Subfertility versus ART: unraveling the origins of fetal cardiac programming

STUDY QUESTION

Do spontaneously conceived (SC) fetuses from subfertile couples show the same signs of cardiac remodeling as those observed after IVF treatments?

SUMMARY ANSWER

As opposed to fetuses from IVF, SC fetuses from subfertile couples do not show cardiac remodeling and present a similar cardiac structure and function to those of SC fetuses from fertile couples.

WHAT IS KNOWN ALREADY

Subjects conceived by IVF present signs of cardiac remodeling and suboptimal function in utero and during childhood, including larger atria, more globular and thicker ventricles, reduced longitudinal motion, and impaired relaxation as compared to SC individuals from fertile couples. There are no previous publications investigating the independent cardiac programming effects of infertility in SC fetuses from subfertile couples (with time-to-pregnancy (TTP) over 12 months).

STUDY DESIGN, SIZE, DURATION

A prospective cohort study of 289 singleton pregnancies exposed and not exposed to subfertility recruited from 2019 to 2021, including 96 SC pregnancies from fertile couples (TTP under 12 months), 97 SC from subfertile couples (TTP over 12 months), and 96 from IVF after fresh embryo transfer. Fetal echocardiography was performed in all pregnancies. Epidemiological data and perinatal outcomes were collected in all pregnancies. The overall attrition rate was 15.7%.

PARTICIPANTS/MATERIALS, SETTING, METHODS

SC from subfertile couples and IVF pregnancies were identified as eligible at pregnancy diagnosis, and eligible SC pregnancies from fertile couples who attended our maternal-fetal unit were invited to participate at third trimester, being matched to the other groups by maternal age. Fetal echocardiography was performed at 29-34 weeks of pregnancy to assess cardiac structure and function, and results were adjusted by parental age, maternal smoking status, child's birth order, birthweight centile, gestational age, and estimated fetal weight at scan.

MAIN RESULTS AND THE ROLE OF CHANCE

Parental age, ethnicity, BMI, and smoking exposure, median gestational age and estimated fetal weight were similar in all study groups. There were no significant differences in infertility duration or etiology between the subfertile and the IVF populations (TTP: subfertile median 35 months (interquartile range 20-48) versus IVF: 47 (25-61); P-value = 0.051). While both fertile and subfertile SC groups presented similar fetal cardiac results, IVF fetuses showed larger atria (right atria-to-heart ratio: IVF mean 18.9% (SD 3.4) versus subfertile 17.8% (3.5) versus fertile 17.6% (3.3); adjusted P-value < 0.001), more globular ventricles (right ventricular sphericity index: IVF 1.56 (0.25) versus subfertile 1.72 (0.26) versus fertile 1.72 (0.26); <0.001), and thicker myocardial walls (relative wall thickness: IVF 0.86 (0.22) versus subfertile 0.64 (0.13) versus fertile 0.64 (0.18); <0.001). Whereas SC fetuses from fertile and subfertile couples had preserved cardiac function, IVF fetuses showed signs of suboptimal systolic and diastolic function, with reduced tricuspid ring displacement (IVF 7.26 mm (1.07) versus subfertile 8.04 mm (1.18) versus fertile 7.89 mm (1.51); <0.001) and increased left myocardial performance index (IVF 0.49 (0.08) versus subfertile 0.45 (0.09) versus fertile 0.45 (0.10); <0.001). A sub-analysis including only unexplained infertility cases in subfertile SC and IVF groups showed similar results.

LIMITATIONS, REASONS FOR CAUTION

The fetal cardiac changes reported here are subclinical, and most of the cardiovascular parameters were within normal ranges. Although echocardiographic changes are recognized as potential cardiovascular risk factors, their association with long-term cardiovascular disease remains to be demonstrated.

WIDER IMPLICATIONS OF THE FINDINGS

Subfertility per se does not seem to be associated to fetal cardiac remodeling, which has been previously described in IVF fetuses. Future studies are warranted to further investigate other factors related to the observed fetal cardiac changes associated with ART.

STUDY FUNDING/COMPETING INTEREST(S)

This project has been partially funded with support from the Erasmus + Programme of the European Union (Framework Agreement number: 2013-0040). This publication reflects the views only of the author, and the Commission cannot be held responsible for any use, which may be made of the information contained therein. Additionally, the research leading to these results has received funding from 'la Caixa' Foundation under grant agreement LCF/PR/GN18/10310003, the Instituto de Salud Carlos III (PI15/00130, PI16/00861, PI17/00675, PI18/00073, INT21/00027)-co-funded by the European Union, Cerebra Foundation for the Brain Injured Child (Carmarthen, Wales, UK) and AGAUR 2017 SGR grant no 1531. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Fetal neurosonography and infant neurobehavior following conception by assisted reproductive technology with fresh or frozen embryo transfer

OBJECTIVE

We aimed to explore fetal cortical brain development by neurosonography in fetuses conceived by assisted reproductive technology (ART), including frozen and fresh embryo transfer (ET), compared with those conceived spontaneously (SC), and to investigate its association with infant neurobehavior at 12 months of age.

METHODS

This was a prospective cohort study of 210 singleton pregnancies, including 70 SC pregnancies, 70 conceived by in-vitro fertilization (IVF) following frozen ET and 70 conceived by IVF after fresh ET. Fetal neurosonography was performed at 32 ± 2 gestational weeks to assess cortical development. Sulci depths were measured offline and normalized by biparietal diameter (BPD). Ages and Stages Questionnaires (ASQ) were completed postnatally, at 12 ± 1 months of corrected age. Neurosonographic findings were adjusted by regression analysis for maternal age, ethnicity, parity, fetal sex and fetal-weight centile and gestational age at scan, and ASQ scores were adjusted for maternal age, ethnicity, parity, educational level and employment status, gestational age at birth, breastfeeding, infant sex and infant age at the ASQ evaluation.

RESULTS

Overall, in comparison to the SC fetuses, fetuses conceived by ART showed statistically significant differences in cortical development, with reduced parieto-occipital sulci depth adjusted for BPD (mean ± SD: fresh ET, 12.5 ± 2.5 vs frozen ET, 13.4 ± 2.6 vs SC, 13.4 ± 2.6, P < 0.001), cingulate sulci depth adjusted for BPD (median (interquartile range (IQR)): fresh ET, 5.8 (4.2-7.4) vs frozen ET, 5.8 (4.1-7.5) vs SC, 6.5 (4.8-7.8), P = 0.001) and calcarine sulci depth adjusted for BPD (median (IQR): fresh ET, 13.5 (10.1-16.1) vs frozen ET, 14.5 (12.1-15.8) vs SC, 16.4 (14.3-17.9), P < 0.001), together with lower Sylvian fissure grading score. Changes in cortical development were more pronounced in the fresh ET than in the frozen ET group. ART infants showed lower ASQ scores as compared to SC infants, particularly in the fresh ET group (mean ± SD global ASQ Z-score: fresh ET, -0.3 ± 0.4 vs frozen ET, -0.2 ± 0.4 vs SC, 0 ± 0.4, P < 0.001).

CONCLUSIONS

Fetuses conceived by ART show a distinctive pattern of cortical development and suboptimal infant neurodevelopment, with more pronounced changes in those conceived following fresh ET. These findings support the existence of in-utero brain reorganization associated with ART and warrant follow-up studies to assess its long-term persistence. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Unique cardiac remodeling in young adults born Small for Gestational Age with subsequent central obesity

Background

Being born small-for-gestational age (SGA, 10 percent of all births) is associated with increased risk of cardiovascular mortality (1,2) in adulthood together with lower exercise tolerance (3), but mechanistic pathways are unclear. Central obesity is known to worsen cardiovascular outcomes, but it is uncertain how it affects the heart in adults born SGA.

Purpose

We aimed to assess whether central obesity makes young adults born SGA more susceptible to cardiac remodelling and dysfunction.

Methods

A perinatal cohort study including 80 young adults born SGA (birth weight below 10th centile) and 75 adults with normal birth weight (controls). Current waist-to-hip ratio was used as a surrogate of central obesity. Cardiac structure and function were assessed by cardiac magnetic resonance. Statistical shape analysis was used to study the regional geometric variability of the biventricular surfaces produced by central obesity and SGA, and synthetic surfaces representative of obese and non obese were generated for both SGA and controls.

Results

Figure 1 shows the superimposed representative surfaces of obese and non-obese according to our model, for controls (right column) and SGA (left column). Both SGA and waist-to-hip were highly associated to cardiac shape (F=3.94 p&lt;0.001; F=5.18 p&lt;0.001 respectively) with a statistically significant interaction (F=2.29, p=0.02), indicating a different cardiac remodelling due to obesity in SGA. While controls tend to increase left ventricular end-diastolic volumes, mass and stroke volume with increasing waist-to-hip ratio, young adults born SGA showed unique response with inability to increase cardiac dimensions or mass resulting in reduced stroke volume (both in absolute values and indexed by body surface area) and increased heart rate.

Conclusions

SGA young adults show unique cardiac adaptation to central obesity, which is associated with a decrease in stroke volume. Preventive strategies aiming to reduce cardiometabolic risk in SGA population may be warranted.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Horizon 2020 Programme

P-771 Subfertility versus in vitro fertilization procedures: unravelling the origins of fetal cardiac remodeling in assisted reproductive technologies

Study question

Do spontaneously conceived (SC) fetuses from subfertile couples present signs of cardiac remodeling as those observed after in vitro fertilization (IVF) treatments?

Summary answer

SC fetuses from subfertile couples do not associate cardiac remodeling, and their cardiac structure and function are similar to those of SC from fertile couples.

What is known already

Fetuses and children from IVF associate cardiac remodeling and suboptimal function, including dilated atria, more globular and thicker ventricles, reduced longitudinal motion and impaired relaxationin uteroand after birth. Fetal cardiac changes have been demonstrated both after fresh and frozen embryo transfer. The SC fetuses used as ‘controls’ in our previous publications were conceived by fertile couples thus making it difficult to separate the contribution of infertilityper sefrom the IVF procedures on cardiac programming. There are no previous cardiovascular studies investigating the independent effects of infertility in SC fetuses from subfertile couples (time-to-pregnancy (TTP) over 12 months).

Study design, size, duration

Prospective cohort study of 289 singleton pregnancies recruited from 2017 to 2021, including 96 SC pregnancies from fertile couples (TTP less than 12 months), 97 SC from subfertile couples (TTP over 12 months) and 96 from IVF after fresh ET. Fetal echocardiography was performed in all pregnancies. Epidemiological data and perinatal outcomes were collected in all pregnancies.

Participants/materials, setting, methods

IVF pregnancies from our centre were identified as eligible at pregnancy diagnosis. Eligible SC pregnancies from fertile and subfertile couples who attended our Maternal-Fetal Unit were invited to participate at third trimester, being matched to the IVF pregnancies by maternal age. Fetal echocardiography was performed at 29-34 weeks of pregnancy to assess cardiac structure and function. Echocardiographic comparisons were adjusted by nulliparity, birthweight centile, gestational age and estimated fetal weight at scan.

Main results and the role of chance

Parental age, ethnicity, body mass index and smoking exposure, median gestational age and estimated fetal weight were similar in all study groups. There were no significant differences in infertility duration or aetiology between the subfertile and the IVF populations (TTP: subfertile median 30 months [IQR 20-54] versus IVF: 47 [25-61]; p-value=0.052). While both fertile and subfertile SC groups presented similar fetal cardiac results, IVF fetuses showed larger atria (right atria-to-heart ratio: IVF mean 18.9% [SD 3.4] versus subfertile 17.8% [3.5] versus fertile 17.6% [3.3]; adjusted P-value&lt;0.001), more globular ventricles (right ventricular sphericity index: IVF 1.56 [0.25] versus subfertile 1.72 [0.26] versus fertile 1.72 [0.26]; &lt;0.001), and thicker myocardial walls (relative wall thickness: IVF 0.86 [0.22] versus subfertile 0.64 [0.13] versus fertile 0.64 [0.18]; &lt;0.001). Whereas SC fetuses from fertile and subfertile couples had preserved cardiac function, IVF fetuses showed signs of suboptimal systolic and diastolic function with reduced tricuspid ring displacement (IVF 7.26 mm [1.07] versus subfertile 8.04 mm [1.18] versus fertile 7.89 mm [1.51]; &lt;0.001) and increased left myocardial performance index (IVF 0.49 [0.08] versus subfertile 0.45 [0.09] versus fertile 0.45 [0.10]; &lt;0.001). A sub-analysis including only unexplained infertility cases in subfertile SC and IVF groups showed similar results.

Limitations, reasons for caution

The fetal cardiac changes reported here are subclinical, with most cardiovascular parameters lying within normal ranges. Although echocardiographic changes are recognized as potential cardiovascular risk factors, their association with long-term cardiovascular disease remains to be proven.

Wider implications of the findings

Subfertility per se does not seem to be associated to fetal cardiac remodeling, which have been previously described in IVF fetuses. Future studies are warranted to further investigate the factors related to fetal cardiac changes associated to ART.

Trial registration number

Not a trial

Fetal neurosonography at 31-35 weeks reveals altered cortical development in pre-eclampsia with and without small-for-gestational-age fetus

OBJECTIVE

To explore the pattern of fetal cortical development in pregnancies complicated by pre-eclampsia (PE), with and without a small-for-gestational-age (SGA) fetus, compared to uncomplicated pregnancies.

METHODS

This was a prospective observational study including singleton pregnancies complicated by normotensive SGA (birth weight < 10^th centile) (n = 77), PE with an appropriate-for-gestational-age (AGA) fetus (n = 76) or PE with a SGA fetus (n = 67), and 128 uncomplicated pregnancies (normotensive AGA) matched by gestational age at ultrasound. All pregnancies underwent detailed neurosonography, using a transabdominal and transvaginal approach, at 31-35 weeks' gestation to assess the depth of the insula, Sylvian fissure, parieto-occipital sulcus, cingulate sulcus and calcarine sulcus. All measurements were adjusted for biparietal diameter (BPD). In addition, a grading score of cortical development was assigned to each brain structure, ranging from Grade 0 (no development) to Grade 5 (maximum development). Univariate and multiple regression analyses were conducted.

RESULTS

Similar to findings in previous studies, normotensive pregnancies with a SGA fetus showed significant differences in cortical development compared with controls, with reduced Sylvian fissure depth adjusted for BPD (14.5 ± 2.4 vs 16.6 ± 2.3; P < 0.001) and increased insula depth adjusted for BPD (33.2 ± 2.0 vs 31.8 ± 2.0; P < 0.001). Interestingly, a similar cortical development pattern was observed in PE pregnancies with a SGA fetus and in PE pregnancies with an AGA fetus, manifested by reduced Sylvian fissure depth adjusted for BPD (14.2 ± 2.3 and 14.3 ± 2.3 vs 16.6 ± 2.3; P < 0.001 for both) and greater insula depth adjusted for BPD (33.2 ± 2.1 and 32.8 ± 1.7 vs 31.8 ± 2.0; P < 0.001 for both) compared with controls. No significant differences were observed in parieto-occipital, cingulate sulcus or calcarine sulcus depth across the study groups. The Sylvian fissure was scored as Grade 4 in significantly more (93.2% vs 59.5%) and as Grade 5 in significantly fewer (2.7% vs 37.3%) PE pregnancies with an AGA fetus compared with controls (P < 0.05 for both). These differences remained significant even after statistical adjustment for potential confounders, including ethnicity, low socioeconomic status, nulliparity, chronic hypertension, pregestational diabetes, assisted reproductive technologies, smoking and fetal gender, with the application of Benjamini-Hochberg procedure for multiple comparisons.

CONCLUSIONS

PE with or without SGA is associated with a differential fetal cortical development pattern which is similar to that described previously in small fetuses. Future research is warranted to elucidate better the mechanism(s) underlying these changes. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

P-766 Neurodevelopment in fetuses conceived by assisted reproductive technologies following fresh and frozen embryo transfer

Study question

Do in vitro fertilization (IVF) offspring present different neurodevelopment assessed by fetal neurosonography and infant neurobehavioral tests as compared to those spontaneously conceived (SC)?

Summary answer

IVF offspring, especially those obtained after fresh embryo-transfer (ET), showed subtle structural differences in fetal neurosonography and poorer neurobehavioral scores at twelve months of age.

What is known already

The number of pregnancies following assisted reproductive technologies (ART) is currently increasing worldwide. Concerns about the neurodevelopment of subjects conceived by IVF have been rising and mostly studied in children and adolescents with inconsistent results. Many of the identified risk associations were only observed in subgroups or disappeared after adjustment for covariates, mainly multiple pregnancy and gestational age at birth. It is unknown whether fetal brain development and cortical folding differ prenatally in IVF fetuses as compared to SC.

Study design, size, duration

This is the first study examining fetal neurodevelopment by neurosonography in IVF fetuses.

A prospective cohort study of 210 singleton pregnancies recruited from 2017 to 2020, including 70 SC gestations, 70 conceived by IVF following frozen ET (FET) and 70 IVF after fresh ET.

Fetal neurosonography was performed in all pregnancies. Additionally, Ages & Stages Questionnaires (ASQ) were obtained at 12 months of corrected age.

Participants/materials, setting, methods

IVF pregnancies were recruited from a single Assisted Reproduction Center, ensuring homogeneity in IVF stimulation protocols, endometrial preparation, laboratory procedures and embryo culture conditions. SC pregnancies were randomly selected from low-risk fertile couples and paired to IVF by maternal age. Fetal neurosonography including transvaginal approach was performed at 32±2 weeks of gestation, measured off-line by a single investigator and normalized by biparietal or occipitofrontal diameter. ASQ were obtained postnatally, at 12 months of corrected age.

Main results and the role of chance

Study groups were similar and comparable regarding maternal age, body mass index, study level and employment rate together with exposure to smoke, alcohol, aspirin and corticoids during pregnancy, gestational age (32±2 weeks) and estimated fetal weight (1700±400g) at neurosonography.

As compared to SC pregnancies, both IVF populations showed differences in cortical development with reduced parieto-occipital (fresh ET 12.5mm [SD 2.5] vs FET 13.4 [2.6] vs SC 13.4 [2.6]), cingulate (fresh ET 5.8 [IQR 4.2-7.4] vs FET 5.8 [4.1-7.5] vs SC 6.5 [4.8-7.8]) and calcarine (fresh ET 13.5 [IQR 10.1-16.1] vs FET 14.5 [12.1-15.8] vs SC 16.4 [14.3-17.9]) sulci depth together with lower Sylvian fissure grading. Cortical development changes were more pronounced in the fresh ET group as compared to FET. Corpus callosum length and insula depth were lower in FET and fresh ET groups, respectively. Neurosonographic changes remained statistically significant after adjustment by ethnicity, gender, gestational age and weight centile at scan.

IVF infants showed worse ASQ scores, especially in fresh ET for communication, personal-social, fine-motor and problem-solving skills. Gross-motor scores were significantly lower in FET as compared to SC and fresh ET. Differences were statistically significant after adjustment by maternal ethnicity, study level, employment status, breastfeeding, gender and corrected age.

Limitations, reasons for caution

The reported neurodevelopmental differences are subtle, with most neurosonographic findings lying within normal ranges.

Infertility factors contribution to the outcome cannot be unraveled from the ART procedure itself.

The milder features found in FET individuals cannot condition the techniqués choice and must be considered together with their global perinatal results.

Wider implications of the findings

Neurosonography is an appropriate tool to identify subtle brain differences between fetuses exposed and not exposed to ART. Prenatal features were consistent with postnatal neurobehavioral findings. These results support the relevance of a neurodevelopmental follow-up in IVF patients. Further studies are warranted to assess the long-term performance in these subjects.

Trial registration number

not applicable

P–766 Neurodevelopment in fetuses conceived by assisted reproductive technologies following fresh and frozen embryo transfer

Study question

Do in vitro fertilization (IVF) offspring present different neurodevelopment assessed by fetal neurosonography and infant neurobehavioral tests as compared to those spontaneously conceived (SC)?

Summary answer

IVF offspring, especially those obtained after fresh embryo-transfer (ET), showed subtle structural differences in fetal neurosonography and poorer neurobehavioral scores at twelve months of age.

What is known already

The number of pregnancies following assisted reproductive technologies (ART) is currently increasing worldwide. Concerns about the neurodevelopment of subjects conceived by IVF have been rising and mostly studied in children and adolescents with inconsistent results. Many of the identified risk associations were only observed in subgroups or disappeared after adjustment for covariates, mainly multiple pregnancy and gestational age at birth. It is unknown whether fetal brain development and cortical folding differ prenatally in IVF fetuses as compared to SC.

Study design, size, duration

This is the first study examining fetal neurodevelopment by neurosonography in IVF fetuses. A prospective cohort study of 210 singleton pregnancies recruited from 2017 to 2020, including 70 SC gestations, 70 conceived by IVF following frozen ET (FET) and 70 IVF after fresh ET. Fetal neurosonography was performed in all pregnancies. Additionally, Ages & Stages Questionnaires (ASQ) were obtained at 12 months of corrected age.

Participants/materials, setting, methods

IVF pregnancies were recruited from a single Assisted Reproduction Center, ensuring homogeneity in IVF stimulation protocols, endometrial preparation, laboratory procedures and embryo culture conditions. SC pregnancies were randomly selected from low-risk fertile couples and paired to IVF by maternal age. Fetal neurosonography including transvaginal approach was performed at 32±2 weeks of gestation, measured off-line by a single investigator and normalized by biparietal or occipitofrontal diameter. ASQ were obtained postnatally, at 12 months of corrected age.

Main results and the role of chance

Study groups were similar and comparable regarding maternal age, body mass index, study level and employment rate together with exposure to smoke, alcohol, aspirin and corticoids during pregnancy, gestational age (32±2 weeks) and estimated fetal weight (1700±400g) at neurosonography.

As compared to SC pregnancies, both IVF populations showed differences in cortical development with reduced parieto-occipital (fresh ET 12.5mm [SD 2.5] vs FET 13.4 [2.6] vs SC 13.4 [2.6]), cingulate (fresh ET 5.8 [IQR 4.2–7.4] vs FET 5.8 [4.1–7.5] vs SC 6.5 [4.8–7.8]) and calcarine (fresh ET 13.5 [IQR 10.1–16.1] vs FET 14.5 [12.1–15.8] vs SC 16.4 [14.3–17.9]) sulci depth together with lower Sylvian fissure grading. Cortical development changes were more pronounced in the fresh ET group as compared to FET. Corpus callosum length and insula depth were lower in FET and fresh ET groups, respectively. Neurosonographic changes remained statistically significant after adjustment by ethnicity, gender, gestational age and weight centile at scan.

IVF infants showed worse ASQ scores, especially in fresh ET for communication, personal-social, fine-motor and problem-solving skills. Gross-motor scores were significantly lower in FET as compared to SC and fresh ET. Differences were statistically significant after adjustment by maternal ethnicity, study level, employment status, breastfeeding, gender and corrected age.

Limitations, reasons for caution

The reported neurodevelopmental differences are subtle, with most neurosonographic findings lying within normal ranges. Infertility factors contribution to the outcome cannot be unraveled from the ART procedure itself. The milder features found in FET individuals cannot condition the techniqués choice and must be considered together with their global perinatal results.

Wider implications of the findings: Neurosonography is an appropriate tool to identify subtle brain differences between fetuses exposed and not exposed to ART. Prenatal features were consistent with postnatal neurobehavioral findings. These results support the relevance of a neurodevelopmental follow-up in IVF patients. Further studies are warranted to assess the long-term performance in these subjects.

Trial registration number

Not applicable

Cardiac remodeling in fetuses conceived by ARTs: fresh versus frozen embryo transfer

STUDY QUESTION

Do fetuses from frozen embryo transfer (FET) present signs of cardiac remodeling and suboptimal function similar to those observed in fetuses from fresh embryo transfer (ET)?

SUMMARY ANSWER

Fetuses from both fresh ET and FET present signs of fetal cardiac remodeling and suboptimal function, with more pronounced changes after fresh ET as compared to FET.

WHAT IS KNOWN ALREADY

Our group and others have previously demonstrated that fetuses and children conceived by ARTs present cardiac remodeling and suboptimal function. These fetuses show dilated atria, more globular and thicker ventricles, reduced longitudinal motion, and impaired relaxation. Cardiac changes were already present in utero and persisted after birth. Most of the ART fetuses included in previous publications were from fresh ET. However, singletons from FET have different perinatal outcomes compared to those from fresh ET. There are no previous studies comparing cardiac morphology and function between fetuses following fresh and FET.

STUDY DESIGN, SIZE, DURATION

This is a prospective cohort study of 300 singleton pregnancies recruited from 2017 to 2020, including 100 spontaneously conceived (SC) pregnancies, 100 fetuses conceived by IVF with FET, and 100 fetuses conceived by IVF with fresh ET. Fetal structural and functional echocardiography was performed in all pregnancies.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pregnancies conceived by IVF were recruited from a single assisted reproduction center, ensuring homogeneity in IVF stimulation protocols, endometrial preparation for FET, laboratory procedures, and embryo culture conditions. SC pregnancies from fertile couples were selected from the general population and matched to IVF pregnancies by maternal age. Epidemiological and perinatal outcomes were collected in all cases. Fetal echocardiography was performed at 28-33 weeks of pregnancy to assess cardiac structure and function in all pregnancies. All echocardiographic comparisons were adjusted by maternal age, nulliparity, birthweight centile, preeclampsia, and prematurity.

MAIN RESULTS AND THE ROLE OF CHANCE

Parental age, ethnicity, body mass index and smoking were similar among the study groups. Median gestational age at echocardiography and estimated fetal weight were similar in all study groups. Both fresh ET and FET groups showed similar fetal echocardiographic changes, with more pronounced features in the fresh ET as compared to FET pregnancies. Fetuses conceived by IVF showed larger atria (right atria-to-heart ratio: fresh ET mean 18.1% (SD 3.2) vs FET 18.0% (3.9) vs SC 17.3% (3.2); linear tendency P-value <0.001), more globular ventricles (right ventricular sphericity index: fresh ET 1.62 (0.29) vs FET 1.61 (0.25) vs SC 1.68 (0.26); <0.001) and thicker myocardial walls (relative wall thickness: fresh ET 0.79 (0.21) vs FET 0.74 (0.22) vs SC 0.65 (0.25); <0.001) as compared to SC pregnancies. Both fresh ET and FET groups also had signs of suboptimal systolic and diastolic function, with reduced tricuspid annular systolic peak velocity (fresh ET 7.17 cm/s (1.22) vs FET 7.41 cm/s (1.19) vs SC 7.58 cm/s (1.32); <0.001) and increased left myocardial performance index (fresh ET 0.53 (0.08) vs FET 0.53 (0.08) vs SC 0.50 (0.09); <0.001) as compared to SC pregnancies.

LIMITATIONS, REASONS FOR CAUTION

The cardiac changes reported here are subclinical, with most cardiovascular indexes lying within normal ranges. Although echocardiographic changes are recognized as potential cardiovascular risk factors, their association with the long-term cardiovascular disease remains to be proven. The observed milder fetal cardiac features in FET fetuses cannot condition the choice of this technique and must be considered together with the global perinatal results related to these gestations.

WIDER IMPLICATIONS OF THE FINDINGS

The identification of cardiac remodeling in fetuses conceived by IVF with fresh ET and FET represents an opportunity for early detection. Future studies are warranted to study the potential long-term consequences of these findings.

STUDY FUNDING/COMPETING INTEREST(S)

This project has been partially funded with support from the Erasmus + Programme of the European Union (Framework Agreement number: 2013-0040). This publication reflects the views only of the author, and the Commission cannot be held responsible for any use, which may be made of the information contained therein. Additionally, the research leading to these results has received funding from 'la Caixa' Foundation under grant agreement LCF/PR/GN18/10310003, the Instituto de Salud Carlos III (PI15/00130, PI17/00675, PI18/00073) integrated into the Plan Nacional de I + D+I and cofinanced by ISCIII-Subdirección General de Evaluación and Fondo Europeo de Desarrollo Regional (FEDER) 'Una manera de hacer Europa', Cerebra Foundation for the Brain Injured Child (Carmarthen, Wales, UK) and AGAUR 2017 SGR grant n° 1531. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Fetal neurosonography detects differences in cortical development and corpus callosum in late-onset small fetuses

OBJECTIVE

To explore whether neurosonography can detect differences in cortical development and corpus callosal length in late-onset small fetuses subclassified into small-for-gestational age (SGA) or growth restricted (FGR).

METHODS

This was a prospective cohort study in singleton pregnancies, including normally grown fetuses (birth weight between the 10^th and 90^th centiles) and late-onset small fetuses (estimated fetal weight < 10^th centile, diagnosed after 32 weeks of gestation and confirmed by birth weight < 10^th centile). Small fetuses were subclassified into SGA (birth weight between the 3^rd and 9^th centiles and normal fetoplacental Doppler) and FGR (birth weight < 3^rd centile and/or abnormal cerebroplacental ratio and/or abnormal uterine artery Doppler). Neurosonography was performed at 33 ± 1 weeks of gestation to assess the depth of the insula, Sylvian fissure and parieto-occipital sulcus in the axial views and corpus callosal length in the midsagittal plane. Measurements were performed offline using Alma Workstation software and were adjusted by biparietal diameter or cephalic index. Linear regression analysis was used to assess the association between the neurosonographic variables and study group, adjusting for confounding factors such as gender, gestational age at neurosonography, nulliparity and pre-eclampsia.

RESULTS

In total, 318 fetuses were included, of which 97 were normally grown and 221 were late-onset small fetuses that were further subdivided into late-onset SGA (n = 67) or late-onset FGR (n = 154). Compared to controls, both SGA and FGR cases showed significantly increased insular depth adjusted for biparietal diameter (median (interquartile range), controls 0.329 (0.312-0.342) vs SGA 0.339 (0.321-0.347) vs FGR 0.336 (0.325-0.349); P = 0.006). A linear tendency to reduced Sylvian fissure depth adjusted for biparietal diameter was also observed across the study groups (mean ± SD, controls 0.148 ± 0.021 vs SGA 0.142 ± 0.025 vs FGR 0.139 ± 0.022; P = 0.003). However, differences were significant only between the FGR and control groups. Corpus callosal length adjusted for cephalic index was significantly reduced in FGR cases compared with both controls and SGA cases, while there was no difference between SGA cases and controls (median (interquartile range), controls 0.500 (0.478-0.531) vs SGA 0.502 (0.487-0.526) vs FGR 0.475 (0.447-0.508); P = 0.005). No differences were found in parieto-occipital sulcus depth between the three study groups.

CONCLUSION

Neurosonography seems to be a sensitive tool to detect subtle structural differences in brain development in late-onset small fetuses. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Distinctive patterns of placental lesions in pre-eclampsia vs small-for-gestational age and their association with fetoplacental Doppler

OBJECTIVES

To describe placental histopathological findings in a large cohort of pregnancies complicated by pre-eclampsia (PE) and/or small-for-gestational age (SGA), and to investigate their association with fetoplacental Doppler parameters.

METHODS

This was a prospective observational study of normotensive pregnancies with SGA (defined as birth weight < 10^th centile) (n = 184), PE pregnancies with a normally grown fetus (n = 102), pregnancies with both PE and SGA (n = 120) and uncomplicated pregnancies (n = 202). Uterine (UtA), umbilical (UA) and fetal middle cerebral (MCA) artery pulsatility indices (PI) were assessed. The cerebroplacental ratio (CPR) was calculated by dividing MCA-PI by UA-PI. Doppler parameters were considered abnormal when UtA-PI or UA-PI was > 95^th centile or MCA-PI or CPR was < 5^th centile. Placental lesions were categorized as vascular (maternal or fetal side), immunoinflammatory or other, according to the 2014 Amsterdam Placental Workshop Group Consensus Statement. Comparison between the study groups was performed using univariate and multiple regression analysis, and logistic regression was used to determine the relationship between abnormal Doppler parameters and placental lesions.

RESULTS

Maternal-side vascular lesions were significantly more common in PE pregnancies with SGA than in the other groups (PE + SGA, 73% vs PE, 46% vs SGA, 38% vs controls, 31%; P = 0.01) and included mainly two types of lesion: developmental (PE + SGA, 13% vs PE, 5% vs SGA, 3% vs controls, 1.5%; P < 0.001) and malperfusion (PE + SGA, 70% vs PE, 39% vs SGA, 32% vs controls, 25%; P = 0.001). In contrast, the incidence of fetal-side developmental lesions was significantly higher in normotensive SGA pregnancies than in controls and PE pregnancies (PE + SGA, 0% vs PE, 3% vs SGA, 8% vs controls, 2%; P = 0.001). All cases displayed a lower prevalence of infectious lesions than did controls, with the highest prevalence of immune lesions observed in pregnancies with both PE and SGA (PE + SGA, 18% vs PE, 8% vs SGA, 10% vs controls, 9%; P = 0.001). All fetoplacental Doppler parameters evaluated were associated with maternal-side vascular lesions, mainly malperfusion (mean UtA-PI: odds ratio (OR), 2.45 (95% CI, 1.51-3.97); UA-PI: OR, 2.05 (95% CI, 1.02-4.47); MCA-PI: OR, 2.75 (95% CI, 1.40-5.42); CPR: OR, 1.75 (95% CI, 1.04-2.95)). This association was evident mainly in the normotensive SGA group, being non-significant in controls or PE pregnancies without SGA. No significant associations were observed between fetoplacental Doppler parameters and other placental lesions in any of the study groups.

CONCLUSIONS

PE and SGA are associated with different patterns of placental histopathological lesions in accordance with the clinical manifestation of the placental disorder (maternal vs fetal). Fetoplacental Doppler findings show an association with placental malperfusion lesions on the maternal side, supporting the use of abnormal Doppler as a surrogate for placental insufficiency. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Premature placental aging in term small-for-gestational-age and growth-restricted fetuses

OBJECTIVE

To perform a comprehensive assessment of the placental aging process in small term fetuses classified as being small-for-gestational age (SGA) or having fetal growth restriction (FGR) through analysis of senescence and apoptosis markers.

METHODS

This was a prospective nested case-control study of singleton pregnancies delivered at term, including 21 control pregnancies with normally grown fetuses and 36 with a small fetus classified as SGA (birth weight between the 3^rd and 9^th percentiles and normal fetoplacental Doppler; n = 18) or FGR (birth weight < 3^rd percentile and/or abnormal cerebroplacental ratio and/or uterine artery Doppler; n = 18). Telomerase activity, telomere length (quantified by comparing the amount of amplification product for the telomere sequence (T) to that of a single copy of the gene 36B4 (S)) and RNA expression of senescence (Sirtuins 1, 3 and 6) and apoptosis (p53, p21, BAX and Caspases 3 and 9) markers (analyzed using the 2^-ΔΔCt method) were determined in placental samples collected at birth and compared between the three groups.

RESULTS

Compared to pregnancies with a normally grown fetus, both SGA and FGR pregnancies presented signs of accelerated placental aging, including lower telomerase activity (mean ± SD, 12.8 ± 6.6% in controls vs 7.98 ± 4.2% in SGA vs 7.79 ± 4.6% in FGR; P = 0.008), shorter telomeres (mean ± SD T/S ratio, 1.20 ± 0.6 in controls vs 1.08 ± 0.9 in SGA vs 0.66 ± 0.5 in FGR; P = 0.047) and reduced Sirtuin-1 RNA expression (mean ± SD 2^-ΔΔCt , 1.55 ± 0.8 in controls vs 0.91 ± 0.8 in SGA vs 0.63 ± 0.5 in FGR; P = 0.001) together with increased p53 RNA expression (median (interquartile range) 2^-ΔΔCt , 1.07 (0.3-3.3) in controls vs 5.39 (0.6-15) in SGA vs 3.75 (0.9-7.8) in FGR; P = 0.040). FGR cases presented signs of apoptosis, with increased Caspase-3 RNA levels (median (interquartile range) 2^-ΔΔCt , 0.94 (0.7-1.7) in controls vs 3.98 (0.9-31) in FGR; P = 0.031) and Caspase-9 RNA levels (median (interquartile range) 2^-ΔΔCt , 1.21 (0.6-4.0) in controls vs 3.87 (1.5-9.0) in FGR; P = 0.037) compared with controls. In addition, Sirtuin-1 RNA expression, telomerase activity, telomere length and Caspase-3 activity showed significant linear trends across groups as severity of the condition increased.

CONCLUSIONS

Accelerated placental aging was observed in both clinical forms of late-onset fetal smallness (SGA and FGR), supporting a common pathophysiology and challenging the concept of SGA fetuses being constitutionally small. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Transgenerational transmission of small-for-gestational age

OBJECTIVE

To evaluate the transgenerational transmission of small-for-gestational age (SGA).

METHODS

This was a cohort study of a random sample of 2043 offspring delivered between 1975 and 1993 at Hospital Sant Joan de Déu in Barcelona. Exclusion criteria were multiple pregnancy, aneuploidy or genetic syndrome, major birth defects, severe mental disease and macrosomia. Eligible individuals were contacted and those with at least one offspring were included in the study. Participants were classified according to the presence of SGA (defined as birth weight < 10^th percentile) at birth. Multiple regression analysis was used to determine the presence of SGA or placenta-mediated disease (defined as the presence of SGA, pre-eclampsia, gestational hypertension and/or placental abruption) in the following generation.

RESULTS

Of 623 individuals who agreed to participate, 152 (72 born SGA and 80 born appropriate-for-gestational age (AGA)) were reported to have at least one child. Descendants of SGA individuals presented with a lower birth-weight percentile (median, 26 (interquartile range (IQR), 7-52) vs 43 (IQR, 19-75); P < 0.001) and a higher prevalence of SGA (40.3% vs 16.3%; P = 0.001) and placenta-mediated disease (43.1% vs 17.5%; P = 0.001) than did the offspring of AGA individuals. After adjustment for confounding variables, parental SGA background was associated with an almost three-fold increased risk of subsequent SGA or any placenta-mediated disease in the following generation. This association was stronger in SGA mothers than in SGA fathers.

CONCLUSIONS

Our data provide evidence suggesting a transgenerational transmission of SGA, highlighting the importance of public health strategies for preventing intrauterine growth impairment. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of fetal growth restriction using estimated fetal weight vs a combined screening model in the third trimester

OBJECTIVES

To compare the performance of third-trimester screening, based on estimated fetal weight centile (EFWc) vs a combined model including maternal baseline characteristics, fetoplacental ultrasound and maternal biochemical markers, for the prediction of small-for-gestational-age (SGA) neonates and late-onset fetal growth restriction (FGR).

METHODS

This was a nested case-control study within a prospective cohort of 1590 singleton gestations undergoing third-trimester (32 + 0 to 36 + 6 weeks' gestation) evaluation. Maternal baseline characteristics, mean arterial pressure, fetoplacental ultrasound and circulating biochemical markers (placental growth factor (PlGF), lipocalin-2, unconjugated estriol and inhibin A) were assessed in all women who subsequently delivered a SGA neonate (n = 175), defined as birth weight < 10^th centile according to customized standards, and in a control group (n = 875). Among SGA cases, those with birth weight < 3^rd centile and/or abnormal uterine artery pulsatility index (UtA-PI) and/or abnormal cerebroplacental ratio (CPR) were classified as FGR. Logistic regression predictive models were developed for SGA and FGR, and their performance was compared with that obtained using EFWc alone.

RESULTS

In SGA cases, EFWc, CPR Z-score and maternal serum concentrations of unconjugated estriol and PlGF were significantly lower, while mean UtA-PI Z-score and lipocalin-2 and inhibin A concentrations were significantly higher, compared with controls. Using EFWc alone, 52% (area under receiver-operating characteristics curve (AUC), 0.82 (95% CI, 0.77-0.85)) of SGA and 64% (AUC, 0.86 (95% CI, 0.81-0.91)) of FGR cases were predicted at a 10% false-positive rate. A combined screening model including a-priori risk (maternal characteristics), EFWc, UtA-PI, PlGF and estriol (with lipocalin-2 for SGA) achieved a detection rate of 61% (AUC, 0.86 (95% CI, 0.83-0.89)) for SGA cases and 77% (AUC, 0.92 (95% CI, 0.88-0.95)) for FGR. The combined model for the prediction of SGA and FGR performed significantly better than did using EFWc alone (P < 0.001 and P = 0.002, respectively).

CONCLUSIONS

A multivariable integrative model of maternal characteristics, fetoplacental ultrasound and maternal biochemical markers modestly improved the detection of SGA and FGR cases at 32-36 weeks' gestation when compared with screening based on EFWc alone. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Performance of third-trimester combined screening model for prediction of adverse perinatal outcome

OBJECTIVE

To explore the potential value of third-trimester combined screening for the prediction of adverse perinatal outcome (APO) in the general population and among small-for-gestational-age (SGA) fetuses.

METHODS

This was a nested case-control study within a prospective cohort of 1590 singleton gestations undergoing third-trimester evaluation (32 + 0 to 36 + 6 weeks' gestation). Maternal baseline characteristics, mean arterial blood pressure, fetoplacental ultrasound and circulating biochemical markers (placental growth factor (PlGF), lipocalin-2, unconjugated estriol and inhibin A) were assessed in all women who subsequently had an APO (n = 148) and in a control group without perinatal complications (n = 902). APO was defined as the occurrence of stillbirth, umbilical artery cord blood pH < 7.15, 5-min Apgar score < 7 or emergency operative delivery for fetal distress. Logistic regression models were developed for the prediction of APO in the general population and among SGA cases (defined as customized birth weight < 10^th centile).

RESULTS

The prevalence of APO was 9.3% in the general population and 27.4% among SGA cases. In the general population, a combined screening model including a-priori risk (maternal characteristics), estimated fetal weight (EFW) centile, umbilical artery pulsatility index (UA-PI), estriol and PlGF achieved a detection rate for APO of 26% (area under receiver-operating characteristics curve (AUC), 0.59 (95% CI, 0.54-0.65)), at a 10% false-positive rate (FPR). Among SGA cases, a model including a-priori risk, EFW centile, UA-PI, cerebroplacental ratio, estriol and PlGF predicted 62% of APO (AUC, 0.86 (95% CI, 0.80-0.92)) at a FPR of 10%.

CONCLUSIONS

The use of fetal ultrasound and maternal biochemical markers at 32-36 weeks provides a poor prediction of APO in the general population. Although it remains limited, the performance of the screening model is improved when applied to fetuses with suboptimal fetal growth. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Changes in uterine artery Doppler velocimetry and circulating angiogenic factors in the first half of pregnancies delivering a small-for-gestational-age neonate

OBJECTIVE

To assess the relationship between longitudinal changes in placental Doppler indices and maternal circulating angiogenic factors in the first half of pregnancy and delivery of a small-for-gestational-age (SGA) neonate, and ascertain whether longitudinal evaluation of these variables improves the prediction achieved by second-trimester cross-sectional evaluation.

METHODS

From a prospective cohort of unselected singleton pregnancies undergoing first-trimester screening for aneuploidy, 138 were included in this study. Of these, 46 were complicated by SGA (delivering after 34 weeks' gestation with a birth weight < 10^th centile) and 92 were appropriate-for-gestational-age (AGA) pregnancies, which were included as controls (ratio 1:2). First-to-second trimester longitudinal changes in uterine artery (UtA) Doppler indices and maternal circulating levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were analyzed.

RESULTS

Compared with the AGA group, SGA pregnancies had significantly higher UtA impedance in the first (Z-score: 0.46 vs -0.57; P < 0.001) and second (Z-score: 1.71 vs -0.75; P < 0.001) trimesters. Likewise, the sFlt-1/PlGF ratio was significantly higher in SGA than in AGA pregnancies in the first (98.0 vs 67.9; P = 0.01) and early second (22.4 vs 8.8; P < 0.001) trimesters. The predictive performance of the longitudinal changes in UtA Doppler indices for SGA was significantly lower than that of second-trimester cross-sectional values (area under receiver-operating characteristics curve (AUC), 60.8% vs 84.3%; P = 0.0035). The detection rate of SGA, at a 10% false-positive rate (FPR), was 17.7% by longitudinal changes in UtA Doppler and 56.2% by second-trimester cross-sectional UtA Doppler values. Similarly, the predictive performance of the longitudinal changes in PlGF was significantly lower than that of early second-trimester cross-sectional values (AUC, 71.4% vs 76.5%; P = 0.008). The detection rate of SGA at a 10% FPR was 40.6% when screening by longitudinal changes in PlGF and 52.1% when screening by early second-trimester cross-sectional values.

CONCLUSIONS

First- and second-trimester UtA Doppler velocimetry and maternal circulating angiogenic markers have clinical utility as a cross-sectional assessment for the identification of pregnancies at high risk of delivering a SGA neonate, however, they do not improve prediction when their longitudinal changes are used. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Differential performance of first-trimester screening in predicting small-for-gestational-age neonate or fetal growth restriction

OBJECTIVE

To assess the ability of integrated first-trimester screening, combining maternal characteristics and biophysical and biochemical markers, to predict delivery of a small-for-gestational-age (SGA) neonate, and compare this with its ability to predict fetal growth restriction (FGR).

METHODS

This was a prospective cohort study of singleton pregnancies undergoing routine first-trimester screening. SGA was defined as birth weight (BW) < 10^th percentile and FGR was defined as an ultrasound estimated fetal weight < 10^th percentile plus Doppler abnormalities, or BW < 3^rd percentile. Logistic regression-based predictive models were developed for predicting SGA and FGR. Models incorporated the a-priori risk from maternal characteristics, and mean arterial pressure, uterine artery Doppler, placental growth factor and soluble fms-like tyrosine kinase-1.

RESULTS

In total, 9150 births were included. Of these, 979 (10.7%) qualified for a postnatal diagnosis of SGA and 462 (5.0%) for a prenatal diagnosis of FGR. For predicting SGA, the model achieved a detection rate of 35% for a false-positive rate (FPR) of 5% and 42% for a 10% FPR. The model's performance was significantly higher for predicting FGR (P < 0.001), with detection rates of 59% and 67%, for a FPR of 5% and 10%, respectively.

CONCLUSION

The predictive performance of first-trimester screening for cases with growth impairment by a combination of maternal characteristics and biophysical and biochemical markers is improved significantly when a prenatal and strict definition of FGR is used rather than a postnatal definition based on BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Validation of a first-trimester screening model for pre-eclampsia in an unselected population

OBJECTIVE

To validate the performance of a previously constructed first-trimester predictive model for pre-eclampsia (PE) in routine care of an unselected population.

METHODS

A validation cohort of 4621 consecutive women attending their routine first-trimester ultrasound examination was used to test a prediction model for PE that had been developed previously in 5170 women. The prediction model included maternal factors, uterine artery Doppler, blood pressure and pregnancy-associated plasma protein-A. Model performance was evaluated using receiver-operating characteristics (ROC) curve analysis and ROC curves from both cohorts were compared unpaired.

RESULTS

Among the 4203 women included in the final analysis, 169 (4.0%) developed PE, including 141 (3.4%) cases of late-onset PE and 28 (0.7%) cases of early-onset PE. For early-onset PE, the model showed an area under the ROC curve of 0.94 (95% CI, 0.88-0.99), which did not differ significantly (P = 0.37) from that obtained in the construction cohort (0.88 (95% CI, 0.78-0.99)). For late-onset PE, the final model showed an area under the ROC curve of 0.72 (95% CI, 0.66-0.77), which did not differ significantly (P = 0.49) from that obtained in the construction cohort (0.75 (95% CI, 0.67-0.82)).

CONCLUSION

The prediction model for PE achieved a similar performance to that obtained in the construction cohort when tested on a subsequent cohort of women, confirming its validity as a predictive model for PE. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

First-trimester screening with specific algorithms for early- and late-onset fetal growth restriction

OBJECTIVE

To develop optimal first-trimester algorithms for the prediction of early and late fetal growth restriction (FGR).

METHODS

This was a prospective cohort study of singleton pregnancies undergoing first-trimester screening. FGR was defined as an ultrasound estimated fetal weight < 10(th) percentile plus Doppler abnormalities or a birth weight < 3(rd) percentile. Logistic regression-based predictive models were developed for predicting early and late FGR (cut-off: delivery at 34 weeks). The model included the a-priori risk (maternal characteristics), mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1).

RESULTS

Of the 9150 pregnancies included, 462 (5%) fetuses were growth restricted: 59 (0.6%) early and 403 (4.4%) late. Significant contributions to the prediction of early FGR were provided by black ethnicity, chronic hypertension, previous FGR, MAP, UtA-PI, PlGF and sFlt-1. The model achieved an overall detection rate (DR) of 86.4% for a 10% false-positive rate (area under the receiver-operating characteristics curve (AUC): 0.93 (95% CI, 0.87-0.98)). The DR was 94.7% for FGR with pre-eclampsia (PE) (64% of cases) and 71.4% for FGR without PE (36% of cases). For late FGR, significant contributions were provided by chronic hypertension, autoimmune disease, previous FGR, smoking status, nulliparity, MAP, UtA-PI, PlGF and sFlt-1. The model achieved a DR of 65.8% for a 10% false-positive rate (AUC: 0.76 (95% CI, 0.73-0.80)). The DR was 70.2% for FGR with PE (12% of cases) and 63.5% for FGR without PE (88% of cases).

CONCLUSIONS

The optimal screening algorithm was different for early vs late FGR, supporting the concept that screening for FGR is better performed separately for the two clinical forms. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Contingent versus routine third-trimester screening for late fetal growth restriction

OBJECTIVE

To evaluate the use of third-trimester ultrasound screening for late fetal growth restriction (FGR) on a contingent basis, according to risk accrued in the second trimester, in an unselected population.

METHODS

Maternal characteristics, fetal biometry and second-trimester uterine artery (UtA) Doppler were included in logistic regression analysis to estimate risk for late FGR (birth weight < 3(rd) percentile, or 3(rd) -10(th) percentile plus abnormal cerebroplacental ratio or UtA Doppler, with delivery ≥ 34 weeks). Based on the second-trimester risk, strategies for performing contingent third-trimester ultrasound examinations in 10%, 25% or 50% of the cohort were tested against a strategy of routine ultrasound scanning in the entire population at 32 + 0 to 33 + 6 weeks.

RESULTS

Models were constructed based on 1393 patients and validated in 1303 patients, including 73 (5.2%) and 82 late FGR (6.3%) cases, respectively. At the second-trimester scan, the a-posteriori second-trimester risk (a-posteriori first-trimester risk (baseline a-priori risk and mean arterial blood pressure) combined with second-trimester abdominal circumference and UtA Doppler) yielded an area under the receiver-operating characteristics curve (AUC) of 0.81 (95% CI, 0.74-0.87) (detection rate (DR), 43.1% for a 10% false-positive rate (FPR)). The combination of a-posteriori second-trimester risk plus third-trimester estimated fetal weight (full model) yielded an AUC of 0.92 (95% CI, 0.88-0.96) (DR, 74% for a 10% FPR). Subjecting 10%, 25% or 50% of the study population to third-trimester ultrasound, based on a-posteriori second-trimester risk, gave AUCs of 0.81 (95% CI, 0.75-0.88), 0.84 (95% CI, 0.78-0.91) and 0.89 (95% CI, 0.84-0.94), respectively. Only the 50% contingent model proved statistically equivalent to performing routine third-trimester ultrasound scans (AUC, 0.92 (95% CI, 0.88-0.96), P = 0.11).

CONCLUSION

A strategy of selecting 50% of the study population to undergo third-trimester ultrasound examination, based on accrued risk in the second trimester, proved equivalent to routine third-trimester ultrasound scanning in predicting late FGR.

Potential rapid evolution of foot morphology in Italian plethodontid salamanders (Hydromantes strinatii) following the colonization of an artificial cave

How organisms respond to environmental change is a long-standing question in evolutionary biology. Species invading novel habitats provide an opportunity to examine contemporary evolution in action and decipher the pace of evolutionary change over short timescales. Here, we characterized phenotypic evolution in the Italian plethodontid salamander, Hydromantes strinatii, following the recent colonization of an artificial cave by a forest floor population. When compared with a nearby and genetically related population in the natural forest floor and a nearby cave population, the artificial cave population displayed significant differences in overall foot shape, with more interdigital webbing relative to the other populations. Further, this population evolved significantly larger feet, which corresponded more closely to those found in other cave populations than to forest floor populations to which the cave population is closely related. Finally, we quantified the rate of evolution for both foot shape and foot area, and found that both traits displayed large and significant evolutionary rates, at levels corresponding to other classic cases of rapid evolution in vertebrates. Together, these findings reveal that the response to novel environmental pressures can be large and rapid and that the anatomical shifts observed in the artificial cave population of H. strinatii may represent a case of rapid evolution in response to novel environmental pressures.

An integrated model with classification criteria to predict small-for-gestational-age fetuses at risk of adverse perinatal outcome

OBJECTIVE

To develop an integrated model with the best performing criteria for predicting adverse outcome in small-for-gestational-age (SGA) pregnancies.

METHODS

A cohort of 509 pregnancies with a suspected SGA fetus, eligible for trial of labor, was recruited prospectively and data on perinatal outcome were recorded. A predictive model for emergency Cesarean delivery because of non-reassuring fetal status or neonatal acidosis was constructed using a decision tree analysis algorithm, with predictors: maternal age, body mass index, smoking, nulliparity, gestational age at delivery, onset of labor (induced vs spontaneous), estimated fetal weight (EFW), umbilical artery pulsatility index (PI), mean uterine artery (UtA) PI, fetal middle cerebral artery PI and cerebroplacental ratio (CPR).

RESULTS

An adverse outcome occurred in 134 (26.3%) cases. The best performing predictors for defining a high risk for adverse outcome in SGA fetuses was the presence of a CPR < 10th centile, a mean UtA-PI > 95th centile or an EFW < 3rd centile. The algorithm showed a sensitivity, specificity and positive and negative predictive values for adverse outcome of 82.8% (95% CI, 75.1-88.6%), 47.7% (95% CI, 42.6-52.9%), 36.2% (95% CI, 30.8-41.8%) and 88.6% (95% CI, 83.2-92.5%), respectively. Positive and negative likelihood ratios were 1.58 and 0.36.

CONCLUSIONS

Our model could be used as a diagnostic tool for discriminating SGA pregnancies at risk of adverse perinatal outcome.

Correlation between histological signs of placental underperfusion and perinatal morbidity in late-onset small-for-gestational-age fetuses

OBJECTIVE

To investigate whether signs of placental underperfusion (PUP), defined as any maternal and/or fetal vascular pathology, confer an increased risk of neonatal morbidity in late-onset small-for-gestational-age (SGA) fetuses with normal umbilical artery (UA) Doppler indices.

METHODS

A cohort of 126 SGA singleton fetuses with normal UA Doppler indices that were delivered after 34 weeks' gestation was studied. For each case, the placenta was evaluated histologically for signs of PUP using a hierarchical and standardized classification system. Neonatal morbidity was assessed according to the score calculated from the morbidity assessment index for newborns (MAIN), a validated outcome scale. The independent association between PUP and neonatal morbidity was evaluated using multivariable median regression analysis.

RESULTS

In 84 (66.7%) placentae, 97 placental histological findings that qualified as signs of PUP were observed. These PUP cases had a significantly higher incidence of emergency Cesarean section for non-reassuring fetal status (44.1% vs 21.4%, respectively; P = 0.013) and neonatal metabolic acidosis at birth (33.3% vs 14.3%, respectively; P = 0.023), than did those without PUP. The median MAIN score differed significantly between those with PUP and those without (89 vs 0, respectively; P = 0.025). This difference remained significant after adjustment for potential confounders. The proportion of cases with scores indicative of mild to severe morbidity was also significantly higher in the PUP group (31% vs 14.3%, respectively; P = 0.043).

CONCLUSION

In late-onset SGA fetuses with normal UA Doppler indices, signs of PUP imply a higher neonatal morbidity. These findings allow the phenotypic profiling of fetal growth restriction among the general population of late-onset SGA.

Association of Doppler parameters with placental signs of underperfusion in late-onset small-for-gestational-age pregnancies

OBJECTIVE

To elucidate the association between Doppler parameters and histological signs of placental underperfusion in late-onset small-for-gestational-age (SGA) babies.

METHODS

Umbilical, fetal middle cerebral and uterine artery pulsatility indices and umbilical vein blood flow (UVBF), which had been recorded within 7 days prior to delivery, were analyzed from a cohort of SGA singleton pregnancies delivered after 34 weeks' gestation and confirmed as having a birth weight < 10(th) percentile by local standards. In each case, the placenta was histologically evaluated for signs of placental underperfusion using a hierarchical and standardized classification system. The independent association of the Doppler parameters with placental underperfusion was evaluated using logistic regression and decision tree analysis.

RESULTS

In 51 cases (53.7%), there were 61 placental histological findings indicative of placental underperfusion. These cases had a significantly higher incidence of Cesarean section for non-reassuring fetal status (52.1% vs 11.9%; P < 0.001) and neonatal metabolic acidosis at birth (21.6% vs 0%; P = 0.001). Significant and independent contributions to the presence of placental underperfusion lesions were provided by increased mean UtA pulsatility index (PI) (P = 0.018; odds ratio (OR) 2 (95% CI, 1.1-3.7)) and decreased UVBF normalized to estimated fetal weight (P = 0.027; OR 0.97 (95% CI, 0.95-0.99)). The combination of both parameters revealed three groups with differing risks for placental underperfusion: normalized UVBF > 82 mL/min/kg (risk 31.3%), normalized UVBF ≤ 82 mL/min/kg and mean UtA-PI ≤ 95(th) percentile (risk 65.5%), and normalized UVBF ≤ 82 mL/min/kg and UtA-PI > 95(th) percentile (risk 94.4%).

CONCLUSIONS

In late-onset SGA pregnancies, uterine Doppler and UVBF are surrogates for placental underperfusion. These findings facilitate phenotypic profiling of cases of fetal growth restriction among the general population of late-onset SGA babies.

Angiogenic factors vs Doppler surveillance in the prediction of adverse outcome among late-pregnancy small-for- gestational-age fetuses

OBJECTIVES

To compare the value of Doppler surveillance with maternal blood angiogenic factors at diagnosis for the prediction of adverse outcome in late-pregnancy small-for-gestational-age (SGA) fetuses.

METHODS

In a cohort of 198 SGA fetuses we evaluated the association of Doppler indices (mean uterine artery pulsatility index (UtA-PI) and cerebroplacental ratio (CPR)) and angiogenic factors (maternal serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF)) with the development of pre-eclampsia and adverse perinatal outcome (operative delivery for non-reassuring fetal status or neonatal metabolic acidosis).

RESULTS

In SGA fetuses subsequently developing pre-eclampsia, mean UtA-PI (P < 0.001), sFlt-1 MoM (P < 0.001) and sFlt-1/PlGF MoM ratio (P < 0.001) were higher, while PlGF MoM was lower (P = 0.004). In SGA fetuses with adverse perinatal outcome, CPR (P < 0.002) and PlGF MoM (P < 0.001) were lower, and sFlt-1/PlGF MoM ratio was higher (P = 0.001). For predicting pre-eclampsia, the areas under the receiver-operating characteristics (ROC) curves for mean UtA-PI, sFlt-1 MoM and the combination of both were 0.852, 0.839 and 0.860, respectively. For adverse perinatal outcome, the areas under the ROC curves for CPR, PlGF MoM and the combination of both were 0.652, 0.656 and 0.684, respectively. The combination of Doppler indices and angiogenic factors did not significantly improve prediction of either pre-eclampsia (P = 0.851) or adverse outcome (P = 0.579).

CONCLUSIONS

In SGA fetuses, angiogenic factors at diagnosis and follow-up with Doppler ultrasound both predict adverse outcome with a similar performance.

Angiogenic factors at diagnosis of late-onset small-for-gestational age and histological placental underperfusion

OBJECTIVE

This study was designed to explore the association between angiogenic factors levels at diagnosis of small-for-gestational age (SGA) and placental underperfusion (PUP).

METHODS

In a cohort of SGA singleton pregnancies, each delivered at >34 weeks, uterine (UtA), umbilical (UA), and middle cerebral (MCA) arteries were evaluated by Doppler upon diagnosis of SGA status. In addition, maternal circulating concentrations of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were assayed by ELISA, and each placenta was evaluated for histologic signs of PUP using a hierarchical and standardized classification system. Logistic regression was applied to analyze independent relationships (at diagnosis) between angiogenic factors and Doppler parameters.

RESULTS

A total of 122 suspected SGA pregnancies were studied, 70 (57.4%) of which ultimately met PUP criteria. In this group, 85 placental findings qualified as PUP. Both mean UtA pulsatility index z-values (1.26 vs. 0.84; p = 0.038) and PlGF multiples of normal median (0.21 vs. 0.55; p = 0.002) differed significantly in pregnancies with and without PUP, respectively. By logistic regression, PlGF alone was independently predictive of PUP (OR = 0.11 [95% CI 0.025-0.57]; p = 0.008).

DISCUSSION

Histologic placental abnormalities in term SGA neonates reflect latent insufficiency in uteroplacental blood supply. The heightened risk of adverse perinatal outcomes in this context underscores a need for new Doppler or biochemical prenatal markers of placental disease. Angiogenic factors may be pivotal identifying SGA neonates.

CONCLUSIONS

Diminished circulating levels of placental growth factor, determined upon discovery of SGA status, are associated with histologic evidence of PUP.

First-trimester screening for early and late small-for-gestational-age neonates using maternal serum biochemistry, blood pressure and uterine artery Doppler

OBJECTIVE

To assess the effectiveness of first-trimester screening for early and late small-for-gestational-age (SGA) neonates using maternal serum biochemistry, blood pressure and uterine artery Doppler.

METHODS

This was a prospective study of 4970 women with a singleton pregnancy who underwent routine first-trimester screening between 2009 and 2011. A logistic regression-based predictive model for SGA, defined as birth weight < 10(th) percentile, divided into early- or late-onset based on gestational age at delivery before or after 34 weeks' gestation, was constructed. The model included maternal baseline characteristics: serum levels of pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin at 8-12 weeks and blood pressure and uterine artery Doppler at 11 + 0 to 13 + 6 weeks.

RESULTS

The prevalence of early and late SGA was 0.6% and 7.9%, respectively. Association with pre-eclampsia was 67% and 8%, respectively. At a false-positive rate of 15%, the detection rate for early SGA was 73%; however it differed substantially for cases with and without pre-eclampsia (90% vs 40%). For late SGA, at false-positive rates of 15 and 50%, detection rates were 32% and 70%, respectively, and did not substantially differ between cases with and without pre-eclampsia.

CONCLUSIONS

First-trimester screening predicts early SGA mainly because of its strong association with pre-eclampsia. Although prediction of late SGA was poorer, at a high false-positive rate it might be considered as part of a first-trimester strategy to select women requiring ultrasound assessment in the third trimester.

Placental findings in late-onset SGA births without Doppler signs of placental insufficiency

OBJECTIVES

To describe placental pathological findings in late-onset small-for-gestational age (SGA) births for which Doppler signs of placental insufficiency are lacking.

METHODS

A series of placentas were evaluated from singleton pregnancies of SGA births (birth weight below the 10th percentile) delivered after 34 weeks with normal umbilical artery Doppler (pulsatility index below the 95th percentile), that were matched by gestational age with adequate-for-gestational age (AGA) controls. Using a hierarchical and standardized system, placental lesions were classified histologically as consequence of maternal underperfusion, fetal underperfusion or inflammation.

RESULTS

A total of 284 placentas were evaluated (142 SGA and 142 AGA). In the SGA group, 54.2% (77/142) of the placentas had weights below the 3rd percentile for GA while it was a 9.9% (14/142) in the AGA group (p < 0.001). Only 21.8% (31/142) of SGA placentas were free of histological abnormalities, while it was 74.6% (106/142) in the AGA group (p < 0.001). In the abnormal SGA placentas (111/142) there were a total of 161 lesions, attributable to MUP in 64% (103/161), FUP in 15.5% (25/161), and inflammation in 20.5% (33/161).

DISCUSSION

In most placentas of term SGA neonates with normal UA Doppler histological abnormalities secondary to maternal underperfusion prevail, reflecting latent insufficiency in uteroplacental blood supply. This is consistent with the higher risk of adverse perinatal outcome reported in this population and underscores a need for new markers of placental disease.

CONCLUSIONS

A significant proportion of late-onset SGA births with normal umbilical artery Doppler may still be explained by placental insufficiency.

Added value of umbilical vein flow as a predictor of perinatal outcome in term small-for-gestational-age fetuses

OBJECTIVE

To compare umbilical vein (UV) flow with standard Doppler parameters in prediction of adverse perinatal outcome in late-onset small-for-gestational age (SGA) fetuses.

METHODS

Umbilical, uterine and middle cerebral arteries, and UV blood flow were evaluated by Doppler before delivery in a cohort of 193 term SGA fetuses. The value of the Doppler parameters to predict risk of emergency delivery for non-reassuring fetal status and neonatal metabolic acidosis was analyzed.

RESULTS

Fifty-three (27%) fetuses had non-reassuring fetal status requiring emergency delivery, whereas 21 (11%) newborns developed neonatal metabolic acidosis. Multivariable analysis showed that significant contributions to prediction of emergency delivery for non-reassuring fetal status and neonatal metabolic acidosis were provided by middle cerebral artery (MCA) pulsatility index (PI) and UV blood flow normalized by fetal weight. Decision tree analysis defined three groups with increasing risk of need for emergency delivery for non-reassuring fetal status: MCA-PI > 1.46 (risk 15.6%); MCA-PI ≤ 1.46 and UV blood flow > 68 mL/min/kg (risk 25%); and MCA-PI ≤ 1.46 and UV flow ≤ 68 mL/min/kg (risk 53.1%); and two groups with different risks of neonatal metabolic acidosis: UV flow > 68 mL/min/kg or UV flow ≤ 68 mL/min/kg and MCA-PI > 1.23 (risk ≤ 10%); and UV flow ≤ 68 mL/min/kg and MCA-PI ≤ 1.23 (risk 39.1%).

CONCLUSION

The evaluation of UV blood flow with spectral brain Doppler allows better identification of SGA fetuses with late-onset intrauterine growth restriction at risk of adverse perinatal outcome.