The time of separation of the umbilical cord

Clinical and immunological characteristics of 69 leukocyte adhesion deficiency-I patients

BACKGROUND

In order to support the comprehensive classification of Leukocyte Adhesion Deficiency-I (LAD-I) severity by simultaneous screening of CD11a/CD18, this study assessed clinical, laboratory, and genetic findings along with outcomes of 69 LAD-I patients during the last 15 years.

METHODS

Sixty-nine patients (40 females and 29 males) with a clinical phenotype suspected of LAD-I were referred to Immunology, Asthma, and Allergy research institute, Tehran, Iran between 2007 and 2022 for further advanced immunological screening and genetic evaluations as well as treatment, were enrolled in this study.

RESULTS

The diagnosis median age of the patients was 6 months. Delayed umbilical cord separation was found in 25 patients (36.2%). The median diagnostic delay time was 4 months (min-max: 0-82 months). Forty-six patients (66.7%) were categorized as severe (CD18 and/or CD11a: below 2%); while 23 children (33.3%) were in moderate category (CD18 and/or CD11a: 2%-30%). During the follow-ups, 55.1% of children were alive with a mortality rate of 44.9%. Skin ulcers (75.4%), omphalitis (65.2%), and gingivitis (37.7%) were the most frequent complaints. Genetic analysis of the patients revealed 14 previously reported and three novel pathogenic mutations in the ITGB2 gene. The overall survival of patients with and without hematopoietic stem cell transplantation was 79.3% and 55.6%, respectively.

CONCLUSION

Physicians' awareness of LAD-I considering delayed separation of umbilical cord marked neutrophilic leukocytosis, and variability in CD11 and CD18 expression levels, and genetic analysis leads to early diagnosis and defining disease severity. Moreover, the prenatal diagnosis would benefit families with a history of LAD-I.

Umbilical Cord Separation Time and Influencing Factors in Very-Low-Birth-Weight Preterm Neonates

OBJECTIVE

The average time for umbilical cord separation in term neonates is 7 to 10 days. Prematurity, phototherapy, prolonged duration of antibiotic treatment, and parenteral nutrition are other factors which were demonstrated to delay cord separation. In the previous studies including greater premature infants, the time of separation of the umbilical cord was shown to vary 2 to 3 weeks. We aimed to determine the cord separation time and associated factors in very-low-birth-weight (VLBW) infants.

STUDY DESIGN

In this retrospective study, VLBW infants (birth weight [BW] <1,500 g, gestational age [GA] < 32 weeks) without umbilical catheterization were included. Specific cord care was not applied. The cord separation time, gender, mode of delivery, presence of sepsis, duration of antibiotic treatment, serum free thyroxine, free triiodothyronine (FT3), thyroid-stimulating hormone, lowest leukocyte, polymorphonuclear leukocytes (PMNLs), and platelet counts were recorded.

RESULTS

The study included 130 infants (GA: 29 ± 2 weeks, BW: 1,196 ± 243 g). Mean cord separation time was 14 ± 5 days, while 95th percentile was 22nd day of life. A positive correlation was demonstrated between duration of antibiotic treatment and cord separation time (p < 0.001, r: 0.505). Cord separation time did not differ regarding gender or mode of delivery. Corrected leukocyte count (p = 0.031, r: -0.190) and PMNL count (p = 0.022, r: -0.201), and serum FT3 level (p = 0.003, r: -0.261) were found to be negatively correlated with cord separation time. The cord separation time was found to be delayed in the presence of sepsis (with sepsis: 18 ± 7 days and without sepsis: 13 ± 3 days; p = 0.008). Sepsis was found to delay the cord separation time beyond second week (odds ratio = 6.30 [95% confidence interval: 2.37-15.62], p < 0.001).

CONCLUSION

The 95th percentile for cord separation time was 22nd day. Sepsis might be either the reason or the consequence of delayed cord detachment. The exact contribution of low serum FT3 levels to the process of cord separation should be investigated in further studies.

KEY POINTS

· Mean cord separation time was 14 ± 5 days, while 95th percentile was 22nd day, in VLBW infants.. · Sepsis was found to delay the cord separation time by sixfold beyond second week.. · Serum free triiodothyronine level was negatively correlated with cord separation time..

Multiple Family Members With Delayed Cord Separtion and Combined Immunodeficiency With Novel Mutation in IKBKB

Background: Inhibitor of kappa kinase 2 (IKK2) deficiency is a recently described combined immunodeficiency. It undermines the nuclear factor-kappa B (NF-κB) activation pathway. Methods: The clinical and immunological data of four patients diagnosed with combined immunodeficiency (CID) from two related Saudi families were collected. Autozygosity mapping of all available members and whole exome sequencing of the index case were performed to define the genetic etiology. Results: The patients had early onset (2-4 months of age) severe infections caused by viruses, bacteria, mycobacteria, and fungi. They all had hypogammaglobulinemia and low absolute lymphocyte count. Their lymphocytes failed to respond to PHA mitogen stimulation. A novel homozygous non-sense mutation in the IKBKB gene, c.850C>T (p. Arg284*) was identified in the index patient and segregated with the disease in the rest of the family. He underwent hematopoietic stem cell transplantation (HSCT) from a fully matched sibling with no conditioning. The other three patients succumbed to their disease. Interestingly, all patients had delayed umbilical cord separation. Conclusion: IKK2 deficiency causes CID with high mortality. Immune reconstitution with HSCT should be considered as early as possible. Delayed umbilical cord separation in CID patients may be a clue to IKK2 deficiency.

Is my baby normal? A review of seemingly worrisome but normal newborn signs, symptoms and behaviors

Infant patients are a unique challenge to emergency department (ED) physicians as the spectrum of normal infant signs, symptoms and behaviors are often difficult to differentiate from abnormal and potentially life-threatening conditions. In this article, we address some common chief complaints of neonates and young infants presenting to the ED, and contrast reassuring neonatal and young infant signs and symptoms against those that need further workup and intervention.

Disorders of the Umbilical Cord

The umbilical cord, a vital conduit between the placenta and the fetus, loses much of its significance after birth. However, newborns can often present with various abnormalities of the umbilicus, such as benign granulomas or more serious lesions due to persistent remnants, many of which can change the normal course of cord separation and may be associated with significant morbidities if left unrecognized and uncorrected. Although not uncommon, sanguineous drainage from the umbilical stump can be quite alarming to new parents. Parental counseling regarding normal umbilical cord changes, as well as abnormal findings, such as discharge and skin changes, are important for the recognition and timely treatment of potentially significant umbilical cord disorders.

[Umbilicus in children]

The umbilicus is our first scar. It is the last remain of our life in utero. Besides the umbilical hernia, a common pathology during the first three years of life that rarely requires surgery, there are some rare congenital abnormalities such as gastroschisis and omphalocele, which occur in about 1-5/10,000 births. Gastroschisis is a birth defect of the anterior abdominal wall, through which the fetal intestines freely protrude and are not covered by any membranes. During the 13th week prenatal ultrasound, the umbilical cord can be seen to be properly attached while the intestines float freely in the amniotic fluid. This defect is most common in young women who smoke and/or use cocaine and is not typically associated with genetic disorders. Omphalocele is an average coelosomy, in which a visceral hernia protrudes into the base of the umbilical cord. Omphalocele is typically diagnosed during the prenatal phase, and occurs most commonly in older mothers. It is frequently associated with genetic and morphologic abnormalities, therefore a karyotype should automatically be performed. For these two pathologies, the surgical problem lies in managing, during the reintegration, the conflict container/content responsible to lower vena cava syndrome and disorders ventilatory. Deciding on the technique will depend on the clinical form, and on the tolerance to reinsertion. The success of the surgery is directly linked to the postoperative emergence care for the pre-, per- and postnatal phases. The umbilical cord is preserved in the case of a gastroschisis. A primary or secondary umbilicoplasty will be performed for an omphalocele closure. The umbilicoplasty aims to create an umbilicus in a good position by giving it a shape, ideally oval, but also and especially an umbilication. The primary or secondary umbilicoplasty remains a challenge in a growing abdomen (change in position, deformation, loss of intussusception with growth). Many techniques are described: cutaneous flaps randomly placed, excision and skin plasty, resection and controlled wound healing. The choice of technique is a matter of practice but must be done in a rational way, depending on the scar condition when secondary reconstruction, and with minimal scarring, for primary reconstruction. To avoid morphological changes associated with growth, secondary umbilicoplasty should be proposed after the age of five.

Molecular characterization of leukocyte adhesion deficiency-I in Indian patients: identification of 9 novel mutations

PURPOSE

Leukocyte adhesion deficiency type-I (LAD-I) is caused by mutations in the ITGB2 gene, encoding the β2-subunit of β2-integrin (CD18) which leads to markedly reduced expression of CD18 on leukocytes resulting into recurrent life threatening infections. Here we aim to identify the molecular defects underlying LAD-I in Indian patients and correlate with the clinical presentation.

METHODS

Blood was collected from 30 patients and their parents for absolute neutrophil count, expression of CD18 and CD11 by flow cytometry and DNA extraction. PCR and DNA sequencing of the ITGB2 gene was done for mutation characterization.

RESULTS

Phenotypically, 22 patients were LAD-I(0), 1 was LAD-I(-) and 7 were LAD-I(+) showing no expression and reduced expression of CD18 respectively. Nine novel mutations in 15 patients and 11 known mutations in 16 patients were detected. Prenatal diagnosis was performed for 5 families.

CONCLUSION

In this study 30 patients were phenotypically and genotypically evaluated for a less known disease LAD-I. Unavailability of curative options to majority of the patients and high cost of supportive care emphasize the need to increase awareness about a suspicious case so that timely management can be given to the patient and prenatal diagnosis can be offered to their families.

Umbilical cord antiseptics for preventing sepsis and death among newborns

BACKGROUND

The umbilical cord is a structure made of blood vessels and connective tissue that connects the baby and placenta in utero. The umbilical cord is cut after birth, which separates the mother and her baby both physically and symbolically. Omphalitis is defined as infection of the umbilical cord stump. Tracking of bacteria along the umbilical vessels may lead to septicaemia that can result in neonatal morbidity and mortality, especially in developing countries.

OBJECTIVES

To determine the effect of application of antimicrobials on newborn's umbilical cord versus routine care for prevention of morbidity and mortality in hospital and community settings.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2012). In addition, we also searched LILACS (1982 to 11 October 2012) and HERDIN NeON (October 2012)

SELECTION CRITERIA

We included randomized, cluster-randomized and quasi-randomized controlled trials of topical cord care compared with no topical care, and comparisons between different forms of care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, trial quality and subsequently extracted data. Data were checked for accuracy.

MAIN RESULTS

The search identified 77 trials. We included 34 trials in the review involving 69,338 babies, five studies are awaiting classification and there are two ongoing community trials. Included studies were conducted in both developed and developing countries. Among the 34 included trials, three were large, cluster-randomized trials conducted in community settings in developing countries and 31 studies were conducted in hospital settings mostly in developed countries. Data for community and hospital studies were analyzed separately. The three trials conducted in community settings contributed 78% of the total number of children included in this review. Of the trials conducted in hospital settings, the majority had small sample sizes. There were 22 different interventions studied across the included trials and the most commonly studied antiseptics were 70% alcohol, triple dye and chlorhexidine.Only one antiseptic, chlorhexidine was studied in community settings for umbilical cord care. Three community trials reported data on all-cause mortality that comprised 1325 deaths in 54,624 participants and combined results showed a reduction of 23% (average risk ratio (RR) 0.77, 95% confidence interval (CI) 0.63 to 0.94, random-effects, T² = 0.02, I² = 50%) in the chlorhexidine group compared with control. The reduction in omphalitis ranged from 27% to 56% depending on the severity of infection. Cord separation time was increased by 1.7 days in the chlorhexidine group compared with dry cord care (mean difference (MD) 1.75 days, 95% CI 0.44 to 3.05, random-effects, T² = 0.88, I² = 100%). Washing of umbilical cord with soap and water was not advantageous compared with dry cord care in community settings.Among studies conducted in hospital settings, no study reported data for mortality or tetanus. No antiseptic was advantageous to reduce the incidence of omphalitis compared with dry cord care in hospital settings. Topical triple dye application reduced bacterial colonization with Staphylococcus aureus compared with dry cord care (average RR 0.15, 95% CI 0.10 to 0.22, four studies, n = 1319, random-effects, T² = 0.04, I² = 24%) or alcohol application (average RR 0.45, 95% CI 0.25 to 0.80, two studies, n = 487, random-effects, T² = 0.00, I² = 0%). There was no advantage of application of alcohol and triple dye for reduction of colonization with streptococcus. Topical alcohol application was advantageous in reduction of colonization with Enterococcus coli compared with dry cord care (average RR 0.73, 95% CI 0.58 to 0.92, two studies, n = 432, random-effects, T² = 0.00, I² = 0%) and in a separate analysis, triple dye increased the risk of colonization compared with alcohol (RR 3.44, 95% CI 2.10 to 5.64, one study, n = 373). Cord separation time was significantly increased with topical application of alcohol (MD 1.76 days, 95% CI 0.03 to 3.48, nine studies, n = 2921, random-effects, T² = 6.54, I² = 97%) and triple dye (MD 4.10 days, 95% CI 3.07 to 5.13, one study, n = 372) compared with dry cord care in hospital settings. The number of studies was insufficient to make any inference about the efficacy of other antiseptics.

AUTHORS' CONCLUSIONS

There is significant evidence to suggest that topical application of chlorhexidine to umbilical cord reduces neonatal mortality and omphalitis in community and primary care settings in developing countries. It may increase cord separation time however, there is no evidence that it increases risk of subsequent morbidity or infection.There is insufficient evidence to support the application of an antiseptic to umbilical cord in hospital settings compared with dry cord care in developed countries.

Characterization of 11 new cases of leukocyte adhesion deficiency type 1 with seven novel mutations in the ITGB2 gene

BACKGROUND

Leukocyte adhesion deficiency type 1 (LAD I) is an autosomal recessive disorder caused by mutations in the ITGB2 gene, encoding the beta2 integrin family. Severe recurrent infections, impaired wound healing, and periodontal diseases are the main features of disease.

METHODS

In order to investigate clinical and molecular manifestations of new LAD I cases, 11 patients diagnosed in one center during 7 years were studied. Patients were screened for the ITGB2 gene mutations, using polymerase chain reaction, followed by single-strand conformation polymorphism and sequencing.

RESULTS

The most common first presenting feature of the patients was omphalitis. The mean age of cord separation was 19.9 +/- 1 days. The most common clinical manifestations of the patients during the follow-up period included omphalitis, skin ulcers with poor healing, sepsis, and otitis media. During the follow-up, eight patients died. Eight homozygous changes, including seven novel mutations, were detected: two splicing (IVS4-6C>A, IVS7+1G>A), three missense (Asp128Tyr, Ala239Thr, and Gly716Ala), and three frameshift deletions (Asn282fsX41, Tyr382fsX9, and Lys636fsX22).

CONCLUSION

Our results indicate that different mutations underlie the development of LAD I. Definitive molecular diagnosis is valuable for genetic counseling and prenatal diagnosis. Regarding clinical presentations, it seems that omphalitis is the most consistent finding seen in LAD I infants.

Leukocyte adhesion deficiency type 1 presenting as leukemoid reaction

Leukocyte Adhesion Deficiency (LAD) is characterized by the inability of leukocytes, in particular neutrophilic granulocytes, to emigrate from the blood stream towards sites of inflammation. Infectious foci are nonpurulent and may eventually become necrotic because of abnormal wound healing. LAD-I is characterized by the absence of the beta-2 integrins CD II and CD 18 on leukocytes. We present a male neonate referred with continuation of leukemoid reaction in spite of antibiotic therapy of simultaneous omphalitis. The diagnosis of LAD-I was confirmed by flow cytometry, showing a deficiency of beta-2 integrins on the surface of the leukocytes. After management, the patient was discharged with prophylactic antibiotics.

Urachal duct remnant-like umbilical clear cell acanthoma in an infant: an unusual presentation and pitfall in clinical practice

BACKGROUND

Although an umbilical nodule is common in neonates and young infants, an umbilical nodule of poor therapeutic response will increase the likelihood of other uncommon etiology. Clear cell acanthoma (CCA) has never been described as an oozing umbilical nodule on infants.

METHODS

To present a case of CCA which occurred on an 8-month-old female infant presenting with one weeping nodule on the umbilicus since early neonate. The lesion underwent skin biopsy and subsequent hematoxylin-eosin and periodic acid-Schiff staining.

RESULT

Three courses of liquid nitrogen cryosurgery were performed after the diagnosis of CCA was confirmed. The lesion resolved rapidly.

CONCLUSION

This report presents the first and youngest case of umbilical CCA in the English literature. This case supports the inflammatory dermatosic nature of CCA.

Leukocyte adhesion deficiency in a female patient without delayed umbilical cord separation

Leukocyte adhesion deficiency type 1 (LAD-1), a rare disorder of neutrophil function, is classically characterised by delayed umbilical cord separation. We report a case of LAD-1 in a female infant whose umbilical cord separated within 2 weeks of birth and review the literature pertaining to the timing of umbilical cord separation.

Impact of umbilical cord cleansing with 4.0% chlorhexidine on time to cord separation among newborns in southern Nepal: a cluster-randomized, community-based trial

OBJECTIVE

Within a community-based, cluster-randomized study of the effects of 4.0% chlorhexidine on omphalitis and mortality risk, we aimed to describe the distribution of times to separation and the impact of topical chlorhexidine treatment on cord-separation times.

METHODS

Between November 2002 and March 2005, 15123 infants were assigned randomly within communities in southern Nepal to receive 1 of the following 3 cord-care regimens: cleansing with 4.0% chlorhexidine, cleansing with soap and water, or dry cord care. In intervention clusters, field workers cleansed the cord in the home on days 1, 2, 3, 4, 6, 8, and 10 after birth. Newborns were monitored throughout the newborn period for signs of omphalitis, and the time to cord separation was noted. Separation times were compared across treatment groups. Cord infection risk and a range of infant and household characteristics were assessed for their relationships to separation time.

RESULTS

The mean separation time was shorter in dry cord care (4.24 days) and soap/water (4.25 days) clusters than in chlorhexidine clusters (5.32 days; mean difference: 1.08 days). Cords of infants who received chlorhexidine were 3.6 times more likely to separate after 7 days. Separation time was not associated with omphalitis. Home-delivered topical antiseptics, facility-based birth, and birth attendant hand-washing were associated with greater likelihoods of cord separation after 7 days of age.

CONCLUSIONS

In this setting, the umbilical cord separated more rapidly than observed in hospital-based studies, and the impact of chlorhexidine cleansing on separation times was negligible. Increased cord-separation time attributable to topical chlorhexidine treatment should not be considered a factor in decision-making in settings where the baseline risk of omphalitis is high and chlorhexidine might reduce infection and mortality risks significantly.

Umbilical cord care: a pilot study comparing topical human milk, povidone-iodine, and dry care

OBJECTIVE

To compare the incidence of omphalitis among three groups, each using a different type of newborn cord care: povidone-iodine, dry care, and topical human milk.

DESIGN

Case control.

SETTING

A large urban university hospital in Turkey and participant homes after discharge.

PARTICIPANTS

150 healthy, full-term newborns and their mothers.

INTERVENTIONS

Umbilical cord care consisted of one of three methods: topical application of povidone-iodine twice daily, topical application of mother's milk twice daily, or dry care (keeping the cord dry and clean).

MAIN OUTCOME MEASURE

Outcome was measured in terms of the presence or absence of omphalitis and the number of days elapsed before cord separation. An ongoing questionnaire was administered by telephone every other day after the participants left the hospital. In addition to demographic information, the cord separation day and any signs of omphalitis were recorded in the questionnaire.

RESULTS

There were no significant differences between the three groups in terms of omphalitis occurrence. Two cases of omphalitis were observed (one in the human milk group, one in the povidone-iodine group). Interestingly, babies in the dry care or topical human milk group had shorter cord separation times than those in the povidone-iodine group.

CONCLUSION

The cultural practice of applying human milk to the umbilical cord stump appears to have no adverse effects and is associated with shorter cord separation times than are seen with the use of antiseptics.

Anomalies, abnormalities, and care of the umbilicus

This article discusses various anomalies and abnormalities of the umbilical cord and issues related to cord care. The issue of screening newborns with an isolated single umbilical artery for renal abnormalities is addressed. The clinical presentation of infants with omphalomesenteric and urachal duct remants along with the more common umbilical granuloma is reviewed. All three of these abnormalities can present with a wet or draining cord. The need for umbilical cord treatment with antimicrobial/antiseptic agents versus dry cord care is discussed, as are serious infections that involve the cord.

Topical umbilical cord care at birth

BACKGROUND

Umbilical cord infection caused many neonatal deaths before aseptic techniques were used.

OBJECTIVES

To assess the effects of topical cord care in preventing cord infection, illness and death.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (September 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003). We also contacted experts in the field.

SELECTION CRITERIA

Randomized and quasi-randomized trials of topical cord care compared with no topical care, and comparisons between different forms of care.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed trial quality and extracted data.

MAIN RESULTS

Twenty-one studies (8959 participants) were included, the majority of which were from high-income countries. No systemic infections or deaths were observed in any of the studies reviewed. No difference was demonstrated between cords treated with antiseptics compared with dry cord care or placebo. There was a trend to reduced colonization with antibiotics compared to topical antiseptics and no treatment. Antiseptics prolonged the time to cord separation. Use of antiseptics was associated with a reduction in maternal concern about the cord.

REVIEWERS' CONCLUSIONS

Good trials in low-income settings are warranted. In high-income settings, there is limited research which has not shown an advantage of antibiotics or antiseptics over simply keeping the cord clean. Quality of evidence is low.

Assessment of the umbilical cord outside of the delivery room. Part 2

The umbilical cord is crucial to the growth and development of the fetus. Careful inspection in the delivery room and throughout the newborn period is essential. Part 1 of this 2-part series, entitled "Look Before You Clamp: Delivery Room Examination of the Umbilical Cord" (Advances in Neonatal Care, Vol. 2, No. 1, pp 19-26), reviewed umbilical problems that present in the delivery room. A number of subtle but significant umbilical cord abnormalities present outside the delivery room. These abnormalities will be the focus of Part 2 of this series. A review of the embryologic development of the umbilical cord enhances the clinician's understanding of umbilical abnormalities that present in the newborn period. The process of umbilical cord separation is outlined. Conditions associated with delayed cord separation are discussed. A systematic approach to the physical examination of the umbilicus is offered, with an emphasis on early detection of abnormalities. Common and uncommon physical findings, such as omphalitis, periumbilical necrotizing fascitis, vitelline duct remnants, and urachal anomalies are presented along with select photographs. A brief discussion of the clinical implications for newborn care is provided for the practicing clinician.

Delayed umbilical cord separation in alloimmune neutropenia

Delayed umbilical cord separation in association with neonatal alloimmune neutropenia is reported. Delayed umbilical cord separation has been described in association with defects in neutrophil function. The present case indicates that deficiency in neutrophil number should also be considered as a cause of delayed cord separation.

The umbilical cord: normal parameters

The average length of the umbilical cord is 50-60 cm in the normal full term newborn infant. The length of the cord is an index of foetal activity and is dependent on the tension caused by the freely moving foetus, primarily during the second trimester. The short cord is associated with foetal akinesis or maldevelopment of the central nervous system and is a significant early marker of developmental abnormalities including Down syndrome. Abnormal girth of the cord should make one suspicious of a patent urachus or an umbilical hernia and caution should be used before clamping. The importance of the twist is that, if not present, one should suspect congenital anomalies. The twist should be to the left or counter clockwise. The cord stump separates from the baby at about two weeks of age at present in the era of triple dye care with a large variability due to multiple factors.

Time of separation of the umbilical cord: a comparative study of treatment with alcohol and Rikospray

The time of cord separation and the umbilical changes post cord falling were studied in 394 infants, 35 to 42 weeks gestation, 1900 to 4500 g birth weight. Two methods of treatment; alcohol 70% with 0.5% chlorhexidine, and Rikospray were compared. The mean +/- SD age of cord separation was 6.36 +/- 2.64 days (range 3-20 days) in all infants studied. The time of cord separation and post fall umbilical complications were similar in the two treated groups. The only point of difference was the repulsive odor in the alcohol-treated group, making handling of the infants very unpleasant.

Umbilical cord separation in twins

In this study of twins it was found that the separation of the umbilical cord generally occurred earlier in the first born than in the second born infant. The times of cord separation of twin members are correlated and this correlation is stronger than could be expected by random pairing. However, the correlation was not stronger between monozygotic twin members than between dizygotic twin members.