Obstetrics Review 2

Ana H. Corona, MSN, FNP-CNursing InstructorNovember 2007

Diagnosis of Pregnancy

Positive Signs of Pregnancy identification of fetal heart action

separate from the mother's (normal: 120-160 BPM).

perception of active fetal movements by the examiner (by palpation of the abdomen).

recognition of the embryo or fetus sonographically (may be detected after only 5 weeks of amenorrhea).

Probable Evidence of Pregnancy

Enlargement of the abdomen (by 12 weeks gestation, the uterus can be felt through the abdominal wall just above the symphysis).

changes in the size, shape, and consistency of the uterus (uterus becomes softened or "doughy"), softening of the isthmus between the still firm cervix and the softened uterus (Hegar's Sign).

changes in the cervix (softening of the cervix at 6-8 weeks gestation-can also occur with OCPs).

Braxton Hicks contractions (palpable but ordinarily painless contractions at irregular intervals from early stages of gestation).

ballottement (near midpregnancy, pressure on the uterus will cause the fetus to sink in the amniotic fluid, and with release of pressure, the rebound to its original position will be felt as a tap).

outlining the fetus (in the second half of pregnancy).

Presumptive Evidence of Pregnancy

results of endocrine tests (presence of hCG in matemal plasma and its excretion in urine).

cessation of the menses (especially after predictable menstruation).

changes in breasts (tenderness, tingling, increase in size). discoloration of vaginal mucosa (dark bluish or purplish-

red and congested- Chadwick's Sign). increased skin pigmentation and the appearance of

abdominal striae (can be absent during pregnancy or present with the use of OCPs).

nausea with or without vomiting (appears usually at 6 weeks, lasting 6 to 12 weeks).

frequent micturation. easy fatigueability. sensation of fetal movement (16-20 weeks).

Initial Obstetric Visit

Identification of Risk Factors History and Physical Exam

Assess general health and risk factors. Attempt dating of pregnancy: Last menstrual period

(LMP) - accurate if verified by calendar or coincident with holiday, etc.; reliable if no interfering factors present (i.e., prior menstrual irregularity, oral contraception).

Bimanual exam for uterine size and pelvic adequacy (esp. diagonal conjugate).

Auscultation or doppler exam for FHT General exam of all other systems.

Prematurity Risk Factors

Age <18, low socioeconomic status, sexual promiscuity, DES exposure, prior premature delivery, 2 or more spontaneous abortions, uterine anomalies or fibroids, thin patient or poor weight gain, multiple gestation, polyhydramnios, UTI/renal disease, acute infections.

Placental Insufficiency Risk Factors Post dates, previous stillbirth, intrauterine

growth retardation, anemia/hemoglobinopathies, medical illness (DM, HTN, thyroid disease, renal disease, cardiac disease, collagen vascular disease)

Congenital Anomalies/Disease Risk Factors

Race (Asian, Jewish, Mediterranean, Black)

Mother >34 yers of age Advanced paternal age Family history of congenital anomaly Previous delivery of child with anomalies Teratogen exposure Infection exposure Diabetes.

Clinical Criteria LMP Bimanual exam in first trimester Doppler FHTs at 10-12 weeks Fetoscopic FHTs at 20 weeks Quickening (primiparous at 18-20 weeks and multiparous

at 17-19 weeks) Fundus reaches umbilicus at 20 weeks, after 20 weeks

fundal height in cm = weeks gestation. Laboratory Measures The UPT in the lab can be positive within 5 days post-

conception. Ultrasound Approximate accuracy: <10 weeks - 3-7 days, <20

weeks - 10 days, <30 weeks - 2 weeks, 30-40 weeks - 3 weeks.

Best single scan for dates and anomalies is 16-18 weeks

Routine Screening Tests

CBC (r/o anemia). Sickle cell prep (Black or Hispanic patients). Urinalysis (r/o bacteriuria, proteinuria,

glycosuria). VDRL/RPR (r/o syphilis). Type, Rh, and antibody (r/o potential hemolytic

disease of the newborn. If Rh- and neg antibody screen, repeat antibody screen at 28 weeks and administer Rhogam if still neg. Administer Rhogam for threatened abortions. If antibody screen is positive, consult HR OB immediately. If positive for any other antibodies except Anti I, Anti Lewis A, and Anti Lewis B, refer to HR OB).

Lab tests continue

Rubella titer (r/o need for post-partum vaccination). PAP smear (inflammation - repeat PAP in 6-8 weeks and

treat possible etiology; other abnormalities - refer for colposcopy).

Glucose screening (Patients at risk, i.e., age >25, family history of DM, previous stillbirth, previous anomalous child, previous child >4000 gm, obesity, HTN, glycosuria. O'Sullivan abn if 1 hour glucose >140. Do at first prenatal visit if very high risk; follow up at 26-28 weeks if normal.)

Triple Screen (should be done at 15-19 weeks; if patient declines, a disclaimer should be signed.)

Hepatitis screening (r/o chronic hepatitis carriers).

Patient Education

Avoidance of possible teratogens; i.e., cigarettes, ethanol, medication, illicit drugs, radiation, work hazards.

Healthy diet and appropriate weight gain (ideally 20#-28# total), prenatal vitamins.

Physiologic changes in pregnancy - quickening should occur at 17-20 weeks.

Sexuality during pregnancy. Warn of potential hazards that may require

immediate attention. Schedule prenatal classes.

Follow-up Prenatal Care

Frequency - monthly until 28 - 32 weeks (weekly from 17-20 weeks if necessary for dating), then biweekly until 36 weeks, then weekly.

Brief history

Parameters to follow each visit

Weight (ideal - 20-28 pounds; think PIH for rapid weight gain).

Blood pressure (Think PIH if B/P >140/90 or if systolic increases >30 or diastolic increases >15 from first trimester B/Ps).

Urine protein (if >1+, think PIH; if no signs of PIH, think UTI).

Fundal height (ultrasound if EGA <36 weeks and size > or < dates by 3 cm, fundal height not increasing over a 2-week period, or fundal height increases by more than 3 cm in 1 week).

Fetal heart tones (120-160). Fetal presentation (after 32 weeks).

Parameters to follow: continue

New problems/patient complaints. Repeat Rh antibody screen and titer on Rh

negative mothers following any episode of supracervical vaginal bleeding or abdominal trauma, and at least once during second trimester and twice during third trimester. Rh negative mothers should receive Rhogam at 28-32 weeks.

Repeat pelvic exam at 36-38 weeks and as indicated.

Encourage preparation for breast feeding of infant.

Explain false labor and onset of labor (i.e., when to come to the hospital).

Schedule parenting classes.

Previous Cesarean Section

Previous Cesarean Section (C/S) 1.  Eligible for vaginal trial (Vaginal Birth After

Cesarean - VBAC): Candidates with two or fewer low transverse C/S or undocumented scar in a patient who underwent an uncomplicated term vertex C/S for failure to progress. 2.  Ineligible for vaginal trial are refer to HROB at 35 weeks for evaluation.

Post Dates

Non-Stress Test at 41 weeks with referral to HR OB. Arrange at 40 weeks.

Family History of Congenital Anomaly, Genetic Disease, or Advanced Maternal Age

Less than 16 weeks EGA are referred to genetic counselor

Greater than 16, less than 22 weeks EGA are immediately referred to genetic counselor

Greater than 22 weeks EGA (make certain dates are correct and encourage genetic counseling).

Herpes

Herpes Culture prenatally only if patient

complains of symptoms near term and/or confirmation of the diagnosis has not been previously established.

Hypertension

1st or 2nd trimester: Consider chronic HTN and obtain OB evaluation.

3rd trimester: Consider pre-eclampsia. Refer to OB ER if B/P >140/90 and/or if symptoms of scotomata, headache, or abdominal pain.

Referred to HR OB for mild disease after obtaining CBC, BUN, creatinine, and LFTs.

Vaginal Bleeding

(More than bloody show) 1st trimester: THINK ECTOPIC PREGNANCY.

Check cervical os with ring forceps to assess for inevitable abortion, check Hct and quantitative B-Hcg, check for doptones if >10 weeks, ultrasound only if patient is having evidence of abdominal cramping/pain, 2nd trimester: Assess for fetal cardiac activity; are refer for ultrasound exam.

3rd trimester: THINK PLACENTA PREVIA. Refer to OB ER immediately. Do not perform cervical exam unless the placenta has already been evaluated by ultrasound and is not a placenta previa

High Risk OB Criteria

Present OB Complications

Age <14 or> 34 Preterm labor this

pregnancy Premature rupture of membranes Third trimester bleeding Fetal anomaly Post-term>41 weeks Pre-eclampsia Incompetent cervix Polyhydramnios Poor weight gain Fetal growth retardation Mutiple gestation Fetal demise/missed

abortion

Prior OB Complications Previous stillborn > 2 miscarriages History of preterm delivery Prior C/S (VBAC eval) 

High Risk (HR) criteriaMaternal Medical Problems

Diabetes  High blood pressure Asthma (COPD) Thyroid disease Liver disease Chronic renal disease Acute pyelonephritis Cardiac disease (not

murmur) Hematologic disorders

 severe anemias sickle cell hemoglobinopathies thrombocytopenia Rh sensitization Seizure disorders Lupus Active tuberculosis Active hepatitis Active mumps, rubella

Premature Labor

OB ER evaluation for abnormal cervical exams or complaints of possible uterine activity.

Premature Rupture of Membranes Confirm PROM by sterile speculum

exam (pooling in vaginal vault, nitrazine positive, ferning).

No digital exams. Refer to OB ER ASAP

Six Week Postpartum Check-Up History

Inquire in general about delivery; i.e., "difficult time," long, painful bleeding, etc.

General state of mother and family How is she coping with the baby? mood, appetite,

exercise activities, rest and sleep Involvement and interest of father. Reactions of siblings to new baby.

Problems with baby at birth or now. Specifically ask the mother about:

Fever, vaginal bleeding, cramping, discharge, episiotomy pain, breast soreness or discharge, swelling, headaches, urinary symptoms, and bowel movement.

Meds currently taking (particularly if breast feeding). Contraception (consider BCPs, diaphragm, IUD, etc.).

Menses should start 6-8 weeks after birth (longer if breast feeding).

Physical Exam

Vital signs (particularly BP and WT). General PE: HEENT, breast. chest, abdomen, and

extremities. Brief HEENT, chest, abd. and ext. Breast exam for infection or masses.

Pelvic examination: including rectal exam

State of perineum (episiotomy, if done). Character of discharge (should be scant blood or normal

menses). Cervix - laceration, uterine size and tenderness, adnexa

for tenderness or masses. Rectal - sphincter tone, fistula. Uterine size - should be normal size and nontender in 6

weeks.

Time Frame Tests

Time Frame Tests

Initial Visit Pap Smear, GC, CT

U/Culture, Cystic Fibrosis

Prenatal Panel, CBC

HIV, RPR, blood Type

Antibody Screen,

Rubella & Hepatitis Titer

15 – 20 weeks AFP Triple Screen

24 – 28 weeks 1 hr glucose test, CBC

34 – 36 weeks GBS culture, CBC, RPR

GC, CT

Pregnancy-Related Disorders

Hypertension Preeclampsia Multiple gestation (twins and higher) Gestational diabetes (a condition that results in

high blood sugar levels during pregnancy). Preterm labor Genetic disorders in the fetus Intrauterine growth restriction (lower than

normal fetal growth) Advanced maternal age by itself may not make

the pregnancy "high-risk" unless there are high-risk conditions present, such as high blood pressure or fetal genetic disorders

Pregnancy Induced Hypertension

HTN can restrict the flow of blood to the developing fetus, causing growth restriction and other problems.

There is a condition unique to pregnancy known as preeclampsia.

Known also by the term PIH (for "pregnancy-induced hypertension"), preeclampsia consists of: Hypertension Edema (swelling) Significant amounts of protein in the urine

(proteinuria)

PIH

Preeclampsia can be relatively mild, although the term "mild" is misleading since serious problems can develop even with a mild form of the disorder.

Preeclampsia can evolve into severe preeclampsia, which can be an indication for immediate delivery of the fetus.

Eclampsia can also result. This consists of generalized seizures and is an obstetric emergency.

PIH Preeclampsia is unusual before 20-weeks

gestation, but can occur even as late as two weeks after delivery.

Preeclampsia is more common among women who are giving birth for the first time, or who are pregnant for the first time by a new partner.

Preeclampsia is also more common among pregnant women with chronic hypertension, as well as those who have kidney disease, a multiple gestation, or who are over 40.

Gestational Diabetes

Pregnant women who are not already diabetic may develop a pregnancy-related form of diabetes called gestational diabetes.

Diabetes in general is the most common medical complication of pregnancy and about 2-3% of pregnant women have some form of diabetes. Of this, 2-3%, 90% are women with gestational diabetes.

Gestational diabetes is also important because it can increase the risks of certain complications in pregnancy such as birth trauma and excessive fetal growth.

Gestational DM

The one-hour glucose test ("glucola") performed between 24 and 28 weeks of pregnancy screens for gestational diabetes.

It consists of taking a special sweetened drink and measuring blood sugar levels one hour later.

For the purposes of this screening test, a pregnant woman does not need to be fasting.

If the test is abnormal, it may or may not mean that a pregnant woman has gestational diabetes, since the one-hour test is designed so that about 2-3% of women will have an abnormal result.

When the one-hour glucose test is abnormally high, the next step is to take a formal three-hour glucose tolerance test (GTT) that does require an overnight fast.