Cesarean section indications and anthropometric parameters in Rwandan nulliparae: preliminary results from a longitudinal survey
1University of Lubumbashi Faculty of Medicine and School of Public
Health, Lubumbashi, Democratic Republic of the Congo, 2University of Rwanda,
College of Medicine and Health Sciences, Schools of Medicine and Public Health, Kigali,
Jean-Baptiste Kakoma, University of Lubumbashi Faculty of Medicine and School
of Public Health, Lubumbashi, Democratic Republic of the Congo, University of Rwanda,
College of Medicine and Health Sciences, Schools of Medicine and Public Health,
maternal anthropometric parameters as risk factors for cesarean section have always been a matter of interest and concern for obstetricians. Some of these parameters have been shown to be predictors of dystocia. This study aims at showing the relationship between cesarean section indications and anthropometric parameters sizes in Rwandan nulliparae for the purpose of comparison and appropriate recommendations.
a cross-sectional and analytical study was made on data collected from 32 operated parturients among 152 nulliparae with singleton pregnancy at term and vertex presentation. Concerned anthropometric parameters were height, weight and six pelvic distances. Fisher exact and Student’s t tests were used to compare observed proportions and mean values, respectively.
findings were as follows: 1) the overall cesarean section rate was 21.05%; 2) acute fetal distress (31.3 %), generally contracted pelvis (28.1 %), and engagement failure (25%) were the most frequent indications of cesarean section; 3) all patients ≤ 145 cm tall were operated on for general pelvis contraction whose proportion was significantly higher in them than in the others (p < 0.01); 4) more than half of pelvis contraction cases were observed in patients weighing ≤ 50 kg, but the difference with other weight categories was not significant; 5) considered external pelvic diameters but the Biiliac Diameter displayed average measurements smaller in clinically contracted pelvis than in other CS indications.
external pelvimetry associated with specific other anthropometric parameters could be helpful in the screening of generally contracted pelves, and consequently pregnancies at high risk of cephalopelvic disproportion in nulliparous women, particularly in developing countries with limited resources. Further investigations are requested to deal with this topic in depth.
Maternal anthropometric parameters (i.e. height, weight, body mass index and external pelvic diameters) as risk factors for cesarean section have been for a long time a matter of interest and concern for obstetricians [1-14]. Furthermore, some of these parameters have been shown to be predictors of dystocia due to cephalopelvic disproportion [3, 8, 13] or contracted pelvis , thus leading to lower segment cesarean section in nulliparous women. The absence of well-documented data in that field has justified a number of studies in Rwandan nulliparae from an extensive survey on pelvimetry and other anthropometric parameters. Research findings from one of these studies have highlighted some discrepancies about cesarean section rate distribution as per considered anthropometric parameters, namely height, weight and main external pelvic diameters, due to some supposed bias factors . Cesarean section indications were among these suggested bias factors, hence this study, which is a further analysis of above-mentioned study data. It aims at showing the relationship between anthropometric sizes and cesarean section indications in Rwandan nulliparae. Its findings will be next compared to those from elsewhere, and Central African region especially. Ultimately, recommendations will be made towards a simple, efficient and predictor tool for unavoidable timely cesarean sections.
A cross-sectional and analytical study was made on data collected
from 32 operated parturients among 152 nulliparae who gave birth
with singleton pregnancy at term and vertex presentation within
the three first months
of a prospective longitudinal survey in the Southern Province of
Rwanda. This prospective survey consisted in a close follow-up
of a cohort of Rwandan nulliparae (versus multiparous controls
who never experienced
section) from first antenatal care visit to delivery in order to
match ways of delivery and sizes of concerned anthropometric parameters.
measurements were collected at first antenatal care consultation
(height and external pelvic diameters in cm) and at admission in
the labor room
(weight in kg). At childbirth, midwives and physicians monitored
labor in a blind way and the following data were collected after
delivery by the
investigators: way of delivery (per vaginam or cesarean section),
and cesarean section indication. Fisher exact test and Student’s t test
were used to respectively compare observed proportions and mean
values from a normally
distributed population. The difference was considered significant
for p < 0.05.
Indications of cesarean sections
Indications of the 32 cesarean sections, which represented a prevalence of 21.05% for the study population, were as follows: acute fetal distress (AFD: 10 = 31.3%), generally contracted pelvis (GCP: 9 = 28.1%), engagement failure (EF: 8 = 25%), cephalopelvic disproportion (CPD: 3 = 9.4%), face presentation (FP: 1 = 3.1%) and eclampsia (Ec: 1 = 3.1%).
Height and cesarean section indications
All patients ≤ 145 cm tall underwent cesarean section for general pelvis contraction. GCP proportion decreased when height increased and became null beyond 160 cm. The difference between GCP proportions observed in patients ≤ 145 cm tall and the others (100% versus 17.86%) was highly significant. In the same way, the difference between patients ≤ 145 cm tall and those > 160 cm tall (100% versus 0%) was significant. The average height was 149.78 (± 7.68) cm in patients presenting a GCP and 152.33 (± 3.06) cm in those with cephalopelvic disproportion; the difference was not significant (p = 0.7352). Five out of the eight cases of engagement failure presented a height not exceeding 160 cm (Table 1
Weight and cesarean section indications
More than half of general pelvis contraction cases were observed in patients weighing ≤ 50 kg. GCP proportion decreased in upper weight categories. However, the difference in GCP proportion was not significant either between ≤ 50 kg category and the others (57.14% versus 20%) or between ≤ 50 kg and > 60 kg categories (57.14% versus 10%). The average weight in patients presenting GCP was 52.22 (± 6.04) kg. Even if patients weighing ≤ 50 kg seemed to be prone to GCP, the difference with others was not significant (Table 2
Patients’ external pelvimetry and cesarean section indications
All considered external pelvic diameters (biiliac, antero-superior iliac interspinous, intertrochanter, Baudelocque’s, and intertuberous) and the base length of the Trillat’s triangle displayed average measurements smaller in clinically diagnosed pelvis contraction than in other CS indications. Apart from biiliac diameter, observed differences were all statistically significant (Table 3
Cesarean section rate (21.05%) in our nulliparous study population
was higher than the upper limit (15%) for cesarean section set by WHO 
and by far lower than those registered for the two previous years in a urban
national reference hospital (41%)  and a rural
district hospital (33.7%) of Rwanda . Parturients’ height ≤ 145
cm was significantly characterized by generally contracted pelvis leading
to unavoidable cesarean section in pregnancies at term whereas heights exceeding
160 cm seemed to be free from GCP in our study population. Besides, all
three CPD indications in the present study were related to heights between
146 and 155 cm inclusive. Height < 150 cm in nulliparae has been identified
as a risk factor for cesarean section and cephalopelvic disproportion in
urban and rural populations of different Western, Central and North–Eastern
parts of the neighbouring Democratic Republic of the Congo [8, 9].
This same height cut-off size has also been observed elsewhere .
A cut-off size of < 140 cm has been reported from a well-documented survey
in New Zealand . A maternal height <160 cm has been
nonetheless shown to be associated with an increased risk of CPD as compared
to taller women in Zimbabwe . Shorter maternal height
has been identified as one of the risk factors for operative vaginal delivery
in nulliparous women [3, 4, 7],
and associated to increased risk of emergency cesarean section due to obstructed
labour . Cesarean section rates have been found to
decrease with increasing maternal height , while
cesarean section rate increased gradually with decreasing height .
However, an association of increased cesarean section risk with maternal
age has also been reported in a tallest group of women .
Besides, the likelihood of having a normal delivery with measurements lower than 140 cm should not be excluded as evidenced by the case of some ethnic groups in the Democratic Republic of the Congo, former Belgian Congo and Ruanda – Urundi. Measurements for the Basua pygmies of the Ngayu region (North Eastern region of DR Congo) have shown in parturient women an average height and extremes of 138.4 cm and 118.4-151.5 cm respectively, with newborn at term and normal delivery [19
]. The same observation was made in New Zealand [7
]. Nulliparae weighing ≤ 50 kg at delivery seemed to be also correlated with generally contracted pelvis in our study population. However, delivery low maternal weight (i.e. < 100 pounds = 45.45 kg) was not correlated with cesarean section but active – phase arrest, preterm labor and delivery, and mediolateral episiotomy from a perinatal database study in a high-risk obstetrical and neonatal intensive care center [10
]. An extensive literature, which cannot be cited on the whole, has been dedicated to maternal weight relationship with mode of delivery. Increase of cesarean section rates has been reported with higher prepregnancy weights [5
] or prepregnancy maternal corpulence [12
], an increasing body mass index and greater gestational weight gain [6
], morbid obesity significantly requiring an emergency cesarean section [14
]. It is worth pointing out that most of studies establish a significant relationship between increased body mass index and cesarean section, whereas leanest mothers have the best rate of vaginal delivery [12
]. An average weight and extremes as low as 37.0 and 25-48 kg respectively were found to be compatible with vaginal delivery in female pygmies in DR Congo [19
]. This could be explained by the fact that there could be a certain adaptability of fetal birthweights to maternal corpulence [12
As for external pelvimetry in the current study, significantly lower measurements were displayed in generally contracted pelves that have been clinically diagnosed during labor by health professionals who were not involved in the survey. Apart from average values that did not match, results of this study were similar to findings concerning the relationship between some lower pelvic diameters (e.g. Baudelocque’s, interspinous, and intertrochanter) and cephalopelvic disproportion in Congolese nulliparae [8
]. For many years, a reduced external conjugate (Baudelocque’s) diameter was used as an index of contracted pelvis [1
]. However, if one refers to the case of female pygmies in DR Congo, a Baudelocque’s diameter of 15.6 cm (versus 20 cm in European women) did not prevent the fetal head to easily go through the mother’s pelvis whose sizes were 4-7 cm smaller than those of her European counterpart [20
]. Two explanations were suggested: either internal sizes of pygmies’ pelves are not different from those of both Europeans’ and surrounding Bantu ethnic groups’ pelves or pygmies’ pelves joints greatly relax during delivery, given the very few cases of dystocia and cesarean section in this ethnical group [20
]. The same findings were recorded from neighbour Wanande women whose pelves were platypelloid and generally contracted in comparison with the European anatomical configuration, but with comparatively smaller newborns [21
]. And yet it is known that cephalopelvic disproportion results from mismatch between the size of the fetal head and the maternal pelvic size, hence engagement failure during labor for mechanical reasons [22
]. As one risk factor alone is unlikely to affect delivery management regarding the relationship between anthropometric parameters and way of delivery [7
], taking into consideration risk factors associations, as already initiated by some authors [8
], should be recommended to come up with a simple, efficient and predictor tool. This would allow performing well-timed unavoidable cesarean sections. Consequently, further investigations in different geographical environments of limited resources countries should be promoted, although it has been shown that clinical pelvimetry findings are not at all exploited in practice by general practitioners and obstetricians.
Despite a number of controversial considerations, there could be room for external pelvimetry associated with specific other anthropometric parameters (i.e. height, weight, Body Mass Index, mid upper arm circumference…) to be helpful - at antenatal care consultations and delivery room admission in the screening of generally contracted pelves, and consequently pregnancies at high risk of cephalopelvic disproportion, particularly in developing countries with limited resources. The narrowness of the study population sample size is the major limitation factor for this study whose relevance needs to be confirmed through a more extended and in depth survey.
What is known about this topic
- Significantly smaller height (< 150 cm) in cephalopelvic disproportion than in normal delivery and other complicated deliveries; maternal height < 140 cm compatible with normal delivery in some human groups; and maternal height <160 cm associated with an increased risk of CPD as compared to taller women;
- Relationship between prepregnancy maternal corpulence / increased body mass index / greater gestational weight gain and cesarean section;
- Significantly smaller pelvic diameters (but intertuberous diameter) in cephalopelvic disproportion than in normal delivery and other complicated deliveries.
What this study adds
- First publishable study in Rwandan women anthropometry in relation to cesarean section indications;
- Height ≤ 145 cm as cut-off size for cesarean section in the population of Southern Province of Rwanda;
- Relationship between generally contracted pelvis indication, reduced external pelvic mensurations (including intertuberous diameter and base length of the Trillat’s triangle) and cesarean section.
The author declares no competing interest.
The author has read and agreed to the final version of this manuscript and has contributed to its content and to the management of the case.
The author acknowledges University of Rwanda and Sida/SAREC for having
financially supported the research project on pelvimetry in Rwandan nulliparae
through Former National University of Rwanda-Sida/SAREC Bilateral Research
Cooperation. He also gratefully recognizes the collaboration with Dr Jean
Kalibushi Bizimana and Dr Ramsès Kalumbi Ramazani for their active participation
in data collection and management during the implementation of the above
mentioned research project.
Table 1: height and cesarean section indication in Rwandan nulliparae
Table 2: weight and cesarean section indication in Rwandan nulliparae
Table 3: external pelvimetry and cesarean section indication in Rwandan nulliparae
- Schuman W. A reduced external conjugate (Baudelocque) diameter as an index of contracted pelvis. Sinai Hospital Journal. 1952; 1(1): 45-52. PubMed | Google Scholar
- Hughes AB, Jenkins AD, Newcombe RG, Pearson JF. Symphysis-fundus
height, maternal height, labor pattern and mode of delivery. Am J Obtet Gynecol.1987
Mar; 156(3): 644-648. PubMed | Google
- Tsu VD. Maternal height and age: risk factors for cephalopelvic disproportion in Zimbabwe. Int J Epidemiol. 1992; 21(5): 941-946. PubMed | Google Scholar
- Read AW, Prendiville WJ, Dawes VP, Stanley FJ. Cesarean
section and operative vaginal delivery in low-risk primiparous women, Western
Australia. Am J Public Health. 1994 Jan; 84(1): 37-42. PubMed | Google
- Harlow BL, Frigoletto FD, Cramer DW, Evans JK, Bain RP, Ewigman B, McNellis D. Epidemiologic predictors of cesarean section in nulliparous patients at low risk. AJOG. 1995 Jan; 172(1): 156-162. PubMed | Google Scholar
- Shepard MJ, Saftlas AF, Leo-Summers L, Bracken MB. Maternal anthropometric factors and risk of primary cesarean delivery. Am J Public Health. 1998 Oct; 88(10): 1534-1538. PubMed | Google Scholar
- McGuinness BJ, Trivedi AN. Maternal Height as a risk factor
for caesarean section due to failure to progress in labour. ANZJOG. May 1999
May; 39(2): 152-154. PubMed | Google
- Liselele HB, Boulvain M, Tshibangu KC, Meuris S. Maternal height and external pelvimetry to predict cephalopelvic disproportion in nulliparous African women: a cohort study. BJOG: An International Journal of Obstetrics & Gynaecology. 2000 Aug; 107(8): 947-952. PubMed | Google Scholar
- Mugisho E, Dramaix M, Porignon D, Musubao E, Hennart
P. Evolution des données maternelles et périnatales receuillies en routine
entre 1980 et 1998 à la maternité de référence de Rutshuru en République démocratique
du Congo I Décès maternels et interventions obstétricales. Cahiers d’études
et de recherches francophones / Santé. Avril – Juin 2002; 12(2):247-251. Google
- Ehrenberg HM, Dierker LR, Milluzzi C, Mercer BM. Low
maternal weight, failure to thrive in pregnancy, and adverse pregnancy outcomes.
AJOG. 2003 Dec; 189(6): 1726-1730. PubMed | Google
- Kara F, Yesildaglar N, Uygur D. Maternal height as a risk factor for cesarean section. Archives of Gynecology and Obstetrics. 2005 Apr; 271(4): 336-337. PubMed | Google Scholar
- Barau G, Robillard PY, Hulsey TC, Dedecker F, Laffite
A, Gérardin P, Kauffmann E. Linear association between maternal pre-pregnancy
body mass index and risk of caesarean section in term deliveries. BJOG An International
Journal of Obstetrics and Gynaecology. 2006 Oct; 113(10): 1173-1177. PubMed | Google
- Rozenholc AT, Ako SN, Leke RJ, Boulvain M. The diagnostic accuracy of external pelvimetry and maternal height to predict dystocia in nulliparous women: a study in Cameroon. BJOG An International Journal of Obstetrics and Gynaecology. 2007 May; 114(5): 630-635. PubMed | Google Scholar
- Bhattacharya S, Campbell DM, Liston WA, Bhattacharya S. Effect of Body Mass Index on pregnancy outcomes in nulliparous women delivering singleton babies. BMC Public Health BMC series. 2007 Jul; 7: 168. PubMed | Google Scholar
- Kakoma JB. Cesarean section, height, weight, and external pelvic diameters sizes in Rwandan nulliparae (submitted for publication). Google Scholar
- Gibbons L, Belizán JM, Lauer JA, Betrán AP, Merialdi
M, Althabe F. The Global Numbers and Costs of Additionally Needed and Unnecessary
Caesarean Sections Performed per Year: Overuse as a Barrier to Universal Coverage.
World Health Report. 2010. http://www.who.int/healthsystems/topics/financing/healthreport/30C-sectioncosts.pdf.
Accessed 2 April 2016 | Google Scholar. Google
- Kagaba A. Incidence, indications, and outcome of Cesarean Section at King Faisal Hospital, Kigali (2005 – 2006). MD dissertation, National University of Rwanda, 2006. Google Scholar
- Mugarura JC. Aspects épidémiologiques et cliniques des césariennes pratiquées en 2006 à la Maternité de l’Hôpital de Byumba. MD dissertation, National University of Rwanda, 2007. Google Scholar
- Vincent M, Jans C, Ghesquiere J. The new-born pigmy and his mother. American Journal of Physical Anthropology. 1962 Sep; 20(3): 237-247. PubMed | Google Scholar
- Jans C. Contribution à l’obstétrique des pygmées (Bambuti – Ituri).
Le bassin de la femme pygmée. Ann Soc Belge Méd Trop. Mai 1959; 39: 287-298. Google
- Bernimolin J. La dystocie chez les femmes Wanande. Ann
Soc Belge Méd Trop. Fév 1956; 36: 25-45. Google
- Maharaj D. Assessing Cephalopelvic Disproportion: Back
to the Basics. Obstetrical & Gynecological Survey. 2010 Jun; 65(6): 387-395. PubMed | Google