Impact of type 1 diabetes and glycemic control on fetal aneuploidy biochemical markers

Fetal growth regulation via insulin-like growth factor axis in normal and diabetic pregnancy

OBJECTIVES

Diabetes mellitus (DM) in pregnancy and gestational diabetes remain a considerable cause of pregnancy complications, and fetal macrosomia is among them. Insulin, insulin-like growth factors (IGFs), and components of their signal-transduction axes belong to the predominant growth regulators and are implicated in glucose homeostasis. This study aimed to evaluate the available evidence on the association between the IGF axis and fetal anthropometric parameters in human diabetic pregnancy.

METHODS

PubMed, Medline, Web of Science, and CNKI databases (1981-2021) were searched.

RESULTS

Maternal and cord serum IGF-I levels are suggested to be positively associated with weight and length of neonates born to mothers with type 1 DM. The results concerning IGF-II and IGFBPs in type 1 DM or any of the IGF axis components in type 2 DM remain controversial. The alterations of maternal serum IGFs concentrations throughout diabetic and non-diabetic pregnancy do not appear to be the same. Maternal 1st trimester IGF-I level is positively associated with fetal birth weight in DM.

CONCLUSIONS

Research on the IGF axis should take gestational age of sampling, presence of DM, and insulin administration into account. Maternal 1st trimester IGF-I level might become a predictor for macrosomia development in diabetic pregnancy.

First trimester combined screening test for aneuploidies in anti-Ro carriers pregnant women

INTRODUCTION

Anti-Ro/SSA and anti-La/SSB antibodies are associated with neonatal lupus and congenital heart block. Controversial results regarding perinatal outcomes are found and less is known about aneuploidy screening. The hypothesis is that the presence of anti-Ro and/or anti-La antibodies influences the levels of PAPP-A and ß-HCG, thus interfering in the calculation of risk of aneuploidies.

MATERIAL AND METHODS

Fifty-five anti-Ro/SSA positive pregnant women were included. The demographic characteristics and laboratory variables were studied. Data concerning chromosomopaties screening were also recorded.

RESULTS

PAPP-A and β-HCG levels were calculated (as well as NT and CRL) and compared with a healthy cohort of 12971 pregnant women. PAPP-A levels in mg/mL were lower significatively. In anti-La/SS-B cohort, significant differences were found in PAPP-A in mg/mL and in MoM. Combined risks for Down syndrome (DS) in both groups were higher but the differences were due to age.

CONCLUSIONS

Serum levels of PAPP-A were significative lower but not confirmed when adjusted to MoM. This will have to be confirmed in studies with a larger number of patients and to check whether there is an impact in the calculation of DS risk or not. They could represent a group of pregnant women with significantly a higher risk of adverse perinatal outcome. Key Points • Pregnant patients with anti-Ro/SS-A ant/or anti-La/SS-B antibodies have low PAPP-A levels compared with pregnant women without antibodies. • PAPP-A levels are used in obstetrics for aneuploidies screening in the first trimester, so in these patients, there could be more false positive screening. • In these findings are verified in trials with a larger number of patients, a correction variable would have to be applied for the aneuploidies screening calculation. • Also, low PAPP-A levels are correlated with poor placentation, that is to say, more risk of miscarriages, small fetus for gestational age, and preeclampsia. This is another topic to take into consideration in this population.

Are the first-trimester levels of PAPP-A and fb-hCG predictors for obstetrical complications in diabetic pregnancy?

Objective: To assess the levels of pregnancy-associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (fb-hCG) in cases of diabetic pregnancy, to determine whether these biomarkers can be considered significant predictors for macrosomia, preeclampsia (PE), intrauterine growth restriction (IUGR), and preterm birth in mothers with different types of pregestational diabetes mellitus (DM).Methods: It was a retrospective cohort study. Study groups were presented: type 1 DM (n = 100), type 2 DM (n = 50), and controls (n = 25). At 11 + 0 to 13 + 6 week's gestation, we recorded maternal characteristics and medical history, and performed a combined test for the detection of risk of chromosomal abnormalities. To assess the performance of the markers in the prediction of the main obstetrical complications (PE, IUGR, preterm birth, and macrosomia), receiver-operating characteristic (ROC) curves were produced and area under the curves was calculated.Results: The study has shown that DM is associated with a high rate of perinatal complications: PE, IUGR, macrosomia, and preterm birth. The median level of PAPP-A was significantly lower in case of type 1 DM- 0.89 (inter quartile range (IQR), 0.51-1.1), and type 2 DM-0.88 (IQR, 0.42-1.15) compared to the unaffected group 1.03 (IQR, 0.96-1.12; p = .025). There were no significant differences in the fb-hCG multiples of the normal median (MoM; p = .14) between the diabetic and unaffected groups. More significant results were obtained when calculated by percentile: in diabetic pregnancies, PAPP-A and fb-hCG MoMs values were lower in the 5-10% ranges and higher in the 95% range, compared to the control group. ROC-analysis did not show any significant data that first-trimester PAPP-A and fb-hCG serum levels are predictors for PE, IUGR, macrosomia, and preterm birth.Conclusion: The routine first-trimester serum screening of fetal Down syndrome cannot be used as a tool of risk identification for PE, IUGR, macrosomia, and preterm birth in case of diabetic pregnancy.

The association between antiretroviral therapy and early placental function: a cohort study

Objective: To evaluate the association of antiretroviral therapy (ART) type and duration of exposure with early placental function using biomarkers of aneuploidy screening.Study design: Three hundred thirty-eight pregnant women living with HIV were enrolled in two Canadian centers. Multiple linear regressions were performed adjusting for confounding factors (race, age, gestational age, body mass index, parity, smoking, and fetal sex).Results: Women receiving ART had significantly increased second trimester alpha-fetoprotein (AFP) levels (β = 0.147, 95% CI = [0.067-0.227] for protease inhibitor-based ART and β = 0.176, 95% CI = [0.080-0.272] for ART without protease inhibitor) compared to women who received no treatment. However, there was no significant association between ART type and the levels of free β-human chorionic gonadotrophin (β-hCG), pregnancy-associated plasma protein-A (first trimester), unconjugated estriol, total hCG, and inhibin A (second trimester). No significant association was shown between biomarker levels and duration of ART exposure.Conclusion: Early placental function does not appear to be significantly affected by ART, except for AFP.

Pregestational diabetes and fetal heart rate in the first trimester of pregnancy

OBJECTIVE

The aim of our study is to evaluate if pregestational diabetes affects fetal heart rate (FHR) readings at 11-14 weeks of pregnancy.

STUDY DESIGN

For each patient, we recorded age, body mass index (BMI), presence of pregestational diabetes, nuchal translucency (NT), FHR, crown-rump length (CRL), biparietal diameter (BPD) and gestational age. Pregnancies were grouped according to the presence or absence of pregestational diabetes and maternal and fetal variables were compared. Ordinal regression analysis was performed to assess the influence of maternal and fetal variables on the FHR.

RESULTS

We included 994 pregnancies from 2009 to 2016. Kruskal-Wallis test showed that median FHR was higher in women with pregestational diabetes than in controls (161; IQR 11 vs. 158; IQR 10, χ2 = 5.13, p = 0.02). Ordinal regression analysis showed that differences in FHR were significantly correlated with the presence of pregestational diabetes (p = 0.007) and the CRL (p = 0.042) but not with the maternal BMI, maternal age, gestational age, BPD and NT.

CONCLUSIONS

First trimester FHR is higher in diabetic pregnancies than in non-diabetic pregnancies. Therefore, further research is needed to assess whether these pregnancies may benefit from a correction of FHR for a better estimation of the chromosomal abnormalities risk.

Combined first-trimester Down syndrome screening in HIV-infected women

OBJECTIVE

To determine if human immunodeficiency virus (HIV) infection or antiretroviral therapy interferes with maternal levels of free human β-chorionic gonadotrophin (hCGβ) and pregnancy-associated plasma protein-A (PAPP-A) and whether any such influence alters first-trimester Down syndrome (DS) screening in HIV-infected women.

STUDY DESIGN

We performed a multicenter 1:2 matched case-control study comparing 84 HIV-infected women with singleton pregnancies with controls randomly selected among uninfected women, delivered and screened in the same center and matched for maternal age, geographical origin and fetal sex.

RESULTS

Groups did not differ significantly in screening results, although case women showed a slightly lower median free hCGβ multiple of the median (MoM) (1.11 versus 1.24 MoM, p=0.32) and higher median PAPP-A MoM (1.45 versus 1.32 MoM, p=0.23) than control women. The false-positive rate was similar in the case and control groups (5% versus 6.5%, p=0.5). Biomarker levels did not differ when comparing treated and untreated patients with their respective controls, and with one another.

CONCLUSION

First-trimester DS combined screening biomarker levels and calculated risk do not seem to be significantly altered by HIV infection or antiretroviral treatment. This screening strategy appears to be suitable for HIV-infected women.

First Trimester Aneuploidy Screening Markers in Women with Pre-Gestational Diabetes Mellitus

OBJECTIVE

To investigate whether maternal serum pregnancy associated plasma protein-A (PAPP-A), total β human chorionic gonadotropin (hCG) levels and nuchal translucency (NT) measurements differ in women with pre-gestational diabetes mellitus (PGDM) compared to non-diabetic controls and to assess whether correction factors are needed for diabetic women in calculation of aneuploidy risks.

STUDY DESIGN

We performed a retrospective study of all women who underwent first trimester aneuploidy screening (11 + 0 to 13 + 6 weeks) from 2005 to 2011. The primary study outcome was the difference in PAPP-A, β-hCG and NT multiples of median between women with PGDM and non-diabetic women.

RESULTS

Of 6741 eligible patients, 103 patients with PGDM were using insulin and 4 patients were using oral hypoglycemic agents; the latter were excluded due to small number. There was 12% reduction of median PAPP-A (p = 0.001) and 18% reduction of median hCG (p = 0.006) in women with PGDM receiving insulin. There was no difference in NT.

CONCLUSIONS

In women with PGDM receiving insulin, PAPP-A and β-hCG levels are significantly lower compared to non-diabetic women. This suggests that when calculating risks for aneuploidy, correction factors should be considered to adjust PAPP-A and β-hCG concentrations to those seen in non-diabetic women.

The association between gestational diabetes mellitus and first trimester aneuploidy screening markers

Objective

To establish whether maternal serum first trimester concentrations of PAPP-A and free hCGβ are altered in pregnancies that subsequently are diagnosed by an oral glucose tolerance test (OGTT) with gestational diabetes mellitus (GDM).

Methods

Over the period 2009 and 2011, the results for women who had first trimester screening for aneuploidy were matched with those having an oral glucose tolerance test at 22–26 weeks for suspected GDM. Free hCGβ, PAPP-A and NT MoMs were compared amongst the group having an OGTT with confirmed GDM and those in which GDM was not confirmed. A second comparison group consisted of all non-aneuploidy singleton pregnancies in which no OGTT was performed.

Results

During the three-year period, 27,660 singleton pregnancies were screened of which 7429 cases had an OGTT of which 870 cases were classed as GDM by WHO criteria. There was a significant 7–9% reduction in both PAPP-A and free hCGβ MoM in the GDM group compared with either the OGTT non-GDM group or the remaining pregnancies with no known risk factors for evidence of GDM. There was no difference in the NT measurements.

Conclusions

First trimester concentrations of PAPP-A and free hCGβ are reduced in pregnancies that subsequently are diagnosed with GDM and may be useful in further screening algorithms for this disorder although the sensitivity alone is quite poor.

Fetal growth profiles of macrosomic and non-macrosomic infants of women with pregestational or gestational diabetes

OBJECTIVE

To assess fetal growth profiles in an unselected group of pregnant women with either type-1 diabetes (DM1), type-2 diabetes (DM2) or gestational diabetes (GDM), with emphasis on intergroup differences and development of disproportionate fetal growth and macrosomia.

METHODS

Second- and third-trimester longitudinal ultrasound measurements of fetal growth were made in 77 women with DM1, 68 women with DM2 and in 99 women with GDM. Altogether 897 ultrasound examinations were performed and 145 uncomplicated pregnancies with 843 ultrasound examinations were included as controls. Ultrasound data included head circumference (HC), abdominal circumference (AC), femur length (FL) and HC/AC ratio.

RESULTS

The AC, but not HC and FL, evolved differently in diabetic pregnancies, with a smaller AC in early pregnancy and larger AC at term (significant for DM1 and DM2). The most striking differences were found for the HC/AC ratio, especially in DM1 pregnancies. HC/AC growth trajectories of both macrosomic and non-macrosomic fetuses differed from that of the controls, and the HC/AC ratio at term was lower in all diabetic subgroups except in non-macrosomic DM2 cases.

CONCLUSION

We found altered (disproportionate) fetal growth in macrosomic and non-macrosomic fetuses of women with DM1, DM2 and GDM. This indicates that the abnormal intrauterine environment affects the majority of these infants. Growth profiles differed among these groups, the most prominent growth deviations being found in the fetuses of women with DM1. The latter was most probably caused by poor glucose control. In monitoring fetal growth in diabetic pregnancies the HC/AC ratio should be used to assess altered fetal growth.

Can first-trimester screening program detect women at high risk for gestational diabetes mellitus?

This study was designed to compare first-trimester maternal serum biochemical markers of aneuploidy and fetal nuchal translucency in pregnancies complicated by gestational diabetes mellitus and those of a control group. The study included 60 gestational diabetic and 60 control women who attended the first-trimester combined screening program for Down syndrome between 11 and 14 gestational weeks with complete follow-up data and delivered in our institution. Maternal serum free β-human chorionic gonadotropin, pregnancy-associated plasma protein-A and fetal nuchal translucency were investigated. The combined risks, double test risks and age risks were calculated by PRISCA software version 4.0. Comparison of the results between the two groups yielded no significant differences in serum levels of free β-human chorionic gonadotropin and fetal nuchal translucency. However, women who developed gestational diabetes mellitus had significantly lower pregnancy-associated plasma protein-A. And also, the combined risks and double test risks calculated by PRISCA software were statistically higher in gestational diabetic women than normal pregnant women. These results suggest that differences can be seen between diabetic and healthy pregnant women in first-trimester maternal serum biochemical markers of aneuploidy.