- Section 1: General Obstetrics
- 1. Normal pregnancy
- 2. Pregnancy at an Advanced Maternal Age
- 3. Teenage Pregnancy
- 4. Abnormal Labor
- Section 2: Pregnancy-Related Complications
- 5. Placenta Previa
- 6. Abruptio Placenta
- 7. Premature Rupture of Membranes
- 8. Postterm Pregnancy
- 9. Rh Isoimmunization
- 10. Intrauterine Growth Restriction
- 11. Twin Gestation
- Section 3: Medical Conditions During Pregnancy
- 12. Preeclampsia
- 13. Anemia
- 14. Gestational Diabetes
- 15. Hiv in Pregnancy
- 16. Heart Disease in Pregnancy
- 17. Thyroid Disease in Pregnancy
- Section 4: Abnormal Pregnancy Outcome
- 18. Ectopic Pregnancy
- 19. Spontaneous Miscarriage
- 20. Hydatidiform Mole
- Section 5: Postpartum Complications
Q. 1. What is the next best step in the management of this patient?
- Blood hCG titers
- Ultrasound examination
- Glucose challenge test
- Prescription of folic acid tablets
Ans. A (Blood hCG titers)
The diagnosis of pregnancy is based on clinical signs and symptoms described in Table 1.1. In case of positive urine pregnancy test at home (Fig. 1.1), testing of blood or urine for hCG must be performed. The levels of β-hCG can be detected in maternal plasma or urine by 8–9 days postovulation using sensitive tests such as immunoradiometric assay techniques. The doubling time of β-hCG varies between 1.4 to 2.0 days. Serum β-hCG levels start increasing from the day of blastocyst implantation and peak at about 60–70 days. Thereafter, the levels of β-hCG decline slowly until nadir is reached at about 16 weeks of gestation. The sensitivity for lab detection of β-hCG in serum using immunoradiometric assays is about 1.0 mIU/mL whereas that using home pregnancy test kits is about 12.5 mIU/mL or even more. An intrauterine gestational sac can be visualized on transabdominal scanning by 4–5 weeks of gestational age (Fig 1.2). With transvaginal scanning this finding is likely to appear 1 week earlier. 4
Q. 2. What are the steps involved in the initial prenatal evaluation of this patient?
Ans. Initial prenatal evaluation of this patient comprises of the following steps:
- Assessment of health status of the mother and the fetus
- Estimation of the gestational age: The gestational age is usually calculated from the date of LMP. However, since in this case the patient was not sure of the dates of her last periods, a first trimester ultrasound examination for the estimation of correct gestational age is required.
- Initiation of plan for continuing obstetric care.
Investigations to be done at the time of initial visit comprise of the tests described in Table 1.2.
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The clock moves forward to 18 weeks of gestation…
The woman presents to the antenatal clinic for a routine checkup. She is not experiencing any unusual symptoms such as abdominal pain, bleeding or leaking per vaginum, etc. She has not yet started experiencing any fetal movements. She is not taking any other medicines except folic acid tablets. Her general physical examination is within normal limits. Abdominal examination reveals an enlarged uterus halfway between the umbilicus and pubic symphysis. Fetal Doppler tones are heard.
Q. 3. What is the next step of management in this patient?
- Serum screening for neural tube defects by measuring alphafetoprotein levels
- Ultrasound examination
- Prescription of iron tablets
- Screening for gestational diabetes
Ans. B (Ultrasound examination)
Ultrasound examination at 18–20 weeks allows for detailed fetal anatomy survey, identification of fetal structural anomalies and placental localization. For a woman whose placenta is found to be extending across the internal cervical os during this time should be offered another scan in third trimester and the results of this scan reviewed at next appointment. Although the absolute benefit is not clear, this second trimester ultrasound examination is routinely performed in the clinical practice.
Ultrasound examination also helps in the evaluation of nuchal thickness, which serves as screening method for neural tube defects in the first trimester.
Genetic screening involving the estimation of alpha-fetoprotein levels and triple or quadruple screening test is usually performed between 16 to 20 weeks' gestation. However, this is especially required in women with an advanced age (>35 years) and those having risk factors for neural tube defects or chromosomal abnormalities (Down syndrome, etc.). Triple test involves measurement of three parameters: alpha-fetoprotein levels, levels of hCG and levels of unconjugated estriol. Quadruple test includes estimation of inhibin A levels also along with the measurement of the three parameters described with the triple test. Fetal alpha-fetoprotein levels greater than 2.0–2.5 MOM are suspicious for neural tube defects and require further evaluation. Reduced levels of alpha-fetoprotein are indicative of Down syndrome. In Down syndrome, alpha-fetoprotein levels and levels of unconjugated estriol are reduced whereas that of hCG and inhibin A is elevated.
Screening for gestational diabetes especially in the women with low risk is routinely not required. The woman in the previously described case study does not appear to have any risk factor for development of gestational diabetes.
Prescription of iron tablets is required only in case of women at a high risk for development of anemia or those who are already anemic (as evidenced by blood studies). Low-risk women with normal blood values do not require routine iron supplementation during pregnancy. Iron supplementation is not 7routinely offered to all pregnant women in developed countries. However, this may not be the case in developing countries where anemia is more prevalent amongst the women of childbearing age groups.
The clock moves forward to 28 weeks of gestation…
Woman is feeling well. Though she is not experiencing any unusual symptoms such as abdominal pain, bleeding or leaking per vaginum, etc. she complains of experiencing extreme fatigue and weakness. She has started perceiving fetal movements. Her hemoglobin levels performed during this visit was found to be 9 g/dL.
Q. 4. Does she require any change in medication at this point of time?
- Blood transfusion
- Calcium tablets
- Administration of RhoGAM
- Iron tablets
Ans. D (Iron tablets)
A hemoglobin level of less than 10 g/dL needs to be investigated and oral hematinics (iron supplements) be started. If the period of gestation is less than 30 completed weeks, oral iron preparations (containing 50–100 mg of elemental iron with 500 μg of folic acid) must be prescribed in divided doses. Blood transfusion may be required in cases where there is not enough time to achieve a reasonable hemoglobin levels before delivery, e.g. patient presents with severe anemia beyond 36 weeks; there is acute blood loss or associated infections; hemoglobin levels less than 6 gm%, etc.
Routine supplementation with calcium in the dosage of 1,200 mg is routinely required during pregnancy. Administration of RhoGAM at 28 weeks is required in nonimmunized Rh-negative women. The previously described case study does not give any indication that the woman is Rh negative.