Clinical Overview of Prolonged Pregnancies and Early Neonatal Well-Being in Cameroon: Pilot Case-Control Study at the Laquintinie Hospital in Douala ()
1. Introduction
Prolonged pregnancy is a pregnancy that lasts more than 42 completed weeks of amenorrhea (AS), or 294 days, according to the definitions of the International Federation of Gynecology and Obstetrics (FIGO) and the World Health Organization (WHO) in 2007 [1]. This definition is subject to numerous dating and nomenclature controversies. Thus, a recent definition developed by the National College of French Gynecologists and Obstetricians (NCFGO) in December 2011 updated the old definition, establishing that pregnancy is said to be “prolonged” beyond 41 + 0 weeks, but that the term is only said to be “exceeded” from 42 + 0 weeks due to the increase in fetal mortality and morbidity at this term [2].
At full term, placental apoptosis begins; the placenta becomes less, and less efficient and maternal-fetal exchanges suffer. The main complication of this placental senescence is the appearance of post-maturity syndrome, which is the association of a reduction in active fetal movements, oligohydramnios and emission of meconium into the amniotic fluid [3]. Fetal heart rate abnormalities are also to be feared due to perinatal asphyxia. Finally, macrosomia often combines with fetal characteristics and causes more obstetric risks than fetal risks per se; it is five times greater in post-term newborns [3]. Maternal complications are mainly obstetrical. Indeed, it has been observed and reported that the further the age of pregnancy, the greater the risk of cesarean section. It is multiplied by 1.5 in the event of prolonged pregnancy [2]. It has also been reported that there is a reduction in spontaneous contractility of the uterine muscle and a poorer response to oxytocin when the term is exceeded [4]. This could then explain: the increase in the induction rate, the increase in the number of dynamic dystocias, the increase in post-partum hemorrhages (PPH) (20% of the PPH rate is attributable to overruns), the increase in artificial deliveries, and the moderate increase in the risk of instrumental extractions and 3rd and 4th degree perineal injuries. Finally, the risks of infection (chorioamnionitis, endometritis) and thromboembolism also seem to be increased when the term is exceeded [4].
Following the work of Zeitlin et al., the incidence of deliveries with a gestational age at delivery greater than or equal to 42 weeks for 27 European countries in 2004 varied from 0.2% in Luxembourg and Austria to 7.1% in Sweden [5]. Two groups with extreme incidences stood out. On the one hand, the group of countries where less than 1% of live births are concerned pregnancies carried beyond term: Austria, Belgium, Estonia, Hungary, Lithuania and Luxembourg [2]. On the other hand, Scandinavian countries represented the group of countries with the highest proportions of over-term pregnancies: Sweden (7.1%), Norway (6.6%), Denmark (6.1%) and Finland (4.8%) [2]. The incidences in Ireland and Netherlands were 4.8% and 5.3%, respectively.
Prolonged pregnancy (>41 weeks) concerns nearly 15% of pregnant women in France, while late-term pregnancy (≥42 weeks) only concerns 1%. In the United States, the incidence of overterm pregnancy varied between 1 and 10% of pregnancies [2]. In Africa and more precisely in Mali, the frequency of prolonged pregnancy (>41 weeks) was 3.62% [6]. As for Cameroon, post-term pregnancies (≥42 weeks) vary from 3% to 5% of all deliveries [7].
The mother-child couple in a context of prolonged pregnancy therefore presents an increased risk of morbidity and mortality, which should be remembered to understand the interest and challenges of managing this period of pregnancy. It therefore seems legitimate to implement early and vigilant obstetric and neonatal surveillance in order to reduce them. These data are known in developed countries, with more adequate and efficient means of care. In our environment, this situation may be different because obstacles exist for better monitoring, such as low socio-economic level, financial constraints and a very low level of education. Thus, we proposed to carry out this study in our context for an operational approach to its results. In our study, we considered the definition of the National College of French Gynecologists and Obstetricians for prolonged pregnancy because it is common in our francophone scientific societies and it helps in anticipating complications, notably placental calcifications, oligohydramnios, fetal distress, and macrosomia.
2. Methodology
2.1. Type of Study
We conducted a prospective analytical cross-sectional case-control study.
2.2. Study Location
Our study took place in the maternity ward of Laquintinie Hospital in Douala due to its very high patient queue, but also its cosmopolitan aspect encompassing all social strata.
2.3. Period and Duration of the Study
Our study was conducted over 7 months, January 2020 to July 2020, and data was collected from January 2020 to May 31, 2020.
2.4. Study Population
2.4.1. Target Population
Our target population consisted of all pregnant women admitted to the delivery room of Laquintinie Hospital in Douala during the study period.
2.4.2. Inclusion Criteria
Prolonged pregnancies: Pregnant women whose gestational age (GA) was >41 weeks were included according to the date of the last period and/or the obstetric ultrasound of the 1st trimester.
Un-prolonged pregnancies: Pregnant women whose gestational age was between 37 weeks and 41 weeks.
2.4.3. Exclusion Criteria
Multiple pregnancies, patient’s refusal to participate in the study.
2.5. Material
To carry out this study, we needed equipment, including:
-For the interrogation: A pre-established form which was completed by patients who consented to the study.
-For the clinical examination: A room with chairs and a table; a stethoscope; a weighing scale; a measuring tape; a measuring rod; white coats; an antiseptic soap; and treatment gloves.
-For data collection and analysis: A computer; USB keys; reams of A4 paper; a 200-page notebook; pens, pencils, and erasers.
2.6. Sampling
We carried out consecutive and exhaustive sampling.
The minimum sample size was calculated using the formula proposed by Shulz and Grimes in 2005 [8] below:
n = 10.51 [(R + 1) − P2 (R2 + 1)]/P2 (1 − R)2
where n = minimum size for each group;
P2 = event rate in group 2;
P1 = event rate in group 1;
R = risk ratio (P1/P2).
Digital application
The risk of artificial induction of labor was greater in the event of prolonged pregnancy in the study carried out by Tangara in Mali [6].
P1 = proportion of pregnant women whose gestational age (GA) was >41 weeks for whom artificial induction of labor was carried out: 30.2%.
P2 = proportion of pregnant women whose gestational age was between [37 weeks - 41 weeks] in whom artificial induction of labor was carried out: 4.3%.
Our minimum sample size will therefore be:
n = 10.51 [(7.0 + 1) − 0.043 (7.02 + 1)]/0.043 (1 − 7.0)2
Hence, there were 41 subjects in each group.
2.7. Procedure
2.7.1. Administrative Arrangements and Ethical Consideration
This research obtained the authorizations after its completion, including the research authorization from the director of the Laquintinie Hospital in Douala.
The data were collected and processed in compliance with the fundamental principles of medical research, namely: confidentiality, the principle of safety of research, the principle of the interest and benefit of research and the principle of justice.
Each participant gave informed consent after reading the information letter.
2.7.2. Study Variables
The different variables studied were:
-Socio-demographic: Age, profession, marital status, region of origin, level of education.
-Clinical and reproductive: The method of admission; gyneco-obstetric history of: prolonged pregnancy, intrauterine fetal death, abortion, gestational age, parity; medical history: high blood pressure, diabetes; surgical history: previous cesarean section; history of prolonged pregnancy in the family; data from the current pregnancy: follow-up, author of prenatal consultations, progress, ultrasound data, gestational age; physical examination data: blood pressure, height, weight, fundal height, uterine contraction, fetal heart sounds, Bishop’s, appearance of amniotic fluid, presentation of the fetus, condition of the pelvis; data on childbirth: labor, duration of labor, route of delivery.
-Maternal and fetal complications: Apgar score, birth weight, neonatal resuscitation, signs of post-maturity, malformation, neonatal death, delivery hemorrhage, soft tissue lesions, uterine rupture, and maternal death.
2.7.3. Procedure and Data Collection
The patients identified were approached upon admission to the delivery room. And following their consent, a clinical examination was carried out either in the delivery room or immediately post-partum associated with the use of birth registers or post-operative protocols. The response elements were collected on pre-tested and validated technical sheets. Additional information was received by telephone call from the mother seven days later to inquire about the state of health of her newborn and whether the latter had left the hospital with his mother or not; or if the newborn was followed in pediatrics, as well as to record possible cases of death.
2.7.4. Statistical Analysis
The data were integrated and analyzed by descriptive and analytical statistics methods using Epi-Info 7.2.2.1 and SPSS (Statistical Package for the Social Sciences) version 20.0 software. Qualitative data were presented as frequencies expressed as percentages and quantitative variables as averages. The statistical test used for the comparison was Pearson’s chi2. The difference was significant if p < 0.05.
3. Results
The frequency of prolonged pregnancy: During the study period, we recorded 666 deliveries, including 58 cases of prolonged pregnancy, i.e. a frequency of 8.7%.
The majority age group was [25 - 30] years old, with 77.5% among prolonged pregnancies and 79.1% among non-prolonged pregnancies; the difference was not statistically significant (p = 0.808). Parturients or married women giving birth represented 36.2% in prolonged pregnancies compared to 50% in non-prolonged pregnancies; the difference was not statistically significant (p = 0.073). Housewives represented 25.8% in prolonged pregnancies compared to 28.4% in non-prolonged pregnancies; the difference was not statistically significant (p = 0.703). According to the administrative division of Cameroon, pregnant women originating from the Western region were in the majority, i.e. 58.6% in prolonged pregnancies compared to 51.2% in non-prolonged pregnancies; the difference was not statistically significant (p = 0.337). The majority of our parturients had a secondary level of education, i.e. 56.9% among prolonged pregnancies compared to 39.8% among non-prolonged pregnancies; the difference was statistically significant (p = 0.026) (Table 1).
Referred gestations represented 58.6% in prolonged pregnancies compared to 27.2% for non-prolonged pregnancies, with a statistically significant difference (p < 0.001). The study of medical history was non-contributory. The history of prolonged pregnancy was found in 10.3% of prolonged pregnancies compared to 3.1% in non-prolonged pregnancies, with a statistically significant difference (p = 0.044). Primigravid represented 36.2% in prolonged pregnancies compared to 31.0% for non-prolonged pregnancies without statistically significant difference (p = 0.470). Nulliparous women represented 44.8% in prolonged pregnancies compared to 36.0% for non-prolonged pregnancies without statistically significant difference (p = 0.242). Most of the surgical history was cesarean section, with 17.2% in prolonged pregnancies compared to 11.3% in non-prolonged pregnancies, with no statistically significant difference (p = 0.259). The mother’s history of prolonged pregnancy was found in 17.2% of prolonged pregnancies compared to 4.4% in non-prolonged pregnancies, with a statistically significant difference (p = 0.003) (Table 2).
Table 1. Socio-demographic characteristics.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Age in years |
|
[15 - 20] |
6 (10.3) |
13 (8.2) |
1.2 |
[0.4 - 3.5] |
0.627 |
[20 - 25] |
7 (12.0) |
20 (12.6) |
0.9 |
[0.3 - 2.3] |
0.907 |
[25 - 30] |
45 (77.5) |
125 (79.1) |
0.8 |
[0.4 - 1.8] |
0.808 |
Marital status |
|
|
|
|
|
Married |
21 (36.2) |
79 (50.0) |
0.5 |
[0.3 - 1.0] |
0.073 |
Widow |
0 (0) |
1 (0.6) |
0.8 |
[0.0 - 22.3] |
0.947 |
Single |
37 (63.7) |
78 (49.3) |
1.8 |
[0.9 - 3.3] |
0.061 |
Type of occupation |
|
Trader |
10 (17.2) |
26 (16.4) |
1.0 |
[0.4 - 2.3] |
0.890 |
Pupil/student |
13 (22.4) |
33 (20.8) |
1.0 |
[0.5 - 2.2] |
0.808 |
Housewife |
15 (25.8) |
45 (28.4) |
0.8 |
[0.4 - 1.7] |
0.703 |
Civil servant |
3 (5.1) |
17 (10.7) |
0.4 |
[0.1 - 1.6] |
0.219 |
Other |
17 (29.3) |
37 (23.4) |
1.3 |
[0.6 - 2.6] |
0.376 |
Region of origin |
|
Center |
6 (10.3) |
15 (9.4) |
1.1 |
[0.4 - 2.9] |
0.851 |
East |
0 |
1 (0.6) |
0.8 |
[0.0 - 22.3] |
0.947 |
Far North |
0 |
3 (1.8) |
0.3 |
[0.0 - 7.4] |
0.524 |
Littoral |
11 (18.9) |
31 (19.6) |
0.9 |
[0.4 - 2.0] |
0.914 |
North |
1 (1.7) |
8 (5.06) |
0.3 |
[0.0 - 2.6] |
0.299 |
Northwest |
4 (6.9) |
12 (7.6) |
0.9 |
[0.2 - 2.9] |
0.862 |
South |
1 (1.7) |
4 (2.5) |
0.6 |
[0.0 - 6.1] |
0.728 |
Southwest |
1 (1.7) |
3 (1.8) |
0.9 |
[0.0 - 8.8] |
0.932 |
West |
34 (58.6) |
81 (51.2) |
1.3 |
[0.7 - 2.4] |
0.337 |
Educational level |
|
Non scolarised |
0 (0) |
2 (1.2) |
0.5 |
[0.0 - 11.3] |
0.687 |
Secondary |
33 (56.9) |
63 (39.8) |
1.9 |
[1.0 - 3.6] |
0.026 |
University |
24 (41.3) |
88 (55.6) |
0.5 |
[0.3 - 1.03] |
0.063 |
Primary |
1 (1.7) |
5 (3.1) |
0.5 |
[0.0 - 4.6] |
0.574 |
Table 2. Past history.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Admission method |
|
Referred |
34 (58.6) |
43 (27.2) |
3.7 |
[2.0 - 7.1] |
<0.001 |
Coming by herself |
24 (41.3) |
115 (72.7) |
0.2 |
[0.1 - 0.4] |
<0.001 |
Medical history |
|
|
|
|
|
Other (HIV, hepatitis) |
4 (6.8) |
16 (10.1) |
0.6 |
[0.2 - 2.0] |
0.470 |
Diabetes |
0 (0) |
3 (1.8) |
0.3 |
[0.0 - 7.4] |
0.524 |
None |
54 (93.1) |
139 (87.9) |
1.8 |
[0.6 - 5.6] |
0.2 |
History of prolonged pregnancy |
|
Yes |
6 (10.3) |
5 (3.1) |
3.5 |
[1.0 - 12.0] |
0.044 |
No |
52 (89.6) |
153 (96.8) |
0.2 |
[0.0 - 0.9] |
0.044 |
Gravidity |
|
|
|
|
|
Great multi-gravid (≥G6) |
0 (0) |
13 (8.2) |
0.0 |
[0.0 - 1.5] |
0.099 |
Multigravid (G4 - 5) |
19 (32.7) |
37 (23.4) |
1.5 |
[0.8 - 3.0] |
0.166 |
Paucigravid (G2 - 3) |
18 (31.0) |
59 (37.3) |
0.7 |
[0.3 - 1.4] |
0.391 |
Primigravid (G1) |
21 (36.2) |
49 (31.0) |
1.2 |
[0.6 - 2.3] |
0.470 |
Parity |
|
Multiparous (P4 - 5) |
2 (3.4) |
21 (13.2) |
0.2 |
[0.0 - 1.0] |
0.054 |
Nulliparous (P0) |
26 (44.8) |
57 (36.0) |
1.4 |
[0.7 - 2.6] |
0.242 |
Pauciparou (P2 - 3) |
18 (31.0) |
44 (27.8) |
1.1 |
[0.6 - 2.2] |
0.646 |
Primiparous (P1) |
12 (20.68) |
36 (22.78) |
0.8 |
[0.4 - 1.7] |
0.657 |
Previous cesarean section |
|
Yes |
10 (17.2) |
18 (11.3) |
1.6 |
[0.6 - 3.7] |
0.259 |
No |
48 (82.7) |
140 (88.6) |
0.6 |
[0.2 - 1.4] |
0.259 |
Similar case in the mother |
|
Yes |
10 (17.2) |
7 (4.4) |
4.4 |
[1.6 - 12.4] |
0.003 |
No |
48 (82.7) |
151 (95.5) |
0.2 |
[0.0 - 0.6] |
0.003 |
The number of prenatal consultations was between 4 - 7 in 82.7% of prolonged pregnancies compared to 87.9% in non-prolonged pregnancies without statistically significant difference (p = 0.321). Pregnancy monitoring was carried out by a gynecologist-obstetrician in 32.5% of prolonged pregnancies compared to 41.7% for non-prolonged pregnancies, with no statistically significant difference (p = 0.153). Most pregnant women had a height greater than 1.5 m, i.e. 87.9% in prolonged pregnancies compared to 87.9% for non-prolonged pregnancies without statistically significant difference (p = 0.995). Patients with a normal body mass index were in the majority, i.e. 56.8% in prolonged pregnancies compared to 56.3% for non-prolonged pregnancies, with no statistically significant difference (p = 0.940). Blood pressure was greater than 140/90 mm Hg in 6.8% of prolonged pregnancies compared to 5.0% in non-prolonged pregnancies, with no statistically significant difference (p = 0.603). Fundal height was greater than 35 cm in 46.5% of prolonged pregnancies compared to 29.7% for non-prolonged pregnancies, with a statistically significant difference (p = 0.022) (Table 3).
Table 3. Follow up of pregnancy.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Number of antenatal consultations |
|
[4 - 7] |
48 (82.7) |
139 (87.9) |
0.6 |
[0.2 - 1.5] |
0.321 |
≥8 |
8 (13.7) |
13 (8.2) |
1.7 |
[0.6 - 4.5] |
0.226 |
<4 |
2 (3.4) |
6 (3.7) |
0.9 |
[0.1 - 4.6] |
0.904 |
Author(s) of antenatal consultations |
|
Midwife |
32 (55.1) |
77 (48.7) |
1.2 |
[0.7 - 2.3] |
0.402 |
Obstetrician-gynecologist |
18 (32.5) |
66 (41.7) |
0.6 |
[0.3 - 1.1] |
0.153 |
General practitioner |
3 (5.1) |
2 (1.2) |
4.2 |
[0.6 - 26.1] |
0.118 |
Other |
5 (8.6) |
13 (8.2) |
1.0 |
[0.3 - 3.0] |
0.926 |
Height |
|
>1.5 m |
51 (87.9) |
139 (87.9) |
0.9 |
[0.3 - 2.5] |
0.995 |
≤1.5 m |
7 (12.0) |
19 (12.0) |
1.0 |
[0.3 - 2.5] |
0.995 |
Body mass index |
|
Severe obesity |
1 (1.72) |
2 (1.26) |
1.3 |
[0.1 - 15.3] |
0.799 |
Moderate obesity |
9 (15.5) |
14 (8.8) |
1.8 |
[0.7 - 4.6] |
0.165 |
Overweight |
15 (25.8) |
53 (33.5) |
0.6 |
[0.3 - 1.3] |
0.282 |
Normal |
33 (56.8) |
89 (56.3) |
1.0 |
[0.5 - 1.8] |
0.940 |
Blood pressure |
|
>140/90 mmHg |
4 (6.8) |
8 (5.0) |
1.3 |
[0.4 - 4.7] |
0.603 |
≤140/90 mmHg |
54 (93.1) |
150 (94.9) |
0.7 |
[0.2 - 2.4] |
0.603 |
Fundal height |
|
[32 - 35] cm |
26 (44.8) |
94 (59.4) |
0.5 |
[0.3 - 1.0] |
0.056 |
>35 cm |
27 (46.5) |
47 (29.7) |
2.2 |
[1.1 - 3.8] |
0.022 |
<32 cm |
5 (8.6) |
17 (10.7) |
0.7 |
[0.2 - 2.2] |
0.645 |
The majority of presentations were peak, i.e. 89.6% in prolonged pregnancies compared to 93.6% in non-prolonged pregnancies, with no statistically significant difference (p = 0.322). Fetal heart sounds were normal in 82.7% of prolonged pregnancies compared to 90.5% in non-prolonged pregnancies, with no statistically significant difference (p = 0.119). The Bishop score was favorable in 80.7% of prolonged pregnancies compared to 77.7% in non-prolonged pregnancies, with no statistically significant difference (p = 0.646). The amniotic fluid was meconium in 18.9% of prolonged pregnancies compared to 7.5% in non-prolonged pregnancies, with a statistically significant difference (p = 0.020). The pelvis was normal in 94.8% prolonged pregnancies compared to 94.9% for non-prolonged pregnancies, with no statistically significant difference (p = 0.974). Fetal heart rate was pathological in 6.8% of prolonged pregnancies compared to 6.9% for non-prolonged pregnancies, without statistically significant difference (p = 0.986) (Table 4).
Table 4. Fetal parameters.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Presentation |
|
Face |
1 (1.7) |
3 (1.8) |
0.9 |
[0.0 - 8.8] |
0.932 |
Peak |
52 (89.6) |
148 (93.6) |
0.5 |
[0.2 - 1.6] |
0.322 |
Transverse |
0 (0) |
3 (1.8) |
0.3 |
[0.0 - 7.4] |
0.524 |
Breach |
5 (8.6) |
4 (2.5) |
1.8 |
[0.9 - 14.0] |
0.061 |
Fetal heart sounds |
|
[120 - 160] |
48 (82.7) |
143 (90.5) |
0.5 |
[0.2 - 1.1] |
0.119 |
≥160 |
6 (10.3) |
11 (6.9) |
1.5 |
[0.5 - 4.3] |
0.416 |
<120 |
4 (6.8) |
4 (2.5) |
2.8 |
[0.6 - 11.8] |
0.148 |
Bishop score |
|
|
|
|
|
[5 - 6] |
10 (17.5) |
22 (14.3) |
1.2 |
[0.5 - 2.8] |
0.571 |
≥7 |
46 (80.7) |
119 (77.7) |
1.1 |
[0.5 - 2.5] |
0.646 |
[1 - 4] |
1 (1.7) |
12 (7.8) |
0.2 |
[0.0 - 1.6] |
0.133 |
Appearance of amniotic fluid |
|
Clear |
43 (74.1) |
139 (87.9) |
0.3 |
[0.1 - 0.8] |
0.015 |
Pea puree |
1 (1.7) |
2 (1.2) |
1.3 |
[0.1 - 15.3] |
0.254 |
Yellowish tinted |
3 (5.1) |
5 (3.1) |
1.6 |
[0.3 - 7.2] |
0.492 |
Meconium stained |
11 (18.9) |
12 (7.5) |
2.8 |
[1.1 - 6.8] |
0.020 |
Pelvis |
|
Normal |
55 (94.8) |
150 (94.9) |
0.9 |
[0.2 - 3.8] |
0.974 |
Contracted |
0 (0) |
4 (2.5) |
0.2 |
[0.0 - 5.5] |
0.413 |
Borderline |
3 (5.1) |
4 (2.5) |
2.1 |
[0.4 - 9.6] |
0.341 |
Fetal heart rate recording |
|
Abnormal |
4 (6.8) |
11 (6.9) |
0.9 |
[0.3 - 3.2] |
0.986 |
Not done |
44 (75.8) |
113 (71.5) |
1.2 |
[0.6 - 2.5] |
0.526 |
Normal |
10 (17.2) |
34 (21.5) |
0.7 |
[0.3 - 1.6] |
0.489 |
Artificial induction was carried out in 8.6% of prolonged pregnancies compared to 3.7% for non-prolonged pregnancies, with no statistically significant difference (p = 0.164). Prolonged pregnancy was the indication for artificial induction in 100% of prolonged pregnancies versus 0% of non-prolonged pregnancies, with a statistically significant difference (p = 0.017). Labor lasted more than 12 hours in 12.5% of prolonged pregnancies compared to 3.7% in non-prolonged pregnancies, with a statistically significant difference (p = 0.039). Caesarean section was performed in 56.8% of prolonged pregnancies compared to 36.9% in non-prolonged pregnancies, with a statistically significant difference (p = 0.008). Acute fetal distress was the majority indication for cesarean section in 27.2% of prolonged pregnancies compared to 10.3% for non-prolonged pregnancies, with a difference that was statistically significant (p = 0.042) (Table 5).
Table 5. Follow up of labor.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Mode of entry into labor |
|
Spontaneous |
53 (91.3) |
152 (96.2) |
0.4 |
[0.1 - 1.4] |
0.164 |
Artificial |
5 (8.6) |
6 (3.7) |
2.3 |
[0.7 - 8.1] |
0.164 |
Artificial: indication |
|
Prolonged pregnancy |
5 (100) |
0 (0) |
143.0 |
[2.4 - 8467.6] |
0.017 |
Severe pre-eclampsia |
0 (0) |
2 (33.3) |
0.1 |
[0.0 - 4.3] |
0.279 |
Premature rupture of membranes |
0 (0) |
4 (66.6) |
0.0 |
[0.0 - 1.3] |
0.074 |
Duration of labor |
|
>12 H |
6 (12.5) |
5 (3.7) |
3.6 |
[1.0 - 12.5] |
0.039 |
6 -12 H |
18 (37.5) |
45 (33.8) |
1.1 |
[0.5 - 2.3] |
0.647 |
<6 H |
24 (50.0) |
83 (62.4) |
0.6 |
[0.3 - 1.1] |
0.135 |
Delivery route |
|
With episiotomy |
4 (6.8) |
9 (5.6) |
1.2 |
[0.3 - 4.1] |
0.742 |
Caesarean section |
33 (56.8) |
58 (36.7) |
2.2 |
[1.2 - 4.1] |
0.008 |
Suction cup |
0 (0) |
1 (0.6) |
0.8 |
[0.0 - 22.3] |
0.066 |
Spontaneous |
21 (36.2) |
90 (56.9) |
0.4 |
[0.2 - 0.7] |
0.007 |
Caesarean section: indication |
|
Other |
19 (57.5) |
42 (72.4) |
0.5 |
[0.2 - 1.2] |
0.150 |
Double-scarred uterus |
1 (3.0) |
2 (3.4) |
0.8 |
[0.0 - 10.0] |
0.914 |
Failure of the test |
1 (3.0) |
1 (1.7) |
1.7 |
[0.1 - 29.4] |
0.686 |
Acute fetal distress |
9 (27.2) |
6 (10.3) |
3.2 |
[1.0 - 10.1] |
0.042 |
Obstructed presentation |
3 (9.0) |
7 (12.0) |
0.7 |
[0.1 - 3.0] |
0.663 |
In 51.7% the sex of the newborn was male in prolonged pregnancies compared to 49.3% in non-prolonged pregnancies, with no statistically significant difference (p = 0.758). Signs of post-maturity in newborns were found in 13.7% of prolonged pregnancies compared to 0.6% of non-prolonged pregnancies, with a significant difference (p = 0.002). At the first minute, the Apgar score in newborns was less than 7 in 34.4% of prolonged pregnancies compared to 13.2% for non-prolonged pregnancies, with a significant difference (p < 0.001). At the fifth minute the Apgar score in newborns was less than 7 in 12.0% of prolonged pregnancies compared to 3.1% for non-prolonged pregnancies, with a statistically significant difference (p = 0.018). Newborns were resuscitated in 10.3% of prolonged pregnancies compared to 5.0% in non-prolonged pregnancies, with no statistically significant difference (p = 0.170). Neonatal macrosomia was found in 18.9% of prolonged pregnancies compared to 10.1% for non-prolonged pregnancies, with no statistically significant difference (p = 0.086). Neonatal malformation was found in 1.7% of prolonged pregnancies (hydrocephalus type) compared to 0.64% (laparoschisis type) in non-prolonged pregnancies, with no statistically significant difference (p = 0.476). We recorded 0% neonatal deaths in prolonged pregnancies compared to 0.6% in non-prolonged pregnancies, with no statistically significant difference (Table 6).
Table 6. Fetal outcome.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Gender |
|
Female |
28 (48.2) |
80 (50.6) |
0.9 |
[0.4 - 1.6] |
0.758 |
Male |
30 (51.7) |
78 (49.3) |
1.0 |
[0.6 - 2.0] |
0.758 |
Signs of post-maturity |
|
Yes |
8 (13.7) |
1 (0.6) |
25.1 |
[3.0 - 205.7] |
0.002 |
No |
50 (86.2) |
157 (99.3) |
0.0 |
[0.0 - 0.3] |
0.002 |
Apgar score: 1st min |
|
<7 |
20 (34.4) |
21 (13.2) |
3.4 |
[1.6 - 6.9] |
<0.001 |
≥7 |
38 (65.5) |
137 (86.7) |
0.2 |
[0.1 - 0.5] |
<0.001 |
Apgar score: 5th min |
|
<7 |
7 (12.0) |
5 (3.1) |
4.2 |
[1.2 - 13.8] |
0.018 |
≥7 |
51 (87.9) |
153 (96.8) |
0.2 |
[0.0 - 0.7] |
0.018 |
Neonatal resuscitation |
|
Yes |
6 (10.34) |
8 (5.0) |
2.1 |
[0.7 - 6.5] |
0.170 |
No |
52 (89.65) |
150 (94.9) |
0.4 |
[0.1 - 1.3] |
0.170 |
Birth weight |
|
|
|
|
|
≥4000 g |
11 (18.9) |
16 (10.1) |
2.0 |
[0.9 - 4.7] |
0.086 |
2500 - 3999 g |
46 (79.3) |
139 (87.9) |
0.99 |
[0.1 - 9.7] |
0.990 |
<2500 g |
1 (91.7) |
3 (1.8) |
0.5 |
[0.2 - 1.1] |
0.111 |
Malformation |
|
Yes |
1 (1.7) |
1 (0.6) |
2.7 |
[0.1 - 44.7] |
0.476 |
No |
57 (98.2) |
157 (99.3) |
0.3 |
[0.0 - 5.9] |
0.476 |
Neonatal death |
|
Yes |
0 (0) |
1 (0.6) |
0.8 |
[0.0 - 22.3] |
0.947 |
No |
58 (100) |
157 (99.3) |
1.1 |
[0.0 - 27.7] |
0.947 |
Post-partum hemorrhage was found in 5.1% in prolonged pregnancies compared to 3.1% in non-prolonged pregnancies, with no statistically significant difference (p = 0.492). Perineal tears were found in 3.4% of prolonged pregnancies compared to 6.9% in non-prolonged pregnancies, with no statistically significant difference (p = 0.345). Cervical tearing was found in 3.4% of prolonged pregnancies compared to 0% in non-prolonged pregnancies; the difference is not statistically significant (p = 0.089). Uterine rupture was found in 1.7% of prolonged pregnancies compared to 0% in non-prolonged pregnancies, with no statistically significant difference (p = 0.197). Placental calcification was present in 6.8% of prolonged pregnancies compared to 0% in non-prolonged pregnancies, with a statistically significant difference (p = 0.029) (Table 7).
Table 7. Post-partum complications.
|
Prolonged pregnancies (N = 58) n (%) |
Un-prolonged pregnancies (N = 158) n (%) |
OR |
CI (95%) |
p |
Post-partum hemorrhage |
|
Yes |
3 (5.1) |
5 (3.1) |
1.6 |
[0.3 - 7.2] |
0.492 |
No |
55 (94.8) |
153 (96.8) |
0.5 |
[0.1 - 2.5] |
0.492 |
Perineal tear |
|
Yes |
2 (3.4) |
11 (6.9) |
0.4 |
[0.1 - 2.2] |
0.345 |
No |
56 (96.5) |
147 (93.0) |
2.0 |
[0.4 - 9.7] |
0.345 |
Cervical tear |
|
Yes |
2 (3.4) |
0 (0.0) |
14.0 |
[0.6 - 296.0] |
0.089 |
No |
56 (96.5) |
158 (100.0) |
0.07 |
[0.0 - 1.5] |
0.089 |
Uterine rupture |
|
Yes |
1 (1.7) |
0 (0.0) |
8.2 |
[0.3 - 205.9] |
0.197 |
No |
57 (98.2) |
158 (100.0) |
0.1 |
[0.0 - 3.0] |
0.197 |
Placental calcification |
|
Yes |
4 (6.8) |
0 (0.0) |
26.1 |
[1.3 - 494] |
0.029 |
No |
54 (93.1) |
158 (100.0) |
0.0 |
[0.0 - 0.7] |
0.029 |
4. Discussion
During the study period, we recorded 666 deliveries, including 58 cases of prolonged pregnancy, i.e. a frequency of 8.7%. Our result is variable compared to that of other authors, notably below the 15% to 20% of the National College of French Gynecologists and Obstetricians [2] and higher than the 3.62% of Tangara [6]. Compared to the French middle school rate, our reduced frequency is explained by the preponderance of factors linked to prematurity in our context, in particular, the difficult socio-economic conditions with arduous housework and poorer observation of rest. In the literature, the role of maternal age in the occurrence of prolonged pregnancy is controversial. According to Beisher et al. [9], there is an inversely proportional relationship between maternal age and the incidence of prolonged pregnancies. Vorheer [10] on the other hand notes the inverse correlation. For other authors, maternal age does not affect the incidence of prolonged pregnancies, likewise our study, where the majority age group was [25 - 30] years old, with 77.5% among prolonged pregnancies and 79.1% among non-prolonged pregnancies, and the difference was not statistically significant (p = 0.808).
Previous studies have reported the predominance of the 25- to 35-year-old age group [6] [11] [12]. The latter corresponds to the majority section of human procreation; our findings are no exception. Data from the literature incriminate maternal weight and more precisely a body mass index that is too high in the first trimester, as well as a significant variation in the body mass index between the first and last trimester as exposure to gestational prolongation, i.e. a delay in childbirth [13] [14]. In our study, 56.8% of pregnant women had a normal body mass index in women with a prolonged pregnancy compared to 56.3% for women with a non-prolonged pregnancy; the difference was however not statistically significant (p = 0.940).
For Vorheer [10], a woman who has had a prolonged pregnancy has a 50% risk of subsequently having a second prolonged pregnancy. Parturients with a history of prolonged pregnancy had 3 times the risk of having a prolonged pregnancy in our study (OR = 3.5 [95% CI: 1.0 - 12.0], p = 0.044). Our findings agree with those reported by Tangara and Mogren et al. [6] [15], revealing a 3 times higher risk of occurrence of prolonged pregnancy in parturients with a history of prolonged pregnancy. A significant association between the occurrence of prolonged pregnancy and the presence of similar cases in the mother was found (OR = 4.4 [95% CI: 1.6 - 12.4], p = 0.003). Our results agree with those of Papiermik et al. [16] who found that a woman whose mother had already given birth post-term sees her risk of giving birth after term increased for her pregnancies. These results suggest that there are genetic factors influencing the duration of gestation in women.
However, this hypothesis has not yet been the subject of in-depth scientific studies. The influence of parity has given rise to a number of studies, some of which admit a role in the variability of the duration of gestation. Indeed, several authors have reported that multiparous women give birth on average earlier than primiparous women. For example, Mittendorf et al. [17] estimate that primiparous women reach the term of pregnancy at 288 days from the last period and multiparous women at 283 days. According to Smith [18], who also studied the duration of pregnancy in these two populations using early ultrasound (<13 weeks) and the date of the last period in 1514 pregnant women, the average duration of pregnancy was 284 days and 282 days, respectively. In the first study, primiparous women give birth on average 5 days after multiparous women, according to the second author, the difference between these two populations is 2 days. Similarly, Mohamed [12] found an association between primiparity and prolonged pregnancy. Furthermore, Caughey et al. [19] and Tangara [6] identify nulliparity as a risk factor for prolonged pregnancy. This factor seems controversial, and several studies show no correlation between parity and duration of pregnancy [20]. Beisher et al. [9] in a prospective study of 2972 pregnant women followed since the first trimester did not demonstrate any significant difference: 9.3% of primiparous women gave birth at 42 weeks compared to 8.9% of multiparous women. In our series, the predominant category was represented by nulliparous women, i.e. 44.8% in prolonged pregnancies compared to 36.0% for non-prolonged pregnancies and the difference was not statistically significant (p = 0.242). This is consistent with the studies of Beisher et al. [9]. Studies on the influence of fetal sex on the duration of pregnancy are contradictory. Vorheer [10] observed a predominance of the male sex.
For Divon et al. [21], the average duration of pregnancy was higher in boys (280.6 ± 8.9 days) compared to that of girls (279.8 ± 8.6 days); in his study, the percentage of post-term births in boys (26.5% after 41 weeks and 7.6% after 42 weeks) was significantly higher than in girls (22.5% after 41 weeks and 6.6% after 42 weeks). Smith [18] found an identical duration (283 days) for each sex in a collection of 1514 pregnancies. In our series, 51.7% of cases of newborns were male in prolonged pregnancies compared to 49.3% in non-prolonged pregnancies; the difference was not statistically significant (p = 0.758). This is consistent with the results of the study by Smith [18]. Women with prolonged pregnancy were 3 times more likely to have meconium amniotic fluid (OR = 2.8 [95% CI: 1.1 - 6.8], p = 0.020) in our study. Our findings are in the same direction as those reported by Caughey et al. [22] for whom, from 37 weeks the rate of meconium emission in utero gradually increases (7% between 38 and 39 weeks, 14% between 40 and 41 weeks, and 20% between 42 and 43 weeks), and the frequency of meconium amniotic fluid at delivery is twice as high at 41 weeks compared to 39 weeks; and 2% to 35% of newborns develop meconium aspiration responsible for respiratory distress at birth. Sénat [23] also finds a high level of meconium amniotic fluid in cases of prolonged pregnancy. Using the Apgar score at the 5th minute, the best correlated with neonatal prognosis, neonatal asphyxia was found significantly in 12% of newborns from prolonged pregnancies (OR = 4.2 [95% CI: 1.2 - 13.8], p = 0.018). This result is significantly higher than those of Tangara [6], Faisal [24] and Roach et al. [25], who found 3.9%, 4.1% and 4.4%, respectively.
Sherer et al. [26] note that there is an increased prevalence of alteration of the baseline heart rate during labor after 42 weeks (tachycardia, flat tracing) associated with variable slowing. The high morbidity is explained by the fact that post-term women in our study did not benefit from monitoring from the 41st week of pregnancy. Indeed, monitoring to assess the fetal heart rate, active fetal movements, the Bishop score, the quantity of amniotic fluid and the use of the non-stress and stress test makes it possible to improve the fetal outcome [27]. Signs of post-maturity were 25 times more likely to be found in newborns from prolonged pregnancies, with a frequency of 13.5% (OR = 25.1 [95% CI: 3.0 - 205.7], p = 0.002). This result is higher than those of Tangara [6] and Faisal [24], who found 8.5% and 5.4% respectively, but lower than Vorher [10], who reported a frequency of 20% - 43%. Our results confirm the literature data in the sense that signs of post-maturity are strongly associated with prolonged pregnancy.
For Divon et al. [21], there is a significant increase in the risk of fetal mortality from 41 weeks. The relative risk increases from 1.5 at 41 weeks to 2.9 at 43 weeks. It demonstrates that the risk of neonatal mortality does not increase significantly with gestational age. We did not record any neonatal deaths among those born after prolonged pregnancies in our study. Several authors have long highlighted a link between the indication for cesarean section and prolonged pregnancy, with reported rates ranging from 12% to 25% [23]. Cheng et al. [28] also described in an American cohort 19.8% of cesarean sections at 41 weeks compared to 12.3% at 39 weeks (RR = 1.46 [1.44 - 1.48]). In total, the cesarean section rate increases approximately 1.5 times in cases of prolonged pregnancy [28]. However, the lack of precision in the studies cited does not always allow us to differentiate between the increase in the rate of cesarean sections linked to prolonged pregnancy and the increase in the rate of cesarean sections due to interventionist policies from a given gestational age. Caesarean section was performed in 56.8% of prolonged pregnancies compared to 36.7% of non-prolonged pregnancies with a statistically significant difference (OR = 2.2 [95% CI: 1.2 - 4.1], p = 0.008). Late referral from peripheral health centers and inadequate monitoring would, in our opinion, be responsible for this morbidity. On the other hand, acute fetal distress was the indication for cesarean section in 27.2% of prolonged pregnancies compared to 10.3% of non-prolonged pregnancies, with a statistically significant difference (OR = 3.2 [95% CI: 1.0 - 10.1], p = 0.042). These results correlate with those of Sanchez-Ramos et al. [29], who found that more cesarean sections were indicated for acute fetal distress from the 41st week.
The duration of labor was greater than 12 hours with a statistically significant difference in 12.5% of prolonged pregnancies compared to 3.7% in non-prolonged pregnancies (OR = 3.6 [95% CI: 1.0 - 12.5], p = 0.039); these results correlate with those of Caughey et al. [22] who found a higher risk of long labor in cases of prolonged pregnancy. In our series, we recorded 5.1% of post-partum hemorrhage in prolonged pregnancies compared to 3.1% in non-prolonged pregnancies.
According to the study by Caughey et al. [22], carried out in 12 centers on 120,000 pregnancies in the USA, the risk of post-partum hemorrhage is 2.5% - 5.0% and 3.6% - 5% in the Danish registry [10].
Our results confirm the data in the literature which identifies long labor as a factor in hemorrhage during delivery, to which pregnant women whose pregnancy continues are particularly exposed. In our series, we had 1 case of uterine rupture in prolonged pregnancies, i.e. a rate of 1.7% compared to 0% in non-prolonged pregnancies. This was a parturient who gave birth to a newborn weighing more than 4 kg. In prolonged pregnancies, fetal growth is most often preserved; this results in an increase in average birth weight: from 10% of macrosome newborns between 38 and 40 weeks, this number rises to 20% between 40 and 42 weeks, then to more than 40% between 43 and 44 weeks [20]. Macrosomia itself, being a risk of uterine overdistension, can therefore increase the risk of uterine rupture. Following the work of monitoring a cohort in Sweden by Kaczmarczyk et al. for 18 years [30], there was a risk of uterine rupture during the birth of a fetus weighing more than 4 kg. Indeed, the rate of uterine rupture of 0.76/1000 when the fetus weighed between 2500 and 3000 g increased by 1.39/1000 when the latter had a weight greater than 4 kg (OR = 1.76 [95% CI: 1.32 - 2.35]).
Elkousy et al. [31] found the same data in their 5-year multicenter study. The birth of a fetus weighing more than 4 kg increased the risk of uterine rupture by 2 (p < 0.001 and RR = 2.3). Macrosomia is factual and therefore appears to be a risk factor for uterine rupture in cases of prolonged pregnancy.
To our knowledge, there are no specific studies on the association between prolonged pregnancy and maternal death. Given the rarity of this event, published studies lack power to study this aspect. Furthermore, successive French reports from the National Committee of Experts in Maternal Mortality (CNEMM) as well as the English report do not identify full-term pregnancy as a factor associated with maternal death [32]. In our series, we did not note any cases of maternal mortality.
5. Limitations of the Study
Our inclusion criteria in the study were quite broad; we included a certain number of pregnant women and those who had given birth; this could be the cause of selection bias. Our population is perhaps not sufficient to highlight infrequent or even rare events. On the other hand, we only have a short-term view of the complications. We will not know if these women will be consulted for possible complications in the longer term.
6. Conclusions
At the end of our study on the clinical profile of prolonged pregnancies and neonatal well-being at the Laquintinie hospital in Douala, it emerged that:
The frequency of prolonged pregnancy is 8.7% in our study.
We did not identify socio-demographic variables associated with prolonged pregnancy.
Family and personal history of prolonged pregnancy are clinical variables associated with prolonged pregnancy.
Increased fundal height is a clinical parameter significantly associated with prolonged pregnancy.
Maternal and neonatal complications associated with prolonged pregnancy are cesarean section, increased duration of labor, signs of post-maturity, placental calcifications, chronic fetal distress and acute fetal distress.
Contribution of This Study to Science
Our study highlights the associative nature of family and personal history in the occurrence of prolonged pregnancies in our context.
This clarification should lead us to greater vigilance during prenatal follow-ups.
Acknowledgements
The authors thank the management and staff of the Obstetrics and Gynecology Department of Laquintinie Hospital for all the facilities granted to them for the materialization of this research.
Authors’ Contributions
Essome supervised the study and wrote the manuscript; Ngounoue collected the data; Tocki and Tocky provided the English translation as well as the formatting of the manuscript; Bilkissou, Boten, Nkwele, Motah, Tchounzou, Nalame, Yaneu, Kondo, Mfomo, Ebo, Ilick, Ngouhouo, Mwandje, Ekono, and Njamen read and corrected the manuscript; Wafo and Foumane supervised the study. All authors have read and approved the final manuscript.