Maternal serum hCG and alpha-fetoprotein levels in pregnancies conceived after IVF or ICSI with fresh and frozen-thawed embryos

The impact of fresh versus frozen-thawed embryos on maternal serum analyte levels in IVF singleton and twin pregnancies

PURPOSE

To determine whether embryo cryopreservation is associated with a difference in maternal serum analyte levels in singleton and twin pregnancies conceived via in vitro fertilization (IVF).

METHODS

This was a retrospective cohort study of singleton and twin pregnancies conceived via IVF from a university health system from 01/2014 to 09/2019. Patients with available first and second trimester serum analyte data were included and analyzed separately. Multiple of the median (MoM) values for free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein A, alpha-fetoprotein (AFP), Inhibin A, and unconjugated estriol (uE3) were compared between two groups: pregnancies conceived after the transfer of fresh embryos versus pregnancies conceived after the transfer of frozen-thawed embryos. Multiple linear regression of log MoM values with F test was performed to adjust for potential confounders.

RESULTS

For singletons, fresh embryos were associated with a lower median first trimester free β-hCG (1.00 MoM vs. 1.14 MoM; parameter estimate [PE] 0.90, 95% CI 0.82-0.99, p = .03) compared to frozen-thawed embryos. Fresh embryos were also associated with a lower median second trimester uE3 (0.93 MoM vs. 1.05 MoM; PE 0.88, CI 0.83-0.95, p = .0004) and AFP (1.02 MoM vs. 1.19 MoM; PE 0.91, CI 0.84-0.99, p = .02) compared to frozen-thawed embryos in singletons. There were no significant differences between median first and second trimester serum analytes in twin pregnancies compared between the two groups.

CONCLUSION

Singleton pregnancies derived from fresh embryos had lower first (free β-hCG) and second (uE3 and AFP) trimester analytes compared to frozen-thawed embryos. Twin pregnancies demonstrated no difference between the groups.

Diagnostic value of a single β-hCG test in predicting reproductive outcomes in women undergoing cleavage embryo transfer: a retrospective analysis from a single center

Purpose

The present study investigated the role of β-hCG in predicting reproductive outcomes and established optimal β-hCG cutoff values in women undergoing cleavage embryo transfer.

Methods

The patients were transferred with fresh or frozen-thawed embryos and had serum β-hCG levels tested on the 14th day post-embryo transfer. Serum β-hCG levels were compared between different groups. Different cutoff values of β-hCG were established and used to divide the patients into different groups. Reproductive outcomes between groups based on β-hCG levels were compared.

Results

Significant discrepancies in general characteristics were observed in the subgroups. The cutoff values of β-hCG for predicting the presence/absence of pregnancy, biochemical pregnancy/clinical pregnancy, presence/absence of adverse pregnancy outcomes, and singleton/twin live birth in the cleavage groups were 89.6, 241.1, 585.9, and 981.1 mIU/L, respectively. Biochemical pregnancy rates and adverse pregnancy outcome rates significantly decreased from the low β-hCG group to the higher β-hCG group in sequence. Significantly higher full-term live birth rates were observed in the highest β-hCG group (P < 0.001).

Conclusion

Serum β-hCG levels were strongly associated with reproductive outcomes. However, the interpretation of β-hCG levels must consider the number and quality of embryos and transfer protocols. When β-hCG was tested on a fixed day post-ET, different cutoff values were required for the prediction of early clinical outcomes. The association between β-hCG and obstetric outcomes must be investigated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-022-01455-1.

To investigate the association between β-hCG and reproductive and obstetrical outcomes in women with cleavage ET and to establish different β-hCG cutoff values for the prediction of reproductive outcomes, this study retrospectively included 6909 infertile women who were divided into different groups based on the number and quality of transferred embryos, age, and transfer protocols. The cutoff values of β-hCG for predicting the presence/absence of pregnancy, biochemical pregnancy/clinical pregnancy, presence/absence of adverse pregnancy outcomes, singleton/twin live birth in the cleavage groups were 89.6, 241.1, 585.9, and 981.1 mIU/L, respectively. Biochemical pregnancy rates and adverse pregnancy outcome rates decreased significantly in the higher β-hCG groups. In conclusion, the interpretation of β-hCG levels must consider the number and quality of embryos and transfer protocols. When β-hCG was tested on a fixed day post-ET, different cutoff values were required for the prediction of early clinical outcomes.

Pregnancy outcomes of women with elevated second-trimester maternal serum alpha-fetoprotein

OBJECTIVE

The aim of this study was to investigate the overall distribution of pregnancy outcomes in women with elevated second-trimester maternal serum alpha-fetoprotein (MS-AFP), and to determine the risk of adverse pregnancy outcomes (APOs) by MS-AFP level.

MATERIALS AND METHODS

We retrospectively analyzed the clinical data of 429 women with elevated MS-AFP (≥2.5 multiple of the median (MOM)) and 1555 women with normal MS-AFP (0.5-2.49MOM) from a total of 46,741 prenatally screened singleton pregnant women. The overall distribution of APOs of the two groups, the risk of APOs by MS-AFP level, and the predictive value of elevated MS-AFP to APOs were analyzed.

RESULTS

The incidence rate of APOs in elevated MS-AFP group was significantly higher than that in normal MS-AFP group (42.89 vs. 8.23%). In elevated MS-AFP group, the top three APOs, in term of incidence rate, were structural fetal abnormalities (7.93%), spontaneous abortion (7.46%) and preterm birth (7.23%); regarding to the risk, the top three APOs were stillbirth, spontaneous abortion and early-onset preeclampsia (odds ratio 35.98, 20.81 and 8.58 respectively). For structural fetal abnormalities, MS-AFP had predictive values for fetal open neural tube defects (ONTDs), gastroschisis and multiple malformations.

CONCLUSION

Elevated MS-AFP is associated with increased risks of APOs. ONTDs complicate merely a small proportion of pregnancies with elevated MS-AFP, and the rest of them have high risks of obstetric complications. MS-AFP can help to identify these women at high risk of APOs in earlier second-trimester.

First-trimester maternal serum alpha-fetoprotein is not a good predictor for adverse pregnancy outcomes: a retrospective study of 3325 cases

Background

It is well known that second-trimester maternal serum alpha-fetoprotein (MS-AFP) is a predictor for adverse pregnancy outcomes (APOs), such as preterm birth, stillbirth, preeclampsia and small for gestational age (SGA). However, it is unknown whether first-trimester MS-AFP is also predictive of APOs.

Methods

We retrospectively reviewed the data on the first-trimester MS-AFP levels and pregnancy outcomes of 3325 singleton pregnant women. The cutoff value of 2.5 multiple of the median (MoM) was used to evaluate the risks of APOs regarding MS-AFP. The receiver operating characteristic (ROC) curves were used to evaluate the predictive efficiencies of MS-AFP to these disorders.

Results

A total of 181 pregnancies resulted in preterm birth, 32 in stillbirth, 81 in preeclampsia, and 362 in SGA. Compared to women with MS-AFP < 2.5MoM, those with MS-AFP ≥ 2.5MoM had increased risks (odds ratio, 95% confidence interval) of preterm birth (2.53, 1.65~3.88), preeclampsia (3.05, 1.71~5.43) and SGA (1.90, 1.34~2.69), and had an earlier distribution of gestational weeks at delivery (P = 0.004) and a lower distribution of neonatal birth weights (P = 0.000), but the actual between-group differences were minuscule. The areas under ROC curves were 0.572 (P = 0.001), 0.579 (P = 0.015) and 0.565 (P = 0.000) for preterm birth, preeclampsia and SGA, respectively. Subdivisions for the disorders did not obviously improve the performances of MS-AFP.

Conclusions

Elevated first-trimester MS-AFP is associated with increased risk of preterm birth, preeclampsia and SGA. However, the predictive efficiencies were low and it is not a good predictor for these APOs.

The association between first trimester AFP to PAPP-A ratio and placentally-related adverse pregnancy outcome

INTRODUCTION

Low maternal serum levels of pregnancy-associated plasma protein A (PAPP-A) measured in the first trimester and high levels of alpha fetoprotein (AFP) measured in the second trimester have been associated with adverse pregnancy outcomes reflective of placental insufficiency, and there is a synergistic relationship between the two. We investigated the utility as a screening test of a simple ratio of maternal serum AFP to PAPP-A (AFP:PAPP-A) measured in the first trimester.

METHODS

We studied 4057 nulliparous women with a singleton pregnancy from the Pregnancy Outcome Prediction (POP) study. We studied the predictive ability for adverse outcome of the AFP:PAPP-A ratio measured in the first trimester with and without correction for maternal weight and gestational age at measurement. We compared the AFP:PAPP-A ratio with corrected AFP and PAPP-A on their own and in combination.

RESULTS

An AFP:PAPP-A ratio >10 was associated with placentally-related adverse outcomes, including fetal growth restriction (risk ratio (RR) 3.74, 95% confidence interval (CI) 2.30-6.09), severe preeclampsia (RR 2.12, 95% CI 1.39-3.25) and stillbirth (RR 5.05, 95% CI 1.48-17.18). The ratio performed favorably in predicting adverse pregnancy outcomes when compared with corrected measurements of either AFP or PAPP-A, and was equivalent to a model combining the two. Its predictive ability was not affected by correction for maternal weight or gestational age at measurement.

DISCUSSION

An elevated maternal AFP:PAPP-A ratio in the first trimester is associated with placentally-related adverse outcomes in a cohort of unselected nulliparous women.

Trends in primeval β-hCG level increment after fresh and frozen-thawed IVF embryo transfer cycles

Mid-trimester beta-human chorionic gonadotropin (BHCG) levels are considerably higher in pregnancies resulting from frozen embryo transfer (FET) compared with fresh (FRET), leading to a higher false positive rate in aneuploidy screening tests. We aimed to investigate the dynamics of BHCG increment and its predictive value for cycle outcome. A retrospective analysis of FRET and FET cycles. BHCG values on days 14 and 16 post embryo transfer were compared and stratified according to the number of sacs demonstrated on US scan at six weeks gestation, and pregnancy outcome (biochemical pregnancy, ectopic pregnancy, spontaneous abortion, and a singleton or twin birth). A prediction model for live birth was built. A total of 430 treatment cycles were analyzed. The average BHCG levels were significantly higher in FET compared with FRET group in nonviable pregnancies on day 14, 450 vs. 183 IU/L, p < .05 and day 16, 348 vs. 735 IU/L, p < .05, respectively. The increment of BHCG was significantly steeper in the FET compared with FRET group in biochemical pregnancies (F = 6.485, p = .012*). Optimal cutoff level for live birth prediction in the FRET group was 211 IU/L (sensitivity 84%, specificity 76.2%) for day 14 and 440 IU/L (sensitivity 86.0% and specificity 72.5%) for day 16. The increment in BHCG differed significantly between the FRET and FET cycles in nonviable pregnancies. Nevertheless, the difference in BHCG levels observed in the second trimester in pregnancies conceived after FRET and FET cycle may begin as early as the fourth week of pregnancy.

Placental volume and other first-trimester outcomes: are there differences between fresh embryo transfer, frozen-thawed embryo transfer and natural conception?

RESEARCH QUESTION

Does mode of conception influence placental volume and other first-trimester outcomes?

DESIGN

This retrospective single-centre case-control study led in Dijon University Hospital included 252 singleton pregnancies (84 IVF with either fresh embryo transfer or frozen-thawed embryo transfer [FET] and 168 natural conceptions). First-trimester placental volume, uterine artery pulsatility index and maternal serum PAPP-A and beta-HCG were measured. Statistical analyses were adjusted for gestational age, the newborn's gender, maternal age, parity, body mass index and smoking status.

RESULTS

Placental volume was significantly greater in the FET group than in the control group (P = 0.043) and fresh embryo transfer (P = 0.023) groups. At birth, fresh embryo transfer newborns were significantly smaller than controls (P = 0.01) and FET newborns (P = 0.008). Postpartum haemorrhage was far more frequent in FET than in controls and fresh embryo transfer group (38.1%, 2.6% and 1.9%, respectively; P < 0.0001). Placental volume positively correlated with PAPP-A, beta-HCG and the newborn's birth weight, and negatively correlated with uterine artery pulsatility index.

CONCLUSIONS

Placental volume and other first-trimester parameters are modified by IVF with fresh embryo transfer and FET compared with natural conception, but with opposite trends. Given the different protocols used for these techniques, hormonal treatment per se may have a major effect on pregnancy outcomes through the modification of placental invasiveness.

First trimester ultrasound tests alone or in combination with first trimester serum tests for Down's syndrome screening

BACKGROUND

Down's syndrome occurs when a person has three, rather than two copies of chromosome 21; or the specific area of chromosome 21 implicated in causing Down's syndrome. It is the commonest congenital cause of mental disability and also leads to numerous metabolic and structural problems. It can be life-threatening, or lead to considerable ill health, although some individuals have only mild problems and can lead relatively normal lives. Having a baby with Down's syndrome is likely to have a significant impact on family life.Non-invasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing.Before agreeing to screening tests, parents need to be fully informed about the risks, benefits and possible consequences of such a test. This includes subsequent choices for further tests they may face, and the implications of both false positive and false negative screening tests (i.e. invasive diagnostic testing, and the possibility that a miscarried fetus may be chromosomally normal). The decisions that may be faced by expectant parents inevitably engender a high level of anxiety at all stages of the screening process, and the outcomes of screening can be associated with considerable physical and psychological morbidity. No screening test can predict the severity of problems a person with Down's syndrome will have.

OBJECTIVES

To estimate and compare the accuracy of first trimester ultrasound markers alone, and in combination with first trimester serum tests for the detection of Down's syndrome.

SEARCH METHODS

We carried out extensive literature searches including MEDLINE (1980 to 25 August 2011), Embase (1980 to 25 August 2011), BIOSIS via EDINA (1985 to 25 August 2011), CINAHL via OVID (1982 to 25 August 2011), and The Database of Abstracts of Reviews of Effects (the Cochrane Library 2011, Issue 7). We checked reference lists and published review articles for additional potentially relevant studies.

SELECTION CRITERIA

Studies evaluating tests of first trimester ultrasound screening, alone or in combination with first trimester serum tests (up to 14 weeks' gestation) for Down's syndrome, compared with a reference standard, either chromosomal verification or macroscopic postnatal inspection.

DATA COLLECTION AND ANALYSIS

Data were extracted as test positive/test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS criteria. We used hierarchical summary ROC meta-analytical methods to analyse test performance and compare test accuracy. Analysis of studies allowing direct comparison between tests was undertaken. We investigated the impact of maternal age on test performance in subgroup analyses.

MAIN RESULTS

We included 126 studies (152 publications) involving 1,604,040 fetuses (including 8454 Down's syndrome cases). Studies were generally good quality, although differential verification was common with invasive testing of only high-risk pregnancies. Sixty test combinations were evaluated formed from combinations of 11 different ultrasound markers (nuchal translucency (NT), nasal bone, ductus venosus Doppler, maxillary bone length, fetal heart rate, aberrant right subclavian artery, frontomaxillary facial angle, presence of mitral gap, tricuspid regurgitation, tricuspid blood flow and iliac angle 90 degrees); 12 serum tests (inhibin A, alpha-fetoprotein (AFP), free beta human chorionic gonadotrophin (ßhCG), total hCG, pregnancy-associated plasma protein A (PAPP-A), unconjugated oestriol (uE3), disintegrin and metalloprotease 12 (ADAM 12), placental growth factor (PlGF), placental growth hormone (PGH), invasive trophoblast antigen (ITA) (synonymous with hyperglycosylated hCG), growth hormone binding protein (GHBP) and placental protein 13 (PP13)); and maternal age. The most frequently evaluated serum markers in combination with ultrasound markers were PAPP-A and free ßhCG.Comparisons of the 10 most frequently evaluated test strategies showed that a combined NT, PAPP-A, free ßhCG and maternal age test strategy significantly outperformed ultrasound markers alone (with or without maternal age) except nasal bone, detecting about nine out of every 10 Down's syndrome pregnancies at a 5% false positive rate (FPR). In both direct and indirect comparisons, the combined NT, PAPP-A, free ßhCG and maternal age test strategy showed superior diagnostic accuracy to an NT and maternal age test strategy (P < 0.0001). Based on the indirect comparison of all available studies for the two tests, the sensitivity (95% confidence interval) estimated at a 5% FPR for the combined NT, PAPP-A, free ßhCG and maternal age test strategy (69 studies; 1,173,853 fetuses including 6010 with Down's syndrome) was 87% (86 to 89) and for the NT and maternal age test strategy (50 studies; 530,874 fetuses including 2701 Down's syndrome pregnancies) was 71% (66 to 75). Combinations of NT with other ultrasound markers, PAPP-A and free ßhCG were evaluated in one or two studies and showed sensitivities of more than 90% and specificities of more than 95%.High-risk populations (defined before screening was done, mainly due to advanced maternal age of 35 years or more, or previous pregnancies affected with Down's syndrome) showed lower detection rates compared to routine screening populations at a 5% FPR. Women who miscarried in the over 35 group were more likely to have been offered an invasive test to verify a negative screening results, whereas those under 35 were usually not offered invasive testing for a negative screening result. Pregnancy loss in women under 35 therefore leads to under-ascertainment of screening results, potentially missing a proportion of affected pregnancies and affecting test sensitivity. Conversely, for the NT, PAPP-A, free ßhCG and maternal age test strategy, detection rates and false positive rates increased with maternal age in the five studies that provided data separately for the subset of women aged 35 years or more.

AUTHORS' CONCLUSIONS

Test strategies that combine ultrasound markers with serum markers, especially PAPP-A and free ßhCG, and maternal age were significantly better than those involving only ultrasound markers (with or without maternal age) except nasal bone. They detect about nine out of 10 Down's affected pregnancies for a fixed 5% FPR. Although the absence of nasal bone appeared to have a high diagnostic accuracy, only five out of 10 affected Down's pregnancies were detected at a 1% FPR.

First and second trimester serum tests with and without first trimester ultrasound tests for Down's syndrome screening

BACKGROUND

Down's syndrome occurs when a person has three copies of chromosome 21 (or the specific area of chromosome 21 implicated in causing Down's syndrome) rather than two. It is the commonest congenital cause of mental disability. Non-invasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing.  Before agreeing to screening tests, parents need to be fully informed about the risks, benefits and possible consequences of such a test. This includes subsequent choices for further tests they may face, and the implications of both false positive (i.e. invasive diagnostic testing, and the possibility that a miscarried fetus may be chromosomally normal) and false negative screening tests (i.e. a fetus with Down's syndrome will be missed). The decisions that may be faced by expectant parents inevitably engender a high level of anxiety at all stages of the screening process, and the outcomes of screening can be associated with considerable physical and psychological morbidity. No screening test can predict the severity of problems a person with Down's syndrome will have.

OBJECTIVES

To estimate and compare the accuracy of first and second trimester serum markers with and without first trimester ultrasound markers for the detection of Down's syndrome in the antenatal period, as combinations of markers.

SEARCH METHODS

We conducted a sensitive and comprehensive literature search of MEDLINE (1980 to 25 August 2011), Embase (1980 to 25 August 2011), BIOSIS via EDINA (1985 to 25 August 2011), CINAHL via OVID (1982 to 25 August 2011), the Database of Abstracts of Reviews of Effectiveness (the Cochrane Library 25 August 2011), MEDION (25 August 2011), the Database of Systematic Reviews and Meta-Analyses in Laboratory Medicine (25 August 2011), the National Research Register (Archived 2007), and Health Services Research Projects in Progress database (25 August 2011). We did not apply a diagnostic test search filter. We did forward citation searching in ISI citation indices, Google Scholar and PubMed 'related articles'. We also searched reference lists of retrieved articles SELECTION CRITERIA: Studies evaluating tests of combining first and second trimester maternal serum markers in women up to 24 weeks of gestation for Down's syndrome, with or without first trimester ultrasound markers, compared with a reference standard, either chromosomal verification or macroscopic postnatal inspection.

DATA COLLECTION AND ANALYSIS

Data were extracted as test positive/test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS criteria. We used hierarchical summary ROC meta-analytical methods to analyse test performance and compare test accuracy. Analysis of studies allowing direct comparison between tests was undertaken. We investigated the impact of maternal age on test performance in subgroup analyses.

MAIN RESULTS

Twenty-two studies (reported in 25 publications) involving 228,615 pregnancies (including 1067 with Down's syndrome) were included. Studies were generally high quality, although differential verification was common with invasive testing of only high risk pregnancies. Ten studies made direct comparisons between tests. Thirty-two different test combinations were evaluated formed from combinations of eight different tests and maternal age; first trimester nuchal translucency (NT) and the serum markers AFP, uE3, total hCG, free βhCG, Inhibin A, PAPP-A and ADAM 12. We looked at tests combining first and second trimester markers with or without ultrasound as complete tests, and we also examined stepwise and contingent strategies.Meta-analysis of the six most frequently evaluated test combinations showed that a test strategy involving maternal age and a combination of first trimester NT and PAPP-A, and second trimester total hCG, uE3, AFP and Inhibin A significantly outperformed other test combinations that involved only one serum marker or NT in the first trimester, detecting about nine out of every 10 Down's syndrome pregnancies at a 5% false positive rate. However, the evidence was limited in terms of the number of studies evaluating this strategy, and we therefore cannot recommend one single screening strategy.

AUTHORS' CONCLUSIONS

Tests involving first trimester ultrasound with first and second trimester serum markers in combination with maternal age are significantly better than those without ultrasound, or those evaluating first trimester ultrasound in combination with second trimester serum markers, without first trimester serum markers. We cannot make recommendations about a specific strategy on the basis of the small number of studies available.

Serum hCG-β levels of postovulatory day 12 and 14 with the sequential application of hCG-β fold change significantly increased predictability of pregnancy outcome after IVF-ET cycle

PURPOSE

To investigate hCG-β level on postovulatory day (POD) 12 and its fold increase as predictors for pregnancy outcome after in vitro fertilization (IVF) cycles.

METHODS

A retrospective cohort study was performed in total 1408 fresh and 598 frozen cycles between November 2008 and October 2011, which resulted in biochemical pregnancy, early pregnancy loss, or live birth of singleton pregnancy. The serum hCG-β levels of POD 12 and 14 were compared among biochemical pregnancy, early pregnancy loss, and live birth groups. The cutoff values of POD 12 and 14 hCG-β levels and the degree of hCG-β increase from POD 12 to 14 were determined for each pregnancy outcome.

RESULTS

POD 12 and 14 hCG-β levels stratified based on pregnancy outcomes were significantly different among the biochemical pregnancy, early pregnancy loss, and live birth in both fresh and frozen cycles. Serum hCG-β levels of POD 12 and 14 and the fold increase of hCG-β levels from POD 12 to 14 significantly predict pregnancy outcomes after fresh and frozen cycles. Among these, the cutoff value of POD 14 hCG-β had the highest sensitivity and positive predictive value (PPV). In fresh cycles, the cutoff values of POD 12 and 14 serum hCG-β levels for clinical pregnancies were 30.2 mIU/mL (sensitivity 81.3 %, specificity 79.6 %, and PPV 92.3 %) and 70.5 mIU/mL (sensitivity 88.4 %, specificity 85.2 %, and PPV 94.7 %). In pregnancies with POD 12 serum hCG-β levels ≥30.2 mIU/mL, the cutoff level of increase of hCG-β for clinical pregnancy was 2.56 (sensitivity 73.6 %, specificity 72.4 %, and PPV 97.8 %). Sequential application of cutoff values such as POD 12 hCG-β and fold increase of hCG-β improved predictability of pregnancy outcome as compared with that of POD 12 hCG-β alone. The cutoff values of POD 12 and 14 serum hCG-β levels for live birth were 40.5 mIU/mL (sensitivity 75.2 %, specificity 72.6 %, PPV 78.9 %) and 104.5 mIU/mL (sensitivity 80.3 %, specificity 74.1 %, PPV 80.8 %). In the frozen cycles, the cutoff values of POD 12 and 14 serum hCG-β level for clinical pregnancy were 31.5 IU/L (sensitivity 80.4 %, specificity 71.1 % and PPV 90 %) and 43.5 mIU/mL (sensitivity 72.6 %, specificity 71.7 %, PPV 77.2 %). In pregnancies with POD 12 serum hCG-β level ≥31.5 mIU/mL, the cutoff value for fold increase of hCG-β was 2.38 for clinical pregnancy (sensitivity 81.6 %, specificity 71.4 % and PPV 87.9 %). The cutoff values of POD 12 and 14 for live birth were 43.5 mIU/mL (sensitivity 72.6 %, specificity 71.7 %, PPV 77.2 %) and 101.6 mIU/mL (sensitivity 79.6 %, specificity 71.1 %, PPV 78.4 %). Sequential application of cutoff values for POD 12 hCG-β level and fold increase of hCG-β significantly increased PPV for live birth but not clinical pregnancy in frozen cycles.

CONCLUSIONS

Early prediction of pregnancy outcome by using POD 12 and 14 cutoff levels and sequential application of cutoff value of fold increase could provide appropriate reference to health care providers to initiate earlier management of high-risk pregnancies and precise follow-up of abnormal pregnancies.

Association of the very early rise of human chorionic gonadotropin with adverse outcomes in singleton pregnancies after in vitro fertilization

OBJECTIVE

To determine if very early serum hCG, a marker of trophoblast differentiation, is associated with adverse perinatal outcomes in singleton pregnancies.

DESIGN

Retrospective cohort study.

SETTING

University fertility program.

PATIENT(S)

A total of 360 singleton IVF live births.

INTERVENTION(S)

Serial hCG measurements were used to determine the within-woman slope for hCG (hCG rise).

MAIN OUTCOMES MEASURE(S)

Primary outcomes included birth weight and gestational age at delivery. Statistical comparisons used t test, chi-square test, and linear and logistic regressions as appropriate.

RESULT(S)

hCG rise was positively associated with birth weight but not gestational age at delivery. Infant sex, gestational age, and type of embryo transfer (fresh vs. frozen/thawed) were significantly associated with birth weight and confounded the associations of interest. hCG rise was slower among subjects delivering an infant with low birth weight (slope 0.386 ± 0.05 vs. 0.407 ± 0.06) or small for gestational age (slope 0.371 ± 0.07 vs. 0.406 ± 0.06). Analysis of hCG rise by quartile showed that, compared with the first quartile (slowest), subjects with a rate of hCG rise in the fourth quartile (fastest) had a significantly decreased risk of delivering an infant of low birth weight. No relationship was noted between hCG rise and hypertensive disorders of pregnancy.

CONCLUSION(S)

Slower very early first-trimester hCG rise is associated with low birth weight but not gestational age at delivery among singleton IVF conceptions. The rate of increase in serum hCG may reflect early trophoblast differentiation and placentation and, possibly, may predict subsequent development.

Urine tests for Down's syndrome screening

BACKGROUND

Down's syndrome occurs when a person has three copies of chromosome 21, or the specific area of chromosome 21 implicated in causing Down's syndrome, rather than two. It is the commonest congenital cause of mental disability and also leads to numerous metabolic and structural problems. It can be life-threatening, or lead to considerable ill health, although some individuals have only mild problems and can lead relatively normal lives. Having a baby with Down's syndrome is likely to have a significant impact on family life. The risk of a Down's syndrome affected pregnancy increases with advancing maternal age.Noninvasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing. Before agreeing to screening tests, parents need to be fully informed about the risks, benefits and possible consequences of such a test. This includes subsequent choices for further tests they may face, and the implications of both false positive and false negative screening tests (i.e. invasive diagnostic testing, and the possibility that a miscarried fetus may be chromosomally normal). The decisions that may be faced by expectant parents inevitably engender a high level of anxiety at all stages of the screening process, and the outcomes of screening can be associated with considerable physical and psychological morbidity. No screening test can predict the severity of problems a person with Down's syndrome will have.

OBJECTIVES

To estimate and compare the accuracy of first and second trimester urine markers for the detection of Down's syndrome.

SEARCH METHODS

We carried out a sensitive and comprehensive literature search of MEDLINE (1980 to 25 August 2011), EMBASE (1980 to 25 August 2011), BIOSIS via EDINA (1985 to 25 August 2011), CINAHL via OVID (1982 to 25 August 2011), The Database of Abstracts of Reviews of Effectiveness (The Cochrane Library 2011, Issue 7), MEDION (25 August 2011), The Database of Systematic Reviews and Meta-Analyses in Laboratory Medicine (25 August 2011), The National Research Register (archived 2007), Health Services Research Projects in Progress database (25 August 2011). We studied reference lists and published review articles.

SELECTION CRITERIA

Studies evaluating tests of maternal urine in women up to 24 weeks of gestation for Down's syndrome, compared with a reference standard, either chromosomal verification or macroscopic postnatal inspection.

DATA COLLECTION AND ANALYSIS

We extracted data as test positive or test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria. We used hierarchical summary ROC (receiver operating characteristic) meta-analytical methods to analyse test performance and compare test accuracy. We performed analysis of studies allowing direct comparison between tests. We investigated the impact of maternal age on test performance in subgroup analyses.

MAIN RESULTS

We included 19 studies involving 18,013 pregnancies (including 527 with Down's syndrome). Studies were generally of high quality, although differential verification was common with invasive testing of only high-risk pregnancies. Twenty-four test combinations were evaluated formed from combinations of the following seven different markers with and without maternal age: AFP (alpha-fetoprotein), ITA (invasive trophoblast antigen), ß-core fragment, free ßhCG (beta human chorionic gonadotrophin), total hCG, oestriol, gonadotropin peptide and various marker ratios. The strategies evaluated included three double tests and seven single tests in combination with maternal age, and one triple test, two double tests and 11 single tests without maternal age. Twelve of the 19 studies only evaluated the performance of a single test strategy while the remaining seven evaluated at least two test strategies. Two marker combinations were evaluated in more than four studies; second trimester ß-core fragment (six studies), and second trimester ß-core fragment with maternal age (five studies).In direct test comparisons, for a 5% false positive rate (FPR), the diagnostic accuracy of the double marker second trimester ß-core fragment and oestriol with maternal age test combination was significantly better (ratio of diagnostic odds ratio (RDOR): 2.2 (95% confidence interval (CI) 1.1 to 4.5), P = 0.02) (summary sensitivity of 73% (CI 57 to 85) at a cut-point of 5% FPR) than that of the single marker test strategy of second trimester ß-core fragment and maternal age (summary sensitivity of 56% (CI 45 to 66) at a cut-point of 5% FPR), but was not significantly better (RDOR: 1.5 (0.8 to 2.8), P = 0.21) than that of the second trimester ß-core fragment to oestriol ratio and maternal age test strategy (summary sensitivity of 71% (CI 51 to 86) at a cut-point of 5% FPR).

AUTHORS' CONCLUSIONS

Tests involving second trimester ß-core fragment and oestriol with maternal age are significantly more sensitive than the single marker second trimester ß-core fragment and maternal age, however, there were few studies. There is a paucity of evidence available to support the use of urine testing for Down's syndrome screening in clinical practice where alternatives are available.

First trimester serum tests for Down's syndrome screening

BACKGROUND

Down's syndrome occurs when a person has three, rather than two copies of chromosome 21; or the specific area of chromosome 21 implicated in causing Down's syndrome. It is the commonest congenital cause of mental disability and also leads to numerous metabolic and structural problems. It can be life-threatening, or lead to considerable ill health, although some individuals have only mild problems and can lead relatively normal lives. Having a baby with Down's syndrome is likely to have a significant impact on family life.Noninvasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing. However, no test can predict the severity of problems a person with Down's syndrome will have.

OBJECTIVES

The aim of this review was to estimate and compare the accuracy of first trimester serum markers for the detection of Down's syndrome in the antenatal period, both as individual markers and as combinations of markers. Accuracy is described by the proportion of fetuses with Down's syndrome detected by screening before birth (sensitivity or detection rate) and the proportion of women with a low risk (normal) screening test result who subsequently had a baby unaffected by Down's syndrome (specificity).

SEARCH METHODS

We conducted a sensitive and comprehensive literature search of MEDLINE (1980 to 25 August 2011), Embase (1980 to 25 August 2011), BIOSIS via EDINA (1985 to 25 August 2011), CINAHL via OVID (1982 to 25 August 2011), The Database of Abstracts of Reviews of Effectiveness (The Cochrane Library 25 August 2011), MEDION (25 August 2011), The Database of Systematic Reviews and Meta-Analyses in Laboratory Medicine (25 August 2011), The National Research Register (Archived 2007), Health Services Research Projects in Progress database (25 August 2011). We did forward citation searching ISI citation indices, Google Scholar and PubMed 'related articles'. We did not apply a diagnostic test search filter. We also searched reference lists and published review articles.  

SELECTION CRITERIA

We included studies in which all women from a given population had one or more index test(s) compared to a reference standard (either chromosomal verification or macroscopic postnatal inspection). Both consecutive series and diagnostic case-control study designs were included. Randomised trials where individuals were randomised to different screening strategies and all verified using a reference standard were also eligible for inclusion. Studies in which test strategies were compared head-to-head either in the same women, or between randomised groups were identified for inclusion in separate comparisons of test strategies. We excluded studies if they included less than five Down's syndrome cases, or more than 20% of participants were not followed up.

DATA COLLECTION AND ANALYSIS

We extracted data as test positive or test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS (Quality Assessment of Diagnostic Accuracy Studies) criteria. We used hierarchical summary ROC meta-analytical methods or random-effects logistic regression methods to analyse test performance and compare test accuracy as appropriate. Analyses of studies allowing direct and indirect comparisons between tests were undertaken.

MAIN RESULTS

We included 56 studies (reported in 68 publications) involving 204,759 pregnancies (including 2113 with Down's syndrome). Studies were generally of good quality, although differential verification was common with invasive testing of only high-risk pregnancies. We evaluated 78 test combinations formed from combinations of 18 different tests, with or without maternal age; ADAM12 (a disintegrin and metalloprotease), AFP (alpha-fetoprotein), inhibin, PAPP-A (pregnancy-associated plasma protein A, ITA (invasive trophoblast antigen), free βhCG (beta human chorionic gonadotrophin), PlGF (placental growth factor), SP1 (Schwangerschafts protein 1), total hCG, progesterone, uE3 (unconjugated oestriol), GHBP (growth hormone binding protein), PGH (placental growth hormone), hyperglycosylated hCG, ProMBP (proform of eosinophil major basic protein), hPL (human placental lactogen), (free αhCG, and free ßhCG to AFP ratio. Direct comparisons between two or more tests were made in 27 studies.Meta-analysis of the nine best performing or frequently evaluated test combinations showed that a test strategy involving maternal age and a double marker combination of PAPP-A and free ßhCG significantly outperformed the individual markers (with or without maternal age) detecting about seven out of every 10 Down's syndrome pregnancies at a 5% false positive rate (FPR). Limited evidence suggested that marker combinations involving PAPP-A may be more sensitive than those without PAPP-A.

AUTHORS' CONCLUSIONS

Tests involving two markers in combination with maternal age, specifically PAPP-A, free βhCG and maternal age are significantly better than those involving single markers with and without age. They detect seven out of 10 Down's affected pregnancies for a fixed 5% FPR. The addition of further markers (triple tests) has not been shown to be statistically superior; the studies included are small with limited power to detect a difference.The screening blood tests themselves have no adverse effects for the woman, over and above the risks of a routine blood test. However some women who have a 'high risk' screening test result, and are given amniocentesis or chorionic villus sampling (CVS) have a risk of miscarrying a baby unaffected by Down's. Parents will need to weigh up this risk when deciding whether or not to have an amniocentesis or CVS following a 'high risk' screening test result.

Concentrations of human chorionic gonadotrophin in very early pregnancy and subsequent pre-eclampsia: a cohort study

STUDY QUESTION

Are low serum concentrations of human chorionic gonadotrophin (hCG) in very early pregnancy associated with pre-eclampsia risk?

SUMMARY ANSWER

Low hCG concentrations in very early pregnancy are associated with increased risk of severe pre-eclampsia.

WHAT IS KNOWN ALREADY

Low maternal serum concentrations of hCG early in pregnancy may indicate impaired proliferation or invasion of trophoblast cells, and thus low hCG concentrations may serve as a marker for impaired placental development. Impaired placental development is assumed to be a cause of pre-eclampsia, but there is little prospective evidence to support this hypothesis.

STUDY DESIGN, SIZE, DURATION

We performed a prospective cohort study of pregnancies after IVF at Oslo University Hospital 1996-2010 with linkage to the Medical Birth Registry of Norway to obtain information on pre-eclampsia development.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included 2405 consecutive singleton pregnancies and examined the association of maternal serum hCG concentrations (measured using Elecsys, Roche) on Day 12 after embryo transfer with the risk of any pre-eclampsia and of mild and severe pre-eclampsia.

MAIN RESULTS AND THE ROLE OF CHANCE

HCG concentrations were inversely associated with pre-eclampsia risk in a dose-dependent manner (Ptrend 0.02). Compared with women with hCG ≥150 IU/l, women with hCG <50 IU/l were at 2-fold higher overall risk of pre-eclampsia [absolute risk 6.4 versus 2.8%; odds ratio (OR) 2.3, 95% confidence interval (CI) 1.2-4.7]. The inverse association was restricted to severe pre-eclampsia (Ptrend 0.01), thus, women with hCG <50 IU/l were at 4-fold higher risk of severe pre-eclampsia than women with hCG ≥150 IU/l (absolute risk 3.6 versus 0.9%; OR 4.2, 95% CI 1.4-12.2). For mild pre-eclampsia, there was no corresponding association (Ptrend 0.36).

LIMITATIONS, REASONS FOR CAUTION

Results for IVF pregnancies may not be generalizable to spontaneously conceived pregnancies.

WIDER IMPLICATIONS OF THE FINDINGS

Plausible causes of low maternal hCG concentrations very early in pregnancy include impaired placental development and delayed implantation. Thus, these results provide prospective evidence to support the hypothesis that impaired placental development may be associated with subsequent development of severe pre-eclampsia.

STUDY FUNDING/COMPETING INTEREST

The study was financially supported by the Research Council of Norway. None of the authors has any conflict of interest to declare.

Second trimester serum tests for Down's Syndrome screening

BACKGROUND

Down's syndrome occurs when a person has three copies of chromosome 21 - or the specific area of chromosome 21 implicated in causing Down's syndrome - rather than two. It is the commonest congenital cause of mental retardation. Noninvasive screening based on biochemical analysis of maternal serum or urine, or fetal ultrasound measurements, allows estimates of the risk of a pregnancy being affected and provides information to guide decisions about definitive testing.  

OBJECTIVES

To estimate and compare the accuracy of second trimester serum markers for the detection of Down's syndrome.

SEARCH METHODS

We carried out a sensitive and comprehensive literature search of MEDLINE (1980 to May 2007), EMBASE (1980 to 18 May 2007), BIOSIS via EDINA (1985 to 18 May 2007), CINAHL via OVID (1982 to 18 May 2007), The Database of Abstracts of Reviews of Effectiveness (The Cochrane Library 2007, Issue 1), MEDION (May 2007), The Database of Systematic Reviews and Meta-Analyses in Laboratory Medicine (May 2007), The National Research Register (May 2007), Health Services Research Projects in Progress database (May 2007). We studied reference lists and published review articles.  

SELECTION CRITERIA

Studies evaluating tests of maternal serum in women at 14-24 weeks of gestation for Down's syndrome, compared with a reference standard, either chromosomal verification or macroscopic postnatal inspection.

DATA COLLECTION AND ANALYSIS

Data were extracted as test positive/test negative results for Down's and non-Down's pregnancies allowing estimation of detection rates (sensitivity) and false positive rates (1-specificity). We performed quality assessment according to QUADAS criteria. We used hierarchical summary ROC meta-analytical methods to analyse test performance and compare test accuracy. Analysis of studies allowing direct comparison between tests was undertaken. We investigated the impact of maternal age on test performance in subgroup analyses.

MAIN RESULTS

Fifty-nine studies involving 341,261 pregnancies (including 1,994 with Down's syndrome) were included. Studies were generally high quality, although differential verification was common with invasive testing of only high-risk pregnancies. Seventeen studies made direct comparisons between tests. Fifty-four test combinations were evaluated formed from combinations of 12 different tests and maternal age; alpha-fetoprotein (AFP), unconjugated oestriol (uE3), total human chorionic gonadotrophin (hCG), free beta human chorionic gonadotrophin (βhCG), free alpha human chorionic gonadotrophin (αhCG), Inhibin A, SP2, CA125, troponin, pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PGF) and proform of eosinophil major basic protein (ProMBP).Meta-analysis of 12 best performing or frequently evaluated test combinations showed double and triple tests (involving AFP, uE3, total hCG, free βhCG) significantly outperform individual markers, detecting six to seven out of every 10 Down's syndrome pregnancies at a 5% false positive rate. Tests additionally involving inhibin performed best (eight out of every 10 Down's syndrome pregnancies) but were not shown to be significantly better than standard triple tests in direct comparisons. Significantly lower sensitivity occurred in women over the age of 35 years. Women who miscarried in the over 35 group were more likely to have been offered an invasive test to verify a negative screening results, whereas those under 35 were usually not offered invasive testing for a negative screening result. Pregnancy loss in women under 35 therefore leads to under ascertainment of screening results, potentially missing a proportion of affected pregnancies and affecting the accuracy of the sensitivity.

AUTHORS' CONCLUSIONS

Tests involving two or more markers in combination with maternal age are significantly more sensitive than those involving one marker. The value of combining four or more tests or including inhibin have not been proven to show statistically significant improvement. Further study is required to investigate reduced test performance in women aged over 35 and the impact of differential pregnancy loss on study findings.

Obstetrical complications associated with abnormal maternal serum markers analytes

OBJECTIVE

To review the obstetrical outcomes associated with abnormally elevated or decreased level of one or more of the most frequently measured maternal serum marker analytes used in screening for aneuploidy. To provide guidance to facilitate the management of pregnancies that have abnormal levels of one of more markers and to assess the usefulness of these markers as a screening test.

OPTIONS

Perinatal outcomes associated with abnormal levels of maternal serum markers analytes are compared with the outcomes of pregnancies with normal levels of the same analytes or the general population.

EVIDENCE

The Cochrane Library and Medline were searched for English-language articles published from 1966 to February 2007, relating to maternal serum markers and perinatal outcomes. Search terms included PAPP-A (pregnancy associated plasma protein A), AFP (alphafetoprotein), hCG (human chorionic gonadotropin), estriol, unconjugated estriol, inhibin, inhibin-A, maternal serum screen, triple marker screen, quadruple screen, integrated prenatal screen, first trimester screen, and combined prenatal screen. All study types were reviewed. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies. Key individual studies on which the recommendations are based are referenced. Supporting data for each recommendation are summarized with evaluative comments and references. The evidence was evaluated using the guidelines developed by the Canadian Task Force on Preventive Health Care.

VALUES

The evidence collected was reviewed by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada.

BENEFITS, HARMS, AND COSTS

The benefit expected from this guideline is to facilitate early detection of potential adverse pregnancy outcomes when risks are identified at the time of a maternal serum screen. It will help further stratification of risk and provide options for pregnancy management to minimize the impact of pregnancy complications. The potential harms resulting from such practice are associated with the so called false positive (i.e., uncomplicated pregnancies labelled at increased risk for adverse perinatal outcomes), the potential stress associated with such a label, and the investigations performed for surveillance in this situation. No cost-benefit analysis is available to assess costs and savings associated with this guideline. SUMMARY STATEMENTS: 1. An unexplained level of a maternal serum marker analyte is defined as an abnormal level after confirmation of gestational age by ultrasound and exclusion of maternal, fetal, or placental causes for the abnormal level. (III) 2. Abnormally elevated levels of serum markers are associated with adverse pregnancy outcomes in twin pregnancies, after correction for the number of fetuses. Spontaneous or planned mutifetal reductions may result in abnormal elevations of serum markers. (II-2) RECOMMENDATIONS: 1. In the first trimester, an unexplained low PAPP-A (< 0.4 MoM) and/or a low hCG (< 0.5 MoM) are associated with an increased frequency of adverse obstetrical outcomes, and, at present, no specific protocol for treatment is available. (II-2A) In the second trimester, an unexplained elevation of maternal serum AFP (> 2.5 MoM), hCG (> 3.0 MoM), and/or inhibin-A (> or =2.0 MoM) or a decreased level of maternal serum AFP (< 0.25 MoM) and/or unconjugated estriol (< 0.5 MoM) are associated with an increased frequency of adverse obstetrical outcomes, and, at present, no specific protocol for treatment is available. (II-2A) 2. Pregnant woman with an unexplained elevated PAPP-A or hCG in the first trimester and an unexplained low hCG or inhibin-A and an unexplained elevated unconjugated estriol in the second trimester should receive normal antenatal care, as this pattern of analytes is not associated with adverse perinatal outcomes. (II-2A) 3. The combination of second or third trimester placenta previa and an unexplained elevated maternal serum AFP should increase the index of suspicion for placenta accreta, increta, or percreta. (II-2B) An assessment (ultrasound, MRI) of the placental-uterine interface should be performed. Abnormal invasion should be strongly suspected, and the planning of delivery location and technique should be done accordingly. (III-C) 4. A prenatal consultation with the medical genetics department is recommended for low unconjugated estriol levels (<0.3 MoM), as this analyte pattern can be associated with genetic conditions. (II-2B) 5. The clinical management protocol for identification of potential adverse obstetrical outcomes should be guided by one or more abnormal maternal serum marker analyte value rather than the false positive screening results for the trisomy 21 and/or the trisomy 18 screen. (II-2B) 6. Pregnant woman who are undergoing renal dialysis or who have had a renal transplant should be offered maternal serum screening, but interpretation of the result is difficult as the level of serum hCG is not reliable. (II-2A) 7. Abnormal maternal uterine artery Doppler in association with elevated maternal serum AFP, hCG, or inhibin-A or decreased PAPP-A identifies a group of women at greater risk of IUGR and gestational hypertension with proteinuria. Uterine artery Doppler measurements may be used in the evaluation of an unexplained abnormal level of either of these markers. (II-2B) 8. Further research is recommended to identify the best protocol for pregnancy management and surveillance in women identified at increased risk of adverse pregnancy outcomes based on an abnormality of a maternal serum screening analyte. (III-A) 9. In the absence of evidence supporting any specific surveillance protocol, an obstetrician should be consulted in order to establish a fetal surveillance plan specific to the increased obstetrical risks (maternal and fetal) identified. This plan may include enhanced patient education on signs and symptoms of the most common complications, increased frequency of antenatal visits, increased ultrasound (fetal growth, amniotic fluid levels), and fetal surveillance (biophysical profile, arterial and venous Doppler), and cervical length assessment. (III-A) 10. Limited information suggests that, in women with elevated hCG in the second trimester and/or abnormal uterine artery Doppler (at 22-24 weeks), low-dose aspirin (60-81 mg daily) is associated with higher birthweight and lower incidence of gestational hypertension with proteinuria. This therapy may be used in women who are at risk. (II-2B) 11. Further studies are recommended in order to assess the benefits of low-dose aspirin, low molecular weight heparin, or other therapeutic options in pregnancies determined to be at increased risk on the basis of an abnormal maternal serum screening analyte. (III-A) 12. Multiple maternal serum markers screening should not be used at present as a population-based screening method for adverse pregnancy outcomes (such as preeclampsia, placental abruption, and stillbirth) outside an established research protocol, as sensitivity is low, false positive rates are high, and no management protocol has been shown to clearly improve outcomes. (II-2D) When maternal serum screening is performed for the usual clinical indication (fetal aneuploidy and/or neural tube defect), abnormal analyte results can be utilized for the identification of pregnancies at risk and to direct their clinical management. (II-2B) Further studies are recommended to determine the optimal screening method for poor maternal and/or perinatal outcomes. (III-A).

Nuchal translucency in pregnancies conceived after assisted reproduction technology

PURPOSE OF REVIEW

Nuchal translucency is one of the important markers in the first trimester during antenatal screening for fetal Down's syndrome. With the observation of alterations in biochemical markers in pregnancies conceived after assisted reproduction, this review presents current information related to the thickness of nuchal translucency in these pregnancies.

RECENT FINDINGS

Early small studies did not demonstrate any discrepancy in the thickness of nuchal translucency in fetuses from assisted reproduction and from spontaneous pregnancies, but there has been recent evidence to suggest an increased level of nuchal translucency in singletons from various modes of assisted-reproduction technology. Nuchal translucency in twins following assisted reproduction did not, however, show a similar increase. Although the effect of chorionicity was not specifically addressed, nuchal translucency thickness in twins born after assisted reproduction was reported to be comparable to that in spontaneous singletons. It is possible that singletons and twins after assisted reproduction exhibit different antenatal behavior and pregnancy courses.

SUMMARY

Similar to other biochemical markers of fetal Down's syndrome, nuchal translucency is increased in singletons after assisted-reproduction technology. Further studies on twin pregnancies, in particular dichorionic twins, are necessary before conclusive evidence can be drawn for multiple pregnancies.

Sirenomelia of an intracytoplasmic sperm injection conceptus: a case report and review of mechanism

Postmortem dissection of the 18-week male conceptus, product of intracytoplasmic sperm injection (ICSI), demonstrated the hallmark findings of sirenomelia. The lower legs were fused and the left knee was rotated medially. Internal organs showed hypoplastic lungs, a multicystic kidney, and unilateral ureteral hypoplasia. The vitelline artery was absorbed, in a classic fashion, into the umbilical artery and communicated with the aorta at a point proximal to the iliac arteries. The tributaries distal to this point were hypoplastic. This finding is consistent with previously documented cases of sirenomelia and is thought to be the pathogenetic mechanism resulting in a vascular steal from the lower extremities. A rare finding was the presence of a penis on the dorsal side just below a perforate anus. In this case report, we discuss the pertinent clinical history and autopsy findings. A brief review of the mechanism thought to give rise to sirenomelia is provided. To our knowledge, this is the first reported case of sirenomelia in an ICSI conceptus.

Maternal C-reactive protein levels in patients undergoing frozen embryo replacement cycles: a prospective study

This prospective study shows that the early pregnancy inflammatory response following frozen embryo replacement (FER) cycles may be absent or suppressed, in contrast to that following IVF. To our knowledge, this is the first study to evaluate the maternal inflammatory response following FER cycles, but larger studies are still required to explore this novel finding, and investigate whether this may explain the lower ongoing pregnancy rates generally achieved following FER cycles.

First- and second-trimester Down syndrome screening markers in pregnancies achieved through assisted reproductive technologies (ART): a FASTER trial study

OBJECTIVE

To determine whether first- and second-trimester Down syndrome screening markers and screen-positive rates are altered in pregnancies conceived using assisted reproductive technologies (ARTs).

METHODS

ART pregnancies in the multicenter FASTER trial were identified. Marker levels were evaluated for five types of ART: in vitro fertilization with ovulation induction (IVF-OI), IVF with OI and egg donation (IVF-OI-ED), IVF with ED (IVF-ED), and intrauterine insemination with OI (IUI-OI) or without OI (IUI). Each group was compared to non-ART controls using Mann-Whitney U analysis.

RESULTS

First-trimester marker levels were not significantly different between ART and control pregnancies, with the exception of reduced PAPP-A levels in the IUI-OI group. In contrast, second-trimester inhibin A levels were increased in all ART pregnancies, estriol was reduced and human chorionic gonadotropin (hCG) was increased in IVF and IUI pregnancies without ED, and alpha-fetoprotein (AFP) was increased in ED pregnancies. Second-trimester screen-positive rates were significantly higher than expected for ART pregnancies, except when ED was used.

CONCLUSIONS

These data show that ART significantly impacts second-, but not first-, trimester markers and screen-positive rates. The type of adjustment needed in second-trimester screening depends on the particular type of ART used.

First trimester biochemical screening for Down's syndrome in singleton pregnancies conceived by assisted reproduction

BACKGROUND

Serum biochemical markers [free betahCG (fbetahCG); pregnancy-associated plasma protein-A (PAPP-A)] used in first trimester Down's syndrome screening have not been fully investigated in pregnancies achieved by assisted reproduction techniques. We present data on pregnancies conceived by all types of assisted reproduction techniques, including pregnancies following ovum donation (OD) and a large sample by ICSI.

METHODS

First trimester Down's syndrome screening was performed in 1054 normal singleton pregnancies: natural conception (n = 498), ovulation induction (OS, n = 97), IVF (n = 47), ICSI (n = 222) and OD (n = 190).

RESULTS

No differences in maternal levels of fbetahCG and PAPP-A, measured by the Kryptor system, appeared between naturally conceived pregnancies (n = 498) and those obtained with assisted reproduction techniques (n = 556). Several differences were apparent when comparing fbetahCG levels between different technologies but PAPP-A levels only differed between OS and IVF pregnancies (P < 0.05). In a further small study, no differences were observed using frozen embryos (n = 37), preimplantation genetic diagnosis (n = 53) or sperm from testicular biopsy (n = 21).

CONCLUSIONS

Data accumulated so far suggest that first trimester biochemical markers either do not need any adjustments (e.g. in pregnancies obtained after OS and ICSI), or have very little impact (e.g. IVF pregnancies) or no impact (e.g. OD pregnancies) on the false positive rates.

Nuchal translucency in pregnancies conceived after assisted reproduction technology

OBJECTIVES

Levels of maternal serum markers of fetal Down syndrome in pregnancies conceived after assisted reproduction are different from those of normal spontaneous pregnancies. The present study examined the effects of conventional in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and embryo cryopreservation on nuchal translucency (NT) thickness.

METHODS

A retrospective analysis on 16 673 spontaneous pregnancies, 119 pregnancies with fresh embryos from IVF, 62 pregnancies with frozen-thawed embryos from IVF, 81 pregnancies with fresh embryos from ICSI and 39 frozen-thawed embryos from ICSI was performed. All were singletons with known normal outcomes. Multiples of the median (MoM) of NT were compared.

RESULTS

The median NT MoM of spontaneous pregnancies was 1.01. In the assisted reproduction pregnancies, the median NT MoM were significantly increased to 1.07 (P = 0.003), 1.09 (P = 0.009) and 1.09 (P = 0.001) in pregnancies conceived with fresh embryos from IVF, frozen-thawed embryos from IVF and fresh embryos from ICSI, respectively. A non-significant increase in median NT MoM (1.04; P = 0.489) was also observed in pregnancies with frozen-thawed embryos from ICSI.

CONCLUSIONS

Increased NT in assisted reproduction pregnancies is postulated to be due to some delay in fetal development. Another possible reason might be related to adverse antenatal course in these pregnancies.

Maternal serum pregnancy-associated plasma protein-A and free β-human chorionic gonadotrophin in pregnancies conceived with fresh and frozen-thawed embryos fromin vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

Maternal serum pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotrophin (beta-hCG) are useful markers in the screening of Down syndrome in the first trimester. We investigated the effect of intracytoplasmic sperm injection (ICSI), freezing and thawing of embryos on the levels of these two analytes in assisted reproduction pregnancies.

METHODS

We recruited 149 women who conceived after assisted reproduction with fresh embryos (92 from conventional IVF and 57 from ICSI), 85 women who conceived with frozen-thawed embryos (54 from conventional IVF and 31 from ICSI) and 401 women with spontaneous conceptions as controls. The concentrations of PAPP-A and free beta-hCG were measured between 10 and 14 weeks and were converted to multiples of medians (MoM) for comparisons.

RESULTS

Median PAPP-A MoMs were significantly reduced in ICSI pregnancies in the fresh and frozen-thawed embryo subgroups (0.70 and 0.66 MoM respectively) and in the IVF fresh embryo subgroups (0.83 MoM), as compared to controls (1.00 MoM). Free beta-hCG MoM was significantly reduced in the IVF fresh embryos subgroup (0.87 MoM), but not in the other three subgroups.

CONCLUSION

Further studies for exploring the underlying pathophysiology and adjustment in the marker levels for screening of Down syndrome are warranted in pregnancies conceived after assisted reproduction.

Mid-gestation Down syndrome screening test and pregnancy outcome among unstimulated assisted-conception pregnancies

OBJECTIVES

Alteration of mid-gestation serum markers in assisted-conception pregnancies is believed to be attributable to ovarian superovulation treatment modalities. We compared alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), and unconjugated estriol (uE(3)) in two groups of unstimulated assisted-conception pregnancies, that is, own-oocyte frozen embryos (own-FET) versus oocyte-donated (OD) embryos.

METHODS

Forty-three OD-conceived and 31 own-FET-conceived singleton parturient women (aged 29 +/- 4 years and 31 +/- 4 years respectively, P < 0.05) were followed from embryo transfer throughout pregnancy.

RESULTS

The daily pattern of first-trimester serum beta-hCG was similar in both groups. The OD group had only significantly increased AFP concentrations compared to the own-FET group (1.38 vs 0.99 median MoM respectively, P = 0.002). Although there were no chromosomal abnormalities and no fetal or neonatal deaths in either group, 12% OD women and 6.5% own-FET women were found screen-positive. Eight OD women and 11 FET women had an adverse obstetric outcome (P = NS).

CONCLUSION

OD embryos are a unique clinical model for evaluating the uterine compartment and its contribution to mid-gestation serum marker secretion.

Amniotic fluid human chorionic gonadotrophin and alpha-fetoprotein levels in pregnancies conceived after assisted reproduction

OBJECTIVES

To study the alteration in the second-trimester maternal serum levels of human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP) in pregnancies conceived after assisted reproduction.

METHODS

We compared the amniotic fluid hCG and AFP concentrations of 45 pregnancies with fresh embryo transfer and 25 pregnancies with frozen-thawed embryo transfer with 269 spontaneous pregnancies. Wilcoxon rank-sum test was used for analysis.

RESULTS

The median amniotic fluid hCG MoM in pregnancies conceived after frozen-thawed embryo transfer was significantly increased to 1.41 compared to 1.00 (p = 0.01) in naturally occurring pregnancies and 0.96 (p = 0.049) in pregnancies after fresh embryo transfer. Further analysis showed that this was only observed in frozen embryos fertilized by conventional insemination with MoM of 1.59. The AFP MoMs were similar among the groups.

CONCLUSIONS

The observed raised amniotic fluid hCG level in IVF-FET pregnancies may reflect the elevated maternal serum level in these pregnancies. Further studies should be directed towards exploring the underlying pathophysiology.