Sunday, March 21, 2010

Cardiotocogram (CTG)

CTG done during labor is a CST with contractions as stress to the baby. It can be used to watch for fetal distress as well as as predictor of fetal distress.

Variability and Reactivity: Variability is the result of fluctation of basal output of parasympathetic output from brain (Basal Ganglia), which is a sign of healthy brain. A depressed brain will have low intrensic activity (due to depressed reticular activating system). Reticular Activating System also controls sleep-awake cycle, so, it's depressed and we get reduced variability during fetal sleep also.

Reactivity is due to activation of fetal Sympathetic system during fetal movements. Sympathetic system is a crisis management system, and it accelerates the heart in anticipation of increased energy requirements. (not due to actual increased need, as reactivity occurs even with a small movement, which will not increase the oxygen demand in the fetus). During fetal Sleep, the motor system activity and activation of sympathetic system is low too, and as a result there will be no reactivity.

Deceleration: 3 types of decelerations :

Early Deceleration - is due to head compression in late labor, which creates a increased intracranial pressure, which increases fetal blood pressure by cushings reflex, which reduces the heart rates by means of nervous reflex from baroreceptors in Aorta. So, early deceleration indicates a healthy nervous system, and like variability and reactivity may be a sign of fetal well being, and it's absence is ominous.

Late Deceleration - is due to fetal hypoxia. When placental function is strained, during uterine contractions, there is a drop in fetal oxygen pressure, which depresses the fetal heart, and reduces the rate. Because fetus is yet unaffected during uterine relaxation, it forewarns the fetal hypoxia which is still occuring only during contractions, which may become more severe if contractions become harder and labor gets prolonged. Appropriate actions may be taken if labor is expected to take long time.

Variable Deceleration - is due to cord compression. variable deceleration can occur irrespective of presence or timing of uterine contractions. It can be distinguished by the shape of the curve, which is quite irregular and deep, and has two shoulders, which are initial and end accelerations. Initially, when cord is lightly compressed, the vein is occluded, which decreases fetal cardiac preload, causing fall in cardiac output, and there's mild tachycardia as a response (1st shoulder). Then the arteries are compressed, which increases the fetal blood pressure (compressing the fetal umbilical artery is like directly compressing it's aorta, as most of the flow from aorta goes to internal ileac, then to umbilical arteries), and causes reflex fetal bradycardia. The amount of bradycardia is proportional to fetal hypertension, which is proportional to umbilical compression, which is usually severe, abrupt, and irregular. At the end of compression, there's a phase, where arteries are released, but thinner veins are compressed, causing tachycardia.

Though any cord is liable for compresson, cords of IUGR babies, because they are thinner, than because of pausity of amniotic fluid, are more likely to be compressed. Though variable deceleration is not a direct result of fetal hypoxia, repeated compression, especially in a IUGR baby, can cause fetal hypoxia.

Case 1:

Early decelerations in Late labour. Patient delivered a healthy baby after one hour. (toco probes not kept properly, diagnosed as early by timing manually with patient's contractions)

case 2:

variable decelerations in early labor in a second gravida. delivered by CS, baby depressed, but recovered well.

Thursday, March 18, 2010

Depot Provera in endometriosis

Medical Treatment for endometriosis can be tried in unmarried girls, those who have finished family, and in whom pain is the troublesome symptom. Two strategies for medical treatment are:

  • pseudo-menopausal regime

  • pseudo-pregnancy regime

Pseudo- menopausal state is achieved using GnRH analogues, and pseudo-pregnancy regime by progestrone. both alters the hormonay mileu, suppresses HPO axis (there by reduces the growth of ectopic endometrium), alters peritoneal immune system (controlled by hormones and is associated with the development of endometriosis).

Pseudomenopausal regime is associated with menopausal symptoms, osteoporosis, and GnRHa s are costly. pseudo-pregnancy regime can be administered much more easily, using Depot Provera (Medroxy Progestrone Acetate). It's given once in 3 months injection (more frequent injections as adviced in certain texts are not required). It maintains a constant level of progestrone in the body, suppresses HPO, and keeps endometrium thin. We expect the ectopic endometrium also to be maintained thin, and together with altered immune function, endometrium is expected to heal.

Unpredictable irregular bleeding is the side effect with Depot Provera. As endometrium is thin, estrogen can be administered, which heals the endometrium. (Ethnyl Estradiol 10mcg TDS during bleeding days). Patient is adviced to take estrogen during bleeding days. Initially during therapy bleeding is more frequent. It's usually minimal or scanty, not painful. gradually, bleeding becomes quite infrequent, even amenorrhea will occur. There's no fear of permanant amenorrhea, as the state is purely hormonal, and any time, on treatment with estrogen-progestrone, normal cycles can be brought about.

I have treated many cases of endometriosis with this regime. Symptomatic relief is great, and ultrsonically regression of endometriosis can be proven. There's little side effects or discontinuation of treatment. Patients are so happy that, they refuse to stop the drug.

Here's one of the patients, who was P2L2, had troublesome secondary dysmenorrhea (Secondary dysmenorrhea to be distinguished from Primary Dysmenorrhea, which is sever on the first day, and is alleviated as the bleeding increases on the second day. Secondary dysmenorrhea becomes more severe as bleeding increases on second and third day.) She was given Depot Provera 2 years back. She took 2 injections (6 months) and as the symptoms reduced, she stopped the drug, and was having normal cycles. She came back again recently, as her symptoms have reappeared. I sent her for scan expecting to see the lesions increased. To my surprise, the lesions had reduced drastically (even with no treatment for 2 years). This not only proves the effect of Depot Provera, but also that endometriosis can spontaneously regress.

2 years back:




Wednesday, March 3, 2010

Cervical encirclage

Cervical circlage is very much misused surgery. The use of circlage is often questionable. And in cases where circlage seems to have worked, we have to doubt, if it would have gone well, even without cirlage also.


This is a second gravida, first term cesarean, who had short cervix and membranes bulging into cervix in her routine second trimester scan. As her first pregnancy was normal, I told her to continue her pregnancy her normal, without even advising her rest. She has gone to term, and is posted for elective CS today!

short cervix.jpg