Combined Influence of Gestational Weight Gain and Estimated Fetal Weight on Risk Assessment for Small- or Large-for-Gestational-Age Birth Weight: A Prospective Cohort Study

Performance of fetal ultrasound and magnetic resonance imaging in predicting birthweight according to the test-to-delivery interval: A cohort study

OBJECTIVE

To assess the influence of the test-to-delivery interval (TDI) on the performance of ultrasound (US) and magnetic resonance imaging (MRI) for predicting birthweight (BW).

STUDY DESIGN

This is a secondary analysis of a prospective, single center, blinded cohort study that compared MRI and US for the prediction of BW ≥ 95th percentile in singleton pregnancies. Patients that were included in the initial study underwent US and MRI for estimation of fetal weight between 36 + 0/7 and 36 + 6/7 weeks of gestation (WG). The primary outcome of the current study was to report the changes of US and MRI sensitivity and specificity in the prediction of BW > 95th percentile, BW > 90th percentile, BW < 10th percentile, and BW < 5th percentile, according to the TDI. The secondary outcome was to represent the performance of both tools in the prediction of BW > 90th percentile when TDI is<2 weeks, between 2 and 4 weeks, and>4 weeks. Receiver operating characteristic (ROC) curves were constructed accordingly.

RESULTS

2378 patients were eligible for final analysis. For the prediction of BW > 95th or 90th percentile, the sensitivity of MRI remains high until 2 weeks, and it decreases slowly between 2 and 4 weeks, in contrast to the sensitivity of US which decreases rapidly 2 weeks after examination (p < 0.001). For the prediction of BW < 10th or 5th percentile, the sensitivity of both tools decreases in parallel between 1 and 2 weeks. The specificities of both tools remain high from examination till delivery. These findings are reproducible with the use of the antenatal customized and the postnatal national growth charts.

CONCLUSION

The performance of MRI in the prediction of BW, especially in large-for-gestational age, is maximal when delivery occurs within two weeks of the examination, decreasing slightly thereafter, in contrast with the performance of US which decreases drastically over time.

Additional single third trimester ultrasound scan in detection of large for gestational age fetuses

PURPOSE OF REVIEW

To evaluate the accuracy of growth scans in the third trimester. To evaluate the accuracy of universal third trimester ultrasound scans in the detection of large for gestational age (LGA) fetuses. To investigate how universal ultrasound scans affect the delivery and outcomes.

RECENT FINDINGS

Universal third trimester screening for LGA recorded a 22% positive predictive value (PPV), and 96% negative predicted value (NPV). The sensitivity in most studies reaches around 70% or more, of all the LGA fetuses delivered, there are different studies for and against universal ultrasonic screening of LGA. Estimated fetal weight (>4 kg/90th centile) and abdominal circumference are the best predictors of LGA with nearly 70% sensitivity. One study reported that an antenatal ultrasonic diagnosis of LGA in a low risk population has a weak association with the incidence of shoulder dystocia or poor neonatal outcomes. Universal screening in the third trimester for LGAs is not cost effective.

SUMMARY

Low risk pregnancies constitute the majority of the pregnancy population. All low risk pregnancy women will only receive two routine scans throughout the whole pregnancy. There is no evidence at present that conclusively demonstrates that an additional scan at 36 weeks improves maternal and neonatal outcomes and is cost effective.

Trimester-specific gestational weight gain in women with and without previous bariatric surgeries

OBJECTIVES

The study aimed 1) to compare trimester-specific and total gestational weight gain (GWG) between mothers who had undergone biliopancreatic diversion with duodenal switch (BPD) and two control groups of unoperated women and 2) to examine the associations between GWG, intrauterine fetal growth and neonatal birthweight.

METHODS

This retrospective study included data collected in medical records of newborns and mothers from 3 groups: the first control group (PP) included mothers (n = 158) with a pre-pregnancy BMI similar to that of the surgical group (n = 63) and the second one (PS) included mothers (n = 85) with a pre-pregnancy BMI corresponding to that of the surgical group prior to BPD or a BMI > 40 kg/m². Trimester-specific GWG was obtained using linear interpolation and compared to the recommendations.

RESULTS

Women exposed to BPD have an increased prevalence of insufficient weight gain in the second and third trimesters as well as for the whole pregnancy in comparison with women in the PP group. The weekly GWG rate in the third trimester was significantly lower in women exposed to BPD, compared to both control groups. Although the newborns of women with previous BPD were significantly smaller during pregnancy and at birth, no association was found with GWG.

CONCLUSION

Women exposed to BPD are at substantial risk of insufficient GWG, however, mechanisms and long-term impacts require further investigation.

Weight gain and pregnancy outcomes in overweight or obese women with twin gestations

BACKGROUND

While adequate weight gain in twin pregnancies with normal prepregnancy BMI has been associated with improved pregnancy outcomes, it remains unclear whether adequate weight gain in patients with overweight or obese prepregnancy BMI is associated with similarly improved pregnancy outcomes, and whether this comes at the expense of maternal health risks such as increased risk for gestational diabetes or hypertension.

OBJECTIVE

To estimate the association between adherence to weight gain recommendations and pregnancy outcomes in overweight and obese women with twin pregnancies.

METHODS

This is a retrospective cohort study of women with overweight (BMI 25.0-29.9 kg/m²) and obese prepregnancy BMI (≥30.0 kg/m²) and twin pregnancies delivered >24 weeks by a single MFM practice between 2005 and 2017. Baseline characteristics, weight gain patterns, and pregnancy outcomes were compared between women who met or exceeded, and who did not meet gestational weight gain requirements, as recommended by the Institute of Medicine (IOM) in 2009. Since total weight gain is also dependent on gestational age at delivery, we used weight gain per week to define adequate weight gain for overweight (0.85 lb/week) and obese (0.68 lb/week) women.

RESULTS

A total of 252 overweight and obese women with twin pregnancies met inclusion criteria, 171 (67.9%) of whom met or exceeded weight gain requirements and 81 (32.1%) of whom did not. There were no differences in baseline clinical and demographic characteristics between the two groups. Women with inadequate weight gain had significantly less weight gain in each trimester, as well as less total weight gain for the whole pregnancy. Women with inadequate average gestational weight gain had significantly lower birthweights of the larger twin (2440 versus 2675 g, p = .001) and the smaller twin (2212 versus 2398 g, p = .005), higher incidence of spontaneous preterm birth <37 weeks (33.3 versus 21.1%, p = .03), higher incidence of premature rupture of membranes (24.7 versus 11.7%, p = .008), and greater likelihood of any twin birthweight < 10th percentile for gestational age (51.9 versus 35.5%, p = .01). There were no differences in the likelihood of cesarean delivery, preeclampsia, or gestational diabetes between the two groups. These results did not differ after excluding the 24 women in the cohort with excessive weight gain.

CONCLUSIONS

For overweight and obese women with twin gestations, meeting the IOM recommendations for weight gain in pregnancy is associated with improved pregnancy outcomes. CondensationWomen with overweight or obese prepregnancy BMI in twin gestations who gain the recommended amount of weight in pregnancy have improved pregnancy outcomes.