CHAPTER 18 Obstetrics

Obstetrics Overview Obstetrics Pregnancy Field of medicine that deals with pregnancy (prenatal), delivery of the baby, and the first six weeks after delivery (postpartum period) Pregnancy Nine calendar months or 10 lunar months Forty weeks or 280 days Divided into trimesters Three intervals of three months each Known as gestational period

Pregnancy Fertilization or conception Union of a sperm and a mature ovum Takes place in outer third of the fallopian tube Zygote Initial name for fertilized ovum Embryo Name of product of conception from second through 8th week of pregnancy Fetus Name of product of conception from 9th week through duration of gestational period

Pregnancy Two major accessory structures of pregnancy Amniotic sac Strong, thin-walled membranous sac that envelops and protects the growing fetus Also known as the fetal membrane Outer layer of sac is called the chorion Inner layer of sac is called the amnion Amniotic fluid within sac cushions and protects fetus during pregnancy

Pregnancy Accessory structures of pregnancy Placenta Temporary organ of pregnancy Provides for fetal respiration, nutrition, excretion Functions as an endocrine gland by producing hormones necessary for normal pregnancy Human chorionic gonadotropin (HCG), estrogen, progesterone, and human placental lactogen (HPL)

Pregnancy Accessory structures of pregnancy Maternal side of placenta Attached to wall of uterus Has a “beefy” red appearance Fetal side of placenta Has shiny, slightly grayish appearance Contains arteries and veins that intertwine to form umbilical cord Umbilical cord arises from center of placenta and attaches to umbilicus of fetus

Physiological Changes During Pregnancy Amenorrhea Absence of menstruation Menstruation stops as a result of hormonal influence during pregnancy Changes in the uterus Small, pear-shaped organ before pregnancy Grows to accommodate growing fetus, placenta, amniotic sac, and amniotic fluid during pregnancy

Physiological Changes During Pregnancy Changes in the cervix Chadwick’s Sign Cervix and vagina take on a bluish-violet hue due to local venous congestion Goodell’s Sign Cervix softens in consistency in preparation for childbirth

Physiological Changes During Pregnancy Changes in the vagina Vagina takes on same bluish-violet hue of the cervix during pregnancy Increase of glycogen in vaginal cells Causes increased vaginal discharge and heavy shedding of vaginal cells Leukorrhea Thick, white vaginal discharge during pregnancy

Physiological Changes During Pregnancy Changes in breasts Increase in size and shape Nipples increase in size and become more erect Areola become larger and more darkly pigmented Montgomery’s tubercles become more active and secrete substance that lubricates the nipples

Physiological Changes During Pregnancy Changes in breasts Colostrum is secreted Thin, yellowish discharge from nipples throughout pregnancy Forerunner to breast milk

Physiological Changes During Pregnancy Changes in blood pressure May experience hypotension during second and third trimesters (4th – 9th month) Weight of pregnant uterus presses against descending aorta and inferior vena cava When woman is lying on her back (supine) May complain of faintness, lightheadedness, and dizziness

Physiological Changes During Pregnancy Changes in urination First trimester Urinary frequency due to increasing size of uterus, creates pressure on bladder Second trimester Uterus rises up out of the pelvis and pressure on bladder is relieved Third trimester Frequency returns due to pressure of baby’s head on the bladder

Physiological Changes During Pregnancy Changes in posture Waddling gait Manner of walking in which the feet are wide apart and the walk resembles that of a duck Due to softening of pelvic joints and relaxing of pelvic ligaments Pregnant woman’s center of gravity is offset

Physiological Changes During Pregnancy Changes in the skin Possible increased feeling of warmth and sweating Due to increased activity of the sweat glands Possible problems with facial blemishes Due to increased activity of sebaceous glands Chloasma Hyperpigmentation (brown patches) seen on forehead, cheeks, and bridge of nose Known as the “mask of pregnancy”

Physiological Changes During Pregnancy Changes in the skin Linea Nigra Darkened vertical midline between the fundus and the symphysis pubis on the abdomen Areola Becomes darker as pregnancy progresses Stria Gravidarum Stretch marks on the abdomen, thighs, and breasts that occur during pregnancy

Physiological Changes During Pregnancy Changes in weight Recommended weight gain during pregnancy Ranges from 25 to 30 pounds Pattern of weight gain is important 1st – 3rd month = 3 - 4 pounds total 4th – 9th month = 1 pound per week Critical to monitor weight gain for unexpected increases Fluid retention Pregnancy-induced hypertension

Signs and Symptoms of Pregnancy Presumptive signs Expectant mother Suggests pregnancy but are not necessarily positive Include amenorrhea, nausea and vomiting, fatigue, urinary disturbances, and breast changes Quickening Movement of fetus felt by the mother Occurs around 18 – 20 weeks gestation Described as a faint abdominal fluttering

Signs and Symptoms of Pregnancy Probable signs Observable by examiner Much stronger indicators of pregnancy, but can be due to other pathological conditions Should not be used as sole indicator of pregnancy Include Goodell’s sign, Chadwick’s sign, uterine enlargement, hyperpigmentation of skin, abdominal stria, palpation of fetal outline, positive pregnancy tests

Signs and Symptoms of Pregnancy Probable signs Hegar’s sign Softening of the lower segment of the uterus Braxton Hicks contractions Irregular contractions of the uterus May occur throughout the pregnancy and are relatively painless

Signs and Symptoms of Pregnancy Probable signs Ballottement Technique of using the examiner’s finger to tap against the uterus, through the vagina, to cause the fetus to “bounce” within the amniotic fluid and feeling it rebound quickly

Signs and Symptoms of Pregnancy Positive signs Fetal Heartbeat Detected by ultrasound at approximately 10 weeks gestation Detected by fetoscope at 18 to 20 weeks gestation Rate can vary from 120 to 180 beats per minute

Signs and Symptoms of Pregnancy Positive signs Identification of embryo or fetus by ultrasound Can be detected as early as 5 to 6 weeks with 100 percent reliability Provides earliest positive confirmation of a pregnancy Fetal movements felt by examiner Palpable by physician/examiner by the second trimester of pregnancy

Calculation of Date of Birth Birth date for the baby Expected Date of Confinement (EDC) Expected Date of Delivery (EDD) Expected Date of Birth (EDB) Nagele’s rule for calculation of date Subtract three months from beginning of last menstrual period (LMP) Add seven days to date = expected date of delivery

Discomforts of Pregnancy Temporary discomforts of pregnancy Backache Common during second and third trimester Edema Swelling of lower extremities not uncommon Fatigue Usually occurs during first trimester

Discomforts of Pregnancy Temporary discomforts of pregnancy Heartburn Mainly during last few weeks of pregnancy Hemorrhoids Develop as result of increasing pressure on area Nausea Usually occurs during first trimester Varicose veins Occur as result of blood pooling in the legs

COMPLICATIONS OF PREGNANCY Obstetrics

Abortion Pronounced Defined (ah-BOR-shun) Termination of a pregnancy before the fetus has reached a viable age, that is, an age at which the fetus could live outside of the uterine environment

Abruptio Placenta Pronounced Defined (ah-BRUP-she-oh pla-SEN-tah) Premature separation of a normally implanted placenta from the uterine wall After the pregnancy has passed 20 weeks gestation or during labor

Ectopic Pregnancy Pronounced Defined (ek-TOP-ic PREG-nan-see) Abnormal implantation of a fertilized ovum outside of the uterine cavity Also called a tubal pregnancy Approximately 90 percent of all ectopic pregnancies occur in the fallopian tubes

Gestational Diabetes Pronounced Defined (jess-TAY-shun-al diy-ah-BEE-teez) Defined Disorder in which women who are not diabetic before pregnancy develop diabetes during the pregnancy Develop an inability to metabolize carbohydrates (glucose intolerance), with resultant hyperglycemia

Gestational Diabetes Risk factors Obesity Maternal age over 30 years History of birthing large babies Usually over 10 pounds Family history of diabetes Previous, unexplained stillborn birth Previous birth with congenital anomalies (defects)

HELLP Syndrome Pronounced Defined HELLP SIN-drom Serious obstetrical complication that occurs in approximately 10 percent of pregnant women with pre-eclampsia or eclampsia HELLP stands for Hemolytic anemia, Elevated Liver enzymes, and Low Platelet count

HELLP Syndrome Early diagnosis is critical Any woman who presents with malaise or a viral-type illness in third trimester of pregnancy should be evaluated for possibility of HELLP Syndrome Laboratory diagnosis necessary to confirm HELLP syndrome Complete blood cell count Liver function tests

Hydatidiform Mole Pronounced Defined (high-dah-TID-ih-form mohl) Abnormal condition that begins as a pregnancy and deviates from normal development very early Diseased ovum deteriorates (not producing a fetus) Chorionic villi of placenta changes to a mass of cysts resembling a bunch of grapes

Hydatidiform Mole Hydatidiform mole Molar pregnancy Hydatid mole Growth of this mass progresses much more rapidly than uterine growth with a normal pregnancy

Hyperemesis Gravidarum Pronounced (high-per-EM-eh-sis grav-ih-DAR-um) Defined Abnormal condition of pregnancy characterized by severe vomiting that results in maternal dehydration and weight loss

Incompetent Cervix Pronounced Defined (in-COMP-eh-tent SER-viks) Condition in which cervical os dilates before the fetus reaches term, without labor or uterine contractions Usually occurs during second trimester of pregnancy Results in spontaneous abortion of fetus

Placenta Previa Pronounced Defined (plah-SEN-tah PRE-vee-ah) Condition of pregnancy in which the placenta is implanted in the lower part of the uterus Precedes the fetus during the birthing process

Pregnancy-Induced Hypertension (PID) Pronounced (PREG-nan-see induced high-per-TEN-shun) Defined Development of hypertension during pregnancy, in women who had normal blood pressure readings prior to pregnancy

Pregnancy-Induced Hypertension (PID) Three categories of PID Gestational hypertension Develops after 20 weeks gestation with no signs of edema or proteinuria Pre-eclampsia Develops after 20 weeks gestation with proteinuria or edema Eclampsia Most severe form of hypertension during pregnancy Evidenced by presence of seizures

Rh Incompatibility Pronounced Defined (Rh Incompatibility) Incompatibility between and Rh negative mother’s blood with her Rh positive baby’s blood Causes mother’s body to develop antibodies that will destroy the Rh positive blood

SIGNS AND SYMPTOMS OF LABOR Obstetrics

Signs and Symptoms of Labor Bloody show Vaginal discharge that is a mixture of thick mucus and pink or dark brown blood Occurs as a result of the softening, dilation, and thinning (effacement) of the cervix in preparation for childbirth

Signs and Symptoms of Labor Braxton Hicks contractions Mild, irregular contractions that occur throughout pregnancy Increased vaginal discharge Clear, nonirritating vaginal secretions Occurs as result of congestion of vaginal mucosa

Signs and Symptoms of Labor Lightening Settling of the fetal head into the pelvis Occurs a few weeks prior to the onset of labor Rupture of the amniotic sac Rupture of fetal membranes, releasing amniotic fluid inside May result in a sudden gush of amniotic fluid Women may say their “water broke”

Signs and Symptoms of Labor Sudden burst of energy Occurs in some women shortly before onset of labor May have energy to do major housecleaning duties

False Labor versus True Labor Contractions (False) Contractions (True) Irregular Regular Not too frequent More frequent Shorter duration Longer duration Not too intense More intense

False Labor versus True Labor Discomfort (False) Discomfort (True) Felt in abdomen Felt in lower back Felt in groin area Radiates to lower abdomen --- Feels like menstrual cramps

False Labor versus True Labor Walking (False) Walking (True) May relieve or decrease contractions May strengthen contractions

False Labor versus True Labor Effacement/Dilatation (False) Effacement/Dilatation (True) Dilatation and effacement of cervix does not change Cervix progressively effaces (thins) and dilates (enlarges)

DIAGNOSTIC TECHNIQUES, TREATMENTS AND PROCEDURES Obstetrics

Diagnostic Techniques, Treatments, and Procedures AFP screening Serum screening test for birth defects such as spina bifida, Down syndrome, and Trisomy 18 Test is offered to pregnant women between 15 and 21 weeks gestation

Diagnostic Techniques, Treatments, and Procedures Amniocentesis Surgical puncture of the amniotic sac for the purpose of removing amniotic fluid Cesarean section Surgical procedure in which the abdomen and uterus are incised and a baby is delivered transabdominally

Diagnostic Techniques, Treatments, and Procedures Contraction stress test Stress test used to evaluate ability of fetus to tolerate stress of labor and delivery Also known as oxytocin challenge test Fetal monitoring Use of an electronic device to monitor fetal heart rate and maternal uterine contractions

Diagnostic Techniques, Treatments, and Procedures Nipple stimulation test Noninvasive technique that produces same results as contraction stress test Pregnant woman stimulates the nipples of her breasts by rubbing them between her fingers Causes natural release of oxytocin that causes contractions of uterus

Diagnostic Techniques, Treatments, and Procedures Obstetrical ultrasound Noninvasive procedure that uses high-frequency sound waves to examine internal structures and contents of the uterus Ultrasonography

Diagnostic Techniques, Treatments, and Procedures Pelvic ultrasound Noninvasive procedure that uses high-frequency sound waves to examine the abdomen and pelvis Pelvimetry Process of measuring the female pelvis, manually or by x-ray to determine its adequacy for childbearing

Diagnostic Techniques and Procedures Pregnancy testing Tests performed on maternal urine and/or blood to determine presence of hormone HCG (human chorionic gonadotropin) HCG is detected shortly after first missed menstrual period