Birth weight references for triplets

Fetal Growth and Antenatal Testing in Uncomplicated Multiple Gestations

Multiple gestations experience a slowing of fetal growth in the third trimester and have been described as having a higher risk of growth restriction. Whether this increased diagnosis of fetal growth restriction is physiological or pathologic is controversial. In an attempt to better identify those fetuses most at risk, twin-specific growth charts have been developed and tested. In addition, there are data to suggest that multiple gestations experience an increased risk of unexpected third-trimester stillbirth in apparently uncomplicated pregnancies. This chapter reviews the current data and recommendations for fetal growth assessment, antenatal surveillance, and delivery timing in uncomplicated multiple gestations.

Perinatal outcome comparing triplets and singleton births at a reference maternity hospital

OBJECTIVE

The objective of the present study was to evaluate adverse perinatal outcome in a group of high order pregnancies pared with singletons by BW and GA at birth.

METHODS

Data was reviewed for all admissions of triplets and quadruplets in a 7 year period. For each study neonate we selected two singleton infants to constitute a control group. Variables analyzed included: respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis (NEC), bronchopulmonary dysplasia, retinopathy of prematurity and periventricular leukomalacia.

RESULTS

We studied a total of 128 multiple and 260 singleton infants. Mean gestational age and birth weight were similar in both groups (31.3 ± 2,5 wks e 31.5 ± 2,8 wks; 1470 ± 461 g vs 1495 ± 540 g). There was no significant difference between the groups in the majority of main morbidities. The incidence of NEC was higher in triplets (6.3 vs 0.8%, p value <0.01). Mortality was higher in singletons (9.6 vs 3.1%, p value <0.037).

CONCLUSIONS

Results show that major neonatal outcomes are very similar between multiples and singletons births when paired by gestational age and birth weight. NEC remained a significant morbidity in infants born from multiple gestations after adjustment for maternal and neonatal risk factors.

Clinical features and short-term outcomes of triplet pregnancies in Japan

OBJECTIVE

To review clinical features and short-term outcomes of triplet pregnancies among Japanese women.

METHODS

A retrospective analysis was carried out among 320 Japanese women with triplet pregnancies (8 monochorionic, 75 dichorionic, and 150 trichorionic triplets; 87 with unknown placental chorionicity) who delivered at 22 gestational weeks or more between January 2005 and December 2008.

RESULTS

Delivery was by cesarean for 315 (98%) women. Gestational age at delivery was 32.3±2.8 weeks (mean±SD) and 33.2 weeks (median), and 97%, 61%, and 14% of women delivered at less than 37, less than 34, and less than 30 gestational weeks, respectively. For live-born infants, mean birth weight was 1762±437 g, 1608±396 g, and 1406±380 g for the heaviest, middle, and lightest triplet, respectively. Eighteen (5.6%) women experienced perinatal mortality (3 triplets for 1 woman, 2 triplets for 4 women, and 1 triplet for 13 women). Perinatal mortality was 25 deaths per 1000 deliveries, and decreased with increasing number of chorionic membranes (125, 44, and 20 per 1000 mono-, di-, and trichorionic triplet deliveries, respectively).

CONCLUSION

Short-term outcomes were good among triplet pregnancies in Japan. The data may be useful for counseling Japanese women with triplet pregnancies.

Weight growth of triplet infants from birth to twelve years of age

We analyzed the characteristics associated with the growth in weight of Japanese triplets from birth to 12 years of age. The study included 376 mothers and their 1,128 triplet children, who were born between 1978 and 2006. Data were collected through a mailed questionnaire sent to the mothers asking for information recorded in medical records. For these births, data on triplets' weight growth, gestational age, sex, parity, maternal age at delivery, maternal height, and maternal body mass index were obtained from records in the Maternal and Child Health Handbooks and records in the school where children receive health check-ups. The weight deficit of the triplets compared to the general population of Japan remained between 10% and 17% until 12 years of age. Moreover, at 12 years of age, the differences of weight between the general population and triplets were approximately -4.75 kg for boys and -6.00 kg for girls. Very low birth weight had the strongest contribution to body weight until 8 years of age. After 8 years of age, maternal body mass index was a significant factor affecting the weight of triplets until 12 years of age.

Weight Growth Charts from Birth to 6 Years of Age in Japanese Triplets

We analyzed the characteristics of weight growth and present the weight growth charts from birth to 6 years of age in Japanese triplets. The study included 366 mothers and their 1098 triplet children, who were born between 1978 and 2006. Data were collected through a mailed questionnaire sent to the mothers asking for information recorded in medical records. For these births, data on triplets' weight growth, gestational age, sex, parity, and maternal age at delivery were obtained from records in the Maternal and Child Health Handbooks, which is provided by the authorities after a report of pregnancy. Birthweight proved to be the strongest contribution on weight of triplets from 1 to 6 years of age. In addition, gestational age was also a significant contributing factor to weight from birth to 6 years of age. Moreover, males had a higher weight from birth to 6 years of age than females. Compared to the 50th percentile of the growth standard for the general population of Japan, the weight deficit of the triplets was more than 40% at birth (male, –1.28 kg; female, –1.28 kg), decreased within the first 1 year of age, and fluctuated between 4% and 9% until 6 years of age (male, –1.82 kg; female, –1.78 kg). In conclusion, triplets have lower birth weight than singletons and in spite of the rapid catch-up growth during first year of life they are behind singletons even in mid-childhood. This study provides growth curves for use in triplets.

Birth weight in a large series of triplets

BACKGROUND

Triplets are often born premature and with a low birth weight. Because the incidence of triplet births is rare, there are relatively few studies describing triplet birth weight characteristics. Earlier studies are often characterized by small sample sizes and lack information on important background variables such as zygosity. The objective of this study is to examine factors associated with birth weight in a large, population-based sample of triplets registered with the Netherlands Twin Register (NTR).

METHODS

In a sample of 1230 triplets from 410 families, the effects of assisted reproductive techniques, zygosity, birth order, gestational age, sex, maternal smoking and alcohol consumption during pregnancy on birth weight were assessed. The resemblance among triplets for birth weight was estimated as a function of zygosity. Birth weight discordance within families was studied by the pair-wise difference between triplets, expressed as a percentage of the birth weight of the heaviest child. We compare data from triplets registered with the NTR with data from population records, which include live births, stillbirths and children that have deceased within days after birth.

RESULTS

There was no effect of assisted reproductive techniques on triplet birth weight. At gestational age 24 to 40 weeks triplets gained on average 130 grams per week; boys weighed 110 grams more than girls and triplets of smoking mothers weighted 104 grams less than children of non-smoking mothers. Monozygotic triplets had lower birth weights than di- and trizygotic triplets and birth weight discordance was smaller in monozygotic triplets than in di- and trizygotic triplets. The correlation in birth weight among monozygotic and dizygotic triplets was 0.42 and 0.32, respectively. In nearly two-thirds of the families, the heaviest and the lightest triplet had a birth weight discordance over 15%. The NTR sample is representative for the Dutch triplet population that is still alive 28 days after birth.

CONCLUSION

Birth weight is an important determinant of childhood development. Triplet status, gestational age, sex, zygosity and maternal smoking affect birth weight. The combined effects amount to a difference of 364 grams between monozygotic girl triplets of smoking mothers compared to dizygotic boy triplets of non-smoking mothers of the same gestational age. Birth weight in triplets is also influenced by genetic factors, as indicated by a larger correlation in monozygotic than in di- and trizygotic triplets.

Monochorionic diamniotic triplet pregnancy with prenatal diagnosis of cord entanglement

BACKGROUND

Monozygotic monochorionic triplet pregnancies in which triplets share an amniotic cavity (di- or monoamniotic) are very rare. In addition to the other risks of high-order multiple pregnancy, such triplets are at risk for cord entanglement and therefore cord accident and intrauterine demise.

CASE

A 32-year-old primigravid woman was found on ultrasound at 25 to 26 weeks' gestation to have a monochorionic diamniotic triplet pregnancy, a short dilated cervix, one fetus with biometry < 10th centile, and cord entanglement. The woman was hospitalized, ultrasound assessment was performed three times per week, and elective Caesarean section was performed at 30 weeks. The triplets subsequently did well.

CONCLUSION

Monochorionic diamniotic triplet pregnancy with cord entanglement can be successfully managed by admission, close inpatient monitoring, and elective delivery.

Birth weight reference for triples in Korea

An estimation of the baseline value of birth weight depending on gestational age is helpful for reducing morbidity and mortality following the early diagnosis and treatment of intrauterine growth retardation. In Korea, there are established baseline values for singletons and twins. But no definite criteria exist for triplets yet. Given the above background, we obtained the baseline value of birth weight depending on the gestational age in triplets with a gestational age of 27-38 weeks using a raw data about birth records which had been obtained during a 10-yr period from 1998 to 2007. This baseline value was compared with those of singletons and twins. During the 10-yr period, the total number of newborns who were born between gestational age 27 and 38 was 1,330,822. Of these, the number of singletons, twins and triplets was 1,330,822, 90,245, and 840, respectively. A mean gestational age was 37.3+/-1.5 weeks, 36.0+/-2.0 weeks and 33.3+/-2.4 weeks in the corresponding order. A mean birth weight was 3,071+/-490 g, 2,414+/-455 g, and 1,836+/-454 g in the corresponding order. A comparison of the birth weight depending on the gestational age of triplets was made with the normal value of singletons and twins. According to this, in the overall gestational age ranging from weeks 27 to 38, it was relatively smaller as compared with the birth weight of twins and singletons. The current study was of significance in that it first obtained the normal value of birth weight of triplets in the overall gestational age ranging from weeks 27 to 38, whose results are expected to be helpful for studies or treatments of triplets.

Growth charts of length and height from birth to six years of age in Japanese triplets

We analyzed the characteristics associated with the growth in length and height of Japanese triplets from birth to 6 years of age and present the growth charts for them. The study included 354 mothers and their 1,061 triplet children, who were born between 1978 and 2006. Data were collected through a mailed questionnaire sent to the mothers asking for information recorded in medical records. For these births, data on triplets' length and height growth, gestational age, sex, parity, and maternal age at delivery were obtained from records in the Maternal and Child Health Handbooks, which is provided by the authorities after a report of pregnancy. Birth length showed the strongest contribution to height of triplets from 1 to 6 years of age. In addition, birthweight was also a significant contributing factor to height from 1 to 3 years of age. Compared to the 50th percentile of the growth standard for the general population of Japan, the length and height deficit of the triplets was approximately 15% at birth (male, -7.0 cm; female, -7.0 cm), decreased within the first year of age, and fluctuated between 2 and 5% until 6 years of age (male, -3.7 cm; female, -3.3 cm). In conclusion, triplets have lower birth length and subsequent height than singletons. In spite of the catch-up growth during the first year of life, they are behind singletons even in mid-childhood. This study provides height growth curves for triplets.

Growth abnormalities and multiple gestations

Growth abnormalities which include intrauterine growth restriction and weight discordance between twins are common in pregnancies complicated by multiple gestations and may be associated with poor perinatal outcomes. Knowledge of chorionicity is paramount when managing a multiple pregnancy. Monochorionic twins are at greater risk than dichorionic twins for growth issues, which may result in long-term complications including adverse neurological sequelae for the offspring. The purpose of the following article is to define normal and abnormal growth in multiples. In addition, the management of growth abnormalities in relationship to chorionicity will be discussed.

Neonatal outcomes in triplet pregnancies: assisted reproduction versus spontaneous conception

AIMS

The purpose of this study is to compare neonatal outcomes of spontaneously conceived triplets with triplets conceived by assisted reproduction.

METHODS

This was a retrospective cohort study of all cases from assisted triplet pregnancies and controls from spontaneous triplet pregnancies. A total of 24 triplet pregnancies were studied: six spontaneous and 18 assisted. The following variables were evaluated in all newborns: prematurity, birth-weight, small for gestational age, birth-weight discordance, Apgar scores, major neonatal morbidity and perinatal mortality.

RESULTS

Gestational age (33+/-1 vs. 33+/-2 weeks) and birth-weight (1760+/-256 vs. 1907+/-452 g) were similar in spontaneous and assisted triplet pregnancies. There were no significant differences in the rates of small for gestational age, discordance, and major neonatal morbidity. In the assisted reproduction group only the following cases were recorded: 1 surgically treated patent ductus arteriosus, 1 feto-fetal transfusion syndrome, 2 grade II intraventricular hemorrhage, 1 Cri du Chat syndrome and 1 stillbirth with malformations.

CONCLUSIONS

This study is unable to assess the influence of assisted reproduction on the neonatal outcomes of triplet pregnancies. However, the results suggest that the incidence of major neonatal morbidity, especially malformations, might increase due to assisted reproduction. This finding requires further confirmation.

The effect of plurality and gestation on the prevention or postponement of infant mortality: 1989-1991 versus 1999-2001

Advances in perinatal technology that improved survival may have also resulted in prolonged death from the neonatal to the postneonatal period for some infants. The objectives of this study were to determine if the medical advances that occurred in the 1990s benefited infants of multiple births more than their singleton counterparts, and if these changes prevented or postponed mortality for the smallest and most immature infants. The study population included live births of 22 to 43 weeks' gestation from the 1989-1991 and 1999-2001 US Birth Cohort Linked Birth/Infant Death Data Sets. Odds ratios were calculated to evaluate the change in risk by plurality, gestation, and to compare the change to that for singletons. Neonatal and infant mortality rates declined for all pluralities; postneonatal mortality increased for births at less than 26 weeks, but declined at later gestations. In general, the risk of death for twins and triplets compared to singletons decreased, and the improvement in survival was greater for multiples during the early neonatal period and overall. Infant mortality rates improved by 28% for singletons, 32% for twins and triplets during the 1990s, although for the most premature infants, some deaths were postponed from the early to the late neonatal period.

Genetic liability to schizophrenia in Oceanic Palau: a search in the affected and maternal generation

While liability to schizophrenia (Scz) is due to genetic and environmental factors, specific factors are largely unknown. We postulate a two-hit model for Scz, in which initial liability is generated during fetal brain development: this "hit" is precipitated by environmental stressors biologically interacting with maternal genetic vulnerability to the stress. Additional liability to Scz is generated by individual genetic vulnerability. To evaluate these putative levels of vulnerability, we search in the genome of both affected individuals and their mothers for variation that differs, statistically, from that in the general population. For parental analyses, mothers were treated as "affected," rather than their offspring, and the fathers were treated as "controls". We used a sample from the Palauan population: 175 individuals diagnosed with Scz, broadly defined; 87 mothers and 45 fathers of affected individuals. Pedigree and diagnostic data were available on 2,953 living and deceased subjects. DNA from 553 individuals was genotyped for short tandem repeats (STR) spaced approximately every 10 cM across the genome. We tested for association between affection status and STR alleles; such an approach was reasonable, despite the widely spaced markers, because this population has far-ranging linkage disequilibrium (LD). Results for the truly affected individuals were modest, whereas results from the maternal generation were promising. For a recessive model and a test for excess allele matching across mothers, significant findings occurred for D20S481, D10S1221, D6S1021, D13S317, and D18S976. Regions in which at least two adjacent markers produced substantial association statistics include 2p12-11.2, 2q24.1-32.1, 6q12-14.1, 10q23.2-24.21, 12q23.2-24.21 and 17q23.2-23.3.

The changing risk of infant mortality by gestation, plurality, and race: 1989-1991 versus 1999-2001

OBJECTIVE

Our aim was to quantify contemporary infant mortality risks and to evaluate the change by plurality, gestation, and race during the most recent decade.

PATIENTS AND METHODS

The study population included live births of 20 to 43 weeks' gestation from the 1989-1991 and 1999-2001 US Birth Cohort Linked Birth/Infant Death Data Sets, including 11,317,895 and 11,181,095 live births and 89,823 and 67,129 infant deaths, respectively. Adjusted odds ratios and 95% confidence intervals were calculated to evaluate the change in risk by plurality and gestation and to compare the change with that for singletons.

RESULTS

Overall, the infant mortality risk decreased significantly for singletons, twins, and triplets but nonsignificantly for quadruplets and quintuplets. Compared with singletons, significantly greater reductions were experienced by twins overall and at <37 weeks and triplets at <29 weeks. The largest reduction was for triplets at 20 to 24 weeks and for quadruplets and quintuplets at 25 to 28 weeks. For white infants, significant reductions were achieved overall for singletons, twins, and triplets and at every gestation. For black infants, significant reductions occurred for singletons overall and at every gestation, for twins at <37 weeks, and for triplets at 25 to 28 weeks. Compared with white infants, black infants had significantly lower risks before and higher risks after 33 weeks, although between 1989-1991 and 1999-2001 this survival advantage at earlier ages diminished, and the risk at later gestations increased.

CONCLUSIONS

The improvements in survival were greater for multiples versus singletons and for white versus black infants. Within each plurality, at each gestation the racial disparity in mortality has widened.

Triplet ultrasound growth parameters

OBJECTIVE

To create ultrasound growth curves for normal growth of fetal triplets using statistical methodology that properly accounts for similarities of growth of fetuses within a mother as well as repeated measurements over time for each fetus.

METHODS

In this longitudinal study, all triplet pregnancies managed at a single tertiary center from 1992-2004 were reviewed. Fetuses with major anomalies, prior selective reduction, or fetal demise were excluded. Data from early and late gestation in which there were fewer than 30 fetal measurements available for analysis were excluded. We used multilevel models to account for variation in growth within a single fetus over time, variations in growth between multiple fetuses within a single mother, and variations in fetal growth between mothers. Medians (50th), 10th, and 90th percentiles were estimated by the creation of multiple quadratic growth models from bootstrap samples adapting a previously published method to compute prediction intervals. Estimated fetal weight was derived from Hadlock's formula.

RESULTS

One hundred fifty triplet pregnancies were identified. Twenty-seven pregnancies were excluded for the following reasons: missing records (23), fetal demise (3), and fetal anomaly (1). The study group consisted of 123 pregnancies. The gestational age range was restricted to 14-34 weeks. Figures and tables were developed showing medians, 10th and 90th percentiles for estimated fetal weight, femur length, biparietal diameter, abdominal circumference, and head circumference.

CONCLUSION

Growth curves for triplet pregnancies were derived. These may be useful for identification of abnormal growth in triplet fetuses.

LEVEL OF EVIDENCE

III.

Investigation of confined placental mosaicism (CPM) at multiple sites in post-delivery placentas derived through intracytoplasmic sperm injection (ICSI)

Although earlier studies on pregnancies derived through intracytoplasmic sperm injection (ICSI) reported increased non-mosaic aneuploidy among ICSI children, undetected mosaicism, such as confined placental mosaicism (CPM) has not been evaluated. We investigated the incidence of CPM in post-delivery placentas derived from ICSI, evaluated whether CPM was increased and whether it was a contributing factor to negative pregnancy outcome. [Fifty-one post-delivery placentas were collected from patients who underwent ICSI with a normal or negative pregnancy outcome]. Trophoblast and chorionic stroma from three sites were analyzed by comparative genomic hybridization (CGH) and flow cytometry. Detected abnormalities were confirmed by fluorescence in situ hybridization (FISH). The incidence of CPM in the ICSI population was compared to the general population from published data. We detected three cases of CPM in our study. One abnormality was found by CGH analysis; partial trisomy 7q and a partial monosomy Xp limited to the trophoblast at two sites. The abnormality was associated with a child affected by spina bifida. Two cases of mosaic tetraploidy were observed by flow cytometry in pregnancies with a normal outcome. All three abnormalities were confirmed by FISH analysis. The incidence of CPM in the ICSI study population was 5.88% (3/51), which was not statistically different from published reports in the general population (5.88% (42/714), Chi square, P > 0.05). The post-ICSI population was not at risk for CPM in this study.