Week 2 Pregnancy preconception to brith

Preconceptual Care

Targets all women of childbearing age, reduces risk and improves women’s health before conception, assesses readiness, identifies goals to meet before parenthood, develop a lifestyle of wellness in the childbearing years

Nursing interventions for modifiable risk factors

• Safe Spacing between pregnancies

• Substance abuse

• Exercise

• Nutrition

• Exposure to infectious disease

  • Vaccine

• Mental Health

• Support system, family dynamics, personal safety

• Readiness for pregnancy and parenthood

• preventative care(screening)

• environmental (home or workplace) conditions

Sperm

• Haploid Gamete

• Lifespan in the female reproductive tract is 2 to 3 days (48-72 hours)

• Can reach the ova in as little as 30 minutes

Ovum

• Gamete (haploid)

• Oogenesis begins during fetal development

• Ovulation

  • The ovarian follicle ruptures and releases the ovum

  • corpus luteum remains on ovarian surface to temporarily provide necessary hormones until the placenta is large enough to take over (placental takeover at 7 weeks)

• Ovum is fertile for 24 hours after ovulation

• cannot move on its own

• Because sperm live longer than ovum, fertilization more likely to occur if sperm already present in fallopian tubes at the time of ovulation

Fertilization(conception)

• 2 gametes combine to 1 zygote (diploid)

• ovum and sperm unite at the ampullary portion(long part) of the fallopian tube the usual site of site of fertilization

• once 1 sperm enters, ovum closes to additional sperm

• zygote propelled along the fallopian tube through the peristaltic movements of the fallopian tube and the tube’s cilia

Blastocyst

• Has 3 primary germ layers

  • Ectoderm: Forms the exoskeleton

  • Mesoderm: develops into organs

  • Endoderm: forms the inner lining of organs

Implantation

• occurs 6 days after fertilization

• Occasionally, implantation bleeding occurs as the blastocyst implants in endometrial lining, and decidua differentiates

Support Structures during pregnancy

• Placenta

• Amniotic membranes

• Amniotic fluid

• Umbilical cord

Placenta

• develops at the site of implantation

• fetal tissue

• originates from Chorionic Villi

• Produces hormones HCG and HPL

Placental growth timeline

0-20 weeks

• Grows rapidly

• Covers large portion of the inner uterine surface

20-40 weeks

• will only grow thicker for remainder of pregnancy, and proportionately less of the inner uterine surface

Placenta: the life support system for the fetus

• No exchange of maternal/fetal blood in healthy pregnancy

  • there are 2 distinct circulatory systems

  • passage of smaller molecules

• adequacy of maternal circulation will affect adequacy of fetal perfusion

Placental Functions

• Respiratory unit

  • Oxygen and co2 exchange

• nutritional unit

  • Glucose, amino acids, vitamins, minerals fatty acids, water

• Elimination

Amniotic Membranes and Fluid

• Chorion (outer) and amnion(inner) become amniotic membranes

• prostaglandins

• barrier from infections

Amniotic Fluid

• Protects the fetus and umbilical cord from trauma and compression

• regulates the temperature for the fetus

• aids in muscular development, allowing the fetus to move, develop and grow

• amniotic fluid volume will affect size of uterus

Alterations in Amniotic Fluid

• Oligohydramnios (not enough amniotic fluid)

• Polyhydramnios(too much amniotic fluid)

Polyhydramnios

• increased amniotic fluid relatice to gestational age

• Maternal adverse effects

  • Diabetes

  • Discomfort, Dyspnea, generalized edema

  • Umbilical cord prolapse

  • Postpartum Hemorrhage

• Fetal adverse effects

  • Upper GI Abnormalities

  • Neural tube Defects

Oligohydramnios

• Decreased amniotic fluid relative to gestational age

• Maternal adverse events

  • Maternal dehydration

  • Preeclampsia

• Fetal Adverse effects

  • Congenital anomalies of kidneys, bladder

  • placental insufficiency: IUGR

  • Limb contractures

  • Lung dysplasia

  • Cord compression in labor

Fetal Circulatory System

• Gas exchange occurs in placenta instead of the lungs

• Opposite from adult circulation

• Umbilical Cord

• 2 arteries: carry unoxygenated blood and waste products from the fetus to the placenta

• 1 vein carries oxygenated blood to fetus

Umbilical Cord

• Connects the embryo to the chorionic villi of the placenta

• wharton’s jelly coats umbilical cord

Alterations in umbilical cord

• 2 vessel cord with one artery and one vein

• occurs in 1% of singletons, 5% multples

• Umbilical cord alterations have increased risk for other anomalies

  • Heart

  • cns

  • renal

  • chromasomal

Embryonic Stage

• IMPLANTATION TO 8 WEEKS GESTATION

• Begins about the time of missed period

• Embryonic stage is a critical period of organogenesis

• Placenta/support structures present

• maternal/fetal perfusion intact

• risks for teratogenicity within embryonic stage

Teratogens

Substances that interfere with fetal growht and development

Examples of teratogens

Recreational substances

• Alcohol

• tobacco

• maarijuana

Medications

• warfarin

• isotretinoin

• phenytoin

Environmental toxins

• xray

• MERCURY

• suana

Infections

• Rubella

• varicella

• rubella and varicella are live vaccines, to be avoided in pregnancy

Chronic Health Conditions

• Diabetes

• Lupus

Systems in critical stage of development at 6-8 weeks

• Ears, eyes, and nose

• brain and cranial nerves

• Gastrointestinal

• cardia septum and valves

• Liver making RBC

• Development of fetal circulation