CORRELATION OF FETAL UMBILICAL CORD CHARACTERISTICS WITH AND LABOUR COMPLICATIONS AT THE EBONYI STATE UNIVERSITY TEACHING HOSPITAL, ABAKALIKI.

BY

DR. UZOMA MARYROSE AGWU MBBS(ABU)

Being

A DISSERTATION SUBMITTED TO THE NATIONAL POSTGRADUATE MEDICAL COLLEGE OF NIGERIA IN PART FULFILLMENT OF THE REQUIREMENT FOR THE PART II FELLOWSHIP EXAMINATION (FMCOG) OF THE FACULTY OF AND GYNAECOLOGY.

SUPERVISORS:

1 Professor VE. Egwuatu MBBS, FWACS,FMCOG, FRCOG, FICS

1 Dr. OUJ Umeora MBBS, FWACS, FMCOG,FICS

1Department of Obstetrics and Gynaecology, Ebonyi State University Teaching Hospital, Abakaliki. Ebonyi State.

Oct/Nov 2009

1 CERTIFICATION

This is to certify that Dr. Uzoma M. Agwu a resident doctor in the department of

Obstetrics and Gynaecology, Ebonyi State University Teaching hospital,

Abakaliki, conducted this research work here on The Fetal Umbilical Cord, here under our supervision.

------Professor VE. Egwuatu Dr. OUJ Umeora Supervisor Supervisor

------Dr. I Sunday- Adeoye HOD

2

DECLARATION

This work is hereby declared as original unless otherwise acknowledged. It has not been presented to any other college for fellowship, nor has it been submitted elsewhere for publication.

------

UZOMA MARYROSE AGWU MB;BS,(ABU) 1999/2000

3 ACKNOWLEDGEMENT

I wish to express my profound gratitude goes to all the consultants in the department of Obstetrics and Gynaecology, Ebonyi State University Teaching

Hospital, Abakaliki for their contributions during my preparation of this dissertation. I am particularly indebted to Prof. VE Egwuatu and Dr OUJ

Umeora, for taking the pains to supervise all my work .Thank you for your persuasion, guidance, and encouragement. I am also grateful to Dr PC Ibekwe,

Dr Ese Anezi-Okoro, my unit consultants, Dr Eze, Dr Ejikeme and Dr Kalu for their guidance and Dr I Sunday –Adeoye the head of department, Obstetrics and Gynaecology, EBSUTH AI, for his assistance and encouragement.

I remain ever grateful to my dear husband who is always there for me. I love you so much. I am indeed indebted to my angels Chidinma and John who endured my absence to enable me to conclude this study.

I wish to thank the members of the Egwuatu-Aneziokoro Medical Research

Club and all the midwives, for their immerse help in collecting the data and to my parents, Mr. and Mrs Francis Umahi Nwaze, I remain eternally indebted. May

God bless you abundantly.

Finally I wish to express my sincere appreciation to the senior registrars and my colleagues, in the department for their corrections and words of encouragement.

Agwu

4 DEDICATION

This book is dedicated to my Father in heaven who gave me back my life as a gift and for the call into this unique specialty, to my husband for his love, encouragement, unequalled support and understanding and to my two angels,

Chidinma and John.

5 LIST OF ABBREVIATION

Ai ------Abakaliki

Cm ------centimeter

EBSUTH ------Ebonyi State University Teaching Hospital

Gm------Gram

Kg------Kilogram n------Number

Nc------Nuchal cords

%------Percentage

<------Less than

>------More Than

Std dev------Standard deviation

6 TABLE OF CONTENT

1. Title page------i

2. certification ------ii

3. Declaration------iii

4. Acknowledgement ------iv

5. Dedication------v

6. List of Abbreviations used in the study------vi

7. Table of contents------vii

8. Abstracts. ------viii

9. Introduction------1

10. Literature Review------3

11. Aims and Objective------8

12. Statement of the Problem------8

13. Working Hypothesis------8

14. Justification for the Study ------9

15. Materials and Methods------10

16. Results------14

17. Tables------18

18. Discussion------25

19. Conclusion------32

20. References------33

21. Appendix 1------39

7

ABSTRACT

The presence of short umbilical cord has been associated with antepartum abnormalities, and the very short umbilical cord with certain intrapartum complications. The very long umbilical cords are associated with cord entanglement and true knots. Few studies have investigated both risk factors and outcomes associated with this relatively rare condition. These studies contain conflicting reports on the association of factors, such as parity, and sex of the with umbilical cord length.

This study aims at documenting the length of the fetal umbilical cord in pregnant women of the Ebonyi State University Teaching Hospital (EBSUTH), as well as any association between umbilical cord length and birth weight, placental weight, sex, parity and certain intrapartum complications.

Prospective descriptive and analytical study of umbilical cords characteristics of deliveries conducted in the department of Obstetrics and Gynaecology of

EBSUTH, Abakaliki, between 1st October, 2008 and 6th of April 2009 were done.

Analyses were done using EPI info.

A total of 588 consecutive deliveries met the inclusion criteria. The female babies were 296(50.3%) in number, while males accounted for 292(49.7%). The mean cord length was 57.87(+12.6) and ranged between 22cm and 124cm.Mean cord

8 length of the male babies was 58.16(+13.3) and that of the female babies was

57.59(+11.9). There was no association between umbilical cord length and parity.

There was a positive but insignificant correlation between cord length and placenta weight and gestational age. The mean umbilical cord length of cases with loops of cord was significantly higher than that of the study population.

Shoulder dystocia, hand prolapse, abruption placentae and prolonged second stage of labour were found to have relatively shorter cords. While

(non-reassuring fetal heart rate) cord prolapse and meconium stained liquor had longer cords.

Umbilical cord length was positively associated with increasing gestational age, placental weight and sex of the babies, but not with parity of the women or cord insertion. Extremes of cord length could predispose to certain intrapartum and cords complications.

9 INTRODUCTION

The Umbilical cord containing two arteries and one vain, connects the developing fetus to the placenta an essential organ for exchange of nutrients and metabolites between mother and fetus. It is a narrow, tube –like structure normally attaching to the centre of the placenta at the fetal side1. At birth, the mature cord measures about 50-60cm in length and 12mm in diameter. Variation in cord length have been recorded, giving rise to descriptive terms such as long cord (defined as cord length greater than 100cm) and short cord ( defined as cord length less than 30cm)2.

The presence of a short umbilical cord has been associated with antepartum abnormalities3 , amnion rupture, uterine structural anomalies4, 5, and the very short umbilical cord with certain intrapartum complications like prolonged second stage of labour, abruptio placentae, fetal heart irregularities and cord rupture3. The very long umbilical cords are associated with cord entanglement and true knots6.

Few studies have investigated both risk factors and outcomes associated with this relatively rare condition. These studies contain conflicting reports on the association of factors, such as parity, and sex of the fetus with umbilical cord length 7,8,. Similarly inconsistent associations have been noted between outcomes, such as neonatal asphyxia and short umbilical cords8.

A number of abnormalities have been noted in umbilical cords from single umbilical artery, velamentous insertion and vasa previa, to cord complications

10 like cord knots, , cord stricture, cord hematoma, cord cysts to cord varix Hemagiomas, teratomas and cord prolapse9.

This study aims at documenting the characteristics of the fetal umbilical cord in pregnant women of the Ebonyi State University Teaching Hospital, as well as any association between umbilical cord length and birth weight, placental weight, sex, parity and certain intrapartum complications.

11

LITERATURE REVIEW

Placenta is an organ vital for exchange of nutrients and metabolites between mother and fetus. The umbilical cord or funis extends from the fetus to the placenta and transmits the umbilical blood vessels: two arteries and one vein.

The vein carries oxygen-rich blood and nutrients from the placenta to the baby, while the two arteries transport waste from the baby to the mother’s blood and disposed of by her kidneys. There vessels are enclosed in and protected by

Wharton’s jelly, a gelatinous substance formed from mesoderm. This jelly has physical properties much like a polyurethane pillow, which is resistant to twisting and compression. This property serves to protect the critical vasculature between the placenta and fetus. The whole cord is covered in a layer of amnion continuous with that covering the placenta.

The umbilical cord begins to form about five weeks after conception. The amnion expands to fill the entire extraembryonic coelom. This process forces the yolk sac against the embryonic stalk and covers the entire contents with a tube of amniotic ectoderm forming the umbilical cord. The cord is narrower in diameter than the embryonic stalk and rapidly increases in length. It becomes progressively longer until about 28 weeks of pregnancy. The cord generally twists around itself and becomes coiled. Varying length for the cord has been reported in literature. Knuppel quoted a range of between 50cm -60cm2. Beall documented Umbilical cord length varying from no cord (achordia) to 300cm, with

12 diameters up to 3cm17. Umbilical cords are helical in nature, with as many as 380 helices17.

An average cord is about 55cm long, with a diameter of 1-2 cm and 11 helices6.

About 5% of cords are shorter than 35cm, and another 5% are longer than

80cm10.The cause of this extreme variation of umbilical cord length is uncertain.

It has been attributed to differences in rate of fetal movement, being shorter in reduced movement and longer with increased movement. Short cord has been associated with fetal movement disorder, breech presentation, oligohydramnios, , intrauterine constraint4,. Adinma (1993) in his study on the umbilical cord, found that the mean cord length for cephalic presentation (51.7cm) was significantly shorter than that for unstable lie (66.5cm) and longer than mean cord lengths for transverse lie (43.6cm) and breech presentation (46.9cm). Also mean cord length of term twins was significantly shorter than that for all births

(44.3cm vs 51.5cm)7. The long umbilical cord associated with unstable fetal lie could cause cord encirclement of the fetus, true knots, and cord presentation or prolapse. In cases of placental abruption, oligohydramious, or breech presentation, consideration may be given to measurement and documentation of cord length after birth, because an abnormal cord length may influence a long- term fetal condition9. A study on 602 Nigerian infants delivered at term, found a significant positive correlation between cord length and fetal weight and between cord length and placental weight but no correlation with other fetal and maternal variables8.

13 The umbilical cord normally inserts near the centre of the placenta. It has been documented that the eccentric attachment of the umbilical cord was most common in normal placenta. However in approximately 7% of single births the insertion point occurs at the very edge of the placenta (marginal insertion) and in about 1% of cases the umbilical cord does not insert into the placenta at all, but the fetal vessels ramify through the external membrane before entering the placenta (velamentous insertion) when the umbilical cord inserts into the chorionic plate of the placenta, the fetal vessels are stabilized, and thus protected from torsional and sheer forces. On the other hand insertion into the membranes exposes the fetal vessels to the potential for rupture due to shearing forces or if the vessels pass near the internal cervical os (vasa previa), or from an ascending inflammation prior to the time of delivery.

It has been noted that parturient with severe high blood pressure tend to have placenta with marginal insertion of the umbilical cord and this has been postulated to be the possible cause of the low birth weight babies observed in this group of patients11. Based on this, it has been suggested that, when marginal insertion is diagnosed in the first and second trimester, additional precautions should be instituted during labour to reduce further risk to the mother and fetus.

Ashfaq et al (2005) however showed that the placenta in pregnant hypertensive women showed no significant change in weight, shape, central thickness and attachment of umbilical cord when compared with that of the normotensivel group1. Velamentous or marginal type of cord insertion in infants weighing less than 2500gm have been documented1. However in a determination of the site of

14 placenta insertion of the umbilical cord in 940 consecutive term infants, no relation was found between birth weight and site of insertion12.

Umbilical cord complications in pregnancy are numerous, ranging from false knots, which have no clinical significance, to vasa previa, which may lead to fetal death17. True knots occur in 1% of , with the highest rate occurring in monoamnionic twins17. False knots (Kinks in the umbilical cord vessels) are more common9. The cord may become coiled around various parts of the body of the fetus. Nuchal cord is defined as cord round the fetal neck at least once. One loop around the neck occurs in approximately 20% of cases13 and multiple loops occur in up to 5% of pregnancies14. Vasa previa occurs when fetal vessels extend over the region of the internal cervical os. Its incidence is between once in

1200-5000 deliveries15. When there is a vasa previa, spontaneous rupture of the membranes may lacerate the fetal vessels, resulting in rapid fetal exsanguination.

Occasionally one umbilical artery is absent. Single umbilical arteries are associated more commonly with fetal anomalies than normal cords. Single umbilical artery occurs in fewer than 1% of cords in singletons and 5% of cords in at least one twin16, and 20% or more of babies with one umbilical artery at birth are reported to have associated fetal anomalies including cardiovascular abnormalities, gastrointestinal defects, oesophageal atresia, a variety of renal defects, and multiple anomaly syndromes17,18. Single umbilical arteries are found twice as often in Caucasians than in blacks and Japanese women. Its risk is increased significantly in and occurs more in female than in the male babies (ratio 1:0.85). Single umbilical artery is believed to be caused by atrophy

15 of a previously normal artery, presence of the original artery of the body stalk, or agenesis of one of the umbilical arteries9.

The relationship between the weight of the placenta and the cord length has not been conclusive. Bolisetty in his study on the correlation of umbilical cord weight with fetal birth weight, found, there was a significant positive correlation between cord weight and length and placental weight and birth weight19. This is probably the first known study to measure umbilical cord weight and examine its correlation with placental and fetal birth weight. It supported the common observation that the size of the umbilical cord is proportional to the baby’s size at birth. Total cord weight has been found to be dependent on cord length, which in turn is greatly influenced by fetal movements1. Adinma in his study on 1000 consecutive deliveries (1993) found that the shorter the cord length, the lower the placental weight7. The relation between birth weight, placental area and placental volume in normal infants has also been documented11.

In a study of 179 Indonesian newborns Sarwono (1991) found that the risk of intrapartum complications such as meconium stained liquor, asphysia and cord entanglement increased parallel with cord length, and male babies had significantly longer umbilical cords than females20. Furthermore he investigated the relationship between intrauterine fetal environment and cord length, fetal sex gestational age, birth weight and head circumference20.

Wu (1996), Investigated the clinical significance of umbilical cord length in human pregnancies in 1087 deliveries. His data showed that male had longer cord length than female fetuses but found no significant correlation between

16 umbilical cord length with maternal age, gestational age, parity, fetal outcome or intrauterine fetal well being21. However Stefos (2000), investigated the relationship between parity and umbilical cold length with respect to peripartum characteristics in 534 parturient and found that mean cord length was significantly higher in women of parity >3 than in women with lower parity and concluded that cord length appears to increase with advancing parity, the cut off point being between the second and the third labour and suggested that closer intrapartum monitoring be performed in all multiparous parturients, because of their propensity for longer cords, and thus for related complication22.

AIMS AND OBJECTIVE.

1. To determine the average umbilical cord length of babies delivered in Ebonyi

State University Teaching Hospital.

2. To assess correlation between Umbilical cord insertion and Birth weight.

3. To assess the association between the umbilical cord length and parity,

gestational age, placental weight, sex of the baby and certain intrapartum

complications.

STATEMENT OF THE PROBLEM:

It has been reported that umbilical cord length, when long may predispose to certain pregnancy complications like cord prolapse and to some others such as prolonged second stage when short. This study investigates these assumptions and determines any relationship between umbilical cord length and gestational age at birth, placental weight, fetal sex and birth weight.

WORKING HYPOTHESIS: There is no relationship between umbilical cord length, pregnancy, labour complications, and outcome.

17 JUSTIFICATION FOR THE STUDY The presence of a short umbilical cord has been associated with antepartum abnormalities3 and intrapartum complications like abruptio placenta, prolonged second stage, fetal heart irregularities and cord rupture3, 11. Also, short cords have also been associated with oligohydramnios, amnion rupture, uterine structural anomalies 4, 5, while very long cords are associated with cord prolapsed, cord entanglements and true knots6.These complications are known contributors to perinatal morbidity and mortality.

Previous studies on this issue have been done with inconsistent association between these intrapartum complications and the umbilical cord length. There are also studies containing conflicting results on the association of factors, such as parity, and sex of the fetus to umbilical cords length 7, 8. This study will establish the relationship between cord parameters and certain intrapartum complications. This will be used as basis for recommending putting in place preventive measures for at risk parturient and hopefully therefore reducing the incidence of perinatal morbidity and mortality. Establishing the association between abnormal cord lengths with congenital anomalies may indicate a need to follow up a fetus with short umbilical cords when seen in ultrasound with further genetic tests3. Also since they are considered at high risk for having potentially fetal problems during their first year of life, they may also be monitored carefully by both their parents and their paediatrician during that first year. This will be recommended.

This study also seeks to analyse the cord length of all deliveries to provide baseline data on umbilical cords length as well as examine its relationship to gestational age and parity of the mother, twinning, birth weight and placental weight. A provision of a baseline data will provide data for future comparisons or means by which other studies may be based.

18 MATERIALS AND METHOD

This is a prospective descriptive and analytical study that was conducted in the department of Obstetrics and Gynaecology of EBSUTH Abakaliki. Abakaliki is the capital city of Ebonyi State with an estimated population of over 2.1 million. The population is mainly agrarian with a high illiteracy and poverty levels. EBSUTH is one of the two tertiary health institutions in the state receiving referrals throughout the state and her neighbours. The department has 20 Gynaecological and 50 Obstetrics beds, and conducts about 1300 deliveries annually. Informed consents were obtained from the parturient and Ethical clearance obtained from the hospital Research Ethics Committee.

Study Population

This study included all patients who delivered (vaginally and through ) consecutively in our department and who consented to the study, between 1st October 2008 and 6th April 2009.Exclusion criteria include; unknown gestational age (however “term” is documented as 38 weeks and all fetus delivered with a sign of life was included when the gestational age is less than 28 weeks), failure to consent to the study, incomplete data and home deliveries that presented with retained placentae when the cord had been tampered with.

The purpose of the study was explained to the patients and an informed consent obtained before proceeding with the study. All patients were managed according to the departmental protocol.

19 Sample size Sample Size Determination for Estimation of the Population Mean, µ with a desired Confidence Level of 100(1-α)23. In a previous study of 1000 consecutive deliveries, the mean umbilical length of 51.5cm with 12.4 standard deviation, s, was found7. Suppose we wished our estimate to be no greater or less than 0.1cm from the true population mean µ (the Greek letter ‘mu’), i.e suppose we wished our estimate to be within a bound of error, B, of no more than 0.1cm from µ. We want to be 95% confident in our estimate. B is given by the formula: B=2(s/ √n) Sample size required for this estimate: Remembering that 95% confidence limits for the population mean, µ, calculated from a large sample is given by the formula: µ=x+ 2(SE0) , SE=Standard error. B=2(SE0) =0.1,

Remember that SEx=s/√n Therefore, B =2(SEx)=2(s/√n)=0.1, where s=12.4, our approximate o. 2(12.4/√n)=0.1 We now solve the equation for n, the sample size: Dividing each side of the equation by 2, we get .12.4/ √n=0.05.=> 12.4=0.05√n => 24.8= √n => n= (24.8)2 Therefore sample size n= (24.8)2 =615.0 Total number of deliveries conducted during the study period was 748.However 160 cases were excluded, leaving 588 that were eligible for inclusion.

Data collection Placenta from 588 consecutive deliveries was obtained from the labour room of the department of Obstetrics and Gynaecology and from the theatre of the hospital in cases of caesarean deliveries for evaluation. The length of the cord was measured using the common Tailors Tape, after it had been emptied of blood by manual squeezing. Measurement is taken from 4cm of the fetal attachments to the point of insertion on the placentae. The 4cm is subsequently added to the figure obtained.

20 A short cord was defined as 30cm or less (lower sixth percentile). A long cord was defined as 80cm or more (upper sixth percentile).

The antenatal records, where available, were examined. All the midwives and resident doctors in the department of obstetrics and gynaecology were informed about the study and maximum cooperation solicited. The midwives were instructed on how to measure the length of the cord and other parameters of the placenta. The umbilical cord insertion, weight of the baby and placenta were recorded and pregnancy and labour details out comes were documented including any cord prolapse, meconium stained liquor, abruptio placentae fetal distress (Non reassuring fetal heart rate was defined as fetal distress in this study), prolonged second stage of labour (second stage lasting more than

120minutes), abnormal lies, twin birth, and failure of fetal descent. The presence of true knot, false knots, nuchal cord and loop of cord around various part of the body, were also documented.

The point of insertion of umbilical cord of placenta in pregnancy were obtained by using insertion percentage that was calculated with the help of d/r x 100 (‘d’ stands for the minimum distance between the site of insertion and margin of placenta and ‘r’ for radius of the surface area of placenta.) as used in previous studies11. Insertion percentage (d/r x 100 ) of 76-100% was recorded as central,

26-75% was recorded as eccentric, while 0-25% was recorded as marginal.

Appropriate number of cases was recruited within 6 month, starting from the 1st

October, 2008. The commencement off an industrial strike terminated the study

21 on the 6th of April 2009.Of the total 748 deliveries conducted, 160 cases were excluded, leaving 588 that were eligible for inclusion.

LIMITATION

Occasionally the placenta is not delivered in one piece this could affect the measurements. Furthermore, loops of cords are occasionally mistaken for

Nuchal cords. Assessment of meconium stained liquor is often subjective.

DATA MANAGEMENT AND ANALYSIS

All information obtained was recorded on a data collection sheet designed for the study. The coded data was then fed into the computer and analysed using EPI info version 3.4.5 programme. The average umbilical cord length for both male and female neonate were computed. Running a logistic regression to determine the influence, tested the presence of any association between the umbilical cord length and birth weight, umbilical cord length and placental weight, umbilical cord length and parity, umbilical cord length and gestational age. Chi-square was used to test for significance for qualitative variables. P-value <0.05 was taken as significant. Anova was used to check for difference between means of quantitative data. Student t-test was used to test for significance, where indicated.

P-value <0.05 was taken as significant. Fisher was used to test for significance for quantitative data that had cell variables less than 5.

22 RESULTS

A total of seven hundred and forty-eight deliveries were conducted during the study interval. A total of 160 cases did not meet the inclusion criteria and were excluded. A total of five hundred and eighty-eighty deliveries was analyzed. 452

(76.9 %) spontaneous vaginal deliveries, 101(17.1%) Caesarean sections and

35(6.0%) instrumental deliveries. 296(50.3%) of the babies were female while

292 (49.7 %) were males. The mean parity was 3 (+ 2.24) and ranged between

1-11.

Table l, shows the socio biological characteristics of the subjects. 364 of the parturient were multiparous (61.9%) and 224(38.1%) primiparous. The deliveries were mainly term deliveries (80.6%). Posterm and preterm deliveries accounted for 16.3% and 3.1% respectively. The mean gestational age at delivery was 38.3 weeks (+2.4) and ranged between 18 and 44 weeks.

Four hundred and seventy-eight (81.3%) of the babies born, weighed 2500g and above.

One hundred and five (17.9%) weighed between 1500g and 2499g and 5(1%) babies weighed below 1500g. The mean birth weight of all deliveries was 3.00kg (+1.26) and ranged between 0.65kg –6kg.The mean birth weight of the male babies was 3.09Kg

(+0.51 Range, 0.8- 5.01kg.) while that of the female group was 2.93Kg (+0.61 Range

0.65-6.00kg).

Table 2 assesses the anthropometric characteristics of the umbilical cord and placenta.

The mean umbilical cord length was 57.87cm (+12.6) and ranged between 22cm to 124

23 cm. Median was 64cm and mode 60cm. Mean length of the umbilical cord for female babies was 57.59cm (+11.9) and that of the male babies was 58.16 (+13.3). Table 2 also shows the mean placental weight for both male and female babies, 0.59kg (+0.19) and

0.58kg (+0.13) respectively. The placental weight for the general population was 0.58kg

(+016) ranged between 0.2-2.75kg.

The mean cord length of the breech presentation was 54.0cm (+10.03). There was no statistically significant difference between the mean cord length of the breech deliveries and that of the study group ( P>0.05).

The mean cord length among multiple deliveries (25 in number) was 49.25cm (+10.66).

There was statistically significant difference between the cord length of multiple deliveries and that of the singleton deliveries ( P <0.05)

The mean cord length of fetuses with congenital malformations (9 in number) was

64.11cm (+11.8). There was no statistically significant difference between the cord length of the 9 babies and the rest of the study population, p>0.05(p –value 0.1345).

The mean cord length of all umbilical cord abnormalities (True knot, false knot, stricture,) was 63.00cm (+ 13.2). This was higher than the rest of the study population, 57.82cm

(+12.6).But this difference is not statistically significant, p > 0.05, ( P-value =0.3168 ).

24 However the mean umbilical cord length of cases with loops of cord (loops round the neck irrespective of the number, round the legs, round the body was 63.58(+14.6) this is longer than in the rest of the study population 57.28 (+12.3) and the difference is statistically significant p<0.05 (T statistic 3.5656, P-value 0.0004).

Table 3 shows the summary of the correlation of umbilical cord length and placental weight, birth weight, gestational age and parity and between placental weight and birth weight, using Pearson correlation coefficient. There was no association between umbilical cord length and parity. A relationship between cord length and both placenta weight and gestational age respectively were not significant. A significant relationship existed between birth weight and placental weight.

Table 4 assesses the relationship between cord length and gestational age. The cord length increased as gestational age increased, 51.7cm (+13.0) at 29-34weeks, 57.7cm

(+12.4) at 35-40 weeks and 61.17(+13.2) at > 40 weeks.

Table 5 shows the relationship between cord length and parity. The mean cord length of primipara (57.45cm)is lower than that of multipara (58.12cm) but the difference is not statistically significant p>0.05( p=0.8928.).

Table 7 and 8, shows the number and mean cord length in certain intrapartum complications respectively. The following conditions show shorter cords shoulder dystocia, hand prolapse in a transverse lying fetus, abruptio placentae and prolonged second stage of labour. While fetal distress (non reassuring fetal heart rate) cord prolapse

25 and mecunium stained liquor had longer cords. These differences were statistically significant (p<0.05,).

Table 9 shows a negative association between cord prolapse and cord length, the higher the cord length the more likelihood for cord prolapse to occur.

Table 10 and figure l, assess the relationship between birth weight and insertion of umbilical cord and the mean umbilical cord length respectively. The commonest insertion type was eccentric, 318 (54.1%), followed by central, 187(31.8%) and last is marginal 83

(14.1%). There was no significant difference between the mean cord length and birth weight between the types p>0.05.

Placental abnormalities were noted in 5(0.9%) cases and with calcification 8( 1.4%) and congenital abnormalities recorded include; central cleft lip and palate (10), extra digit in both hands (2), hypospadias (1), polydachyly (2), saddle nose(1) and talipes (1).

26

TABLE 1. Socio -Biological Characteristics of the Subjects.

Socio –Demographic Characteristics n %

PARITY Primipara 224 38.1%

Multiparous 235 40.0%

Grandmultiparous 129 21.9%

Total 588 100%

GESTATIONAL AGE Preterm 18 3.1%

Term 474 80.0%

Postterm 96 16.3%

Total 588 100%

BIRTH WEIGHT <1500 5 0.9%

>!500- <2500 105 17.9%

>2500 478 81.3%

Total 588 100%

UMBILICAL CORD LENGTH <30cm 4 0.7%

30-80cm 544 92.5%

27 >80cm 40 6.8%

TABLE 2. Anthrometric characteristic of the umbilical cord and placenta

Mean Umbilical Cord length Mean Placenta Weight Sex Cm (Std Dev). Cm (Std Dev)

Male 58.16 (+13.3) 0.59 ( +0.19)

(n=292)

Female 57.59( +11.8) 0.58 ( +0.13)

(n=296)

P value 0.0000 0.0060

TABLE 3. Correlation of umbilical cord length and placental weight, birth weight using Pearson correlation coefficient (Summary)

Umbilical cord parameters Correlation(r) P Value

28 Cord length v Placental weight 0.06 0.0600

Cord length v Birth weight 0.08 0.0000

Placental weight v Birth weight 0.34 0.0000

Cord length v Gestational age 0.03 0.0000

Cord length v Parity 0.00 0.9508

TABLE 4. Cord Length by Gestational Age

Gestational Mean Umbilical cord Length (cm)(Std dev.) Mean Umbilical Cord length

Age Male Female (cm) (Std dev)

<28 weeks 56.3(+9.3) 58.0(+0.0) 56.75 (+7.63)

(n=4) (n=3) (n=1)

29-34 weeks 54.9(+15.2) 49.4(+11.2) 51.70 (+13.03)

(n=26) (n=11) (n=15)

35-40 weeks 57.6 (+13.2) 57.8(+11.6) 57.70 (+12.40)

(n=483) (n=237) (n=246)

>40 weeks 62.4(+13.0) 59.4(+13.3) 61.17(+13.16)

(n=75) (n=41) (n=34)

Bartlett’s Chi square=1.5698 df3 P-value 0-6663. Kruskal-wallis H (equivalent to chi square) =10.4936 df=3 p-value0.0148

TABLE 5: Mean Cord length by Parity

29 Parity Mean Cord Length (cm) (Std dev)

1 57.45cm(11.99) (n=224) 2-3 58.12cm(13.23) (n=235) >5 58.18cm(12.00) (n=129) Mann- whitney/wilcoxon two sample test (Kruskal –wallis test for 2 groups. Kruskal- wallis H (equivalent to chi square = 0.2268 df=2 P-value= 0.8928

TABLE 6: Cord Length and Occurrence of Loops of Cords and Nuchal cords

Cord length Total Total no of loops of cord, Percentage no of

False Knots and true loops of cord, false

knots knots and true knots

<30cm 4 0 0.0%

30-80cm 544 40 7.4%

>80cm 40 8 20.0%

Total 588 48 8.1%

Loops of cord, false knots and true knots are more likely to occur when the cord length is more than 80cm.

Table 7: Cord length versus Intrapartum

30 CORD LENGTH Total No complication *Intrapartum Complications n (%) N (%) n (%) Short Cord (Cord 4 3 (75.0%) 1 (25.0%) length <30cm)

Normal 544 515 (94.7%) 29 (5.3%)

Long Cord (cord 40 34 (85.0%) 6 (15.0%) length >80cm)

Total 588 552 (93.9%) 36 (6.1%)

*Total number of cases with intrapartum complications {fetal distress, Cord prolapse, Abruptio, Prolonged second stage, Meconium stained liguor, Shoulder dystocia and Hand prolapse} Intrapartum complications are more likely to occur when the umbilical cord length is shorter than 30cm and longer than 80cm. TABLE 8 Mean Umbilical cord length of all deliveries by intrapartum

complications.

Intrapartum Complication n Mean umbilical cord Odd ratio

(cm)(Std Dev.)

a) Fetal distress 3 74.3(+26.57) 0.14

b) Cord prolapse 5 86.6(+32.15) 0.05

c) Abruptio 11 48.8(+11.41) 0.00

d) Prolonged second stage of Labour 6 52.8(+13.34) 0.36

e) Meconium stained liquor 8 63.5(+12.88) 0.50

f) Shoulder dystocia 1 22.0(+0.00) 0.00

g) Hand prolapse. 2 47.0(+4.00) 0.00

h) None 552 57.8(+11.78)

ANOVA, a parametric text for inequality of population means P-value =0.0000

31 Kruskal-walli H (equivalent to chi square) P value =0.0114

TABLE 9 Cord length in relation to Cord prolapse

Length of cord Number of fetuses Number of fetuses Total (%)

without cord prolapse(%) with cord prolapse

(%)

< 80cm 546 (99.6%) 2 (0.4%) 548 (93.2%)

>80cm 37 (92.5%) 3 (7.5%) 40 (6.8%)

Total 583 (99.1%) 5 (0.9%) 588 (100.0%)

Odd ratio 0.05(0.01<0R < 0.35), Showing a negative association The higher the cord length the more likelihood for cord prolapse to occur. Chi Square (An expected cell value is less than 5. fisher exact results recommended, so was used.)Fisher exact = 1 –tailed p-value 0.00265,

TABLE10: Birth Weight In relation to insertion of the umbilical cord Birth weight Umbilical cord insertion

(gm) Central Eccentric Marginal

n (%) n (%) n (%) Total (%)

<1500 1 (0.5) 4 (1.3) 0 (0.0) 5(0.9)

>1500-<2500 37 (19.8) 59 (18.6) 9 (10.8) 105(17.9)

>2500 149 (79.7) 255 (80.2) 74 (89.2) 478( 81.3)

Total 187 318 83 588

Figure 2: Means of cord length by Umbilical cord insertion

Descriptive Statistics for Each Value of Cross tab Variable

Number Mean Umbilical cord length Mean Birth weight

32 (cm) (Kg)

Central 187 58.01 (+13.06) 3.0266 (+0.6237)

Eccentric 318 58.05 (+12.41) 2.9679 (+0.5585)

Marginal 83 56.86 (+12.34) 3.1211 (+0.4503)

ANOVA testing inequality of population means, p-value= 0.7302 and p-0.0789 respectively.P>0.05

TABLE11: Cord Length: Singleton Vs Multiple Cord Length Number of Fetuses Total Singleton Multiple

<30cm 4 0 4

30-80cm 519 25 544

>80cm 40 0 40

Total 563 25 588

33

DISCUSSION

Beall et al in an extensive review of umbilical cord complications cited umbilical cord length to range between 0-300cm with average length of 55cm long9. Our study recorded a mean length of 57.87cm (range 22-124 cm). This is similar to the finding by Purola (1968) who recorded a range of 22-130cm and average length of 59cm24 and that of Rayburn et al (1981) who found mean umbilical cord length to be 55cm and range, 14 to 129cm25 and Moore et al (1995 documented approximately 55cm (range 32-146)26. In this study, there was significant difference between the male and female umbilical cord length (58.16cm +13.3 and 57.59 cm + 11.8kg respectively (p <0.05). This is similar to other studies3,20,21, but contrast the finding by Jaya (1995)27,which reported no difference between the umbilical cords of the male and female fetuses.

Incidence of short cord varies extensively. Four (4) cases measured were less than 30 cm in our study (0.7%) deliveries. This is lower than recorded in most

34 other studies3. This may have been influence by the cut off of 30 cm used in this study. Rayburn (1981) defined short cord as cord length less 35 cm (lower sixth percentile) and cited to occur in about 6% of pregnancies25. The pressure of short cord has been associated with antepartum abnormalities and as risk factor for complication of labour and delivery. The very short cord length 22 cm recorded in this study was a case of shoulder dystocia a rare occurrence. Past studies have consistently reported selected labour and delivery complications associated with the presence short cords3, including abruptio placentae, prolonged labour25 and fetal distress 29,30. The only intrapartum complication associated with a “short cord” (defined by less than 30cm) in this study was shoulder dystocia. However, Abruptio placentae (mean cord length 48.80cm

+11.4), and prolonged second stage of labour (Mean cord length 52.8cm+13.3) were associated with shorter cords (below the mean umbilical cord length for the study population) Cord prolapse, fetal distress, and meconium stained liquor were associate with longer cords.

In a study on 96 consecutive healthy term (37 –40 weeks) infants soon after birth,

Bolisetty (2002) found a significant positive correlation between cord weight and length and placental weight and birth weight19. The average placenta weight in our study was 0.58kg (+0.16). There was a positive but insignificant correlation between cord length and placental weight, cord length and birth weight, cord length and gestational age. There was a stronger correlation between placental weight and birth weight. This is in conformity with the findings of Jaya26 and Wu

35 et al21 in studies of Indian and Taiwanese neonates and those of Younoszai and

Haworth among preterm, term and growth retarded infants31. There was no relationship between cord length and parity.

In order to construct a growth chart for umbilical cords Mills (1983) measured the

Umbilical cord length in 9620 male and 9068 female infants and related it to the gestational age. In addition to providing a standard for the US white population, the growth charts obtained, illustrated that umbilical cord length is widely divergent at the same gestational age and that umbilical cord growth continues throughout the third trimester32. In my study, the cord length increases as gestational age increases, 51.7cm(+13.0) at 29-34weeks, 57.7cm(+12.4) at 35-

40 weeks and 61.17(+13.2) at >40 weeks. This contrasts Wu’s (1996) documentation on correlation of cord length with gestational age21, but is in conformity with the finding of Adinma (1993) who reported a significant measure of association between umbilical cord length and gestational age7.

The percentage of female babies at birth was 50.3% while male babies accounted for 49.7%. This is reverse in a study by Jaya (1995) among an Indian population where 49.9% were female babies and 50.1% were male babies27.

The preference for male babies with tendency to abort female fetuses in India, may have caused this trend. Males have longer umbilical cords than females (p- less than 0.0001)20,32. This is similar to findings in this study in which the mean umbilical cord length for male infants was 58.16cm (+13.3) as against 57.59cm

36 (+11.8) for the females. The difference is statistically significant, p<0001. Males also have higher birth weights, placental weights than females. This is similar to other studies 7,20.

Stefos (2003) in a study of 534 Greek parturients found that cord length increased with advancing parity, the cut-off point being between the second and the third deliveries22. In this study, the mean umbilical cord length of primiparae was lower (57.45 cm) than that of multiparae (58.12cm) but the difference was not statistically significant (p>0.05). This observation is similar to Adinma’s findings in a study of 1000 consecutive deliveries where he documented no association between umbilical cord length and parity7. The mean parity in this study was 3 which are similar to that cited by Thieba et al (1998)33 who reported an average of 3 in his study population33.

Nuchal cord (NC) is defined as the umbilical cord being wrapped 360 degrees around the fetal neck 34. One loop around the neck occurs in approximately 20% of cases13 and multiple loops occur in up to 5% of pregnancies14 while true knots are reported in 0.3 –2.1% of deliveries9. Nuchal cords has been associated with fetal heart rate abnormalities9,34. Cord can wrap once or more round the neck leading to strangulation. Dursun reported intrauterine death in a breech presentation at 37Th week of pregnancy, the length of cord was 190cm and wrapped round the neck for 5 times34. Our study suggest an incidence of loops of

37 cord and True knots of 7% and 0.3% respectively. This findings is higher than that reported by Egwuate(1985) who reported cord round the neck and true knots to be 2.5% and 0.05% respectively35. This may have been because we lumped all cases of loops of cord including round the neck, body, leg and hands. Of the fourty –eight cases of cord entanglements/complications, 40 cases (83.3%) occur in umbilical cord length that is within normal range. It is interesting to note that in this study, the mean cord length of all cord abnormalities( True Knot false Knot, stricture) was 63.00cm (+13.2), this is longer than the average but the difference is not significant p>0.05. However the mean umbilical cord length with loops of cord 63.58 (+14.6) this is higher than the mean umbilical cord length of the study

population 57.28(+12.3) but here difference is significant p< 0.05.This is in conformity with Adinma finding7 in which he reported a significant difference in the mean cord length of cases of loops of cord and the cord length of uncomplicated deliveries7 .

The incidence of Cord prolapse is cited to be 0.14-0.62% of deliveries) 35,36. A study on in Burkina Faso recorded on incidence of 7.9 per 1000 deliveries

(0.79%) and Egwuatu reported an incidence of 0.47% in a prospective study of 5905

Nigerian babies35. In this study 5 cord prolapses were recorded giving incidence of

0.85%. This is slightly higher than cited incidence, this may have been due to the fact

that our center has a high incidence of unbooked cases. Three (60%) of the cases of cord

prolapse had cord lengths of over 80cm. Odd ratio 0.05 (0.01

negative associate between cord longer than 80cm and likelihood of cord prolapse. p-

38 value <0.05(0.00265).This is similar to many other studies36. Predisposing factors like

malpresentation, prematurity, twin pregnancy and multiparity were not found to be

contributory in our study. The incidence of Shoulder dystocia in this study is 0.17%.

This is lower than findings documented by Henry (2009) 0.5% -1.5%. The cord length in

this case was very short (22cm).The reason for this very short cord is not clear.

It has been cited that umbilical cord normally inserts near the center of the placenta and in approximately 7% of single births the insertion points occur at very edge of the placenta (marginal insertion) and in about 1 % of cases the umbilical cord does not insert into the placenta at all but the fetal vessels ramify through the external membranes before entering the placenta (velamentous insertion)38. This is buttressed by a study on effect of and maternal Hypertension on gross morphology of placenta by Ashfag (2005), where the insertion of all but one of the placentas studied was centrally located1.

In our study the insertion points of 54.1% of the study population were eccentric and 31.8% central. This is similar to the study by Rath (2000) where eccentric ranked highest followed by central and marginal11.Furthermore a study by

Perceival (1980) reported that in 73 percent of cases the site of insertion of umbilical cord is eccentric in position39. We recorded no case of velamentaous insertion. Woods and Malan (1978) have studied 940 placentas and found no correlation between the birth weight and the site of cord insertion in normal term infants12. The present study also shows no correlation between umbilical cord insertion and birth weight.This contrast Rath (2000) findings in which he reported

39 marginal attachment of umbilical cord to be correlated with low birth weight babies11. This may have been as a result of his study population of hypertensives.

Shanklin (1970) had found similar result to Rath’s in a study of 5000 placentae40.

The umbilical cord length of the breech presentation although shorter is not significantly different from the vertex presentation. 54.0cm(+10.0) vs 57.87

(+12.6) p> 0.05.This contrast a study on 1000 consecutive deliveries of Igbo women at the Iyi-Inu Mission Hospital in Onitsha, Nigeria by Adinma where the mean cord length for cephalic presentation is (51.7cm) was significant longer than that for breech presentation 46.9cm(p<.05)7.

The two factors that determine umbilical cord length are sufficient space in the amniotic cavity for fetal movement and the tensile force applied to the umbilical cord during fetal movements 41,25. It may mean that factors that impede fetal movement may likely result in shorter umbilical cords and those that permit increased fetal activities may result in longer cords. It is noted that umbilical cord length in twins is generally shorter than for singletons42. The mean cord length among multiple deliveries in this study was 49.25cm

(+10.7). This was statistically significant, p<0.05. Adinma reported similar finding

(44.3cm vs. 51.5cm; p<0.05)7. The reduced uterine space in multiple gestations may have accounted for this. Polyhydramnious predisposes to longer umbilical cords with associated sequelae43.

40

CONCLUSION

We conclude that the umbilical cord length does not significantly correlate with parity of the women. Cord prolapse is more likely to occur in cases with umbilical cord longer than 80 cm. Birth weight was found to correlate with the cord length; placental weight and birth weight and cord length increased with gestational age. No association existed between umbilical cord insertion and birth weight or cord length. The umbilical cord of the male babies was longer than that for the female babies. These findings are consistent with reports from other studies on the subject.

41

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