Association of maternal serum PAPP-A levels, nuchal translucency and crown-rump length in first trimester with adverse pregnancy outcomes: retrospective cohort study

Comparison of Fetal Crown-Rump Length Measurements between Thawed and Fresh Embryo Transfer

Background and Objectives: Neonates born from thawed embryo transfers tend to have a significantly higher birthweight compared to those from fresh embryo transfers. The aim of this study was to compare the crown-rump length (CRL) between thawed and fresh embryos to investigate the potential causes of different growth patterns between them. Materials and Methods: This was a retrospective study (July 2010-December 2023) conducted at the Third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece. In total, 3082 assisted reproductive technology (ART) pregnancies (4044 embryos) underwent a routine scan at 11+0-13+6 gestational weeks and were included in the study. Maternal age, the type of embryo transfer (thawed vs. fresh, donor vs. their own oocytes), CRL, twin and singleton gestations were analyzed. Results: The mean maternal age in thawed was significantly higher than in fresh embryos (39.8 vs. 35.8 years, p-value < 0.001). The mean CRL z-score was significantly higher in thawed compared to fresh embryo transfers (0.309 vs. 0.199, p-value < 0.001). A subgroup analysis on singleton gestations showed that the mean CRL z-score was higher in thawed blastocysts compared to fresh (0.327 vs. 0.215, p-value < 0.001). Accordingly, an analysis on twins revealed that the mean CRL z-score was higher in thawed blastocysts (0.285 vs. 0.184, p-value: 0.015) and in oocytes' recipients compared to own oocytes' cases (0.431 vs. 0.191, p-value: 0.002). Conclusions: The difference in CRL measurements between thawed and fresh embryos may be a first indication of the subsequent difference in sonographically estimated fetal weight and birthweight. This finding highlights the need for additional research into the underlying causes, including maternal factors and the culture media used.

Evaluation of the Relationship between Pregnancy-Associated Plasma Protein A (PAPP-A) and Pregnancy Outcomes

Background

In the current study, we aimed to evaluate the association between pregnancy-related plasma protein-A (PAPP-A) levels measured in the first trimester and pregnancy outcomes.

Materials and Methods

This is a descriptive-analytical study that was performed in 2019--2021 on 1061 pregnant women in their first trimester. Demographic and basic information of all women were collected. These data included age, weight, parity, and date of delivery. Then the quantity of PAPP-A was recorded in three groups including less than 0.5 MOM, 0.5 to 2.5 MOM, and more than 2.5 MOM.

Results

Data of 1061 women were analyzed. 900 women (84.8%) had term delivery and 155 women (14.6%) had pre-term deliveries. PAPP-A levels were normal in 83.4% of women. BMI and number of pregnancies had significant relationships with PAPP-A (p < 0.001, P = 0.03 respectively). The mean BMI in mothers with PAPP-A higher than 2.5 was significantly more than mothers with normal or lower PAPP-A levels (26.2 ± 31, P = 0.04). The frequency of term labor in mothers with normal PAPP-A was higher than other mothers (86.3%, P = 0.04). The frequency of preeclampsia in recent pregnancies in mothers with normal PAPP-A was significantly lower than other mothers (p < 0.001) and the frequency of abortions in recent pregnancies in mothers with PAPP-A less than 0.5 was significantly higher than mothers with normal or elevated PAPP-A (p < 0.001).

Conclusion

Mothers with low PAPP-A levels are more likely to have poor pregnancy outcomes such as abortion, pre-term labor, and preeclampsia.

Does endometrial thickness affect birth weight and serum levels of pregnancy-associated plasma protein-A in frozen cycles?

OBJECTIVE

To investigate whether endometrial thickness (EMT) affects birth weight and maternal serum pregnancy-associated plasma protein-A (PAPP-A) level in singleton pregnancies following frozen-thawed blastocyst transfer (FET).

METHODS

This retrospective study included women who underwent first-trimester combined screening for aneuploidy after FET, and subsequently delivered a singleton live birth after 24 weeks of gestation at a private in-vitro fertilization centre. The subjects were stratified into three groups based on EMT percentiles: <7.7 mm (<10th percentile), 7.7-12 mm (10-90th percentile), and > 12 mm (>90th percentile). Multi-variable linear regression analysis was undertaken to identify the association between birth weight and EMT after adjusting for variables with p < 0.1 on univariate analysis.

RESULTS

In total, 560 women met the inclusion criteria. Mean (±standard deviation) birth weight was 3127 ± 783 g in those with EMT < 7.7 mm, 3225 ± 644 g in those with EMT 7.7-12 mm, and 3256 ± 599 g in those with EMT > 12 mm (p = 0.577). Mean PAPP-A and PAPP-A < 0.5 rates were similar in the three groups. On multi-variate analysis, maternal serum PAPP-A was found to be a significant predictor of birth weight (p = 0.013), but EMT was not found to be predictive of birth weight on univariate or multi-variate analysis.

CONCLUSION

This study provided a new angle to evaluate the association between EMT and neonatal birth weight by analysing this association along with maternal serum PAPP-A as a marker for placental function, suggesting that EMT is not an independent factor for neonatal birth weight.

Importance of Low Pregnancy Associated Plasma Protein-A (PAPP-A) Levels During the First Trimester as a Predicting Factor for Adverse Pregnancy Outcomes: A Prospective Cohort Study of 2636 Pregnant Women

OBJECTIVES

The aim of this study is to investigate the predictive value of low levels of pregnancy associated plasma protein-A (PAPP-A) during the first trimester on adverse pregnancy outcomes, namely pregnancy induced hypertension (PIH), preeclampsia (PE), intrauterine growth restriction (IUGR), and fetal loss.

METHODS

This is a prospective cohort study including 2636 women with singleton pregnancies that attended the Prenatal Diagnosis Unit of the First Department of Obstetrics and Gynecology of National and Kapodistrian University of Athens in "Alexandra Hospital" between 2017 and 2019 for the first trimester combined screening routine scan. The study population was divided into two groups according to their PAPP-A levels. The cut-off value of the PAPP-A level was defined as the 0.4 multiple of median (MoM) which is in correspondence with the fifth centile. The women were followed-up prospectively until delivery and the primary outcome measures were the incidence of PIH, PE, IUGR (<10th centile), and fetal loss.  Results: PAPP-A levels of ≤0.4 MoM were associated with increased maternal body mass index (BMI), increased uterine arteries pulsatility index (PI), and lower birth weight. Women with PAPP-A levels ≤0.4 MoM were more likely to develop PE (2.3% vs. 0.2%, p<0.001), PE or PIH (2.3% vs. 0.4%, p=0.003), IUGR (2.3% vs. 0.4%, p=0.003), and combined adverse outcome (25.5% vs. 1.9%, p<0.001) compared to women with PAPP-A>0.4 MoM.

CONCLUSIONS

This study confirms that among women with PAPP-A levels ≤0.4 MoM in the first trimester, there are increased odds for PE or PIH, IUGR, and combined composite pregnancy outcome.

Prediction of preterm birth in nulliparous women using logistic regression and machine learning

OBJECTIVE

To predict preterm birth in nulliparous women using logistic regression and machine learning.

DESIGN

Population-based retrospective cohort.

PARTICIPANTS

Nulliparous women (N = 112,963) with a singleton gestation who gave birth between 20-42 weeks gestation in Ontario hospitals from April 1, 2012 to March 31, 2014.

METHODS

We used data during the first and second trimesters to build logistic regression and machine learning models in a "training" sample to predict overall and spontaneous preterm birth. We assessed model performance using various measures of accuracy including sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) in an independent "validation" sample.

RESULTS

During the first trimester, logistic regression identified 13 variables associated with preterm birth, of which the strongest predictors were diabetes (Type I: adjusted odds ratio (AOR): 4.21; 95% confidence interval (CI): 3.23-5.42; Type II: AOR: 2.68; 95% CI: 2.05-3.46) and abnormal pregnancy-associated plasma protein A concentration (AOR: 2.04; 95% CI: 1.80-2.30). During the first trimester, the maximum AUC was 60% (95% CI: 58-62%) with artificial neural networks in the validation sample. During the second trimester, 17 variables were significantly associated with preterm birth, among which complications during pregnancy had the highest AOR (13.03; 95% CI: 12.21-13.90). During the second trimester, the AUC increased to 65% (95% CI: 63-66%) with artificial neural networks in the validation sample. Including complications during the pregnancy yielded an AUC of 80% (95% CI: 79-81%) with artificial neural networks. All models yielded 94-97% negative predictive values for spontaneous PTB during the first and second trimesters.

CONCLUSION

Although artificial neural networks provided slightly higher AUC than logistic regression, prediction of preterm birth in the first trimester remained elusive. However, including data from the second trimester improved prediction to a moderate level by both logistic regression and machine learning approaches.

Greater fetal crown-rump length growth with the use of in vitro fertilization or intracytoplasmic sperm injection conceptions after thawed versus fresh blastocyst transfers: secondary analysis of a prospective cohort study

OBJECTIVE

To compare first-trimester fetal crown-rump length (CRL) measurements in pregnancies obtained after thawed blastocyst transfer versus fresh blastocyst transfer after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective longitudinal cohort study of CRL Z scores with adjustment for major confounders.

SETTING

University-affiliated obstetrics, fetal medicine, and fertility units.

PATIENT(S)

Singleton gestations conceived via IVF/ICSI and fresh or thawed blastocyst transfer with ultrasound performed at 6-14 weeks of gestational age.

INTEVENTION

None.

MAIN OUTCOME MEASURE(S)

CRL Z scores.

RESULT(S)

A total of 365 IVF/ICSI pregnancies were recruited (fresh: 161; thawed: 204). The mean CRL Z score at 6-14 weeks was significantly greater in thawed versus fresh transfers. Different growth trajectories between thawed and fresh transfers were detected: Mean CRL Z score was 0 at 65 days in fresh versus 80 days in frozen. Comparisons of both fresh and thawed transfers with reference values from the general population confirmed significantly lower CRL Z scores in both IVF/ICSI groups (P<.001). The risks of CRL <5th percentile in fresh versus thawed were, respectively 68% vs. 40% at 6 weeks and 2% vs. 1% at 14 weeks. A significant positive correlation between CRL Z scores and birth weight Z scores was found only for fresh transfers, not for thawed.

CONCLUSION(S)

At 6-14 weeks, thawed blastocyst transfers after IVF/ICSI conceptions present greater CRLs compared with fresh, and both IVF/ICSI groups show smaller CRLs than the general population. This effect is particularly evident before 9 weeks and it may favor birth weight difference of thawed versus fresh BT pregnancies.