Dilemma of increased obstetric risk in pregnancies following IVF-ET

Purpose : To determine the rates of pregnancy complications following in vitro fertilization in comparison with those in a matched control group. Methods : A total of 13,543 deliveries at the Department of Obstetrics and Gynecology, University of Szeged, between January 1, 1995 and February 28, 2002 were subjected to retrospective analysis. The 230 (1.7%) pregnancies following IVF-ET were evaluated and matched with spontaneous pregnancies concerning age, parity, gravidity, and previous obstetric outcome. Demographic and selected maternal characteristics, pregnancy and labor complications, and neonatal outcome were compared in the two groups. Results : The pregnancy complication rate was partly significantly higher among the singleton IVF-ET pregnancies. The obstetric risk was elevated, though not significantly concerning twin pregnancies. Conclusions : IVF-ET presents an additional obstetric risk. The neonatal outcome displays a significant difference only concerning an increased premature birth rate of singleton pregnancies. Triplet IVF-ET pregnancies involve a much higher risk of both pregnancy complications and neonatal outcome.     

Assessment of cervical length by transvaginal ultrasonography to predict preterm delivery in twin pregnancy

Abstract

Objective: In singleton pregnancy, short cervix is associated with the risk of spontaneous preterm delivery (SPD). On the other hand, twin pregnancy increases rate of preterm delivery, so this study was designed to evaluate the transvaginal sonographic (TVS) measurement of cervical length (CL) to predict preterm birth in twin pregnancy.

Methods: This prospective cohort study was performed on 80 twin pregnant women whom the length and funneling of their cervix were evaluated between 22–24 gestational weeks by (TVS). They referred to us at the early signs of labor. Then the gestational age at delivery was recorded. The Fisher exact test and the odds-ratio was used to determine the association between CL and SPD.

Results: Thirty-four (42.5%) women had SPD. Cervical funneling happened in 7.5% of cases and SPD occurred in all women with funneling. There was a significant correlation between CL?≤?30?mm and SPD (66.7% versus 35.5%, p?=?0.029) Also, the risk of SPD was enhanced 3.6 times with CL ≤30?mm, CI 95% (1.1–11).

Conclusion: We recommend TVS for assessment of CL between 22–24 weeks for prediction of SPD in twin pregnancy.     

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.     

体外受精-胚胎移植与单精子卵胞浆内注射妊娠结局的比较与分析

目的　探讨体外受精 胚胎移植 (IVF ET)和单精子卵胞浆内注射 (ICSI)的妊娠结局及围产儿结局。方法　回顾性分析 1999年 1月至 2 0 0 1年 6月 ,行IVF ET获得妊娠的 14 3例 (IVF ET组 )及行ICSI获得妊娠的 173例 (ICSI组 )的临床资料 ,比较两组的生化妊娠、流产、异位妊娠、多胎分娩发生率及新生儿出生体重、胎儿孕龄、先天性畸形、围产儿死亡率的情况 ;并对两组单胎、双胎妊娠的结局分别进行比较。结果　IVF ET组与ICSI组两组患者的年龄、不孕年限、产次、移植胚胎数、流产率 (16 1%、13 3% )、分娩率 (6 5 7%、74 6 % )、多胎分娩发生率 (2 7 3%、31 8% )比较 ,差异均无显著性 (P >0 0 5 )。单胎妊娠中 ,IVF ET组与ICSI组低体重儿的发生率分别为 1 8%、6 8% ,小于胎龄儿的发生率分别为 7 3%、8 1% ,早产的发生率分别为 5 5 %、14 9% ;双胎妊娠中 ,IVF ET组与ICSI组低体重儿的发生率分别为 34 2 %、4 2 6 % ,小于胎龄儿的发生率分别为 30 3%、38 0 % ,早产的发生率分别为 4 2 1%、4 6 3%。两组间上述各发生率比较 ,差异均无显著性 (P >0 0 5 )。但双胎妊娠中 ,上述各发生率均明显高于单胎妊娠。两者比较 ,差异均有极显著性 (P <0 0 1)。先天性畸形的发生率 ,IVF ET组与ICSI组分别为 2 2 %     

Retain singleton or twins? Multifetal pregnancy reduction strategies in triplet pregnancies with monochorionic twins

Objective

To assess the effectiveness and feasibility of retaining a singleton or twins for multifetal pregnancy reduction (MFPR) in triplet pregnancy with monochorionic twins.

Study design

This retrospective study was conducted from January 2006 to September 2011 at a university reproductive medical center. Multifetal pregnant patients (n = 35) with dichorionic triplets underwent MFPR in the first trimester to reduce one or both monochorionic twins. These cases were divided into two groups: Group A (9 MFPR cases to reduce one monochorionic twin) and Group B (26 MFPR for both monochorionic twins). Control A (for Group A) included another 18 cases of trichorionic triplet reduction to twins; Control B (for Group B) included 35 cases of trichorionic triplet reduction to singletons. MFPR was performed during the same period for all groups. Pregnancy outcomes were compared between groups.

Results

Patients were 28–39 years old; the average gestation for fetal reduction was 6–8 weeks. The early abortion rate was lower in Group A than Group B (0 versus 11.5%, p = 0.339), but the late abortion rate was significantly higher in Group A. (33.3% versus 0, p = 0.000). Groups A and B did not differ significantly in premature labor rate, term birth rate, gestation at delivery and take-home baby rate. The rate of very low and low birth weight was significantly higher in Group A than Group B (50% versus 0, p = 0.001), and the average birth weight was significantly lower in Group A (2391.7 ± 318.5 versus 3119.6 ± 523.9, p = 0.001). Group A had significantly more low birth-weight newborns than Control A (50% versus 13.3%, p < 0.05 [0.024]). Group B (retained singleton) had similar pregnancy outcomes and neonatal conditions as Control B.

Conclusions

Retaining a singleton is always the best choice when deciding about using MFPR to improve pregnancy outcomes. For patients having a triplet pregnancy with monochorionic twins and strongly desiring to keep twins, MFPR in one monochorionic twin was feasible by aspirating embryonic parts early in gestation (6–8 weeks) with no drug injection. Pregnancy outcomes are similar with twin reduction in trichorionic triplet pregnancy.     

Recurrence of preterm birth in twin pregnancies in the presence of a prior singleton preterm birth

OBJECTIVE: We examined recurrence of preterm birth in twin pregnancy in the presence of a previous singleton preterm pregnancy, and assessed if these recurrence risks differed for medically indicated and spontaneous preterm birth. METHODS: A retrospective cohort study was designed using the maternally-linked data of women who delivered a first singleton live birth followed by a twin birth in the second pregnancy (n = 2329) in Missouri (1989--97). We examined preterm birth recurrence at <37 in the second twin pregnancy among women with a prior singleton preterm birth. Recurrence risks were based on hazard ratios (HR) and 95% confidence intervals (CI) estimated from Cox proportional hazards models after adjusting for potential confounders. RESULTS: Preterm birth rates in the second twin pregnancy were 69.0% and 49.9% among women who had a previous preterm and term singleton birth, respectively (HR 1.8, 95% CI 1.6-2.1). The preterm birth rate in the second pregnancy was about 95% when the first singleton pregnancy ended at <30 weeks. Women delivering preterm following a medical intervention in the first pregnancy had increased recurrence for both spontaneous (HR 1.4, 95% CI 1.1-2.0) and indicated (HR 2.4, 95% CI 1.8-3.2) preterm birth; similarly among women with a prior spontaneous preterm birth, hazard ratios were 1.8 (95% CI 1.5-2.1) and 1.6 (95% CI 1.3-1.9), for spontaneous and indicated preterm birth in the second twin pregnancy, respectively. CONCLUSIONS: Women with a singleton preterm birth carry increased risk of preterm birth in the subsequent twin pregnancy. A history of a singleton preterm birth has an independent and additive contribution to risk of preterm birth in the subsequent twin gestation.     

Twin pregnancy in patients with a uterine anomaly

Abstract

Objective: In singleton pregnancies, a uterine anomaly is a known risk factor for preterm birth and fetal growth restriction. Data on outcomes of twin pregnancies with uterine anomalies is limited to case reports. The objective of this study was to compare outcomes in twin pregnancies based on the presence or not of a uterine anomaly.

Methods: This was a retrospective cohort of twin pregnancies managed by a single maternal-fetal medicine practice from 2005 to 2012. Patients with monoamniotic twins and twin-twin transfusion syndrome were excluded. Pregnancy outcomes were compared between patients with and without a uterine anomaly. Nonparametric tests (Fisher’s exact test, Mann–Whitney U) were used for analysis. A p value of ≤0.05 was considered significant.

Results: Five hundred and fifty-six twin pregnancies were included, 17 (3.1%) of whom had a known uterine anomaly (nine septate uterus, three bicornuate, three arcuate, one unicornuate and one didelphys). Patients with a uterine anomaly had significantly worse outcomes, including cerclage, preterm birth and lower median birth weights. Birth weight less than the 10th or 5th percentile for gestational age was not more common in patients with a uterine anomaly, nor was there an increase in birth weight discordancy.

Conclusion: In patients with twin pregnancies, the presence of a uterine anomaly is associated with an increased risk of cerclage, preterm birth and lower birth weights, but not fetal growth restriction.     

体外受精/卵胞质内单精子显微注射双卵双胎减胎后妊娠结局的病例对照研究

目的探讨双卵双胎妊娠早期减胎为单胎的妊娠结局。方法 2008年1月—2014年12月期间体外受精及卵胞质内单精子注射-胚胎移植(IVF/ICSI-ET)后双胎妊娠早期(孕45~75 d)减胎为单胎者102例(A组),三胎妊娠早期减胎为双胎者73例(B组)以及双胎妊娠未减胎者4 638例(C组),比较其中晚期流产率、早产率等进一步的妊娠结局。结果 IVF/ICSI-ET后A组与B组和C组比较,早产率(10.8%,58.6%,42.1%)、低出生体质量儿率(6.8%,44.1%,30.3%)明显降低,孕周[(38.0±2.0)周,(35.7±2.3)周,(36.4±2.1)周]、出生体质量[(3.17±0.53)kg,(2.51±0.59)kg,(2.69±0.53)kg]明显增加,差异有统计学意义(P0.05),中晚期流产率差异无统计学意义(P0.05)。结论 IVF/ICSI后的双卵双胎妊娠,于孕早期行减胎术安全,具有更好的妊娠结局。     

Outcomes of ultrasound-indicated cerclage in twin pregnancies with a short cervical length

ObjectiveTo investigate the outcomes of ultrasound-indicated cerclage in dichorionic-diamniotic (DCDA) twin pregnancies with a short cervical length.Materials and methodsThis was a retrospective cohort study of DCDA twin pregnancies with a short cervical length (≤25 mm) from January 2000 to July 2017 to compare maternal and neonatal outcomes. Additional sub-analysis was performed by dividing the patients into two subgroups by a cervical length ≤15 mm and between 16 and 25 mm.ResultsOne hundred and eight women were initially diagnosed with twin pregnancies and cervical insufficiency. After excluding cases not meeting the study criteria, 46 women were recruited for analysis, of whom 33 underwent ultrasound-indicated cerclage. The delivery age of the cerclage group was significantly later than the non-cerclage group (34.85 ± 3.91 versus 31.08 ± 5.25 weeks, p = 0.011), and the latency was significantly longer in the cerclage group than in the non-cerclage group (86.09 ± 41.32 versus 52.31 ± 33.24 days, p = 0.014). Sub-analysis revealed that these benefits were significant in the subgroup of a cervical length ≤15 mm. Both first twin (twin A) and second twin (twin B) had a significantly decreased rate of neonatal intensive care unit admission in the cerclage group. However, twin A had more promising outcomes with significantly decreased rates of neonatal respiratory distress syndrome (6.7% versus 50.0%, p = 0.004) and sepsis (0% versus 25.0%, p = 0.019).ConclusionUltrasound-indicated cerclage in DCDA twin pregnancies can decrease preterm birth and prolong the latency. It also decreases neonatal morbidity, and is especially beneficial for twin A.     

Perinatal Outcome of Pregnancies After Assisted Reproduction: A Case–Control Study

Purpose: A matched case–control study of all pregnancies obtained after either IVF or ICSI was conducted to investigate the perinatal outcome. Methods: Three hundred eleven singleton and 115 twin pregnancies obtained after assisted reproduction were studied. Controls were selected from a regional register and were matched for maternal age, parity, singleton or twin pregnancy, and date of delivery. Results: No significant difference was observed for gestational age at delivery, birth weight, incidence of congenital anomalies, and incidence of perinatal mortality between ART (singleton and twin) pregnancies and spontaneous controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies (52 vs 42%; P < 0.05) and needed more neonatal intensive care (47 vs 26%; P < 0.05). Conclusions: From this case–control study it is concluded that the perinatal outcome of ART singleton pregnancies is not different from that in matched controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies and needed more neonatal intensive care.     

The association between fetal fibronectin and spontaneous preterm birth in twin pregnancies with a shortened cervical length*

Objective: To estimate the association between a positive fetal fibronectin (fFN) and spontaneous preterm birth (SPTB) in twin pregnancies with a shortened cervical length (CL).

Study design: Retrospective cohort study of asymptomatic twin pregnancies managed by a single MFM practice from 2005 to 2016. We included all women with a shortened CL ≤25?mm at 22–28 weeks, and compared outcomes between women with a positive and negative fFN result.

Results: One hundred fifty-five patients were included, 129 (83.2%) of whom had a negative fFN and 26 (16.8%) of whom had a positive fFN. Baseline characteristics were similar between groups, except for the CL at the time of diagnosis of short cervix (15?mm in the positive fFN group versus 20?mm in the negative fFN group, p?=?.002). The risk of SPTB <32 weeks was significantly higher in the positive fFN group (46.2 versus 12.6%, aOR 3.54, 95% CI 1.26, 9.92) and the mean gestational age at delivery was significantly earlier (31.1 versus 35.2 weeks, p?Conclusions: In asymptomatic women with twin pregnancies and a shortened CL, a positive fFN is significantly associated with SPTB and can modify the risk substantially. If performing a screening CL assessment in a twin pregnancy, fFN testing should be done concurrently.     

Effect of twin pregnancy chorionic properties on maternal and fetal outcomes

Objective

This study aimed to determine the effect of twin pregnancy chorionic properties on pregnancy complications and fetal outcomes.

Risk of spontaneous preterm birth in IVF-conceived twin pregnancies

Objective: To compare the mean transvaginal ultrasound (TVU) cervical length (CL) at midtrimester in screening for preterm birth in in vitro (IVF)-conceived twin pregnancies versus spontaneously-conceived twin pregnancies.

Methods: This was a retrospective cohort study. Potential study subjects were identified at the time of a routine second trimester fetal ultrasound exam at 18 0/7 to 23 6/7-week gestation. All women with twin diamniotic pregnancies screened with a single TVU CL for this trial were included. Mean TVU CLs were compared between IVF-conceived twin pregnancies and spontaneously-conceived twin pregnancies. The relationship of TVU CL with gestational age at delivery was assessed. Incidence of short TVU CL, defined as TVU CL ≤30?mm, was also calculated in the two groups. The primary outcome was the mean of TVU CL. Distribution of CL was determined and normality was examined in both groups

Results: A total of 668 women with diamniotic twin pregnancies who underwent TVU CL screening between 18 0/6 and 23 6/7 weeks were included. 158 (23.7%) were IVF-conceived pregnancies, and 510 (76.3%) were spontaneously-conceived pregnancies. No women received progesterone, pessary, or cerclage for preterm birth prevention during pregnancy. The mean TVU CL was significantly lower in the IVF-conceived group (32.2?±?10.5?mm) compared to the spontaneously-conceived group (34.1?±?9.1?mm) (mean difference (MD)???1.90?mm, 95%CI ?3.72 to ?0.08). The incidence of TVU CL ≤30?mm was 30.4% in the IVF-conceived group and 21.6% in the spontaneously-conceived group (adjusted odds ratio (aOR) 1.59, 95%CI 1.06–2.37). IVF-conceived twins had a significantly higher risk of spontaneous preterm birth <34 weeks (32.9 versus 21.2%; aOR 1.83, 95% confidence interval (CI) 1.23–2.71) and higher rate of delivery due to spontaneous onset of labor (64.5 versus 54.9%; aOR 1.50, 95%CI 1.03–2.17). For any given TVU CL measured between 18 0–7 and 23 6/7 weeks, gestational age at delivery for IVF-conceived twins was earlier by about 1 week on average compared with spontaneously-conceived twins.

Conclusions: The higher rate of spontaneous preterm birth in IVF-conceived twin pregnancies is predicted by lower midtrimester TVU CL, as well as by the lower gestational age at birth per any given CL in the IVF-conceived compared to the spontaneously-conceived twin pregnancies.     

Predictors of adverse perinatal outcomes in intrahepatic cholestasis of pregnancy with dichorionic diamniotic twin pregnancies

Objective: The aim of our study was to investigate the predictors of adverse perinatal outcomes in intrahepatic cholestasis of pregnancy (ICP) with dichorionic diamniotic (DCDA) twin pregnancies.

Methods: This study was a retrospective study of women diagnosed with ICP and DCDA twin pregnancies in Chengdu’s women and children’s central hospital. These patients were subdivided into mild and severe ICP groups according to total bile acid (TBA) level. The clinical characteristics and perinatal outcomes were collected and compared between the two groups. Logistic regression analysis was developed to evaluate predictors of adverse perinatal outcomes.

Results: About 134 cases were included in the study. Eighty-four cases were in the mild ICP group, and the other 50 cases were in the severe ICP group. Level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), and direct bilirubin (DBIL) in the severe ICP group were significant higher than those in the mild ICP group. The rate of delivery before 34 gestational weeks, meconium-stained amniotic fluid, and composite adverse neonatal outcome were higher in the severe ICP group than those in the mild ICP group. After adjusting for confounders, ICP onset gestational age (GA)?<30 weeks and AST >200U/l were associated with GA at delivery <34 weeks. ALP >400U/l was an independent risk factor of meconium-stained amniotic fluid. ICP onset GA <30 weeks was an independent risk factor of composite adverse neonatal outcome.

Conclusion: ICP onset GA <30 weeks, TBA >40 µmol/l, AST >200U/l, and ALP >400U/l were associated with composite adverse perinatal outcomes in ICP with DCDA twin pregnancies. For those patients with these characteristics, fetal surveillance and treatment should be enhanced.     

Guideline No. 398: Progesterone for Prevention of Spontaneous Preterm Birth

ObjectivesTo assess the benefits and risks of progesterone therapy for women at increased risk of spontaneous preterm birth (SPB) and to make recommendations for the use of progesterone to reduce the risk of SPB and improve postnatal outcomes.OptionsTo administer or withhold progesterone therapy for women deemed to be at high risk of SPB.OutcomesPreterm birth, neonatal morbidity and mortality, and postnatal outcomes including neurodevelopmental outcomes.Intended UsersMaternity care providers, including midwives, family physicians, and obstetricians.Target PopulationPregnant women at increased risk of SPB.EvidenceMedline, PubMed, EMBASE, and the Cochrane Library were searched from inception to October 2018 for medical subject heading (MeSH) terms and keywords related to pregnancy, preterm birth, previous preterm birth, short cervix, uterine anomalies, cervical conization, neonatal morbidity and mortality, and postnatal outcomes. This document represents an abstraction of the evidence rather than a methodological review.Validation MethodsThis guideline was reviewed by the Maternal–Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and approved by the SOGC Board of Directors.Benefits, Harms, and/or CostsTherapy with progesterone significantly reduces the risk of SPB in a subpopulation of women at increased risk. Although this therapy entails a cost to the woman in addition to the discomfort associated with its use, no other adverse effects to the mother or the baby have been identified.SUMMARY STATEMENTS (GRADE ratings in parentheses)

• 1Progesterone therapy reduces the risk of spontaneous preterm birth in women at an increased risk based on history of previous spontaneous preterm birth or in women with a short cervical length (moderate).
• 2There is insufficient evidence to support the use of progesterone for prevention of spontaneous preterm birth in women with a pregnancy in the absence of cervical shortening (moderate).
• 3There is insufficient evidence to support the use of progesterone for prevention of spontaneous preterm birth in women with a normal cervical length and a prior conization procedure on the cervix or abnormal uterine anatomy (low).
• 4Use of progesterone in women with arrested preterm labour is not associated with a reduced risk of spontaneous preterm birth or with improved postnatal outcomes (moderate).
• 5Use of vaginal progesterone for prevention of spontaneous preterm birth has not been associated with an increase in congenital malformations or with a worsening of postnatal neurodevelopmental outcomes (moderate).

RECOMMENDATIONS (GRADE ratings in parentheses)

• 1In women with a singleton pregnancy and a short cervical length (≤25 mm by transvaginal ultrasound between 16 and 24 weeks), vaginal progesterone therapy for prevention of spontaneous preterm birth is recommended (strong/moderate).
• 2In women with a previous spontaneous preterm birth, vaginal progesterone therapy for prevention of spontaneous preterm birth is recommended (strong/moderate).
• 3In women with a twin pregnancy (and by extrapolation of data, with a higher-order multiple pregnancy) and with a short cervical length (≤25 mm by transvaginal ultrasound between 16 and 24 weeks), vaginal progesterone therapy for prevention of spontaneous preterm birth is recommended (strong/moderate).
• 4In patients with a singleton pregnancy and a previous spontaneous preterm birth or a cervical length ≤25 mm between 16 and 24 weeks in the current pregnancy, if a cerclage is being considered, vaginal progesterone should be offered as an effective and potentially superior alternate therapy (strong/moderate).
• 5In patients using progesterone for prevention of spontaneous preterm birth, additional therapies such as a cervical cerclage (with exception of a rescue cerclage for an examination-based diagnosis) or a pessary are not recommended (strong/moderate).
• 6In patients at increased risk of spontaneous preterm birth due to a previous preterm birth, a short cervical length in the current pregnancy, or a multiple pregnancy, bed rest or reduced activity is not recommended (strong/moderate).
• 7When indicated for prevention of spontaneous preterm birth in a singleton pregnancy, vaginal micronized progesterone in a daily dose of 200 mg is recommended (strong/moderate).
• 8When indicated for prevention of spontaneous preterm birth in a multiple pregnancy, vaginal micronized progesterone in a daily dose of 400 mg is recommended (conditional [weak]/low).
• 9When indicated, vaginal progesterone therapy should be initiated between 16 and 24 weeks gestation, depending on when the risked factor is identified (strong/moderate).
• 10With consideration of individual patient risk factors, vaginal progesterone therapy can be continued up to 34–36 weeks gestation (strong/moderate).

     

Fetal reduction from twins to a singleton: a reasonable consideration?

OBJECTIVE: In the past, our group took the position that we would not provide multifetal pregnancy reduction to a singleton regardless of starting number except for serious maternal medical indications or as a selective termination for diagnosed fetal anomalies. With evidence of increased safety and more women (many aged 40 years or more) asking for counseling about reduction to a singleton, we reviewed our prior reasoning. METHODS: We compared outcomes of 52 first-trimester twin-to-singleton for multifetal pregnancy reduction cases performed by a single operator to twin and singleton data from recent national register studies. RESULTS: Twin-to-singleton reductions represent less than 3% of all cases. Forty of 52 patients were aged 35 years or more, 19 were aged more than 40 years, and 2 were aged more than 50 years (age range 32-54 years). Since 1999, 23 of 28 had chorionic villus sampling before multifetal pregnancy reduction. Fifty-one of 52 reached viability with mean gestational age at delivery of 37.2 weeks. One of 52 patients miscarried (1.9%). Compared with multiple sources of data for twins, the loss rate is lower in twins reduced to a singleton. CONCLUSION: Until recently, multifetal pregnancy reductions to a singleton were rare. Physicians were concerned about the unknown risks of multifetal pregnancy reduction in this situation. They also had moral doubts about the justification to go "below twins." However, physicians know that spontaneous twin pregnancy losses average 8-10%. Also, with experience, multifetal pregnancy reduction has become very safe in our hands. Our data suggest that the likelihood of taking home a baby is higher after reduction than remaining with twins. We propose that twin-to-singleton reductions might be considered with appropriate constraints and safeguards.     

Cervical pessaries for the prevention of preterm birth: a systematic review and meta-analysis

Objective: The objective of this study is to evaluate the effectiveness and safety of cervical pessaries for the prevention of preterm birth.

Methods: We searched PubMed, Embase, Web of Science, and other sources from inception to July 2016. This analysis referred to pregnant women with singleton/multiple viable fetus/fetuses, with or without cervical pessary placement.

Results: Six randomized control trials and five cohort studies involving 3911 participants were included. Overall, cervical pessary placement was slightly associated with the decrease of spontaneous delivery less than 34 weeks (relative risk 0.65 [95% CI: 0.44–0.96]) and increased gestational age at delivery (weighted mean difference 1.03 weeks [95% CI: 0.37–1.70]) in multiple pregnancies, but not with poor perinatal outcomes. Pessary placement in singleton pregnancies did not show any difference. A planned subgroup analysis showed multiple pregnancies with shorter cervical length (≤25?mm) had a longer prolongation of pregnancy (weighted mean difference 2.08 weeks [95% CI: 1.35–2.82]).

Conclusion: This meta-analysis suggested pessary placement could slightly reduce the rate of spontaneous preterm delivery before 34 weeks, and increase gestational age at delivery in multiple pregnancies, but not in singleton pregnancies. More studies of high quality with detailed records are urgent to confirm the efficacy of this procedure.     

The effect of first trimester subchorionic hematoma on pregnancy outcomes in patients underwent IVF/ICSI treatment

Objective: The aim of this retrospective cohort study was to assess the effect of subchorionic hematoma (SCH) on pregnancy outcomes in IVF/ICSI patients.

Methods: We retrospectively analyzed 1097 pregnancies achieved by in vitro fertilization and embryo transfer (IVF-ET) or frozen-thawed embryo transfers (FETs) between January 2013 and June 2013 at the IVF center of Nanjing Drum Tower Hospital. The prevalence of SCH was 12.1% in this group (133/1097). We compared the pregnancy outcomes between the SCH group and non-SCH group, while the risk factors for SCH were also evaluated.

Results: There was no significant difference between SCH group and non-SCH group with regard to patients’ age, spouse’s age, endometrial thickness, miscarriage rate (5.6% versus 6.2%, p?>?0.05), second trimester fetus loss rate (5.6% versus 7.7%, p?>?0.05) or live birth rate (89.5% versus 86.1%, p?>?0.05). While the birth weight in singleton pregnancy in SCH group was significant lower (3207.8?±?595.7?g versus 3349.2?±?59.7?g, p =?0.03). SCH was more common in fresh embryo transfer patients than that in FET patients (16.6% versus 5.1%, p?Conclusion: We concluded that SCH was associated with lower birth weight in singleton pregnancy, but SCH did not increase pregnancy loss rate in IVF/ICSI patients, and fresh embryo transfer may contribute to SCH onset.     

Can early β-human chorionic gonadotropin predict birth of singletons and twins after in vitro fertilization?

Objective: To assess the predictive value for clinical pregnancy outcome of β-hCG level at 13?d after embryo transfer.

Methods: Retrospective study of IVF clinical pregnancies diagnosed at 6 weeks. We calculated the value of β-hCG level at 13?d after embryo transfer to predict live births.

Results: We analyzed 177 IVF cycles between 2009 and 2014 (50 singleton births, 50 twin births, 27 sets with a vanishing twin, 43 first trimester singleton pregnancy loss and seven first trimester total twin pregnancy loss). Singleton pregnancies with a β-hCG concentration?<85 mIU/mL had an 89% risk of having a first trimester loss whereas a concentration?>386?mU/mL had a 91% chance of a live birth. Twin pregnancies with a concentration?<207 mIU/mL had only a 33% chance of delivering twins and a 55% risk of having a vanishing twin; whereas a level?>768 mIU/mL was associated with a 81% chance of live twin birth and a low risk (19%) of having a vanishing twin. Age, type and duration of infertility, body mass index (BMI) and number of fertilized oocytes did not affect these calculations.

Conclusions: β-hCG level at 13?d after embryo transfer might predict outcomes in clinical singleton and twin pregnancies following IVF.     

双绒毛膜及单绒毛膜双胎与妊娠期并发症及围生儿结局分析

目的:探讨双胎妊娠绒毛膜性对孕妇妊娠期并发症及围生儿预后的影响及意义。方法:对我院定期随诊并分娩的472例双胎临床资料进行回顾性分析,根据绒毛膜性分为单绒毛膜双羊膜囊组(MCDA组)和双绒毛膜双羊膜囊组(DCDA组),对两组孕妇的分娩孕周、并发症以及围生儿预后等进行比较分析。结果:两组孕产妇妊娠并发症的发生率比较,差异无统计学意义(P>0.05)。MCDA组低出生体重儿、极低出生体重儿、新生儿窒息及围生儿死亡的发生率均明显高于DCDA组,其差异有统计学意义(P<0.05),MCDA组中双胎输血综合征发生率为7.32%。结论:绒毛膜性对孕妇妊娠并发症的发生无明显影响,而双胎孕妇于孕早期行B超检查诊断单绒毛膜或双绒毛膜对预测围生儿预后具有重要意义。尽早确定双胎类型,加强对单绒毛膜双胎的监护及干预,是改善胎儿和新生儿预后的关键。