Birth Weight In Twin Pregnancies Research Articles

The association of maternal serum biomarkers and birth weight in twin pregnancy: a retrospective cohort study

We retrospectively reviewed the medical records of 524 women with twin pregnancies who underwent antenatal care and gave birth in the past 12 years. Birth weight (BW) data were classified into three groups. We analysed the association between maternal serum biomarkers and BW in twin pregnancies using multiple logistic regression analysis. There were significant differences in the MoM values of pregnancy-associated plasma protein-A (PAPP-A), unconjugated oestriol (uE3) and inhibin A between low BW and healthy newborns. The inhibin A value was significantly higher in women with small-for-gestational-age (SGA) foetuses and the PAPP-A, and uE3 values were lower in the SGA group than in the other groups using the generalised linear mixed model (hierarchical modelling considering cluster effects for twins). Maternal serum biomarkers, including PAPP-A, uE3, and inhibin A, may be associated with SGA in twin pregnancy. Our results might provide useful information for SGA prediction during prenatal period in twin pregnancy. IMPACT STATEMENT What is already known on this subject? The SGA is more frequent in twin pregnancies than in singleton, but there is no clearly identification of the aetiology of SGA. Further, most studies have been conducted in singleton pregnancies. What do the results of this study add? The association of each maternal serum marker with SGA was assessed in the current study, and it is demonstrated that the levels of PAPP-A and uE3 in maternal serum of SGA foetuses were significantly lower than those in the other groups. In contrast, the levels of inhibin A were significantly increased in the SGA. What are the implications of these findings for clinical practice and/or further research? The maternal serum biomarker of inhibin A was a more valuable predictive factor for SGA prediction in twins. The results of this study can be used in counselling prenatal screening. Further prospective research is needed to combine with ultrasound growth parameters, which can be generalised for the prediction of SGA in twins.

Is fetal abdominal circumference predictive of small for gestational age birthweight in twin pregnancies?

Fetal growth restriction (FGR) is defined as an estimated fetal weight (EFW) < 10th percentile. In 2020, this definition was expanded to include an isolated abdominal circumference (AC) < 10th percentile. It is unclear whether isolated lagging AC is a strong predictor for small for gestational age (SGA) birthweight in twins. Our objective was to define the predictive value of lagging AC for SGA in both monochorionic (MC) and dichorionic (DC) twin pregnancies in four gestational age categories.

Prediction of birth weight in twin pregnancies using fractional limb volumes by three-dimensional ultrasonography

Objective: To predict birth weight using fetal fractional limb volumes (FLVs) by three-dimensional (3D) ultrasonography in twin pregnancies.Method: This prospective observational cohort study evaluated 51 twin pregnancies, including 28 dichorionic and 23 monochorionic pregnancies. Ultrasound examinations were performed up to 5 d before delivery. Birth weight prediction models were developed using the fractional arm volume (FAV), fractional thigh volume (FTV), and Hadlock’s formula and were compared with the actual birth weight.Results: The mean gestational age at the time of ultrasound examination was 35.3 weeks. The mean birth weight was slightly higher in dichorionic than in monochorionic pregnancies 2391.2 versus 2352.4 g. The measurements using FTV were the closest to actual birth weights. For the total group, the Hadlock formula had mean percentage change of 7.18% while the FTV model presented mean percentage change of 6.62% in relation to birth weight. However, no significant difference was noted between Hadlock’s formula and FTV p = .363 and .678 for dichorionic and monochorionic pregnancies, respectively.Conclusions: FTV accurately predicted birth weight in twin monochorionic and dichorionic pregnancies. However, Hadlock’s formula should still be used.

Impact of changes in maternal body composition on birth weight and neonatal fat mass in dichorionic twin pregnancies

Although the impact of gestational weight gain (GWG) on birth weight in twin pregnancies has been demonstrated, the specific components of GWG have not been delineated for twin gestations. Fetal body composition has been shown to be modifiable in singleton gestations based on nutritional intervention strategies and may prove to have similar modifications in twin gestations. We aimed to determine the relation of maternal body composition changes to birth weight, birth length, and neonatal fat mass (FM) in dichorionic-diamniotic twin pregnancies. This is a prospective study of 20 women with twin gestations. Comparisons were made between body composition variables during each trimester and for the entire pregnancy and compared with the outcomes of birth weight, neonatal fat percentage, and birth length. GWG within or above compared with below the IOM recommendations was associated with higher birth weights (P=0.03, P=0.04, respectively), but also with higher postpartum weight retention (P=0.001). Total maternal protein gain over the pregnancy was positively associated with birth weight (P=0.03). Changes in maternal fat-free mass (FFM), total body water (TBW), and FM from the first to the third trimester were not associated with either birth weight or neonatal FM percentage. However, maternal FM change from the second to the third trimester was significantly correlated to neonatal FM percentage (P=0.02). Third trimester GWG and total protein gain were positively correlated with neonatal birth length (P=0.02 and 0.03, respectively). Maternal FFM over all 3 trimesters showed a positive relation with neonatal birth length (P=0.01). Significant increases in maternal protein are associated with greater birth weight and neonatal birth length. Protein accretion, in contrast to TBW and FM gains, may be the most critical component of maternal GWG in dichorionic twin gestations.

Gestational Weight Gain per Pre-Pregnancy Body Mass Index and Birth Weight in Twin Pregnancies: A Cohort Study in Wuhan, China

To assess the relationship between gestational weight gain (GWG) of twin-pregnancy women and twin birth weights, as well as to evaluate whether pre-pregnancy body mass index (BMI) influences this relationship. A cohort study was conducted in Wuhan, China, between 1/01/2011 and 8/31/2017. Women with twin pregnancies who delivered live and non-malformed twins were included (6,925 women and 13,850 infants), based on the Wuhan Maternal and Child Health Management Information System. Logistic regression models were employed to examine the association between GWG and paired small for gestational age (SGA, defined as birth weight <10th percentile for gestational age and sex)/SGA and linear regression models were utilized to explore the relationship between GWG and sum of birth weights. The associations of GWG based on both the IOM and Chinese recommendations and SGA/SGA pairs were obtained, as well as the stratified analyses by pre-pregnancy BMI. Additionally, the sum birth weight of one twin pair increased by 15.88 g when the GWG increased by 1 kg. GWG below the IOM and Chinese recommendations was associated with an increased risk of SGA/SGA pairs in all pre-pregnancy BMI categories. However, in underweight, overweight, and obese women, the association between GWG above the IOM and Chinese recommendations and SGA/SGA pairs changed with adjustment.

Sonographic Accuracy of Estimated Fetal Weight in Twins

We aimed to determine the accuracy of sonographic formulas for estimating birth weight in twin pregnancies. We conducted a retrospective cohort study of consecutive twin pregnancies undergoing sonography at within 1 week of delivery. Pregnancies were included if biometric measurements and birth weight were available and excluded if anomalies were present. Estimated fetal weight was calculated using three sonographic formulas: two derived from singletons (Hadlock and Shepard) and one from twins (Ong). The correlation between estimated fetal weight and birth weight was determined using the Pearson correlation coefficient. The accuracy of each formula (bias) was assessed using the mean percentage error [(estimated fetal weight - birth weight)/birth weight × 100], and the precision (random error) was estimated from the standard deviation of the percentage error. The screening efficiency of each formula for intrauterine growth restriction, defined as below the 10th percentile on the Alexander growth standard, was assessed. The effect of twin presentation was determined using a paired analysis. Of 1744 consecutive twin pregnancies, 270 (540 infants) met inclusion criteria. The estimated fetal weight of all 3 formulas strongly correlated with the birth weight (Pearson r = 0.90 for Hadlock, 0.87 for Shepard, and 0.92 for Ong). Each formula had similar sensitivity (65%-70%) and specificity (85%-90%) for intrauterine growth restriction. For each formula, the correlation coefficient was similar between twins A and B (Pearson r = 0.85-0.93); however, the estimated fetal weight for twin A tended to underestimate birth weight, whereas the estimated fetal weight for twin B tended to overestimate birth weight. Three widely used estimated fetal weight formulas, two derived from singletons and one from twins, perform equally well in estimating birth weight in twin gestations.

PP029. Gestational hypertension and birth weight in twin pregnancies

It is well known that hypertensive disorders of pregnancy are most frequent in twin pregnancies than in singleton ones. As demonstrated by a previous work of our group, twin pregnancies complicated by preeclampsia are associated with a higher rate of "small for gestational age" (SGA) neonates and inter-twin weight discordance than normotensive ones. The present study investigates the effect of gestational hypertension (GH) on neonatal birth weight, inter-twin weight discordance and growth restriction rate among twin pregnancies. A 26 year retrospective study was undertaken by examining 196 twin pregnancies complicated by GH, from January 1, 1980 to December 31, 2006, and comparing them to 912 normotensive twin pregnancies. No significant differences were observed between the two groups in relationship to birth weight, inter-twin weight discordance and growth restriction rate, with a trend towards a higher birth weight in GH group. In normotensive group, the discordance >25% was associated with a lower gestational age at the delivery (p<0.00001). Moreover, the rate of pregnancies with SGA second twin gradually rose while paralleling the degree of discordance. Contrary to preeclampsia in twin pregnancies the outcome of those complicated by GH is similar to normotensive ones. The trend towards a higher birth weight in GH seems apparently paradoxical, but it may reflect the role of uncomplicated hypertension in twin pregnancies: the increased blood pressure could be a physiologic response for more blood nutrient supply to the fetuses.

Prenatal Sonographic Prediction of Twin Growth Discordance

AbstractOur aim was to evaluate the ability of prenatal ultrasound scans to predict fetal growth discordance, and to examine the correlation between fetal weight estimated by ultrasound with actual birthweight in twin pregnancies. The study consisted of 221 twin pregnancies with ultrasound fetal weight estimates based on Hadlock's 4 parameter formula. Prediction of intertwin birthweight discordance was examined at 4 different intervals between ultrasound examination and delivery (0–7 days, n = 96; 8–14 days, n = 66; 15–21 days, n = 58; 22–28 days, n = 59 pregnancies), with a total of 279 ultrasound examinations. Birthweight discordance was considered as a difference of 20% or greater. The correlation between fetal weight estimated between 0 and 7 days and actual birthweight was calculated by intraclass correlation coefficient. The predictive values for intertwin discordance of 20% or more in the 0 to 7 days group were: sensitivity = 93.6%, specificity = 79.4%, positive predictive value = 89.2%, negative predictive value = 87.1% and accuracy = 88.6%. In the groups with scans carried out between 8 and 14 days, 15 and 21 days, and 22 and 28 days, the sensitivity and accuracy values were 95.8% and 84.9%, 95.6% and 84.5%, 90.9% and 84.8%, respectively. Fetal growth discordance in twins can be accurately predicted by ultrasound examination performed up to 28 days before birth. There is a good correlation between fetal weight estimated between 0 and 7 days and actual birthweight.

The effect of maternal smoking on birth weight in twin pregnancies.

Information on 869 076 singletons and 17 566 twins, born during the period 1983-1991, was obtained from the Swedish Medical Birth Registry. Data on birth weight, gestational duration, vital status, and maternal smoking habits during pregnancy were analyzed in order to investigate whether twinning potentiates the effect of maternal smoking on birth weight and perinatal mortality. The individual birth weights were expressed as percentages of mean birth weight, where mean birth weights of singletons and twins were calculated separately. The birth weight reducing effect of maternal smoking was found to be of the same magnitude among twins and singletons weighing > 90% of mean birth weight. For infants weighing < 90% of mean birth weight, maternal smoking had a significantly stronger effect on birth weight among singletons than among twins. When gestational duration was taken into consideration, this difference was less pronounced. The effect of maternal smoking on gestational duration was stronger among singletons than twins. The smoking-related risk increase of perinatal death was of about the same magnitude among twins and singletons.

How accurate is antenatal sonographic identification of discordant birthweight in twins?

The association between discordant birth weight in twins and poor perinatal outcome is well recognised. Antenatal identification of discordant fetal growth in twins using ultrasound has been previously reported. In this study we have assessed the accuracy of interpair percentage estimated fetal weight difference determination (interpair EFW%) in identifying an interpair percentage birth weight difference (interpair BW%) of ⩾20% and ⩾25% in 85 twin pregnancies. The maximum sensitivity, specificity, positive and negative predictive values we noted were 54.5, 98.5, 75 and 94.4%, respectively. These results suggest that interpair EFW% results should be interpreted with caution when used in the antenatal assessment of birth weight in twin pregnancies.

The Importance of Plasma Volume Expansion and Nutrition in Twin Pregnancy

The exaggerated physiological adaptation to pregnancy in women bearing twins is exemplifed by the increased plasma volume in both primigravidas and multiparas, as compared to singleton pregnancies. There is a significant relationship between birth weight and plasma volume in both primigravid and multiparous singleton pregnancies and in multiparous twin pregnancies but not in primigravid twin pregnancies. This paper considers the relative importance of plasma volume expansion, maternal nutrition (particularly zinc), and birth weight in twin pregnancies. One hundred seventeen primigravid twin pregnancies with deliveries after 37 weeks of gestation were studied. The pregnancies were divided into three groups: those in which the mothers were normotensive, those in which they had mild preeclampsia, and those in which they developed proteinuric preeclampsia. There was a significant relationship between plasma volume and birth weight in primigravid twins whose mothers had mild preeclampsia. In primigravid twins whose mothers were normotensive, the association was almost identical with that in multiparous twin pregnancies, but, on account of the greater scatter of values, the correlation coefficient was not significant at 0.29. There was no positive relationship between plasma volume and birth weight in twins whose mothers had proteinuric preeclampsia. The results from twins of normotensive mothers and those whose mothers had mild preeclampsia were combined. There was a significant relationship between plasma volume and the combined birth weights of twins born after 37 weeks of gestation to primigravidas. The 117 primigravid twin pregnancies were divided according to presence or absence of preeclampsia and allocated to the appropriate birth weight centile categories (Table 1). In the total group, there was an over-representation of those under the 25th centile, with fewer in the intermediate categories. In those who were normotensive, 40 per cent were under the 25th centile, but in those with mild preeclampsia there was over-representation in the intermediate category (50th to 75th centile; 36 per cent). In proteinuric preeclampsia, as expected, nearly 47 per cent were under the 25th centile birth weight. When twins of normotensive pregnancies and those of mildly preec-lamptic pregnancies were grouped together, there was still a greater than expected proportion over the 25th centile (35 per cent).