fetal wellbeing during pregnancy

ANTEPARTUM ASSESSMENT OF FETAL WELLBEING
The obstetrician is responsible for 2 patients during pregnancy and labor, one of them being the fetus. The hidden patient is guarded by the following barriers:
Anatomical: which can be overcome to some extent by U/S imaging.
Physiological: these need an understanding of the interaction between fetal and maternal physiology.
Fetal assessment begins in the 1st trimester by the confirmation of viability and determining the gestational age.
In the 2nd trimester the fetus should be evaluated by its genetic and structural development.
In the 3rd trimester the assessment involve the evaluation of fetal growth and wellbeing in anticipation of labor.
After determining the GA of the fetus and confirmation of its viability we have to exclude: *congenital anomalies by biochemical screening tests:
Screening for NTD and Down syndrome:
1- Serum ? fetoprotein: NTD account for 50% of all congenital anomalies, serum ? fetoprotein can be measured in the 15 – 17 weeks in the maternal blood.
2- The triple test: serum ? fetoprotein, hCG, estriol are the 3 parameters measured in the maternal blood for detection of risk of down syndrome when the serum ? fetoprotein is lower than the mean, hCG is higher, and estriol is lower the probability of down syndrome is high so we have to do amniocentesis to take fetal cells for kariotypic diagnosis.
The results are expressed as medians of the mean and related to the maternal age and weight and are gestational age dependent.
* nuchal translucency by U/S: measurement of the nuchal fat pad of the baby(behind its neck)
The measurement is done in the 11-13 weeks, it gives a risk like the triple test, for the detection of fetal trisomies and congenital hrt defects, so the definitive diagnosis is by genetic kariotyping by doing chorionic villous sampling.




*Routine anomaly U/S scanning (18-20) weeks( MIDPREGNANCY):
This is done to assess the following:
-GA (by measuring the biparietal diameter) the GA is accurate within 2 weeks
-Localization of the placenta
-Diagnose multiple pregnancies
-Exclude congenital anomalies:
*Neural tube defects and anencephaly
*Double bubble sign of duodenal atresia
*Cardiac abnormalities
*Hydrocephaly
*Renal abnormalities
*Sacral agenesis in diabetic mothers
*Major limbs defects