Maternal obesity in singleton versus twin gestations: a population-based matched case–control study

Objective: To examine the impact of pre-pregnancy obesity on adverse outcomes in twin compared to singleton pregnancies.

Methods: Dichorionic twin gestations with maternal body mass index >30 were matched to three singleton controls. Both obese groups were matched (1:3) with non-obese controls. Rates of preeclampsia, gestational diabetes, cesarean section, and preterm birth were compared.

Results: One hunder eighty-nine dichorionic twin pregnancies in obese mothers were matched to 567 twin pregnancies in non-obese mothers, and to 567 singleton pregnancies in obese mothers. The latter were matched to 1701 non-obese mothers with singletons. Preeclampsia was more common in obese mothers with both twins and singletons (odds ratio (OR) 3.95, 95% confidence interval (CI) 2.18–7.16 and OR 6.53, 95% CI 3.75–11.4, respectively) as was gestational diabetes (OR 4.35, 95% CI 2.18–8.69; OR 5.53 95% CI 3.60–8.50). Obese mothers with singletons were more likely to deliver abdominally, but the cesarean rates were obesity independent in twins. Obese mothers were more likely to deliver at <?34 weeks in both twin and singleton groups (OR 1.65, 95% CI 1.10–2.48, and OR 2.41, 95% CI 1.21–4.77, respectively).

Conclusion: Obesity-attributable adverse outcomes are lower in twins compared to singletons. Obesity increases the risk of preterm birth regardless of plurality.     

The impact of chorionicity on umbilical cord acid–base values in twin gestations

Objective: To evaluate the impact of chorionicity on inter-twin differences in acid–base status at birth.

Methods: Records for twin pregnancies delivered at ??24 weeks' gestation from 1 January 1990 to 31 June 2000 were reviewed. Collected data included maternal demographics, gestational age, fetal presentation, anesthesia, delivery mode, inter-twin interval, umbilical artery (UA) and venous (UV) acid–base values, Apgar scores and birth weights. The influence of chorionicity on umbilical cord biochemistry was evaluated. (p?<?0.05 was considered significant.)

Results: Analysis was carried out in 87 twin pairs (29 monochorionic, MC; and 58 dichorionic, DC). MC and DC twins were similar in maternal age (25.5 vs. 28.2 years), estimated gestational age (33.7 vs. 33.6 weeks), Cesarean delivery (55.2 vs. 52.6%), delivery interval (10 v s.5?min) and respective birth weights (twin A,1882 vs. 1981; and twin B,1828 vs. 1872?g). MC first twins had a higher UA pH (7.31?±?0.05 vs. 7.26?±?0.08; p?=?0.0005) than DC first twins. MC first and second twins had higher UA and UV bicarbonate levels than their DC counterparts (ΔpH?=?21.7?±?5.1 vs. 18.5?±?3.1?mmol/l and 22.0?±?3.5 vs. 19.6?±?2.5?mmol/l, respectively; p?=?0.003). MC twins were more discordant in UA pH than DC twins (ΔpH?=?0.043?±?0.09 vs. 0.003?±?0.07; p?=?0.009). MC and DC twins had a similar venous pH (ΔpH?=?0.01?±?0.06 vs. 0.02?±?0.06; p?=?0.5).

Conclusions: There is a significant association between placental chorionicity and umbilical cord biochemistry in twins. Although it is possible that the mechanism of this finding is related to placental angioarchitecture, it is unlikely to be a result of simple mixing of blood volumes between twins. The physiology of underlying processes requires further study.     

Neonatal hypoxia of the second twin after vaginal delivery of the first twin: what matters?*

Objective: Optimal management of twin deliveries is controversial. We aimed to assess potential risk factors correlated to the development of hypoxia in the second twin after vaginal delivery of the first twin.

Study design: This is a retrospective observational study including diamniotic twin pregnancies delivering at our Institution at 35 weeks of gestational age or more, weighing ≥1800?g. Hypoxia was defined as at least one of the following: Apgar score <5 at 10 minute, neonatal resuscitation for >10 minutes, neonatal acidosis (pH ≤7 and/or BE ≥12?mmol/L).

Results: A number of 275 diamniotic twin pregnancies met the inclusion criteria and were divided within the following groups: (1) second twin not developing neonatal hypoxia (n?=?265); and (2) second twin developing neonatal hypoxia (n?=?10). The rate of second twins with neonatal hypoxia during the study period was 3.6% (10/275). Abnormal cardiotocography during the intertwin delivery interval, defined as ACOG category III, was significantly correlated to second twin hypoxia. Of interest, there was no significant difference in the intertwin delivery interval between the study groups. In addition, breech presentation of the second twin did not show to be a risk factor for neonatal hypoxia. None of the second twins developing neonatal hypoxia was reported to have encephalopathy (follow up of at least 24 months). At multivariate analysis, only abnormal cardiotocography was an independent risk factor for second twin hypoxia (OR 17.8, 95% CI 4.1–77.2).

Conclusions: In our study, neonatal hypoxia was significantly correlated to abnormal cardiotocography, while intertwin delivery interval was not correlated to the development of this adverse neonatal outcome.     

Concurrence of gestational diabetes and pre-gravid obesity (“diabesity”) in twin gestations

Objective: To assess the effect of the concurrence of gestational diabetes mellitus (GDM) and pre-gravid obesity in twin gestations (“diabesity”).

Methods: We compared perinatal outcomes of twin gestation in mothers with GDM and pre-gravid obesity (1.7%), mothers with GDM but with normal BMI (6.2%), and obese mothers without GDM (7.0%).

Results: Twin pregnancies with “diabesity” were associated with significantly higher incidence of stillbirth (OR = 6.4; 95%CI = 1.4, 33.4) and existing chronic hypertension (OR = 4.2; 95%CI = 1.2, 14.8) than in GDM pregnancies without obesity, and with births at 33–36 weeks as compared with the other groups. Otherwise, the comparisons showed remarkable similar results in terms of gestational age, birth weight, preeclampsia, cesarean section rate, and fetal-neonatal outcomes.

Conclusion: It appears that diabesity has a relatively minor effect in twins. If this will be confirmed by other studies, it would be important to elucidate how twins ameliorate the adverse outcomes of diabesity.     

Velamentous cord insertion in dichorionic and monochorionic twin pregnancies – Does it make a difference?

ObjectiveTo estimate the prevalence of velamentous cord insertion (VCI) in dichorionic (DC) and monochorionic (MC) twins with and without twin-twin transfusion syndrome (TTTS), and to study the associated outcomes.MethodsWe recorded the type of umbilical cord insertion in all consecutive DC and MC placentas examined in two European tertiary medical centers. The association between VCI and perinatal outcomes was estimated and compared.ResultsA total of 1498 twin placentas were included in this study (DC placentas n = 550, MC placentas without TTTS n = 513 and MC placentas with TTTS n = 435). The prevalence of VCI in DC, MC without TTTS and MC with TTTS groups was 7.6%, 34.7% and 36.1%, respectively (P < 0.001). In MC twins (non-TTTS and TTTS groups), VCI was associated with severe birth weight discordance (odds ratio [OR] 4.76 95% CI 2.43, 10.47 and OR 4.52 95% CI 1.30, 28.59, respectively). In MC twins without TTTS, VCI was associated with small for gestational age (OR 1.66, 95% CI 1.12, 2.50). VCI was significantly associated with increased risk of intrauterine fetal demise in MC twins, and this effect was greater in the non-TTTS group (OR 2.71 95% CI 1.38, 5.47). These associations did not occur in DC group. Gestational age at birth was lower in the presence of VCI in the DC and MC twins without TTTS.ConclusionOur findings confirm that the prevalence of VCI is higher in MC twins than in DC twin pregnancies. VCI is an important indicator of adverse perinatal outcome, particularly in MC twins.     

Breech presenting twin A: is vaginal delivery safe?

The aim of our study was to compare the neonatal outcome of vaginally delivered breech-presenting twins (VD) to those delivered by cesarean (CS). Maternal and neonatal charts of all live, non-anomalous twins delivered at > or =25 weeks of gestation, in a single tertiary care center, over an 11-year period were reviewed. Of 517 twins delivered, 130 breech-presenting twins were analyzed. Thirty-five (26.9%) were delivered vaginally and 95 (73.1%) by cesarean. More patients presented in labor with advanced cervical dilation in the VD compared to the CS group. There was no difference in the incidence of respiratory distress syndrome, intraventricular hemorrhage, need for mechanical ventilation, length of nursery stay or neonatal mortality rate when twin A was compared in the two groups. However, one breech-presenting twin in the VD group had a traumatic delivery at 32 weeks of gestation that caused a spine fracture followed by immediate neonatal death. Although there seems to be no compromise in the immediate neonatal outcome of breech-presenting twins delivered vaginally compared to those delivered by cesarean, the case of head entrapment that led to intrapartum death is quite alarming. Based on our study, we cannot advocate normal vaginal delivery when twin A is non-vertex: cesarean seems to be a safer route of delivery.     

Appropriate maternal weight gain in singleton and twin pregnancies: what is the evidence?

The quality of the end product from andrology services continues to lack consistency and in some cases fails to meet the needs of the end users (patients or clinicians). Results of external quality assessment (EQA) schemes continue to show unacceptably wide variation for the results of a single specimen. Some laboratories are able to show that the results of semen analyses relate to both natural and assisted pregnancy and are therefore useful in the management of the infertile couple, whereas others claim that their value is limited to the identification of severe male factor infertility. With wide variation in standardisation of methodology, levels of staff training and quality assurance, it is entirely understandable that such discrepancies persist. The following article proposes that Quality Assurance (QA) is derived from standardisation of methods and implementation of good practice for the entire analytical process, i.e. from the collection and delivery of the specimen, through analysis and processing, to the eventual reporting and interpretation of the result to the clinician. Without appropriate QA, the value of diagnostic testing will remain limited and will vary according to the individual or individual laboratory performing the test.     

Vaginal birth after caesarean delivery in twin gestation: is trial of labor allowed?

OBJECTIVE: To determine if a trial of labor in twin pregnancy with previous cesarean section is an acceptable alternative to systematic cesarean section. PATIENTS AND METHODS: Based on a retrospective and comparative study from 1st January 1996 to 30th June 2003 in Maternite Jeanne-de-Flandre (Lille) and Pavillon Paul-Gelle (Roubaix), 35 trials of labor in twin pregnancies with previous cesarean section have been compared with 35 twin gestations attempting vaginal delivery without a prior cesarean. This comparative study has been led by sorting out the patients according to their gestational age, parity and maternity. RESULTS: Twenty-seven women (77%) delivered vaginally and eight (23%) by elective caesarean section. Postpartum hemorrhage was more frequent for caesarean section (75%). No scare dehiscence or rupture occurred. There was not any haemostasis hysterectomy or embolisation related to postpartum haemorrhage. Neonatal outcome was similar in both groups. DISCUSSION AND CONCLUSION: Twin trial of labor after a previous cesarean section seems to be a safe alternative to routine repeat cesarean delivery as maternal and fetal morbidity and mortality are safe.     

Meconium passed in labor: how reassuring is clear amniotic fluid?

OBJECTIVE: Clear amniotic fluid is frequently considered a reassuring sign during labor. Our aim was to examine the incidence of meconium that can only have been passed intrapartum and to determine its neonatal associations and whether its absence is a useful sign. METHODS: This was a prospective cohort study of 8394 "low risk" laboring women at term with clear amniotic fluid at early amniotomy. RESULTS: Meconium was passed in 5.2% of labors but was not detected until delivery of the fetal head in 51.5% of these. It was associated with moderate-severe acidosis (odds ratio [OR] 4.40; 95% confidence interval [CI] 3.21, 6.03), low Apgar score at 5 minutes (OR 6.49; 95% CI 2.73, 15.44), and neonatal seizures (OR 4.33; 95% CI 3.17, 5.93). However, the sensitivity for these outcomes of the intrapartum passage of meconium and, particularly, its detection before delivery was very poor. CONCLUSION: Although correlated with adverse neonatal outcomes, most affected infants had clear amniotic fluid throughout labor. The presence of clear amniotic fluid is an unreliable sign of fetal well-being.     

Laser therapy for twin–twin transfusion syndrome in a dizygotic monochorionic twin pregnancy: A case report

ObjectiveA monochorionic dizygotic (MCDZ) twin is rare, especially when complicated with twin–twin transfusion syndrome (TTTS) and treated by laser therapy.Case reportA pregnancy achieved from oocyte donation and intracytoplasmic sperm injection resulted in two embryos transferred. A monochorionic diamniotic twin pregnancy was diagnosed by an early ultrasound; however, at 16 weeks of gestation, instead of the same sex, the ultrasound suspected there was sex discrepancy between the twins. TTTS with severe polyhydramnios occurred at 22 weeks, leading to a laser therapy, which was followed with a smooth post-operation course. Then the Cesarean section was performed at the gestational age of 29 weeks due to severe preeclampsia, giving birth to two live newborns: one female and one male baby both without neurological sequelae at the time of discharge. Blood chromosomes obtained at delivery and 65 days after delivery all revealed an XX and XY chimera from both babies.ConclusionLaser therapy is also effective in MCDZ twin complicated with TTTS. Determination of chorionicity in early pregnancy could timely prompt us to watch out for complications unique to monochorionic twin pregnancy.     

Isolated polyhydramnios in the third trimester: is a gestational diabetes evaluation of value?*

We evaluated implications of testing for gestational diabetes mellitus (GDM) in pregnancies complicated by third trimester isolated polyhydramnios with previous negative diabetes screening test. In this retrospective cohort study of 104 pregnant women with polyhydramnios between 2005 and 2013, all had normal first trimester fasting glucose and normal glucose challenge test (GCT?p?=?0.38) or fasting glucose values (82 vs. 86?mg/dL, p?=?0.29) between women in the polyhydramnios group with and without late GDM diagnosis. Moreover, no significant difference was found in relation to the mode of delivery or birth weight between the studied groups (3437?±?611 vs. 3331?±?515?g, p?=?0.63). Diagnosis of third trimester polyhydramnios was not associated with increased risk for GDM or neonatal complications.     

Emergency contraception: how effective is it?

This paper explores the efficacy of emergency contraception methods, particularly the Yuzpe regimen and the IUD. The most commonly used Yuzpe regimen of combined oral contraceptive pills prevents 75% of expected pregnancies. The insertion of a copper IUD within 5 days of unprotected sexual intercourse prevents 99% of pregnancies. However, neither of these two methods is fully satisfactory for emergency contraception. In addition to the failure of the Yuzpe regimen to prevent approximately 25% of pregnancies, it can also cause some unpleasant side effects. On the other hand, the copper IUD, while certainly effective as a method of emergency contraception, has a certain number of limitations and disadvantages. First, it is usually not advised for women who do not have children, despite the fact that this population group comprises a larger proportion of those who seek emergency contraception. Second, the IUD is an inappropriate method for women at risk of developing sexually transmitted diseases unless an added barrier method is used. Third, its usage is generally not recommended for women with unclear pregnancy status, as it causes serious complications in women with established pregnancies.     

Second trimester cervical length and risk of preterm birth in women with twin gestations treated with 17-α hydroxyprogesterone caproate

Objective.?To compare rates of preterm birth before 35 weeks based on cervical length measurement at 16–20 weeks in women with twin gestations who received 17-α hydroxyprogesterone caproate (17OHPC) or placebo.

Methods.?This is a secondary analysis of a randomised, double-blind, placebo-controlled trial of twin gestations exposed to 17OHPC or placebo. Baseline transvaginal ultrasound evaluation of cervical length was performed prior to treatment assignment at 16–20 weeks. Cervical length measurements were categorised according to the 10th, 25th, 50th and 75th percentiles in the women studied. The effect of 17OHPC administration in women with a short (25th percentile) and long (75th percentile) cervix was evaluated.

Results.?Of 661 twin gestations studied, 221 (33.4%) women enrolled at 11 centers underwent cervical length measurement. The 10th, 25th, 50th, 75th percentiles for cervical length at 16–20 weeks were 32, 36, 40 and 44?mm, respectively. The risk of preterm birth?<35 weeks was increased in women with a cervical length?<25th percentile (55.8 vs. 36.9%, p?=?0.02). However, a cervical length?>75th percentile at this gestational age interval was not protective for preterm birth (36.5 vs. 42.9%, p?=?0.42). Administration of 17OHPC did not reduce preterm birth before 35 weeks among those with either a short or a long cervix (64.3 vs. 45.8%, p?=?0.18 and 38.1 vs. 35.5%, p?=?0.85, respectively).

Conclusion.?Women with twin gestations and a cervical length below the 25th percentile at 16–20 weeks had higher rates of preterm birth. In this subgroup of women, 17 OHPC did not prevent preterm birth before 35 weeks gestation. A cervical length above the 75th percentile at 16–20 weeks did not significantly reduce the risk of preterm birth in this high risk population.     

Triplet infants with birthweight < or = 1250 grams: how well do they compare with twin and singleton infants at 36 to 48 months of age?

The purpose of this study was to determine if triplet infants with birthweight < or = 1250 g were at increased risk of long-term disability compared with similar birthweight and gestational age singletons and twins. This was a retrospective cohort study of < or = 1250-g infants admitted to a regional neonatal intensive care unit from 1986 to 2001 with follow-up to 36 to 48 months corrected gestational age. Outcomes studied were cognitive ability, cerebral palsy, and neurosensory impairment at 36 to 48 months. Enrollment was 1717 infants: 59 triplets, 402 twins, and 1256 singletons. Triplet infants differed from twin or singleton infants because they were more likely to have older, married mothers (relative risk [RR] 3.62, 95% CI 1.31, 5.94), be products of assisted reproductive technology pregnancies (RR 29.59, 95% CI 13.97, 62.68), be exposed to antenatal steroids (RR 1.55, 95% CI 1.38, 1.75), and were all delivered by cesarean section. Triplet infants had lower risk of having intraventricular hemorrhage (RR 0.19, 95% CI 0.05, 0.75). The risk of cerebral palsy, cognitive delay, total major disability, or chronic lung disease was similar in triplet and twin infants compared with singleton infants. The lower risk of having intraventricular hemorrhage in triplet infants may have been due to the use of antenatal corticosteroids and cesarean section delivery.     

Research jobs: how good is the training?

OBJECTIVES: To determine if a period in a research job improves confidence in research skills and to assess the quality of research training. DESIGN AND SETTING: A questionnaire was designed and piloted to assess the content, structure and process of research training. POPULATION/SAMPLE: All individuals who had passed MRCOG in the five years prior to 1999 and were residents of England or Wales. METHODS: Confidence scores were compared between those with and those without research experience. The availability and value of differing strategies for research training were compared. MAIN OUTCOME MEASURES: Confidence in research skills and attitudes to training. RESULTS: Of the 532 usable questionnaires returned, 226 respondents had done or were doing research and these individuals had higher confidence on a variety of research skills than those with no experience of a formal research job. Confidence was patchy with less than 50% feeling confident at assessing bias in a case-controlled study, understanding the statistics used in a paper or assessing the power of a study. Of those who had done research, 50% or less felt their training had been good or excellent in any area. Self-directed learning and discussion with peers were felt to be the most useful strategies for research training. Short intensive courses were not available for many respondents, but were felt to be useful. CONCLUSION: The high levels of dissatisfaction with the training in key skills required for research suggests that there is a need for a system for recognition of research posts. Reform of training in the research job should build on the current strength of encouraging self-directed learning.