This blog focuses on what is important for any woman who is anxiously awaiting the positive results of β-hCG (human chorionic gonadotropin). Depending on the levels of β-hCG, subsequent ultrasound examinations significantly improve the overall quality of care for pregnant women, and clarify the following topics:
Determining or confirmation of the pregnancy location,
Estimation of gestational age (dating),
Recognition of symptoms of failure, or disruption of early pregnancy,
Recognition of multiple pregnancies,
Detection of uterine abnormalities, or pathologies, that increase the risks of abortion,
Detection of pathological, non-palpable, cystic adnexal masses.
The possibility of further clarification of the above-mentioned topics is the key to ensuring maximum safety and effectiveness, therefore routine ultrasound during pregnancy is the normative basis for healthcare institutions in Ukraine. There is a consensus that the use of first trimester ultrasound should be performed transvaginally due to a more accurate positioning of the transducer and a larger decision. In Ukraine, it is obvious that women should be evaluated around 3-4 weeks after the positive results of human chorionic gonadotropin are received. The most sensitive urinary pregnancy tests currently available without a prescription can result in women who are concerned about the episode of contraception failure, doing serial tests and getting the optimistic resulting values earlier than pregnancy can be detected with ultrasound.
Biochemical pregnancy can be detected 1 week before the period that is missed, and about 2-3 weeks before the first confirmation of pregnancy location on ultrasound. Whenever pregnancy is confirmed biochemically, but ultrasound cannot locate the fetus, the management should include a check if the urine pregnancy test is definitely positive and then goes on a menstrual history, clarifying whether the woman knows when conception is likely happened, and when the pregnancy test first became positive. The initial quantitative level of β-hCG may also be important for safe management. Typically, when pregnancy cannot be found at the second appointment, the corresponding management is a serial human chorionic gonadotropin tests with referral towards an early pregnancy.
The notion that there is a discriminatory zone above which ultrasound should visualize pregnancy, and below which pregnancy should not be seen, has outlived its usefulness. In the case of viable intrauterine pregnancy, the threshold of human chorionic gonadotropin may be from 1,000 to 3,000 mIU/ml or even more. Nevertheless, the increase and decrease in β-hCG levels in both ectopic pregnancy and incomplete miscarriage is very different from the normal pregnancy, and ultrasound signs may be present to assist diagnosis if the uterine and adnexal areas are carefully evaluated regardless of β-hCG level.
Transvaginal ultrasound in combination with the evaluation of serum human chorionic gonadotropin is the best way to diagnose ectopic pregnancy. All medical institutions in Ukraine now have access to serum β-hCG tests, which are useful in assessing women for the progress of pregnancy of unknown location or progressing pregnancy. If the doctor has any doubts, the serum β-hCG test can be repeated.
The human chorionic gonadotropin is secreted from pregnancy and works in conjunction with progesterone secreted by the corpus luteum to support the development of the embryo and fetus until 11-16 weeks when the placenta is formed. β-hCG is found in maternal blood samples by radioimmunoassay 7-8 days after ovulation, although in most cases pregnancy tests will be positive (>2 mlU/ml) by 10 or 11 days post-luteinizing-hormone surge (or hCG-injection in IVF pregnancies). Usually, the increase in β-hCG is 63-100% in 48 hours, although in very early pregnancies, this increase may be slower. Peak levels in about 8-10 weeks, and then begin to fall, remaining at lower levels during the remaining pregnancy.
The Discriminatory Zone (“Obsolete” Concept)
This is the level at which intrauterine pregnancy is expected to be seen, but at present it is usually considered an erroneous concept because of the range of human chorionic gonadotropin showing significant differences. Ultrasound features of ectopic pregnancy may be present at relatively low levels of β-hCG, so the indication of ultrasound and its interpretation should be based on the medical history rather than at the β-hCG level. Calculations and models containing β-hCG used in the diagnosis of pregnancy location contain shortcomings.
A single assessment of maternal progesterone blood levels can give an indication, whether the pregnancy can progress, or failed. Low levels usually indicate non-viability, but, like the level of human chorionic gonadotropin, it does not inform the clinician where the pregnancy is in the pelvic area.
The term “PUL” is suitable when ultrasound cannot determine the place of pregnancy in a woman with a positive pregnancy test. A systematic approach is necessary to avoid an erroneous diagnosis and to provide timely diagnosis and treatment when pregnancy is an ectopic.
There are many places for ectopic pregnancy and characteristic ultrasound results in a large number of cases that have been considered in this post. Expected management is appropriate in certain cases, when a woman is stable, as often, spontaneous resolution occurs.
Those who are unable to conceive in the usual way, and those who prefer not to have biological children, can consider alternative options for family building. Such options include adoption, gestational surrogacy, donor embryos, donor sperm and donor eggs. Parents Life is ready to help such people build a family.