., et al. Antenatal Diagnosis of Single Umbilical Artery: Is Fetal Echocardiography Warranted? Obstetrics and Obstetrics and Gynecology, Gynecology, volume 100, number 5, November 2002, pages 903908. volume 100, number 5, November 2002, pages 903908.

Oyelese, Y. and Smulian, J.C. Placenta Previa, Placenta Accreta, and Vasa Previa. Obstetrics and Gynecology, Obstetrics and Gynecology, volume 107, number 4, April 2006, pages 927941. volume 107, number 4, April 2006, pages 927941.

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Chapter 51.

Overview of s.e.xually Transmitted Diseases (STDs) during Pregnancy Can pregnant women become infected with STDs?

Yes, women who are pregnant can become infected with the same s.e.xually transmitted diseases (STDs) as women who are not pregnant.

Pregnancy does not provide women or their babies any protection against STDs. The consequences of an STD can be significantly more serious, even life threatening, for a woman and her baby if the woman becomes infected with an STD while pregnant. It is important that women be aware of the harmful effects of STDs and know how to protect themselves and their children against infection.

How common are STDs in pregnant women in the United States?

Some STDs, such as genital herpes and bacterial vaginosis, are quite common in pregnant women in the United States. Other STDs, notably HIV [human immunodeficiency virus] and syphilis, are much less common in pregnant women. Table 51.1 shows the estimated number of pregnant women in the United States who are infected with specific STDs each year.

From "STDs & Pregnancy," by the Centers for Disease Control and Prevention (CDC, www.cdc.gov), January 4, 2008.

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Pregnancy and Birth Sourcebook, Third Edition Table 51.1. Pregnant Women Infected with STDs Each Year Pregnant Women Infected with STDs Each Year STDs STDs Estimated Number of Pregnant Women Bacterial vaginosis 1,080,000.

Herpes simplex virus 2 880,000.

Chlamydia 100,000.

Trich.o.m.oniasis 124,000.

Gonorrhea 13,200.

Hepat.i.tis B 16,000.

HIV.

6,400.

Syphilis <>

How do STDs affect a pregnant woman and her baby?

STDs can have many of the same consequences for pregnant women as women who are not pregnant. STDs can cause cervical and other cancers, chronic hepat.i.tis, pelvic inflammatory disease, infertility, and other complications. Many STDs in women are silent; that is, without signs or symptoms.

STDs can be pa.s.sed from a pregnant woman to the baby before, during, or after the baby's birth. Some STDs (like syphilis) cross the placenta and infect the baby while it is in the uterus (womb). Other STDs (like gonorrhea, chlamydia, hepat.i.tis B, and genital herpes) can be transmitted from the mother to the baby during delivery as the baby pa.s.ses through the birth ca.n.a.l. HIV can cross the placenta during pregnancy, infect the baby during the birth process, and unlike most other STDs, can infect the baby through breastfeeding.

A pregnant woman with an STD may also have early onset of labor, premature rupture of the membranes surrounding the baby in the uterus, and uterine infection after delivery.

The harmful effects of STDs in babies may include stillbirth (a baby that is born dead), low birth weight (less than five pounds), conjunctivitis (eye infection), pneumonia, neonatal sepsis (infection in the baby's blood stream), neurologic damage, blindness, deafness, acute hepat.i.tis, meningitis, chronic liver disease, and cirrhosis. Most of these problems can be prevented if the mother receives routine prenatal care, which includes screening tests for STDs starting early in pregnancy and repeated close to delivery, if necessary. Other problems can be treated if the infection is found at birth.

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Overview of s.e.xually Transmitted Diseases during Pregnancy Should pregnant women be tested for STDs?

Yes, STDs affect women of every socioeconomic and educational level, age, race, ethnicity, and religion. The CDC 2006 Guidelines for Treatment of s.e.xually Transmitted Diseases recommend that pregnant women be screened on their first prenatal visit for STDs which may include the following: * Chlamydia * Gonorrhea * Hepat.i.tis B * HIV * Syphilis In addition, some experts recommend that women who have had a premature delivery in the past be screened and treated for bacterial vaginosis at the first prenatal visit.

Pregnant women should ask their doctors about getting tested for these STDs, since some doctors do not routinely perform these tests.

New and increasingly accurate tests continue to become available.

Even if a woman has been tested in the past, she should be tested again when she becomes pregnant.

Can STDs be treated during pregnancy?

Chlamydia, gonorrhea, syphilis, trich.o.m.oniasis, and bacterial vaginosis (BV) can be treated and cured with antibiotics during pregnancy. There is no cure for viral STDs, such as genital herpes and HIV, but antiviral medication may be appropriate for pregnant women with herpes and definitely is for those with HIV. For women who have active genital herpes lesions at the time of delivery, a cesarean delivery (C-section) may be performed to protect the newborn against infection.

C-section is also an option for some HIV-infected women. Women who test negative for hepat.i.tis B, may receive the hepat.i.tis B vaccine during pregnancy.

How can pregnant women protect themselves against in- fection?

The surest way to avoid transmission of s.e.xually transmitted diseases is to abstain from s.e.xual contact, or to be in a long-term 411 Pregnancy and Birth Sourcebook, Third Edition mutually monogamous relations.h.i.+p with a partner who has been tested and is known to be uninfected.

Latex condoms, when used consistently and correctly, are highly effective in preventing transmission of HIV, the virus that causes AIDS.

Latex condoms, when used consistently and correctly, can reduce the risk of transmission of gonorrhea, chlamydia, and trich.o.m.oniasis.

Correct and consistent use of latex condoms can reduce the risk of genital herpes, syphilis, and chancroid only when the infected area or site of potential exposure is protected by the condom. Correct and consistent use of latex condoms may reduce the risk for genital human papillomavirus (HPV) and a.s.sociated diseases (e.g., warts and cervical cancer).

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Chapter 52.

Hepat.i.tis B and Pregnancy Chapter Contents.Section 52.1-What Is Hepat.i.tis? .............................................. 414 Section 52.2-Frequently Asked Questions about Pregnancy and Hepat.i.tis B ................................. 416 413.

Pregnancy and Birth Sourcebook, Third Edition Section 52.1 What Is Hepat.i.tis?

From "Viral Hepat.i.tis," by the Centers for Disease Control and Prevention (CDC, www.cdc.gov), July 22, 2008.

Hepat.i.tis A Hepat.i.tis A is an acute liver disease caused by the hepat.i.tis A virus (HAV), lasting from a few weeks to several months. It does not lead to chronic infection.

* Transmission: Transmission: Ingestion of fecal matter, even in microscopic amounts, from close person-to-person contact or ingestion of contaminated food or drinks. Ingestion of fecal matter, even in microscopic amounts, from close person-to-person contact or ingestion of contaminated food or drinks.