Obstetrics topics - B. Ziv 2007 PDF

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OBSTETRICS TOPICS -TOPIC 1 – History taking- [1-6]The past obstetric history -Demographic details Name ; Age ; Occupation ; Reason for being in hospital/ outpatient/ antenatal clinic. This pregnancy  Gestation / LMP / EDD by LMP, any discrepancy with US dates.  Singleton / multiple ; Planned / acc...

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Private - Beckerman Ziv

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November 19, 2007

OBSTETRICS TOPICSTOPIC 1 – History taking- [1-6] The past obstetric historyDemographic details This pregnancy Presenting problems in this pregnancy US scans Past obstetric history

Always ask Useful extras Gynecological history Past medical and surgical history Drugs Allergies Family history Social history

Name; Age; Occupation; Reason for being in hospital/ outpatient/ antenatal clinic.  Gestation / LMP / EDD by LMP, any discrepancy with US dates.  Singleton / multiple ; Planned / accidental.  Presenting complaint; Symptoms; Signs (Backache, hyepremesis, per vaginal bleeding, constipation, anemia, urinary problems).  Action that has been taken. Her concerns. Likely obstetric outcome. How many scans, where were they performed and why, what was their results.     

Date of delivery and delivery gestation; Antenatal problems. Length of labor and whether spont or induced. Type of delivery and complications (C-section, spont vaginal / assisted). Stillbirths, neonatal deaths, terminations of pregnancy, miscarriages, ectopies. Weight of baby (kg); Age of baby / child now and any salient conditions.

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Is the baby moving (after 20wk). Do you have any contractions ?

 Have you lost any fluid / blood from the vagina. Blood group; Rubella status; Sickle / thalassemia status; HBV / HIV ; Folic acid supplements.  Periods- regular / not. Cycle length & days of bleeding.  Contraceptive history, date when contraceptives stopped.  STD. Cervical smear. Any previous gynecological operations / conditions.  Relevant medical conditions and treatment.  All operations (type of anesthesia).  Include iron tablets, folic acid, vitamins.  Ask specific detail about anti-hypertensive, diabetic, anti-epileptic, thyroid medications. ??? Diseases as DM, HT, cc. Martial status; Work?; Partner’s occupation.; Help; Housing.; Smoking?; Alcohol?; drugs ?

Dating a pregnancy- (Naegele’s rule) done from first day of last menstrual period (LMP)

From this day, the estimated delivery date is 280 days (req that ovulation occur 14 days after the LMP).

o

EDD = (LMP + 7 days + 9 month).

 

from conception 266 days (38wk). This cannot be true in following caseso Irregular periods (anything except 28 day cycle). o Breast feeding within 2 months of becoming pregnant. o Contraceptive pill usage within 3 months of becoming pregnant. o Pregnancy occurring while using hormonal treatment. o Assisted conception techniques.  In these cases, we estimate the EDD (estimated day of delivery) by dating US.  In case of >10 days differ bet EDD and US CRL bet 6-14 wk or BPD bet 14-24 wk  US should be used.  Quickening (para 1)- date (20 wk) + 20 wk; or date + 4.5 calendar months. o according to the first time the mother feels the baby’s movements.  Quickening (para>1)- date (18wk) + 22 wk; or date + 5 calendar months. Subfertility in the history- In case of IVF, the pregnancy is dated to be ~14 days after the LMP.

Obstetric risk factors- (LAPS) 

Pre-eclampsia- more likely to occur in first pregnancy (8%), if occurs in first pregnancy has 12% chance to recur in the second one. If first one was not affected, than second pregnancy has 2 Pos 3

1/2 Medium 2–1 Central 2

3/4 Soft 1 – 0.5 Ant 1/0

5 / more 35yr, very obese, who had C-section.  HT disorders- mostly from 32 wk of gestation, immediate cause of death was ARDS or cerebral edema. Eclampsia occurred in some cases. Substandard care was evident in ~60% of cases.  Early pregnancy deaths- (deaths before 24wk gestation), include deaths due too Ectopic pregnancy- due to delayed diagnosis. Spont abortion-due to infection. o Termination of pregnancy- due to legal abortion.  HemorrhageParticular risk is implanted over a uterine scar. Antepartum hemorrhage Placenta praevia Abruptio placentae Usually complicated by coagulopathy. Postpartum hemorrhage Usually after C-section / vacuum extraction. Indirect deaths Cardiac disease- (in the past mainly rheumatic), today cong diseases, MI, acq conditions (cardiomyopathy, aortic aneurysm).  Psychiatric deaths- suicide.  Other indirect causes- mainly due to epilepsy. “Near miss” enquiries- incidents which might have resulted in maternal death but due to prompt and effective treatment were prevented. were suggested to be included in following reports. Topic 6 – Perinatal mortality (definition, worldwide and in UK, causes, comparison of maternal and perinatal mortality) [27-32]

Perinatal death is ~x100 more common than maternal death. Definitions- follow the- Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI). Private - Created by Beckerman Ziv

Private - Beckerman Ziv page #5 November 19, 2007  Stillbirth- any fetus born with no signs of life, after 24 wk gestation.  Early neonatal death- death during the 1st week after birth.  Late neonatal death- death from age 7-27 completed days of life.  Post-neonatal death- death bet age 28 days-1yr.  Infant death- death at age 3 wk to complete meiosis and >2 months for mature egg. spermatogonia to divide to 4 mature sperm. Conception- conseq of several complex events (include- final maturation of spermatozoa & oocyte, transport of gametes in female genital tr., assembly of diploid # of Ch = syngamy).

Topic 8 – The sperm and the follicle, fertilization and implantation [37-41] The sperm 

Spermatozoa are prod at onset of puberty in males  will be prod conti till age 60yr. After spermatogenesis, spermatozoa pass via seminiferous tubules rete testis vas deferens head of epididymis after 12 days to tail of epididymis.  Seminal fluid is made of- secretions of bulbourethral glands, seminal vesicles, prostate + ½ ml epididymal fluid.  Mature sperm contain  haploid Ch (22 + X/Y), a few m long.  Travel distance of 30-40cm in female genital tr.  fertilize oocyte.  Tail- provide motility & propulsion. Midpiece –energy source. Acrosome- for penetrating the oocyte.  Seminal fluid + sperm coagulates immediately after ejaculation, liquefies within 20min.  Basic pH of the seminal fluid protects the spermatozoa from the vaginal acidity.  Sperm reach the cervix within min after ejaculation, released const over 72hr  move toward the ampulla  fertilization of the mature, ovulated oocyte (req Capacitation (estrogen-dependent, Ca-dependent activation, during which the acrosome cap becomes primed for fusion with the inner mem of the ovum)).  The acrosome reaction exposes the inner mem of sperm, which will fuse with the mem of the ovum. The follicle- Primordial follicle composed of primordial germ cells surrounded by mesenchymal cells from endodermal tissue. primary oocyte is arrested at metaphase of 2nd meiosis till puberty. At puberty, few follicles at a time grows on daily basis, from them follicle destined for next ovulation is selected.  Antral follicles surrounded by inner granulosa cells, outer theca cell layers (both from mesenchyme). o Granulosa cells  estrogens. Theca cells  androgens.  Check pg. 39- figure 4.6. Fertilization: a zygote is formed by fusion of male and female pronuclei- Ovulated egg is picked up by fimbria of fallopian tube swept by ciliary action to the ampulla fertilization: Sperm penetrate the cumulus cell layer interact with egg-specific surface R in zona pellucida (thick GP sheet covering the cyto mem of the egg)  the sperm acrosome reactions  transform the sperm head to male pronucleus, the egg at this time finishes its 2nd meiotic division, form haploid female pronucleus (+ 2nd polar body).  One of early events in male pronuclear formation, is the de-condensation of sperm Ch by release of protamines.  Once released, series of egg-specific proteins bind the sperm Ch = Ch remodeling.  Subseq, new cyto organelles, nuc envelope assemble around remodeled sperm Ch  prod male pronucleus.  Fertilization ends with fusion of male & female pronuclei forming the zygote.  Fertilization is complete within 20hr, the coming together of the 2 haploid sets of Ch = syngamy. Implantation- zygotedivide rapidly, within 5 days Blastocyst is formed (tiny mass of cells). The embryo must escape from the zona pellucida and outer covering of the original egg, “burrow” into the decidua. Endometrium- prepares, undergoes extensive prolif (under estrogen influence), progesterone (from formed corpus luteum), entering the endometrial glands to secretory phase. Local peptides- EGF, IGF-1, PGE2, plasminogen activators, LIF (leukemia inhibitory factor) assist implantation. Embryo remains in fallopian tube for 3-4 days, till reaches morula stage (8-32 cell stage)  isthmus of uterine th cavity, floats here 72 hr  by the 6 day it originates toward the decidua, begin to penetrate its Epi surface by piercing the BM (metalloproteinases) once inside, it generates ECM then secretion of hCG by trophoblastic cells which lead to maternal recognition of pregnancy. Endometrial cytokines, modulate cytotrophoblastic proteolytic activity to control the depth of invasion.  12 days after fertilization, the embryo is embedded within the decidual stroma.  At 11-12 day, implantation site is seen as 1mm red spot on mucosa due to maternal blood in lacunar spaces. Blastocyst is formed Arrives to the Prod of hCG can be recorded Fully embedded in the decidua (syncitiotrophoblast) decidua Private - Created by Beckerman Ziv

Private - Beckerman Ziv 5th day post-fertilization

6th day

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8-9th days

November 19, 2007 12th day

Topic 9 – Embryology (3rd and 4th weeks) [41-44] 2nd wk post-fertilization- generation of embryonic disk  till 8th wk. 3rd week – bi-laminar germ disk with primitive streak on midline near the caudal end.  Primitive streak determines symmetry, defines the cephalic, caudal poles.  Neural plate, somites- appear next, as symmetric eminences on either side of the midline.  Internally, the bilaminar embryo generates mesodermal layer made of cells which migrate from the primitive node at the cephalic end of the primitive streak bet the ectodermal and endodermal layers.  Somites- composed of paraxial mesodermal cells, appear on day 20, at level of future base of skull.  Primary yolk sac than develops, grows rapidly into expanding exocoelomic space. It will attain full development at day 32 and its complex all starts degenerating by end of 6th wk.  Amniotic mem- another extra-embryonic element, by day 17 is closely apposed to embryonic disk. 4th week- the embryonic disk folds to an embryonic cylinder, within it is a cranio-caudal blind ending tube with 3 segments- foregut, midgut (opened to developing yolk sac), hindgut  this marks the start of organogenesis.  Primitive heart- first organ to become apparent, cardiac activity is evident by day 22.  Neurulation- development of nervous system, occur now too, neural plate become a deep groove on dorsal aspect, sinks deeper, the opposing crests fuse, forming the neural tube. As closure occur, the cephalic neuropore closes during day 26, caudal neuropore at end of 4th wk.  Special cell pop detach from lips of neural crests and migrate to several specific location.  By end of 4th wk, central neural system has defined segments, primary brain vesicles, prosencephalon, mesencephalon, rhombencephalon.  Towards end of 4th wk, foregut separates along the midline to resp, digestive primitive elements, the ventral pancreatic bud migrates pos to fuse with the dorsal pancreatic bud. o 2 lung buds are evident at end of 4th wk.  By day 26, mesonephric duct & mesonephros differ, at day 28, ureteric buds, metanephric blastema define.  Towards end, the embryo body is att to the yolk sac via broad vitelline duct, 2 connecting vitelline blood vessels.  In the cephalic pole, 5 pharyngeal arches appear, the buccopharyngeal mem perforates at end of this week. Changes in external appearance- During following 3 wk, outer aspect of the embryo changes dramatically- head grows faster than rest of the body, bent forward till end of 7th wk. Development of upper limbs, precedes the lower ones, upper buds appear at ~27th day, lower a day later. 20 25 27 30 33 35 37 42 56 Day 5.3 7 8.3 9 13 30 CRL (mm) 2.5 3.2 4

Topic 10 – Physiological changes in pregnancy – systemic changes [45-50] Volume homeostasis- Most fundamental change in pregnancy is fluid retention 8-10kg weight gain. The  in plasma Vol begins on the 8th wk, conti till 32-34wk. Most of the water are added to the ECFV- mainly circulating plasma Vol. Other changes- CO, RBF. Factors that contri to fluid retention are Conseq of fluid retention Na retention- amount to total of 900 mmol (3-4 mmol / day) 1. factors that Hb, Htc, [albumin].  Resetting the osmostat. 2. factors that - SV, RBF.  in thirst threshold  THUS IN THIRST FEELING.  in plasma oncotic Pr- albumin conc by ~20% during normal pregnancy contri to development of peripheral edema (feature of normal pregnancy). Blood- There is dilution of many circulating factors- mainly that of RBC (even though there is an prod of RBC).  There is an in iron absorption from the gut, but still there is a need to take supplementary iron.  Folic acid supplementation- is req since the renal clearance of folic acid  during pregnancy. Hematological factors that  Hematological factors that  1. RBC#. 1. WBC# ~ 9*109 / L during 3rd trimester, mainly  in PMNs. 2. [Hb] ~ 10.9 g/dL at 36wk. 2. ESR. 3. Htc. 3. [fibrinogen] – contri to a hypercoagulable state. 4. plasma [folate] 5. PLT# (but  proportion of young PLTs) CV system- Early pregnancy is charac by peripheral VD.   

Private - Created by Beckerman Ziv

Private - Beckerman Ziv page #8 November 19, 2007  Significant in HR is seen by the 5th wk- but not in SV progressive in HR conti till 3rd trimester to 10-15 b/min more than in non-pregnant state At the 20th wk, a CO of ~7 L/min can be seen.  Some women will in conseq develop a supine hypotension, may even lose consciousness.  There is a in ar-BP – the in diastolic Pr is more marked during antenatal period than in systolic Pr. o Later, diastolic Pr significantly to normal non-pregnant level. o Reproducible and accurate measurement are obtained when 5th Korotkoff sound (disappearance of sounds) is used rater than the 4th (muffling).  Normal changes in heart sounds during pregnancy-  of S1, 2. splitting of S1. o Loud S3 by 20wk. 95% develop systolic murmur which disappears after delivery. o 20% have a transient diastolic murmur. o 10% develop conti murmurs due to  mammary blood flow. Phase %  in CO (%) Other CV changes HR  Latent phase (cervix 20 -250 Optimal birth weight- the baseline birth weight for a baby of a non-smoking Anglo- European mother in her first pregnancy, of average height and weight is about 3480hr at 40 wk.  

Maternal weight – 9 gr/ kg. Maternal height – 8g/ cm. Parity – para 1  +110gr, para 2+  +150gr. Baby’s gender- male > female +/- 60gr.

CV system- distinctive features of fetal circulation- Oxygenation occurs in the placenta. 1. R and L ventricles work in parallel. 2. The heart, brain, upper body receive blood from LV, 3. placenta and lower body receive blood from both R & LV(s). These changes are due to- ductus venosus, ductus arteriosus, foramen ovale.  Oxygenated blood from the placenta  fetus via the umbilical v. 2 branches (each receive 50%) portal v. + ductus venosus joins IVC, enter R atrium. Since the ductus venosus is narrow, the generated stream is fast and this streaming prevents mixing of oxygenated and de-oxygenated blood inside the IVC.  When entering the RA oxygenated blood passes via foramen ovale LA LVaorta  o ~50% goes to the head and upper limbs, o the rest passes down the aorta, mix with lower oxygen saturation blood from the RV.  Blood from IVC, SVC RARV  low amount goes to the non-functional lungs, rest passes via ductus arteriosus to the desc aorta below Private - Created by Beckerman Ziv

Private - Beckerman Ziv page #11 November 19, 2007 origin of head & neck vessels. Fetal blood- First fetal blood cells are formed on the surface of the yolk sac.  During 6th wk – extramedullary hematopoiesis begins in liver, spleen (less).  Marrow starts to prod RBC at 16wk, is the predominant source of RBC from 26wk.  Most Hb in fetus is HbF- (2 , 2 ), 90% of fetal Hb is HbF bet 10-28wk. o From 28-34 wk, switch to HbA occurs, the ratio of HbF: HbA = 80:20. o By 6 month age, only 1% of Hb is HbF. o HbF- is resistant to denaturation by acid and alkali, it has a higher affinity for oxygen.  At birth, the mean capillary Hb= 18gr/dL. Fetal lung- full differ of capillary and canalicular elements of fetal lung are apparent by 20wk.  Alveoli develop after 24wk.  Fetal breathing movements occur in utero, mainly during REM sleep, are necessary for lung maturation.  Fetal breathing occurs for 15% of observation time in 2nd trimester, 30% at 3rd trimester.  Surfactant is prod by type 2 alveolar cells, at the end of 6th month, they make 10% of lung parenchyma. Immune system- lympho appear from 8 wk, by middle of 2nd trimester all phagocytic cells, T, B cells, complement are available to mount a response.  Early infection with any of TORCH organisms (Toxoplasmosis, Rubella, CMV, Herpes) will affect a # of systems.  IgG originates mainly from maternal circulation.  Fetus prod small amount of IgM, IgA, which don’t cross the placenta.  General immunological defenses- AF (lysozyme, IgG), placenta (lymphoid cells, phagocytes, barrier), granulocytes (from liver, marrow), INF (from lympho). Skin and homeostasis- fetal skin protects,  homeostasis. Thickness progressively from first month till birth. Stratum corneum- forms in 5th month, during last wk skin is covered by vernix- desquamated skin cells, CL, glycogen Thermal control is limited by a large surface-to-body weight ratio, poor thermal insulation. Alimentary system and energy stores- Rotation of gut is complete by 12wk.  Swallowing reflex develops and matures gradually, the fetus conti swallows AF (~20ml/hr).  Peristalsis in intestine occur from 2nd trimester.  Large bowel is filled with meconium at term (there is no defecation in utero).  Glycogen and fat stores about x5 in last trimester. Kidney and urinary tr.- nephrogenesis is complete by 36wk, but maturation of excretory and conc ability of fetal kidneys is gradual. Its immature in the preterm infant, may lead to abnormal water, glucose, Na, acid-base homeostasis. Fetal urine prod gradually with fetal maturity, from 12ml/hr (32wk), to 38ml/hr (40wk). Fetal behavior- fetal movement can be first perceived by ~18wk in primipara, several wk earlier in multipara. With CNS maturation, the fetus develops more complex patterns 1F state- similar to quiet (non-REM) sleep.  2F- periodic eye and body movements (REM sleep).  3F- eye movements, no body movements.  4F- active phase with eye movements, body activity. >80% time, fetus alternates bet 1F, 2F. AF- by 12wk, amnion contact inner surface of the chorion, obliterates the extraembryonic coelom.  The 2 mem(s) adhere (but don’t fuse).  The choriodecidual function plays pivotal role in initiation of labor via prod of PGE2, F2a.  initially secreted by the amnion, at 10th wk is mainly transudate of fetal serum via skin and umbilical cord. From 16wk fetal skin is impermeable to water, net  in AF is via small imbalance bet contri of fluid via kidneys and lung fluids, removal of fetal swallowing.  AF Vol- 10 wk (30mL), 20wk (300mL), 30wk (600mL), 38wk (1000mL), 40wk (800mL), 42wk (350mL).  Functions- Protect from mechanical injury. Permit movement of fetus while preventing limb contracture. o Prevent adhesions bet fetus and amnion. Permit fetal lung development. Topic 14 – Diagnostic US in pregnancy – clinical applications of US, Doppler US [67-74, 85-86] Diagnostic US- uses 3-7.5 MHz, low intensity sound waves, trans via the abd / pelvis by transducer. Transducer consists of piezo electric crystals, mounted in curved array. Small groups of crystals are triggered in seq and each emits a focused U...