Journal of Clinical Studies & Medical Case Reports Category: Medical Type: Mini Review

Isolated Abnormal Levels of Maternal Alpha Feto-Protein: Is it Significant? A Mini Review

Mohammad Jaffal1, Marco Mouanness1 and Anastasia Salame2*
1 Department Of Obstetrics And Gynecology, American University Of Beirut Medical Center, Beirut, Lebanon
2 Department Of Reproductive Endocrinology And Infertility, Fakih Fertility Center - Al Ain City, Abu Dhabi, United Arab Emirates

*Corresponding Author(s):
Anastasia Salame
Department Of Reproductive Endocrinology And Infertility, Fakih Fertility Center - Al Ain City, Abu Dhabi, United Arab Emirates
Tel:+971 54 3996368,
Email:dranastasiasalame@hotmail.com

Received Date: Feb 10, 2020
Accepted Date: Feb 17, 2020
Published Date: Feb 24, 2020

Abstract

Alpha-feto protein has been used in conjunction with other markers for decades for fetal well-being assessment. Multiple reports exist on the source of this maternally measured glycoprotein as well as on the acceptable upper and lower limits of the normal values. The Dilemma persists however in the setting of isolated elevation of AFP in terms of interpretation of it significance as well it s possible association with adverse pregnancy outcomes.

Keywords

Alpha-fetoproteins; Pregnancy; Prenatal diagnosis

MINI REVIEW

Throughout the course of ante-natal obstetrical care, multiple screening approaches were designed to verify the appropriate development and growth of the fetus. So far, the cause-effect relationship hasn’t been fully understood between all the variables and the negative ante-natal and post-natal outcomes. Of these variables is the alpha-fetoprotein, a maternal serum marker that is measured usually at the beginning of the second trimester. Originally, Alpha-Fetoprotein (AFP) is a glycoprotein of fetal origin produced by the yolk sac, liver and gastrointestinal system in early pregnancy [1]. This protein has the ability to cross the feto-maternal barrier whether intact or due to an unknown damage resulting in detectable values in the maternal serum. After extensive research, maternal serum alpha feto-protein levels became a part of the triple (unconjugated estriol (uE3), hCG, and AFP levels) and quadruple (unconjugated estriol (uE3), hCG, AFP and inhibin A levels) ante-natal screening tests for the assessment of the fetal wellbeing. The different combinations of the mentioned markers and their most common associated abnormalities are presented in table 1. Elevated values more than2.0 or 2.5 MoM as the upper limit of normal usually warrant further investigations to rule out congenital malformations such as Neural Tube Defects (NTD) and gastro-intestinal abnormalities. However, the extensive investigations that are performed ante-nataly including the detailed ultrasounds might show a morphologically normal fetus. It should be highlighted that race and ethnicity, gestational age, multifetal gestation, maternal weight and diabetes status should be taken into consideration when interpreting the reported results as they have been shown to affect the maternal serum alpha fetoprotein levels. 

 

AFP

Estriol

Inhibin A

hCG

NTD/ Abdominal wall defects

Increased

Not affected

Not affected

Not affected

Trisomy 18

Decreased

Decreased

Not affected

Decreased

Trisomy 21

Decreased

Decreased

Increased

Increased

Table 1: Triple and Quadruple antenatal screening tests and the most common associated anomalies.

Studies done so far revealed a hypothetical link between unexplained isolated elevated levels of AFP (above 2.0 MoM) and adverse pregnancy outcomesnamely preterm premature rupture of membranes, preterm birth and low birth weight with an OR of 10.4, 3.5, 2.7 and 2.6 respectively [2-4]. Further evaluations revealed a possible association with life threatening situations such as pre-eclampsia and Intra-Uterine Fetal Demise (IUFD). In 2008, 295 pregnant women who had second trimester MSAFP screening were followed throughout pregnancy in order to document the post-natal outcomes. It was found that significantly higher MSAFP levels were associated with preterm labor, pre-eclampsia, oligo-hydraminios and low birth weight [5]. In 2017, another study showed that elevated MSAFP was associated with a 7.254 OR risk of having poor pregnancy outcomes, with an OR of 4.4 of IUFD [6,7]. It must be noted as well that lower than normal MSAFP levels can be associated with aneuploidies, miscarriages, and intra-uterine fetal demises [8]. However, according to a meta-analysis performed by Goto, et al. in a trial to detect the predictive potential of abnormal values of maternal serum markers and small for gestational age babies, the diagnostic accuracy of both MSAFP and human chorionic gonadotropin was found to be low. In other words, if the pregnant patient was found to have isolated abnormally elevated MSAFP or hCG during the screening tests, a direct link with Intra-Uterine Growth Restriction (IUGR) and Small for Gestational Age (SGA) can’t be assumed [9]. Therefore isolated abnormal MoM values should be interpreted cautiously. Pregnant patients who are found to have elevated MSAFP should be managed as high risk pregnancies and extensive workup should be done in order to assure a plausible ante- and post-natal outcome.

REFERENCES

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Citation: Jaffal M, Mouanness M, Salame A (2020) Isolated Abnormal Levels of Maternal Alpha Feto-Protein: Is it Significant? A Mini Review. J Clin Stud Med Case Rep 7: 081.

Copyright: © 2020  Mohammad Jaffal, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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