Birthweight percentiles by gestational age in multiple births. A population-based study of Norwegian twins and triplets

OBJECTIVE: To assess secular trends for birthweight by gestational age in twins in Norway and to develop current national birthweight standards by gestational age for twin and triplet births using population-based data. MATERIAL AND METHODS: The analysis of secular trends for birthweight and gestational age in twins was based on 32,379 twin livebirths (1967-95). Taking into account the observed secular trends in birthweight for 35-40 weeks of gestation, data on twins born during 1987-95 only were included in the calculation of birthweight percentiles for 35-40 weeks, while for lower and upper weeks, data on twins born during 1967-95 were used. The construction of birthweight-for-gestation curves for triplets was based on the data on 690 triplets. RESULTS: Whereas the overall mean birthweight and gestational age decreased in 1987-95 compared with the previous years, the mean birthweights by gestational age for the 35-40 weeks of gestation was significantly higher in 1987-95. Male twins weighed more than female twins throughout the gestation with consistent and significant differences from 27 to 42 weeks of gestation. Smoothed curves for birthweight-by-gestational-age percentiles of male and female twins are plotted. The birthweight-by-gestational-age curves of triplets were almost identical with twin curves before 30 weeks of gestation, starting to diverge from them progressively thereafter. The intrauterine growth of twin births also starts to differ markedly from singletons at approximately 30 weeks of gestation. CONCLUSION: This study shows that plurality-specific birthweight-by-gestation standards should be used for assessment of fetal growth in multiple births rather than singleton standards.     

Perinatal outcome and peripartum complications in preterm singleton and twins deliveries: a comparative study

OBJECTIVE: Multiple pregnancy is one of the major risk factors for preterm births. The aim of the present study was to compare perinatal outcome and peripartum complications between twins and singletons, born preterm. STUDY DESIGN: The study population consisted of preterm deliveries of 435 pairs of twins (870 neonates) and the comparison group included 4754 preterm deliveries of singletons, born in the same period (January 1, 1989-December 31, 1996). Exclusion criteria were lack of prenatal care and births following infertility treatments. The three steps in statistical analysis consisted of (1) degree of concordance between the twins; (2) comparison between each twin (I and II) to their singleton comparison groups using SPSS computer program; (3) stratified analysis to examine perinatal mortality rates at different gestational age groups. RESULTS: The prevalence of preterm deliveries was 7.9% (6192/77610). Perinatal mortality was lower in twins of both birth orders, however, it was statistically significant only when APD is considered. Mortality rates in all gestational age groups and for both twin groups were lower than that of singleton [OR=0.45 (0.26-0.75; 95% CI) for twin-I; OR=0.36 (0.21-0.59; 95% CI) for twin-II]. Compared to singletons, twin gestations had less congenital malformations. Twin gestation had statistically lower rates of preterm premature rupture of membranes, severe pregnancy induced hypertension, oligohydramnios, placenta previa, placental abruption and clinical chorioamnionitis [12.2 vs.17.3%, 2.5 vs. 6.3%, 2.3 vs. 4.7%, 0.9 vs. 2.9%, 1.8 vs. 5%, 1.8 vs. 5.2%, respectively (P<0.01)]. Mothers of twins had less diabetes mellitus class B-R, hydramnios and chronic hypertension than that of singleton (1.8 vs. 2.6%, 5.5 vs. 7.4%, 3.7 vs. 4.8%, respectively). Cesarean section rates were significantly higher in twin's gestation. Mothers of twins tended to be older and of higher birth and gravidity order. CONCLUSIONS: Perinatal mortality rates and peripartum complications were lower in twin compared to singleton gestations.     

Contribution of Gestational Age and Birth Weight to Perinatal Viability in Singletons Versus Twins

The objective of this study was to determine the effects of birth weight and gestational age on twin vs. singleton mortality. Population-based analysis of live births, fetal deaths, and infant deaths by plurality in the United States from 1983 to 1986 was conducted. Seven mortality rates and relative risks (RRs) of twin vs. singleton mortality were calculated by birth weight, gestational age, and combined birth weight and gestational age. The mortality rates included fetal, perinatal, early neonatal, late neonatal, neonatal, postneonatal, and infant. Twins had 3–4 times the RRs of mortality compared to singletons, ranging from a RR of 2.71 for postneonatal mortality to a RR of 3.73 for late neonatal mortality. Generally, for birth weights of 2,800 g or less and gestational ages of 38 weeks or less, twins had lower combined birth weight and gestational age mortality rates and lower RRs. Between 1,900 and 2,799 g, mortality rates decreased then increased with advancing gestation between 31 and 42 weeks both more severely and consistently for twins than for singletons. In conclusion, twins have lower birth weight and gestational age-specific mortality rates and RRs than singletons below 2,800 g and 39 weeks. The “U”-shaped pattern of mortality beyond 38 weeks gestation, particularly for twins with birth weights below 2,500 g, reflects the combined influence of growth retardation and advancing gestation on mortality. The lowest mortalityfor twins is achieved at birth weights of 2,500-2,799gat35-38 weeks gestation. Only 1 in 7 twins is born within this “ideal window.” Efforts at reducing twin mortality should be directed toward reducing intrauterine growth retardation and achieving optimal timing for delivery.     

7. Multiple pregnancy

Summary. There were 357 twin pairs, six sets of triplets and one pair of conjoined twins born in the group of 15020 booked women compared with 392 twin pairs, 10 sets of triplets, two sets of quadruplets and two sets of conjoined twins in the 7654 emergency admissions (unbooked women). Rising maternal age, parity and height were all associated with rising twinning rate. Maternal death rates were 0.8% for singleton pregnancies, 2.0% for twin pregnancies, 6.3% for triplet pregnancies and none for the two women who had quadruplets. The mean fetal birthweights were 3.08 kg for singletons, 2.28 kg for twins, 1.71 kg for triplets and 1.36 kg for quadruplet babies. Fetal loss was 10% for singletons, 24% for twins, 42% for triplets and 75% for quadruplet babies. The poorer maternal and fetal outcomes in multiple pregnancy compared with those in singleton pregnancy were due to the combined effects of certain pregnancy complications, including the retention of the second twin, of inadequacies in our health care facilities and of unfavourable socioeconomic circumstances especially lack of antenatal care.     

Reduction of twin pregnancy to singleton: does it improve pregnancy outcome?

Objective.?To compare pregnancy complications, obstetrical and neonatal outcome of twin pregnancies reduced to singleton, with both non-reduced twin pregnancies and singleton pregnancies.

Methods.?A retrospective case–control study was performed at the Obstetrics and Gynecology Ultrasound unit of a tertiary referral medical center. Patient's population included 32 bi-chorionic bi-amniotic twin pregnancies reduced to singleton and 35 non-reduced twin pregnancies. Thirty-six patients with singleton pregnancies comprised the second control group. Main outcome measures were rates of pregnancy complications, preterm delivery (both before 37 weeks of gestation and before 34 weeks of gestation), late abortions, intra-uterine growth retardation, cesarean section, mean birth weights, and mean gestational age at delivery.

Results.?The reduced twin pregnancies group had similar rates of total pregnancy complications, preterm deliveries, and cesarean section as non-reduced twins. Gestational age at delivery and mean birth weight were also similar to non-reduced twins and significantly different compared with singletons. Preterm delivery and late abortion incidences were significantly higher when reduction was beyond 15 weeks gestation.

Conclusions.?Reduction of twin pregnancy to singleton does not change significantly pregnancy course and outcome. Favorable obstetrical and neonatal outcomes could be achieved by performing early, first trimester reductions.     

Reference birth-length range for multiple-birth neonates in Japan

AIM: To clarify the birth length of twins according to gestational age. METHODS: We studied a total of 51,910 live-birth-live-birth pairs of twins, 4,561 triplet live births and 256 quadruplet live births, using data obtained from corresponding birth certificates. The birth length of twins was analyzed according to gestational age. RESULTS: Compared to singleton neonates, the median birth length of twins was approximately 0.5 cm smaller after the gestational age of 34 weeks, increasing to approximately 2.0 cm at 42 weeks of gestation. The median birth length according to gestational age was found to be the greatest in twins, lower in triplets and the lowest in quadruplets, in which the difference was <2.0 cm. CONCLUSION: The birth length of twins was smaller than that of singletons, but the difference was smaller than the difference in birthweight between twins and singletons.     

Puerperal complications following elective Cesarean sections for twin pregnancies

OBJECTIVE: To estimate the maternal puerperal morbidity in elective and emergent cesareans in twins. STUDY DESIGN: We evaluated postpartum complications among patients who underwent elective cesarean birth for twin pregnancy. This group was compared to matched singletons and to emergent cesareans in twins. RESULTS: During the period September 1994-March 2006 there were 299 (47.4%) elective and 80 (12.7%) emergent cesarean sections in twin pregnancies, for a total of 379 (60.1%) cesarean births for both twins. Controls included 299 cases of elective cesareans in singletons. The comparison between elective and emergent cesareans and between elective cesareans in twins and in singletons found no significant differences in postpartum fever, scar infection, and postpartum hemorrhage. Venous thromboembolism occurred in two twin pregnancies, one in the elective and one in the emergent cesarean group. Postpartum hysterectomy was required in a singleton pregnancy following an elective cesarean birth. CONCLUSION: At present, no data exist to show a disadvantage for a planned cesarean birth for twins.     

Neurodevelopmental outcomes of twins

In population-based studies, the prevalence of neurodevelopmental disability is consistently higher in twins than singletons. This is largely because birth weight and gestational age (GA) distributions of twin births are shifted to the left when compared with singleton births, and lower birth weight and lower GA are associated with increased risk of neurodevelopmental disability. From a pathophysiologic perspective, a question of interest is whether neurodevelopmental outcomes of twins differ from singletons after controlling for covariates. If significant differences in outcomes persist, this would suggest that the twining process itself or something intrinsic to shared life in the womb may be responsible for observed differences. From a clinical perspective, when counseling parents at risk for preterm delivery of twins, it is useful to understand how twin outcomes compare relative to singleton outcomes at the same birth weight or GA. The purpose of this review is to examine the long-term neurodevelopmental outcomes of twins compared with singletons with control for important covariates.     

Perinatal mortality and morbidity rates among singleton,twin, and triplet gestations

Objective: To determine rates of perinatal mortality and morbidity from 24 to 43 weeks gestation among singletons, twins, and triplets.Methods: Successfully linked data from 1992 Californian maternal and infant discharge records as well as birth and death certificates from acute care civilian hospitals were examined for perinatal mortality and morbidity. Perinatal mortality was defined as the sum of all stillbirths and neonatal deaths. Deliveries from 24 to 43 weeks gestation among singleton, twin, and triplet pregnancies were collected as separate data sets. Perinatal mortality was identified using birth certificate death indicators excluding deaths caused by congenital anomalies. Neonatal deaths were identified from death indicators found in the death certificates. For the purpose of this study, perinatal morbidities were identified by ICD-9 codes and limited to respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH), and necrotizing enterocolitis (NEC). Perinatal mortality and morbidity rates were expressed as a percent of live births stratified by gestational age. Perinatal mortality data were expressed in log scale and perinatal morbidity rates were statistically compared.Results: There were 571,390 total births in California of which 527,677 (92%) were singleton, 12,535 (2%) were twin, and 367 (0.06%) were triplet gestations. Across gestation, the rate of RDS between triplets and twins was comparable (6.6% vs 6.8%). However, the rates of IVH and NEC were significantly greater in triplets than in twins (20% vs 8%, P < .0001, and 25% vs 9%, P < .0001, respectively). The perinatal mortality rates are shown below.

1. Download : Download full-size image

Conclusions: Perinatal mortality rates were comparable among singleton, twin, and triplet gestations delivered between 24 and 30 weeks gestation. Unlike singletons and twins, the triplet perinatal mortality rate did not fall between 31 and 36 weeks gestation and remained at 2.6%. Twin perinatal mortality rate was equivalent to singletons until 36 weeks gestation. IVH and NEC were significantly greater among triplets regardless of gestational age. These data suggest that antepartum fetal surveillance of triplet pregnancies should start as early as 30 weeks gestation while testing for twin pregnancies can begin at 36 weeks gestation.     

A parsimonious explanation for intersecting perinatal mortality curves: understanding the effect of plurality and of parity

BACKGROUND: Birth weight- and gestational age-specific perinatal mortality curves intersect when compared across categories of maternal smoking, plurality, race and other factors. No simple explanation exists for this paradoxical observation. METHODS: We used data on all live births, stillbirths and infant deaths in Canada (1991-1997) to compare perinatal mortality rates among singleton and twin births, and among singleton births to nulliparous and parous women. Birth weight- and gestational age-specific perinatal mortality rates were first calculated by dividing the number of perinatal deaths at any given birth weight or gestational age by the number of total births at that birth weight or gestational age (conventional calculation). Gestational age-specific perinatal mortality rates were also calculated using the number of fetuses at risk of perinatal death at any given gestational age. RESULTS: Conventional perinatal mortality rates among twin births were lower than those among singletons at lower birth weights and earlier gestation ages, while the reverse was true at higher birth weights and later gestational ages. When perinatal mortality rates were based on fetuses at risk, however, twin births had consistently higher mortality rates than singletons at all gestational ages. A similar pattern emerged in contrasts of gestational age-specific perinatal mortality among singleton births to nulliparous and parous women. Increases in gestational age-specific rates of growth-restriction with advancing gestational age presaged rising rates of gestational age-specific perinatal mortality in both contrasts. CONCLUSIONS: The proper conceptualization of perinatal risk eliminates the mortality crossover paradox and provides new insights into perinatal health issues.     

Is the risk of obstetric anal sphincter injuries increased in vaginal twin deliveries?

Objective: Vaginal twin deliveries have a higher rate of intrapartum interventions. We aimed to determine whether these characteristics are associated with an increased rate of obstetric anal sphincter injuries compared with singleton.

Study design: Retrospective study of all twin pregnancies undergoing vaginal delivery trial was conducted from January 2000–September 2014. Sphincter injury rate compared with all concurrent singleton vaginal deliveries. Multivariable analysis was used to determine twin delivery association with sphincter injuries while adjusting for confounders.

Results: About 717 eligible twin deliveries. Outcome was compared with 33?886 singleton deliveries. Twin pregnancies characterized by a higher rate of nulliparity (54.8% versus 49.5%, p?=?0.005), labor induction (42.7% versus 29.1%, p?<?0.001), and instrumental deliveries (27.5% versus 16.7%, p?<?0.001), lower gestational (34.6?±?3.3 versus 38.8?±?2.3, p?<?0.001), and lower birth weight. Total breech extraction was performed in 29.0% (208/717) of twin deliveries. Overall obstetric sphincter injury rate was significantly lower in the twins group (2.8% versus 4.4%, p?=?0.03, OR?=?0.6, 95% CI 0.4–0.9), due to lower rate of 3rd degree tears in twins versus singletons (2.2% versus 4.0%, p?=?0.02), rate of 4th degree tears similar among the groups (0.6% versus 0.4%, p?=?0.5). In multivariable analysis, sphincter injuries were associated with nulliparity (OR?=?3.9, 95% CI 3.4–4.5), forceps (OR?=?6.8, 95% CI 5.8–7.8), vacuum (OR?=?2.9, 95% CI 2.5–3.3), earlier gestational age (OR?=?0.2, 95% CI 0.1–0.3), episiotomy (OR?=?0.8, 95% CI 0.7–0.9), and birth weight over 3500?g (OR?=?1.8, 95% CI 1.6–2.0). However, the association between twins (versus singletons) deliveries and sphincter injuries was lost after adjustment for delivery gestational age (OR?=?0.7, 95% CI 0.4–1.2).

Conclusion: Despite a higher rate of intrapartum interventions, the rate of sphincter injuries is lower in twins versus singleton deliveries, mainly due to a lower gestational age at delivery.     

Twin pregnancies in Sub-Saharan Africa – Lagos experience

A total of 2,879 deliveries were conducted within 2 years and 92 were twin deliveries constituting 3.2% or 1 in 31 deliveries. The mean age and parity was 30.4?±?3.9 years and 1.3?±?1.4 respectively. Male infants constituted 54.4% of the twins with a sex ratio of 1.2 boys to 1.0 girl. Among twin deliveries, presentation of cephalic-cephalic was the commonest. Caesarean section rate was 65.2% in the overall twin pregnancies. Commonest indication for perinatal admission was prematurity. None of the twins delivered before 28 weeks gestation survived whereas survival was almost certain from 32 weeks gestation. There was generally no significance difference in the outcome of the babies with respect to chorionicity. Perinatal mortality was high compared with that of singleton with prematurity being the leading cause of death.     

The intrauterine ponderal index in relation to birth weight discordance in twin gestations

Objective: To establish the relationship between the fetal ponderal index and birth weight discordance in twins. Method: The fetal ponderal index (estimated fetal weight ÷ femur length³) was calculated in 86 pairs of twins delivered within 2 weeks of the last sonography and analyzed in relation to birth weight discordance. Results: A weak but significant correlation between fetal ponderal index and birth weight (r = 0.26, P < 0.0007) but no correlation with gestational age (r = 0.035, P = 0.65) were found. Members of concordant pairs (<15% birth weight difference) had a significantly higher fetal ponderal index compared with members of mildly (15–25%) discordant pairs (P < 0.02), but not as compared with members of severely discordant (>25%) pairs. Conclusion: The characteristics of the fetal ponderal index in twins are similar to those in singletons. Fetal size seems to be diminished in severe but not in mild discordants. However, in its present form, the fetal ponderal index is a poor predictor of discordant growth and therefore should be employed cautiously in twin gestations.     

Comparison of second trimester biometry in singleton and twin pregnancies conceived with assisted reproductive techniques

The objective of this study was to investigate the size of singleton vs twin pregnancies at the time of a second trimester dating scan. The analysis included 86 infants from 63 pregnancies achieved with assisted reproductive techniques, comprising 40 singletons and 46 twins. Measurements of second trimester biparietal diameter ( n = 85) and femur length ( n = 74) were plotted against the precisely known gestational age. A common regression line was calculated for each parameter and the residuals for singletons and twins were compared. Gestational age and weight at birth were also analysed for each group. There was no significant difference between singletons and twins in biparietal diameter or femur length in second trimester. In contrast, twins had a lower mean birthweight, gestational age at birth, and weight-for-gestational age centile compared with singletons. Singleton babies from these pregnancies had an average birthweight centile of 49.8% (i.e. close to the median for spontaneously conceived pregnancies in our population). We concluded that the same pregnancy dating charts can be used for singletons and twins. At corresponding gestational age, twins are smaller than singletons at birth because of slower growth in the third trimester.     

Risk of fetal loss in twin pregnancies undergoing second trimester amniocentesis(1)

OBJECTIVE: To assess the rate of fetal loss among bichorionic twin gestations undergoing genetic amniocentesis compared with singletons undergoing the procedure and untested twins. METHODS: In a retrospective cohort study, three groups were compared: 476 women with twins undergoing amniocentesis, 489 women with singleton gestations undergoing amniocentesis, and 477 women with twins presenting at a similar gestational age for ultrasound studies only. All subjects were scanned at 17-18 weeks' gestation and again approximately 4 weeks after the procedure or first ultrasound scan. Excluded were twin pregnancies after fetal reduction or chorionic villus sampling, fetuses with structural anomalies, and cases in which one fetus had died at the time of examination or after fetal reduction. RESULTS: Thirteen twin gestations in the tested group (2.73%) aborted spontaneously up to 4 weeks after the procedure compared with three twin controls (0.63%, P =.01) and three post-procedure singleton controls (0.6%, P =.01). An abnormal karyotype was discovered in 15 tested twin pregnancies (3%) and in six tested singletons (1.23%). All affected twin pairs were discordant for the chromosomal anomaly. CONCLUSION: The risk of early fetal loss in twins undergoing amniocentesis appears to be higher than that of exposed singletons or unexposed twins.     

The Outcome of Twin Pregnancies in Dunedin 1968–1978

Summary: Of 14,473 pregnancies in Dunedin City between 1968 and 1978, 1.07% were twin (1 in 93.4 pregnancies). Perinatal mortality has decreased over this period for both twins and singletons. To examine the hypothesis that the tendency for twins to be preterm and small for gestational age explained their increased mortality and morbidity, groups of twins and singletons of like birth-weight and gestational age were compared. No significant differences were found, suggesting that birth-weight and gestational age are the major determinants of outcome, and that a twin should fare no worse than a singleton of similar birth-weight and gestational age.     

Sudden infant death syndrome among twin births: United States, 1995-1998.

OBJECTIVES: To compare the incidence and risk factors for sudden infant death syndrome (SIDS) in twin and singleton births and to estimate the concordance of SIDS in twins. STUDY DESIGN: A cohort analysis using the National Center for Health Statistics Linked Birth and Infant Death files (1995-1998). RESULTS: Twins had higher SIDS rate (1.3/1000 live births) compared to singletons (0.7/1000 live births), relative risk: 1.9, 95% confidence interval: 1.68, 2.01. Male and small- for-gestational age infants as well as infants of black, unmarried, and smoking mothers were at increased risk for SIDS in both twins and singletons. Placental abnormalities also were associated with SIDS in singletons and twins, although this association failed to achieve statistical significance in twins. There is a higher rate of SIDS in the second twin after a first twin SIDS. CONCLUSIONS: Twins are at higher risk of SIDS than are singletons. Overall, the epidemiology of SIDS in twins is quite similar to that seen in singletons.     

Population‐Based Study of Cesarean Section After In Vitro Fertilization in Australia

Abstract: Background: Decisions about method of birth should be evidence based. In Australia, the rising rate of cesarean section has not been limited to births after spontaneous conception. This study aimed to investigate cesarean section among women giving birth after in vitro fertilization (IVF). Methods: Retrospective population‐based study was conducted using national registry data on IVF treatment. The study included 17,019 women who underwent IVF treatment during 2003 to 2005 and a national comparison population of women who gave birth in Australia. The outcome measure was cesarean section. Results: Crude rate of cesarean section was 50.1 percent versus 28.9 percent for all other births. Single embryo transfer was associated with the lowest (40.7%) rate of cesarean section. Donor status and twin gestation were associated with significantly higher rates of cesarean section (autologous, 49.0% vs donor, 74.9%; AOR: 2.20, 95% CI: 1.80, 2.69) and (singleton, 45.0% vs twin gestations, 75.7%; AOR: 3.81, 95% CI: 3.46, 4.20). The gestation‐specific rate (60.1%) of cesarean section peaked at 38 weeks for singleton term pregnancies. Compared with other women, cesarean section rates for assisted reproductive technology term singletons (27.8% vs 43.8%, OR: 2.02 [95% CI: 1.95–2.10]) and twins (62.0% vs 75.7%, OR: 1.92 [95% CI: 1.74–2.11]) were significantly higher. Conclusions: Rates for cesarean section appear to be disproportionately high in term singleton births after assisted reproductive technology. Vaginal birth should be supported and the indications for cesarean section evidence based. (BIRTH 37:3 September 2010)     

双胎妊娠分娩时机选择的多中心回顾性分析

目的 降低双胎妊娠围产儿不良预后的发生率，探讨合理的双胎终止妊娠时间。方法 对1993年1月到2003年10月十年期间在上海地区六家医院妇产科分娩的655例双胎妊娠进行回顾性分析，分别计算出各孕周大小胎儿出生体重的百分位数、小于孕龄儿（small for gestational age，SGA）和重度窒息的发生率。结果 1．整个孕期双胎妊娠中小胎儿出生体重的第50百分位数均明显落后于单胎胎儿，33周前大胎儿出生体重的第50百分位数与单胎胎儿接近，33周后差别逐渐增大，39周后大小胎儿出生体重与单胎相比差别更为显著。与单胎妊娠不同，双胎妊娠大胎儿在39周、小胎儿40周达最大出生体重（3073g和2670g），在此之后出生体重反而下降，41周时明显降低（2555g和2303g，P〈0．05）。2．双胎妊娠大小胎儿SGA发生率随孕龄的增加呈上升趋势，39周后上升幅度明显增加，41周达到最高（P〈0．05）。3．39周后小胎儿重度窒息的发生率明显增加。结论 39周后双胎妊娠胎儿出生体重呈下降趋势，SGA及小胎儿围产期重度窒息的发生率明显上升，因此双胎妊娠的分娩时间不应超过39周。     

The natural history of preterm premature rupture of membranes in twin pregnancies

Objective: To compare the characteristics of preterm premature rupture of membranes (PPROM) between twin and singleton pregnancies.

Methods: This was a retrospective study of all women with twin and singleton pregnancies admitted with PPROM between 24–34 weeks of gestation.

Results: Overall 698 women with PPROM were eligible for the study: 101 (14.5%) twins and 597 (85.5%) singletons. Twins presented with PPROM at a more advanced gestational age compared with singletons (29.1?±?2.7 vs. 28.5?±?2.8 weeks, p?=?0.03). The latency period was shorter in twins compared with singletons, especially for women presenting after 28 weeks of gestation (5.0?±?0.8 vs. 7.0?±?0.4 days, p?=?0.01). Women with twins were more likely to deliver within 48?h (OR:?2.7; 95%CI: 1.7–4.2) and were less likely to deliver within 2–7 days (OR: 0.5; 95%CI: 0.3–0.9) following PPROM. The rate of clinical chorioamnionitis or placental abruption following PPROM was lower in twins compared with singletons (15.8% vs. 26.0%, p?=?0.03).

Conclusions: PPROM in twin pregnancies tends to occur at a more advanced gestational age, is associated with a shorter latency period and is less likely to be complicated by chorioamnionitis or placental abruption compared with singletons. This information may be useful for counseling and management decisions in cases of PPROM in women with twins.