Obstetrics 3

• Decidua is the endometrium of the pregnant uterus.  Its layers are:
• a. Superficial compact layer - consists of compact mass of decidual cells, glands and dilated capillaries. 
• b. Intermediate spongy layer - It is through this layer that the cleavage of placental separation occurs.
• c. Basal layer - containing the basal portion of the glands and is apposed to the uterine muscles. This is the part that remains after the placental separation. [IOM 2059]

• After implantation of blastocyst into compact layer of decidua, the  different portion of decidua are named as - 
• - Decidua basalis or serotina - the  portion of decidua in contact with the base of blastocyst. It unites with chorion to form the placenta. [UP 94] 
• - Decidua capsularis or reflexa - thin superficial compact layer covering  the blastocyst. 
• - Decidua vera or parietalis - rest of decidua lining uterine cavity outside the implantation site. 
• 

As overgrowing ovum bulges towards uterine cavity, the space between the decidua capsularis and the decidua vera, called the decidual space is gradually narrowed down and by 4th month,  it is completely obliterated by fusion of the decidua capsularis with decidua parietalis.[IOM 2064]

At  9-10 weeks, hCG level is maximum.   It returns to normal in 20-22 weeks.

In every 1.4-2 days.

• Human placental  lactogen is also called as human chorionic Somatomammotrophin.
• It is actually a fetal growth hormone.
• It is similar to  growth hormone and prolactin in its sequence.
• It causes insulin resistance and decreased glucose uptake in maternal tissue - anti-insluin to mother.

EstrONE (E1)– when menses are all gONE. i.e predominantly in post-menopausal women, [JIPMER 92] secreted from adipose tissue and the substrate is adrenal steroids.  

EstraDIol (E2) – During Intermenstural period, i.e. predominant estrogen in menstruating women from  granulose cells of follicles. 

EsTRIole (E3) – predominant estrogen in TRImesters of pregnancy  from placenta. The substrate is DHEAS from fetal adrenal.

• Ovaries 
• Adrenal cortex 
• Placenta in pregnancy 

The presence of more  stria gravidarum have less stretchable collagen, and chance of  laceration during birth is more in such woman.

Chloasma gravidarum is increased pigmentation on skin during pregnancy.

• Both systolic and diastolic BP are decreased because of decrease in TPR.
• BP during pregnancy is  never higher than  the BP before pregnancy normally. [AI 12]
• Plasma volume is increased by 50%,  HR and  SV are increased, but TPR is decreased.  
• But femoral vein pressure is significantly increased.

• Non pregnant (5 l/min)
• Late pregnant (6.3 l/min) 
• Stage I  (6.7 l/m) – increased  because of pain.  
• Stage II  (8.9 l/min)  -  increased because of the exercise as she is pushing out the baby. 
• Immediately postpartum  (9.3 l/min) - Maximum cardiac output is seen in the immediate postpartum period after the delivery of baby and placenta. [AI 07]  Venous sinusoids in uterus are filled with blood,  when placenta is out and uterus starts to contract,  there is autotransfusion of 600-800 cc of uteroplacental blood  that rapidly comes to the circulation that increases the CO.  This is important because the chance of heart failure is maximum in postpartum state in cardiac cases.

After delivery of placenta.

Mid systolic ejection murmur.

Both are increased. 

All plasma proteins are raised except albumin. 

The rise in Thyroid Binding globulin leads to increased  total T3 &  T4.

• It  causes the relaxation of smooth muscles.
• Relaxation of smooth muscles causes decreased motility of GI  muscles resulting in increased time of emptying.
• This causes reflux esophagitis,  cholelithiasis, constipation. 

Arteriole dilatation results in spider nevi formation.

All other volume decreases except Tidal volume. Increase in tidal volume increases minute ventilation. Increased minute ventilation causes  decrease in pCO2 and increase in  pH. This respiratory alkalosis  is partially corrected by secretion of HCO3 in the  urine leading to alkaline urine.

• Respiratory alkalosis due to increase in minute ventilation results in alkaline urine and there  increased risk of infections in alkaline urine. 
• There is increase in Ureteral size, this increase in diameter decreases the urine velocity  and stasis of urine leading to UTI.

Since the real blood flow is increased in increased cardiac output, there in increased GFR and  creatinine clearance. So BUN, Creatinine and Uric acid is decreased.

Glucose secretion is increased in pregnancy. 

Protein secretion is not changed in Urine during pregnancy.

• The total weigh gain during the course of a singleton pregnancy for a healthy woman averages 11 kg.
• This has been distributed 1 kg in first trimester and 5 kg each  [IOM 01]  in second and third trimester.

The amount of water retained during pregnancy at term is estimated to be 6.5 litres.

B) Smoking

Smoking does not have a significant effect on gestational weight gain although smoking is associated with decreased birth weight.

• HDL increased by 15% - least increased. [IOM 61] 
• LDL and cholesterol is increased by 40% 
• TG increased by 50%

[@Lipid increase: TG>LDL>HDL = alphabetical order]

• The sign is for the detection of pregnany. [UP 92].
•  During 6th and 10th week of pregnancy, on bimanual examination, the lower part of of the  uterus is easily compressed between the fingers placed in the vagina and those of the other hand over the pelvic area.
• This  is due to softening of the lower segments of the uterus and fetus doesnot fill the uterine cavity at this stage, leaving an empty space in the lower part.

• First pregnancy
• Family history
• Hydatidiform mole
• Multiple pregnancy

• Promethazine [IOM 04] 
• Prochlorperazine 
• Metochlopramide

• When there is Acetone free urine.
• Presence of acetone is a sign of starvation and ketones may be harmful to fetal development.

• Estrogen  -  Duct and nipples 
• Progesterone – Lobules and alveoli

• >10 rads   has the   significant risk, and below it, there is minimal risk.
• All  of the diagnostic modalities we use like  Chest X-ray,  Abdominal CT, IVP usually do not go above 10 rads, so, even if the   woman has been exposed to the radiation, we should  never  advise for termination of pregnancy only for this issue.

<5 rads is not associated with any significant congenital malformations. [AIIMS 03]

• - Miscarriage, fetal growth restriction
• - Congenital malformation (e.g. microcephaly),
• - Mental retardation
• - Increased risk for childhood cancer like leukemia [IOM 07]