Assessment of different thresholds of birthweight discordance for early neonatal outcomes: retrospective analysis of 2348 twin pregnancies

Development and validation of a prenatal predictive nomogram for the risk of NICU admission in infants born to Chinese mothers over 35 years of age: a retrospective cohort study

BACKGROUND

The rising number of women giving birth at advanced maternal age has posed significant challenges in obstetric care in recent years, resulting in increased incidence of neonatal transfer to the Neonatal Intensive Care Unit (NICU). Therefore, identifying fetuses requiring NICU transfer before delivery is essential for guiding targeted preventive measures.

OBJECTIVE

This study aims to construct and validate a nomogram for predicting the prenatal risk of NICU admission in neonates born to mothers over 35 years of age.

STUDY DESIGN

Clinical data of 4218 mothers aged ≥ 35 years who gave birth at the Department of Obstetrics of the Second Hospital of Shandong University between January 1, 2017 and December 31, 2021 were reviewed. Independent predictors were identified by multivariable logistic regression, and a predictive nomogram was subsequently constructed for the risk of neonatal NICU admission.

RESULTS

Multivariate logistic regression demonstrated that the method of prenatal screening, number of implanted embryos, preterm premature rupture of the membranes, preeclampsia, HELLP syndrome, fetal distress, premature birth, and cause of preterm birth are independent predictors of neonatal NICU admission. Analysis of the nomogram decision curve based on these 8 independent predictors showed that the prediction model has good net benefit and clinical utility.

CONCLUSION

The nomogram demonstrates favorable performance in predicting the risk of neonatal NICU transfer after delivery by mothers older than 35 years. The model serves as an accurate and effective tool for clinicians to predict NICU admission in a timely manner.

Predictive value of maternal serum placental growth factor levels for discordant fetal growth in twins: a retrospective cohort study

BACKGROUND

Accurate prenatal recognition of discordant fetal growth in twins is critical for deciding suitable management strategies. We explored the predictive value of the level of maternal second-trimester placental growth factor (PLGF) as a novel indicator of discordant fetal growth.

METHODS

A total of 860 women pregnant with twins were enrolled, including 168 women with monochorionic twins (31 cases of discordant fetal growth and 137 without) and 692 with dichorionic twins (79 cases of discordant fetal growth and 613 without). Maternal second-trimester PLGF concentrations were measured via immunofluorescence.

RESULTS

Maternal second-trimester PLGF levels were significantly lower in women pregnant with twins who subsequently developed discordant fetal growth than in those who did not (monochorionic twin pregnancy: P < 0.001; dichorionic twin pregnancy: P < 0.001). A 3-4 fold difference in median PLGF concentrations was detected between the two groups with both monochorionic and dichorionic twin pregnancies. Maternal second-trimester PLGF levels were significantly correlated with birth weight differences (monochorionic twin pregnancy: r =  - 0.331, P < 0.001; dichorionic twin pregnancy: r =  - 0.234, P < 0.001). A receiver operating characteristic curve was used to evaluate the predictive efficiency. In monochorionic twin pregnancies, the area under the curve (AUC) was 0.751 (95% confidence interval [CI]: 0.649-0.852), and the cutoff value was 187.5 pg/mL with a sensitivity of 77.4% and specificity of 71.0%. In dichorionic twin pregnancies, the AUC was 0.716 (95% CI; 0.655-0.777), and the cutoff value was 252.5 pg/mL with a sensitivity of 65.1% and specificity of 69.6%. Based on the above cutoff values, univariate and multivariate logistic regression analyses were performed to calculate the odds ratios (OR) for the PLGF levels. After adjustment for potential confounding factors, low PLGF concentrations still significantly increased the risk of discordant fetal growth (monochorionic twin pregnancy: adjusted OR: 7.039, 95% CI: 2.798-17.710, P < 0.001; dichorionic twin pregnancy: adjusted OR: 4.279, 95% CI: 2.572-7.120, P < 0.001).

CONCLUSIONS

A low maternal second-trimester PLGF level is considered a remarkable risk factor and potential predictor of discordant fetal growth. This finding provides a complementary screening strategy for the prediction of discordant fetal growth and offers a unique perspective for the subsequent research in this field.

Relationships between birth weight discordance and maternal and perinatal risks among twin pregnancies conceived following frozen embryo transfer

STUDY QUESTION

Is intertwin birth weight discordance associated with adverse maternal and perinatal outcomes following frozen embryo transfer (FET)?

SUMMARY ANSWER

For twins conceived following FET, intertwin birth weight discordance is related to elevated risks of neonatal mortality irrespective of chorionicity, and the risk of hypertensive disorders of pregnancy (HDP) is elevated for the mothers of dichorionic twins affected by such birth weight discordance.

WHAT IS KNOWN ALREADY

While the relationships between intertwin birth weight discordance and adverse maternal or fetal outcomes have been studied for naturally conceived twins, similarly comprehensive analyses for twins conceived using ART remain to be performed.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study of all twin births from 2007 to 2021 at Shanghai Ninth People's Hospital in Shanghai, China that were conceived following FET (N = 6265).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Intertwin birth weight discordance was defined as a 20% difference in neonatal birth weights. The primary study outcome was the incidence of HDP and neonatal death while secondary outcomes included gestational diabetes, placenta previa, placental abruption, intrahepatic cholestasis of pregnancy, preterm premature rupture of the membranes, Cesarean delivery, gestational age, birth weight, stillbirth, birth defect, neonatal jaundice, necrotizing enterocolitis, and pneumonia incidence. Logistic regression models were used to estimate adjusted odds ratios (aORs) and 95% CIs for maternal and neonatal outcomes. Subgroup analyses were conducted, and Kaplan-Meier survival analysis was used to estimate the survival probability. The sensitivity analysis was performed with a propensity score-based patient-matching model, an inverse probability weighting model, a restricted cubic spline analysis, and logistic regression models using other percentage cutoffs for discordance.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 6101 females that gave birth to dichorionic twins during the study interval, birth weight discordance was observed in 797 twin pairs (13.1%). In this cohort, intertwin birth weight discordance was related to an elevated risk of HDP (aOR 1.56; 95% CI 1.21-2.00), and this relationship was confirmed through sensitivity analyses. Hypertensive disease risk rose as the severity of this birth weight discordance increased. Discordant birth weight was also linked to increased odds of neonatal mortality (aOR 2.13; 95% CI 1.03-4.09) and this risk also increased with the severity of discordance. Of the 164 women with monochorionic twins, the discordant group exhibited an elevated risk of neonatal death compared to the concordant group (crude OR 9.00; 95% CI 1.02-79.3).

LIMITATIONS, REASONS FOR CAUTION

The limitations of this study are its retrospective nature and the fact that the available data could not specify which twins were affected by adverse outcomes. There is a lack of an established reference birth weight for Chinese twins born at a gestational age of 24-41 weeks.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that twins exhibiting a birth weight discordance are related to an elevated risk of adverse maternal and perinatal outcomes, emphasizing a potential need for higher levels of antenatal surveillance in these at-risk pregnancies.

STUDY FUNDING/COMPETING INTEREST(S)

Authors declare no conflict of interest. This study was funded by the Clinical Research Program of Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine (JYLJ202118) and the National Natural Science Foundation of China (Grant Nos 82271693 and 82273634).

TRIAL REGISTRATION NUMBER

N/A.