Chapter 12 Pregnancy and Birth
Chapter 12 Outline • Fertility • Statistics and Current Trends • Conception • Early Signs of Pregnancy • Pregnancy Testing • Sex Selection: Myth and Modern Methods • Infertility • Assisted Reproductive Technologies
Chapter 12 Outline (Cont.) • A Healthy Pregnancy • The Prenatal Period • Health Care During Pregnancy • Exercise and Nutrition • Drugs and Alcohol • Pregnancy in Women Over 30 • Sex During Pregnancy
Chapter 12 Outline (Cont.) • Problems During Pregnancy • Ectopic Pregnancy • Spontaneous Abortion • Birth Defects • Rh Incompatibility • Toxemia
Chapter 12 Outline (Cont.) • Childbirth • Preparing for Birth • Birthplace Choices • Inducing the Birth • Birthing Positions • Stages of Childbirth
Chapter 12 Outline (Cont.) • Problems During Birthing • Premature Birth • Breech Birth • Cesarean-Section Delivery • Stillbirth
Chapter 12 Outline (Cont.) • Postpartum Parenthood • More Physical Changes for the Mother • Postpartum Psychological Changes • Sexuality for New Parents • Breastfeeding the Baby
Fertility • Statistics and Current Trends • Conception • Early Signs of Pregnancy • Pregnancy Testing • Sex Selection: Myth and Modern Methods
Statistics and Current Trends • In 2009, 4,131,019 registered births in U.S., 3% lower than 2008 • Teen births (ages 15-19) lowest level since 1940 • Average age of first-time mother in the U.S. increased by almost 4 years—from 21.4 to 25-years old from 1920 to 2006 • In 2006, 1 in 12 births was a first birth to women 35 and older
Conception • Our bodies are designed to promote pregnancy • During ovulation: • A woman’s sexual desire peaks • A mucus plug in the cervix disappears • Cervical mucus thins & creates gaps that vibrate with the sperm to aid motility and trap defective sperm; filters bacteria from semen
Figure 12.1 Birth rates by selected age of mother: final 1990–2008 and preliminary 2009.
Figure 12.2 Average age of mother at first birth, by race and Hispanic origin of mother, U.S. 1990 and 2006.
Figure 12.3 Average Age of Mother at First Birth in Selected Countries:1970-2006.
Conception (Cont.) • Female orgasm pushes semen to the uterus and toward the Fallopian tubes • Semen thickens upon ejaculation to stay in the vagina for 20 minutes to aid sperm travel • Pregnancy is also complex • Many sperm are killed by the female’s immune system • Many pregnancies end in spontaneous abortion
Conception (Cont.) • The ovum can live for 24 hours • Sperm can live for 72 hours; less than 1% can live up to one week • Pregnancy may occur a few days before or after ovulation • The ovum may release chemicals to signal its location • If a sperm reaches the ovum, it wriggles violently
As the head of the spermatozoan enters the ovum, the ovum prevents penetration by another spermatozoan.
Conception (Cont.) • Only one sperm fertilizes an ovum by secreting a chemical that makes a hole in the ovum coating • Immediately the ovum coating changes & does not permit further sperm from entering • Fertilization takes about 24 hours, usually in the ampulla • Zygote – a fertilized ovum
Conception (Cont.) • About 12 hours after fertilization, the first cell division occurs & the blastocyst divides every 12 to 15 hours as it travels towards the uterus • 3 to 4 days after conception, it enters the uterus & absorbs nutrients from endometrial glands • 6th day after conception, a uterine chemical dissolves the blastocyst coating, allowing implantation into the uterine wall, typically the upper portion
Figure 12.4 After ovulation, the follicle moves through the Fallopian tube until it meets the spermatozoon. Fertilization takes place in the wide outer part of the tube. Approximately 24 hours later, the first cell division begins. For some 3 or 4 days, the fertilized ovum remains in the Fallopian tube, dividing again and again. When the fertilized ovum enters the uterus, it sheds its outer covering in order to be able to implant in the wall of the uterus.
Conception (Cont.) • After implantation, the blastocyst divides into two layers, the endoderm & ectoderm, followed shortly by the mesoderm • Embryo – developing cell mass of 2–8 weeks • Amnion – membrane covering the embryo that fills with protective fluid • Placenta – attached to the uterine wall, it aids the fetus in respiration, nutrition, excretion • Umbilical cord – connects fetus to placenta
Conception (Cont.) • Multiple births occur in 1 out of 50 couples • Fraternal twins – two ova are released & fertilized; 2/3 of twins are fraternal; dizygotic • May be inherited from the mothers • More likely with women over 30 • Identical twins – single zygote divides into 2 separate zygotes; monozygotic • Siamese twins – fail to completely separate
Early Signs of Pregnancy • Missing a period, or maybe some spotting • Breast tenderness, frequent urination, food aversions • Morning sickness • 50–80% of pregnant women experience nausea &/or vomiting, any time of the day • Due to increased estrogen & progesterone irritating the stomach lining • May protect the fetus from illness
Early Signs of Pregnancy (Cont.) • Pseudocyesis – false pregnancy • May have a physical cause • Most cases have a psychological cause • More common in women who believe childbearing is central to their identity, have a history of infertility &/or depression, have had a miscarriage • Expectant fathers can also experience this, as well as couvade
Pregnancy Testing • Over-the-counter pregnancy tests • Can be less expensive at a clinic • The tests measure for human chorionic gonadotropin (hCG), which is made by placental cells • Detection in blood or urine can occur 8 to 9 days after ovulation • hCG levels peak in the 2nd & 3rd months
Pregnancy Testing (Cont.) • May be inaccurate if tested too soon or after the 12th week • False positives may occur with kidney disease, kidney infection, overactive thyroid, large doses of tranquilizers, aspirin, antidepressants, anticonvulsants • Radioimmunoassay (RIA) blood tests are the most accurate, can detect hCG within a few days after conception
Pregnancy Testing (Cont.) • Due date – calculated from the first day of the last menstrual period • Naegeles rule – subtract 3 months from the first day of the last period and add 7 days for a single birth • Rule is most accurate for women with 28-day cycles
Sex Selection: Myth and Modern Methods • More male babies are born each year • Male fetuses have higher rates of spontaneous abortion or die before birth • There are many cultural myths for choosing and knowing the gender of an unborn child • There are medical techniques that can aid in choosing and determining fetal sex
Sex Selection: Myth and Modern Methods (Cont.) • Microsorting can separate the X and Y sperm, which is then artificially inseminated • Male conception is 50-70% accurate • Female conception is 50-90% accurate • Embryos can be tested and the desired sex embryo then implanted • Amniocentesis involves removal of amniotic fluid through a needle during week 16 or 17; detects chromosomal abnormalities and gender
Sex Selection: Myth and Modern Methods (Cont.) • Controversy surrounds gender selection • Male children are typically valued over females in other countries because • They typically care for their aged parents • Girls require dowries to be paid at their marriage • Males carry on the family name • Female infanticide is a problem in rural India and in China
Infertility • Infertility – the inability to conceive, or impregnate, after one year of regular sexual intercourse without the use of birth control • Infertility may be diagnosed after only 6 months for women over 35 years • Fertility rates decline in men and women with increasing age
Infertility (Cont.) • Negative emotions are often experienced with the frustration of infertility • Women tend to be more committed to finding a solution than their partners • Motherhood mandate – there is a problem with a woman if she does not care for a child • Some reproductive problems can be reduced with changing lifestyles, reducing stress, avoiding strenuous exercise, average weight
Infertility (Cont.) • 61% of the time the problem can be found in one of the partners • 43% female (ovulation disorders, blocked Fallopian tubes, endometriosis, uterine fibroids, uterine structure, STIs) • 18% male (lack of sperm, reduced or malformed sperm production, STIs) • 18% of the time it is a combined problem • 20% the reason is unknown
Assisted Reproductive Technologies • Fertility Drugs • Surgery • Artificial Insemination • In Vitro Fertilization • Gamete and Zygote Intra-Fallopian Tube Transfer • Intracellular Sperm Injections • Oocyte and Embryo Transplants • Surrogate Parenting • Other Options
Assisted Reproductive Technologies (Cont.) • Assisted reproductive technologies (ART) are used by married, unmarried, straight, gay, lesbian, young, and old experiencing infertility • These methods may also cause further stress because they are expensive, time consuming, and may not work • Type of treatment depends on length of infertility, the woman’s age & likelihood of conceiving without treatment
Fertility Drugs • Hormonal irregularities may need to be treated with fertility drugs • The drugs increase ova production, which increases the possibility of multiple births • Possible increased risk of breast and ovarian cancer • Births using assisted reproductive techniques tend to be lower weight, more likely to be premature, and more at risk for miscarriage
Surgery • Structural abnormalities in the cervix, vagina, Fallopian tubes or endometrium may be surgically corrected • Surgery can also be used to remove blockage of the vas deferens or epididymis
Artificial Insemination • Insertion of sperm into the vagina, cervix, uterus or Fallopian tubes without intercourse • Ejaculated sperm is collected via masturbation by the partner or a donor • Sperm banks can freeze treated and washed sperm for up to 10 years • Donor catalogs are available, and sperm is sent to a physician • Fertility drugs are often used in combination
In Vitro Fertilization • “Test-tube babies” are conceived in a petri dish, then implanted in the uterus • Fertility drugs encourage the release of many ova and 4-6 are retrieved, although drugs aren’t always used • The ova are put in a dish and mixed with sperm; the zygotes are implanted • Only 5-30% implant, so many are often implanted
Gamete Intra-Fallopian Tube Transfer • Ova and sperm are placed in the Fallopian tube before conception • Fertility drugs and sperm washing are also used • Higher implantation rate than in vitro fertilization
Zygote Intra-Fallopian Tube Transfer • Fertilization occurs outside of the body • The zygote is placed in the Fallopian tube, allowing it to implant naturally • Higher implantation rates than in vitro, but not higher than gamete intra-fallopian tube transfer
In this enlarged image, a single sperm is injected into the center of an ovum during an intracellular sperm injection procedure.
Intracellular Sperm Injections • A single sperm is injected into the center of an ovum • ICSI results have been controversial • The ovum can be damaged • Possible increased risk of genetic defects
Oocyte and Embryo Transplants • For women who cannot produce healthy ova • Eggs and embryos from other women may be donated • Women over 40 have higher chance of pregnancy using a donated ova
Surrogate Parenting • Another woman’s uterus is used to carry a pregnancy • Ova and sperm are fertilized outside of the body and the zygote is implanted in the gestational carrier • If the surrogate’s ova is used, the carrier is called a surrogate mother • In the U.S., laws regulating surrogacy vary state-by-state
Other Options • Embryos and sperm can be frozen for later use • Often used by those undergoing cancer treatment that want to have children • Sometimes sperm do not survive the thawing • Not all embryos survive the freezing and thawing • It is much more difficult to freeze an ova, they are very vulnerable to chromosomal damage
A Healthy Pregnancy • The Prenatal Period • First Trimester • Second Trimester • Third Trimester • The Partner’s Experience
First Trimester • 1-13 weeks • The fetal heart forms and pumps blood by the end of the first month, as the circulatory system is the first to function • Other systems begin to develop: nervous, digestive, urinary, reproductive, appendages • Liver, kidneys, intestines, lungs begin developing by the end of this trimester • At the end, the fetus is ½ ounce & 3 inches
First Trimester (Cont.) • The woman’s heart pumps more blood, body gains weight, thyroid gland grows, lungs and digestive system work harder • Increases in estrogen & progesterone can cause: fatigue, breast tenderness, constipation, increased urination, nausea, vomiting, food cravings, smell sensitivity • Ultrasound can detect the fetal heartbeat and image as soon as 5 ½ - 6 weeks