1. Section 19.1 Development Before Birth Slide 1 of 21 Objectives Summarize the events that occur during the first week after fertilization. Describe the structures that protect and nourish the embryo and fetus. Section 19.1 Development Before Birth

2. Section 19.1 Development Before Birth Slide 2 of 21 In a paragraph, describe the factors that a married couple should consider before they have children. Quick Quiz Which of the following statements made by a married couple do you think are good reasons for having a baby? Choose one or more. “It’s now or never. We’re almost 40.” “We have lots of love to give a child.” “If we have one more, maybe it will be a girl.” “Our marriage will improve if we have a baby.” “With our new jobs, we’ve finally saved enough money to start a family.” Switch to QuickTake version of the quiz.

3. Section 19.1 Development Before Birth Slide 3 of 21 Once a couple has decided to start a family, they may try to conceive, or get pregnant. The Beginning of the Life Cycle In a fertile woman’s body, about once a month an egg enters one of the fallopian tubes and begins its journey to the uterus. If the egg is on its way to the uterus, a sperm may fertilize it. This moment of fertilization is also called conception.

4. Section 19.1 Development Before Birth Slide 4 of 21 The Beginning of the Life Cycle Only a few hundred sperm of the hundreds of millions that enter the vagina usually make it to the egg, and only one can fertilize it. Fertilization In the first week after fertilization, the fertilized egg undergoes many cell divisions and travels to the uterus.

5. Section 19.1 Development Before Birth Slide 5 of 21 The united egg and sperm is called a zygote (ZY goht). The Zygote Within 36 hours, while the zygote is still traveling through the fallopian tube, it begins to divide. The Beginning of the Life Cycle

6. Section 19.1 Development Before Birth Slide 6 of 21 The original cell divides to make two cells. Cell Division The two-celled embryo divides into four cells, and so on, until the embryo is made up of dozens of cells. The Beginning of the Life Cycle

7. Section 19.1 Development Before Birth Slide 7 of 21 From the two-cell stage until about nine weeks after fertilization, the growing structure is called an embryo (EM bree oh). The Blastocyst About five days after fertilization, the structure, called a blastocyst (BLAS tuh sist), is no longer a solid mass of cells, but a sphere of cells surrounding a hollow center. The Beginning of the Life Cycle

8. Section 19.1 Development Before Birth Slide 8 of 21 Once the blastocyst forms, it begins to attach itself to the wall of the uterus. Implantation The process of attachment is called implantation. The Beginning of the Life Cycle

9. Section 19.1 Development Before Birth Slide 9 of 21 Uterus Implantation Zygote Blastocyst Fallopian tube Cell division Fertilization Ovary

10. Section 19.1 Development Before Birth Slide 10 of 21 Wall of uterus Amniotic fluid Cervix Vagina Placenta This structure lines part of the wall of the uterus during pregnancy and nourishes the embryo with substances from the mother’s blood. Amniotic sac The amniotic fluid contained in this sac cushions the embryo from shock and helps keep the embryo’s temperature constant. Umbilical cord An umbilical cord carries nutrients and oxygen from the placenta to the embryo, and carries wastes away.

11. Section 19.1 Development Before Birth Slide 11 of 21 While the embryo grows, several other structures also develop. Development in the Uterus These structures—the amniotic sac, placenta, and umbilical cord—protect and nourish the developing embryo, and later the fetus.

12. Section 19.1 Development Before Birth Slide 12 of 21 Soon after implantation, a fluid-filled bag of thin tissue called the amniotic sac (am nee AHT ik) develops around the embryo. Amniotic Sac Inside the sac, the embryo floats in amniotic fluid.

13. Section 19.1 Development Before Birth Slide 13 of 21 The attachment holding the embryo to the wall of the uterus develops into a structure called the placenta. Placenta Within the placenta, oxygen and nutrients move from the mother’s blood into tiny blood vessels that lead to the embryo.

14. Section 19.1 Development Before Birth Slide 14 of 21 About 25 days after fertilization, a cordlike structure called the umbilical cord (UM BIL ih kul) develops between the embryo and the placenta. Umbilical Cord Blood vessels in the umbilical cord carry nutrients and oxygen from the placenta to the embryo and wastes from the embryo to the placenta.

15. Section 19.1 Development Before Birth Slide 15 of 21 During the first two months of development, the major body systems and organs start to form in the embryo. The Growing Embryo By the end of eight weeks, the embryo is about an inch long and has recognizable external features.

16. Section 19.1 Development Before Birth Slide 16 of 21 From the third month until birth, the developing human is called a fetus. The Fetus During the third to sixth month, the fetus begins to move and kick. By the end of the ninth month, the fetus is ready to be born.

17. Section 19.1 Development Before Birth Slide 17 of 21

18. Section 19.1 Development Before Birth Slide 18 of 21 Click above to go online. For: More on development before birth

19. Section 19.1 Development Before Birth Slide 19 of 21 Vocabulary zygoteThe united egg and sperm. embryoThe stage of human development from the two- cell stage until about nine weeks after fertilization. blastocystA hollow, spherical structure made up of about 50-100 cells, formed when a zygote divides and grows. implantationThe process in which the blastocyst attaches itself to the wall of the uterus. amniotic sacA fluid-filled bag of thin tissue that develops around the embryo.

20. Section 19.1 Development Before Birth Slide 20 of 21 Vocabulary umbilical cordThe cordlike structure that connects the embryo and the placenta. fetusThe stage of human development from the third month after fertilization until birth. placentaThe structure that holds the embryo to the wall of the uterus.

21. Section 19.1 Development Before Birth Slide 21 of 17 Objectives Identify four behaviors that are essential for a healthy pregnancy. Explain the importance of prenatal care throughout pregnancy. Section 19.2 A Healthy Pregnancy

22. Section 19.1 Development Before Birth Slide 22 of 17 Myth A pregnant woman doesn’t need to visit the doctor until she begins to show, or look pregnant. Fact Regular doctor visits from before conception until the birth of a baby are necessary to ensure health. List some other do’s and don’ts for pregnant women. Review and update your list when you complete this section.

23. Section 19.1 Development Before Birth Slide 23 of 17 Getting proper nutrition and exercise and avoiding drugs and environmental hazards are especially important both before and throughout pregnancy. Staying Healthy During Pregnancy

24. Section 19.1 Development Before Birth Slide 24 of 17 A pregnant woman needs to eat more calories to support the growth of her own body and the developing embryo or fetus. Proper Nutrition The best way to obtain these extra calories is to eat a well-balanced diet. Folic acid is essential for proper development of an embryo’s neural tube, which later develops into the spinal cord and brain.

25. Section 19.1 Development Before Birth Slide 25 of 17 Regular physical activity is important for a healthy pregnancy. Exercise A fit woman will better meet the extra energy demands of carrying the fetus. She also reduces her risk for diabetes and other health problems during pregnancy.

26. Section 19.1 Development Before Birth Slide 26 of 17 As soon as she plans to become pregnant, a woman should abstain from all alcohol, tobacco, and any other drugs not prescribed or approved by her doctor. These substance, even in small amounts can Avoiding Alcohol and Other Drugs harm or kill the developing baby decrease the newborns chance to live cause lifelong problems A pregnant woman should talk to her doctor before using any prescription drugs or over-the-counter drugs.

27. Section 19.1 Development Before Birth Slide 27 of 17

28. Section 19.1 Development Before Birth Slide 28 of 17 X-rays The radiation from X-rays can harm a developing embryo or fetus. Avoiding Environmental Hazards Lead If a pregnant woman lives in a home built before 1978, she should contact her state health department for information on getting her home tested for lead. Mercury Pregnant women should eat commercially caught fish only once a week, and should not eat swordfish or shark. Cat litter Cat feces can contain a parasite that is especially dangerous to a developing fetus.

29. Section 19.1 Development Before Birth Slide 29 of 17 Besides taking care of herself at home, a woman also needs to plan for prenatal care, or medical care during her pregnancy. Prenatal Care Her doctor visits should be under the supervision of an obstetrician, a doctor specialized in pregnancy and childbirth. The chances of having a healthy baby greatly increase if the mother visits her doctor or clinic for regular checkups throughout pregnancy.

30. Section 19.1 Development Before Birth Slide 30 of 17 A pregnancy is divided into three periods of time— trimesters—each of which is approximately three months long. The Three Trimesters

31. Section 19.1 Development Before Birth Slide 31 of 17

32. Section 19.1 Development Before Birth Slide 32 of 17 Ultrasound High-frequency sound waves, or ultrasound, are used in most pregnancies to create an image of the developing fetus. Monitoring Tools Chorionic Villus Sampling Around the eighth week of pregnancy, some women will undergo a test called chorionic villus sampling, or CVS. Amniocentesis Another test that may be done around the fourteenth to sixteenth week of pregnancy is amniocentesis (am nee oh sen TEE sis).

33. Section 19.1 Development Before Birth Slide 33 of 17 Click above to go online. For: Updates on pregnancy care

34. Section 19.1 Development Before Birth Slide 34 of 17 Ectopic pregnancy In very rare cases of ectopic pregnancy, the blastocyst implants in the fallopian tube or elsewhere in the abdomen, instead of in the uterus. Complications Miscarriage The death of an embryo or fetus in the first 20 weeks of pregnancy is called a miscarriage. Preeclampsia Also called toxemia, preeclampsia (pree ih KLAMP see uh) is characterized by high blood pressure, swelling of the wrists and ankles, and high levels of protein in the urine. Gestational Diabetes Diabetes that develops in pregnant women is called gestational diabetes, and is marked by high blood sugar levels.

35. Section 19.1 Development Before Birth Slide 35 of 17 Vocabulary prenatal careMedical care received during pregnancy. obstetricianA doctor who specializes in pregnancy and childbirth. trimesterOne of three periods of time that divide a pregnancy. Each trimester is approximately three months long. ultrasoundHigh-frequency sound waves used to create an image of a developing fetus. chorionic villus sampling A prenatal test in which a piece of the developing placenta is removed and tested for inherited disorders.

36. Section 19.1 Development Before Birth Slide 36 of 17 Vocabulary amniocentesisA prenatal test in which a small amount of amniotic fluid is removed and tested for abnormalities. ectopic pregnancy A condition resulting from the implantation of the blastocyst in a location in the abdomen other than the uterus. miscarriageThe death of an embryo or fetus in the first 20 weeks of pregnancy. preeclampsiaA serious condition during pregnancy characterized by high blood pressure, swelling of the wrists and ankles, and high levels of protein in the urine. gestational diabetes Diabetes that develops during pregnancy.

37. Section 19.1 Development Before Birth Slide 37 of 28 Objectives Identify the three stages of the birth process. Section 19.3 Childbirth Describe four complicating factors that may arise at birth.

38. Section 19.1 Development Before Birth Slide 38 of 28 Health Stats How does smoking during pregnancy affect a baby’s weight? Propose a plan that could help decrease the number of pregnant women who smoke.

39. Section 19.1 Development Before Birth Slide 39 of 28 A certified nurse-midwife is a nurse who is trained to deliver babies. The Birth Process The birth process begins when the muscular walls of the uterus begin a series of contractions that will push the fetus out of the mother. Birth takes place in three stages labor delivery of the baby delivery of the afterbirth

40. Section 19.1 Development Before Birth Slide 40 of 28 The work performed by the mother’s body to push the fetus out is called labor. Labor Labor for a first child may last from about 2 to 24 hours or longer. Near the end of this first stage, the amniotic sac breaks, and the cervix becomes softer and wide enough or the fetus to pass through. The Birth Process

41. Section 19.1 Development Before Birth Slide 41 of 28 The Birth Process

42. Section 19.1 Development Before Birth Slide 42 of 28 Stage two involves the actual birth, or delivery, of the baby. Delivery of Baby This stage can take from half an hour to more than two hours. Once the baby is out the doctor clamps and cuts the umbilical cord the baby’s nose and mouth are suctioned eye drops are put in the baby’s eyes an injection of vitamin K is given The Birth Process

43. Section 19.1 Development Before Birth Slide 43 of 28 The Birth Process

44. Section 19.1 Development Before Birth Slide 44 of 28 The third stage involves contractions of the uterus that push out the placenta, also called the afterbirth. Delivery of Afterbirth This stage typically takes about 15 to 30 minutes. The Birth Process

45. Section 19.1 Development Before Birth Slide 45 of 28 The Birth Process

46. Section 19.1 Development Before Birth Slide 46 of 28 Click above to go online. For: More on the birth process

47. Section 19.1 Development Before Birth Slide 47 of 28 Be a Parent for a Day Materials Place the bag of flour inside the plastic bag and fasten it shut. For the next 24 hours, you will be responsible for your bag of flour as if it were a real baby. 5-pound bag of flour plastic bag with tie Try This

48. Section 19.1 Development Before Birth Slide 48 of 28 Be a Parent for a Day Follow these rules for taking care of your “baby.” Every 5 hours, including night, feed your “baby” for 20 minutes. During this time, you must remain seated in one place and devote your full attention to your “baby.” Choose a name for your “baby.”

49. Section 19.1 Development Before Birth Slide 49 of 28 Be a Parent for a Day Follow these rules for taking care of your “baby.” Every 3 hours during the time that you are awake, allow 5 minutes for changing your “baby’s” diaper. Spend 15 minutes in the evening talking or reading to your “baby.” Never leave your “baby” alone. If necessary, arrange for someone to babysit.

50. Section 19.1 Development Before Birth Slide 50 of 28 Be a Parent for a Day In what ways is a bag of flour an appropriate object to use to represent a baby? Think and Discuss When do you think is the best time for a person to become a parent? Explain. How did being a parent of a bag of flour affect your lifestyle?

51. Section 19.1 Development Before Birth Slide 51 of 28 During the first six weeks, called the postpartum period, many changes take place. The Postpartum Period The newborn’s lungs begin to function for the first time. The circulatory system and heart undergo changes. The nervous system reacts to new sensations. For the mother, changing hormone levels signal the breasts to produce milk and cause the uterus to gradually shrink back to its normal size. Hormonal changes and fatigue may cause the mother to feel overwhelmed.

52. Section 19.1 Development Before Birth Slide 52 of 28 Some complications result in a surgical delivery or premature birth. Complications at Birth Low birthweight and the birth of more than one baby also may cause complications. A stillbirth occurs when a fetus dies and is expelled from the body after the twentieth week of pregnancy.

53. Section 19.1 Development Before Birth Slide 53 of 28 Sometimes delivery through the cervix and vagina is not possible because of Surgical Delivery the position of the fetus in the uterus the narrowness of the mother’s hips illness A cesarean section (suh ZEHR ee un) is a surgical method of birth. other conditions First the doctor makes an incision in the lower abdomen into the uterus, then he or she removes the baby and placenta.

54. Section 19.1 Development Before Birth Slide 54 of 28 Delivery of a live baby before the 37th week of pregnancy is called premature birth. Premature Birth The lungs of a premature baby are usually not fully developed. The baby may have additional problems if other organs aren’t fully developed. A premature baby may receive care in an incubator.

55. Section 19.1 Development Before Birth Slide 55 of 28 A newborn that weighs less than 5.5 pounds at birth is considered to have low birthweight. Low Birthweight Premature and low-birthweight babies face an increased risk of health problems as newborns, chronic lifelong health problems, and even death.

56. Section 19.1 Development Before Birth Slide 56 of 28 The delivery of more than one baby—for example, twins, triplets, or quadruplets—is called a multiple birth. Multiple Births These births carry greater risk to the mother and babies, and are closely monitored by doctors.

57. Section 19.1 Development Before Birth Slide 57 of 28 Twins that develop from a single fertilized egg, or zygote, are called identical twins. Identical Twins Because they develop from identical embryos, identical twins have the same inherited traits and are the same sex.

58. Section 19.1 Development Before Birth Slide 58 of 28 Identical Twins A sperm fertilizes a single egg. Early in development, the embryo splits and forms two identical embryos. Identical twins result.

59. Section 19.1 Development Before Birth Slide 59 of 28 Sometimes two eggs are released from the ovary and are fertilized by two sperm. Fraternal Twins Fraternal twins are no more alike than any other siblings, and they may or may not be the same sex.

60. Section 19.1 Development Before Birth Slide 60 of 28 Fraternal Twins Two different sperm fertilize two eggs. Each of the fertilized eggs develops into an embryo. Fraternal twins result.

61. Section 19.1 Development Before Birth Slide 61 of 28 Triplets, quadruplets, and other multiple births are less common than twins. Triplets or More

62. Section 19.1 Development Before Birth Slide 62 of 28 Vocabulary certified nurse-midwife A nurse who is trained to deliver babies. laborThe work performed by the mother’s body to push the fetus out at the end of pregnancy. postpartum period A period of adjustment for parents and their newborn during the six weeks after birth. stillbirthThe expulsion of a fetus that has died after the twentieth week of pregnancy. cesarean sectionA surgical method of birth.

63. Section 19.1 Development Before Birth Slide 63 of 28 Vocabulary premature birthThe delivery of a live baby before the 37th week of pregnancy. low birthweightA newborn weight of less than 5.5 pounds. multiple birthThe delivery of more than one baby—for example, twins or triplets.

64. Section 19.1 Development Before Birth Slide 64 of 14 Objectives Describe the changes that children undergo during early childhood. Section 19.4 Childhood Identify key areas of development that occur during middle and late childhood.

65. Section 19.1 Development Before Birth Slide 65 of 14 Dear Advice Line, I babysit a 2-year-old. She can’t do things by herself like pour milk into her cup or put on her pajamas, but she gets mad at me when I try to help and insists on doing it herself. What should I do? Explain what factors might be contributing to this two-year-old’s behavior. What advice can you give the babysitter?

66. Section 19.1 Development Before Birth Slide 66 of 14 Babies and young children are not miniature adults. Early Childhood From birth to age six, children change from helpless babies into confident individuals who can do many things for themselves.

67. Section 19.1 Development Before Birth Slide 67 of 14 At birth, many of the baby’s organs and systems are not yet fully developed. Birth to Eighteen Months By the time a baby is 3 or 4 months old, the brain, nerves, and muscles are ready for more coordinated movement. By 18 months of age, he or she now has some “baby” teeth and can chew solid food.

68. Section 19.1 Development Before Birth Slide 68 of 14 Most children learn to talk sometime between 18 months and 3 years of age. Eighteen Months to Three Years Appetite decreases as growth slows down. Physical coordination improves. During this time, most children gain abilities to do things for themselves.

69. Section 19.1 Development Before Birth Slide 69 of 14 Between the ages of 3 and 6, children become more independent and active. Three to Six Years Most 4-year-olds talk in sentences. During this stage, children learn to play together and make friends. They start to develop a sense of right and wrong.

70. Section 19.1 Development Before Birth Slide 70 of 14 Click above to go online. For: Updates on growth and development

71. Section 19.1 Development Before Birth Slide 71 of 14 Physical growth, mastering new skills, and making friends are key areas of development during middle and late childhood. Middle and Late Childhood Middle childhood is defined as the period between age 6 and 8, and late childhood as ages 9 through 12. Late childhood is also called pre-adolescence or the “tween” years.

72. Section 19.1 Development Before Birth Slide 72 of 14 At around age 6 or 7, a child’s facial structure changes with the appearance of permanent teeth. Physical Growth Muscles and bones continue to grow, and coordination develops further. Their appetite also increases.

73. Section 19.1 Development Before Birth Slide 73 of 14 Children will feel pride in accomplishing tasks and attempting new challenges. Mental Development During middle and late childhood, the self- centeredness of early childhood lessens, and children continue to learn values. They may start taking on responsibilities at home, such as chores, during this stage.

74. Section 19.1 Development Before Birth Slide 74 of 14 The approval of friends and the need to fit in with a social group help children learn to work well in group situations. Importance of Friends Having a best friend also becomes important in pre- adolescence and will remain so into the teen years.

75. Section 19.1 Development Before Birth Slide 75 of 14 Vocabulary pre-adolescenceThe stage of development before adolescence.