Academic Editor: Paolo Ivo Cavoretto
Background: This study conducted at the Clinic for Children’s Diseases
of the University Clinical Hospital Mostar, aims to highlight the
characteristics, frequency, course, most common complications and treatment
outcomes of pregnant women and their late preterm infants according to
gestational age. Methods: This study is a retrospective epidemiologic
study for the period from 1/1/2018 to 31/12/2021. The study included all the
preterm infants who were born at a gestational age from 34
Late preterm infants are premature infants who frequently resemble full-term newborn in size and birth weight, but who tend to be susceptible to various medical complications due to their metabolic and physiological immaturity. Late preterm infants constitute 75% of preterm babies and 20–25% of admissions to intensive care units [1]. The reason for the increased proportion of late preterm infants lies in the fact that, in certain situations, a preterm delivery is the optimal outcome for a pregnancy. It is important to realize that some preterm births benefit the mother, baby or both [2]. This makes them a high-risk group of infants who require special care during their hospital stay, and who also frequently require pediatric monitoring upon discharge from hospital [3]. Conducted studies suggest that late preterm infants with a lower birth weight are more susceptible to early sepsis, whereas neonates whose mothers had previously been treated with antibiotics are less susceptible to it [4]. The brain of a late preterm newborn is still undeveloped and is therefore susceptible to detrimental stimuli that can arise from complications after birth, such as respiratory distress syndrome, hypoglycemia, hyperbilirubinemia, or apnea [5], and from poor or insufficient feeding and breastfeeding difficulties after birth [6]. Although many studies indicate that late preterm infants have more developmental issues, they are, nevertheless, a group that is not subject to routine check-ups following discharge unless they had been treated in intensive care units (ICU) [1]. These newborn infants are sorted into different gestational categories and identified by different descriptive terms. Unfortunately, these terms do not satisfactorily encompass the important specificity of these infants, that is, they are still preterm infants and belong to a vulnerable category [7]. Pediatricians should explain to parents that delivery before the gestational age of 39 weeks is accompanied by health and neuro-developmental risks which may extend into childhood and later into adulthood [8]. Failure to recognize specific characteristics, a superficial assessment of their development, early discharge and inadequate monitoring could have far-reaching consequences for the infants and their families [9]. Therefore, detailed pediatric guidelines and recommendations about the care of such infants should be issued. All early interventions and recommendations will reduce subsequent readmittance to hospital and help to improve early and late outcomes and reduce respiratory disorders in early childhood [10]. These studies have reawakened scientific interest in this category of preterm infants, and point to the significance of this, the largest, group of preterm infants for public health.
The aim of this study at the Clinic for Children’s Diseases is to highlight the characteristics, frequency, course, most common complications and treatment outcomes of the pregnant women and their late preterm infants according to gestational age.
This study is a retrospective epidemiologic study conducted over a four-year
period. The study was conducted at the Neonatal and Preterm Intensive Care Unit
(ICU) and the Department of Neonatology of the Clinic for Children’s Diseases,
University Clinical Hospital Mostar (UCH). The study encompassed all the preterm
infants who were born at a gestational age from 34
The statistical analysis was conducted by IBM SPSS Statistics for Windows,
(version 25, IBM Corp, Armonk, NY, USA). The results are expressed as absolute
and relative frequencies. The
In the four-year period, a total of 7178 infants were born at the UCH Mostar, of which 253 (3.52%) were late preterm infants. 2044 newborn infants were treated in the Department of Neonatology. Of these, 12.38% were late preterm infants. Twenty-five sets of twins were among the late preterm infants (Table 1).
Number (%) of mothers | |||||||
Total (n = 228) | p |
Gestational age | p | ||||
34 |
35 |
36 | |||||
Age years | 0.977 | ||||||
6 (2.6) | 1 (1.9) | 3 (3.9) | 2 (2) | ||||
20–30 | 91 (39.9) | 20 (38.5) | 29 (38.2) | 42 (42) | |||
30–40 | 120 (52.6) | 28 (53.8) | 40 (52.6) | 52 (52) | |||
40–50 | 11 (4.8) | 3 (5.8) | 4 (5.3) | 4 (4) | |||
Pregnancy | 0.458 | ||||||
1 | 105 (46.1) | 29 (55.8) | 37 (48.7) | 39 (39) | |||
2 | 54 (23.7) | 9 (17.3) | 20 (26.3) | 25 (25) | |||
3 | 47 (20.6) | 10 (19.2) | 12 (15.8) | 25 (25) | |||
4+ | 22 (9.6) | 4 (7.7) | 7 (9.2) | 11 (11) | |||
Mode of delivery | 0.895 | 0.100 | |||||
Vaginal | 113 (49.6) | 19 (36.5) | 40 (52.6) | 54 (54) | |||
Cesarean | 115 (50.4) | 33 (63.5) | 36 (47.4) | 46 (46) | |||
Pregnancy type | 0.368 | ||||||
Single | 203 (89.0) | 44 (84.6) | 67 (88.2) | 92 (92) | |||
Multiple pregnancy | 25 (11.0) | 8 (15.4) | 9 (11.8) | 8 (8) | |||
Pathological conditions |
0.096 | ||||||
No | 107 (46.9) | 18 (34.6) | 38 (50) | 51 (51) | |||
Hypertension | 33 (14.5) | 7 (13.5) | 8 (10.5) | 18 (18) | |||
Diabetes | 15 (6.6) | 6 (11.5) | 4 (5.3) | 5 (5) | |||
Infections | 21 (9.2) | 6 (11.5) | 4 (5.3) | 11 (11) | |||
Other | 52 (22.8) | 15 (28.8) | 22 (28.9) | 15 (15) | |||
Medication |
0.085 | 0.062 | |||||
No | 127 (55.7) | 22 (42.3) | 48 (63.2) | 57 (57) | |||
Yes | 101 (44.3) | 30 (57.7) | 28 (36.8) | 43 (43) | |||
*Manifestedin pregnancy. |
The results show that most of the mothers were between 30 and 39 years of age, pregnant for the first time with a single pregnancy, with complications. Of the total 228 pregnant women, 121 (53.1%) had pathological conditions during pregnancy, and 115 (50.3%) of the pregnant women delivered via Caesarean section. The results show that the most common complication was hypertension, whilst other complications were anaemia, cholestasis, and epilepsy. The characteristics of the mothers show no statistically significant difference according to gestational age of the late preterm infants. Despite this, the results indicate that pathological pregnancies ended earlier. All the analyzed pathological conditions were more common in the pregnancies which ended in gestational week 34, compared to the analyzed pregnancies that were longer. Of the total 228 pregnant women, 80 (35%) received antenatal corticosteroid therapy, most frequently in gestational week 34 (Table 2).
Number (%) newborn | ||||||||
total (n = 253) | p |
Gestational age | p | |||||
34 |
35 |
36 | ||||||
Gender | 0.001 | 0.717 | ||||||
Male | 153 (60.5) | 35 (58.3) | 55 (64) | 63 (58.9) | ||||
Female | 100 (39.5) | 25 (41.7) | 31 (36) | 44 (41.1) | ||||
Birth weight (g) | ||||||||
1000–1499 | 4 (1.6) | 2 (3.3) | 0 | 2 (1.9) | ||||
1500–1999 | 29 (11.5) | 9 (15) | 11 (12.8) | 9 (8.4) | ||||
2000–2499 | 84 (33.2 ) | 27 (45) | 34 (39.5) | 23 (21.5) | ||||
2500–2999 | 111 (43.9) | 22 (36.7) | 32 (37.2) | 57 (53.3) | ||||
3000–4500 | 25 (9.9) | 0 | 9 (10.5) | 16 (15) | ||||
APGAR | 0.724 | |||||||
8–10 | 236 (93.3) | 58 (96.7) | 81 (94.2) | 97 (90.7) | ||||
4–7 | 14 (5.5) | 2 (3.3) | 4 (4.7) | 8 (7.5) | ||||
0–3 | 3 (1.2) | 0 (0) | 1 (1.2) | 2 (1.9) | ||||
Patological condition | 0.045 | |||||||
No | 49 (19,4) | 5 (8,3) | 19 (21,1) | 25 (23,4) | ||||
Yes | 204 (80,6) | 55 (91,7) | 67 (77,9) | 82 (76,6) | ||||
Perinatal infection | 30 (11,9) | 11 (18,3) | 11 (12,8) | 8 (7,5) | ||||
Respiratory disorders | 43 (17,0) | 9 (15,0) | 11 (12,8) | 23 (21,5) | ||||
Brain hemorrhage | 39 (15,4) | 10 (16,7) | 16 (18,6) | 13 (12,1) | ||||
Jaundice | 114 (45,1) | 35 (16,4) | 36 (41,9) | 43 (10,2) | ||||
Therapy | 0.058 | |||||||
No | 52 (20.9) | 6 (10.0) | 21 (24.4) | 26 (24.3) | ||||
Yes | 200 (79.1) | 54 (90.0) | 65 (75.6) | 81 (75.7) | ||||
Antibiotics | 153 (60.5) | 47 (78.3) | 49 (57.0) | 57 (53.3) | ||||
Supportive therapy | 72 (28.5) | 14 (23.3) | 22 (25.6) | 36 (33.6) | ||||
Cardiotonic | 26 (10.3) | 7 (11.7) | 6 (7.0) | 13 (12.1) | ||||
Phototherapy | 114 (45.1) | 35 (16.4) | 36 (41.9) | 43 (10.2) | ||||
Mechanical ventilation | 0.249 | |||||||
Yes | 43 (17.0) | 9 (15.0) | 11 (12.8) | 23 (21.5) | ||||
No | 210 (83.0) | 51 (85.0) | 75 (87.2) | 84 (78.5) | ||||
Duration of treatment in intensive care (days) | 0.010 | |||||||
No | 92 (36.4) | 12 (20.0) | 37 (43.0) | 43 (40.2) | ||||
Yes | 161 (63.6) | 48 (80.0) | 49 (57.0) | 64 (59.8) | ||||
76 (30.0) | 13 (21.7) | 23 (26.7) | 40 (37.4) | |||||
8–14 | 46 (18.2) | 20 (33.3) | 12 (14.0) | 14 (13.1) | ||||
39 (15.4) | 15 (25.0) | 14 (16.3) | 10 (9.3) | |||||
Start tolerating meals (hours) | 0.946 | |||||||
0–24 h | 213 (84.2) | 47 (81) | 72 (85.7) | 86 (83.5) | ||||
25–72 h | 32 (12.6) | 9 (15.5) | 10 (11.9) | 13 (12.6) | ||||
8 (3.2) | 2 (3.4) | 2 (2.4) | 4 (3.9) | |||||
Outcome of treatment | 0.594 | |||||||
Positive outcome | 245 (96.8) | 59 (98.3) | 84 (97.7) | 102 (95.3) | ||||
Fatal outcome | 8 (3.2) | 1 (1.7) | 2 (2.3) | 5 (4.7) | ||||
The results indicate that significantly more male late preterm infants
(p
Significantly more late preterm infants were treated in the ICU (p
Although the proportion of late preterm infants in the general premature baby
population is above 70% worldwide [11, 12, 13], as is the case in our country, the
care and monitoring of these infants has not been taken seriously enough because
of the prevailing attitude that they were born “a bit” before full-term.
However, the most recent studies in the field of neonatology have provided more
evidence indicating that late preterm infants are at a greater risk of developing
various pathological conditions [14, 15]. Our results indicate that pathological
pregnancies ended in gestational week 34, whereas the health of the infants born
at 36 weeks was unexpectedly poorer. These findings may be the result of a
superficial understanding of such pregnancies, a lack of critical supervision of
them and a lack of foresight for potential poor outcomes. The incidence of
premature births is on the rise across the globe, mostly due to an ever-higher
frequency of induced preterm deliveries [16], most frequently at the gestational
age of late preterm [17], which coincides with our results where half the
pregnancies were pathological, and 50% of the late preterm infants were
delivered by Caesarean section. It is, therefore, necessary to make informed
decisions and to educate parents on the eventual risks involved in continuing a
pregnancy or delivering preterm [2]. The experiences of neonatologists to date
suggest that parents’ lack of awareness leads to unreal expectations of the
outcome of late preterm infants. Since 2006, late preterm birth rates have
decreased in Norway and the United States, whereas clinician-initiated obstetric
interventions have increased among late preterm births in Canada, Denmark, and
Finland [18]. In specific situations, such as hypertension in pregnancy [19] and
gestational diabetes [20], a preterm birth is the optimal outcome to pregnancy
[2]. Our results indicate that the late preterm infants were more susceptible to
developing pathological parameters because of the mother’s risk factors, as 53%
of the pregnant women in our study had pathological pregnancies. However, despite
the large percentage of older pregnant women, and those with pathological
pregnancies, along with those who underwent medical treatment during pregnancy,
our results show that the late preterm infants had a good birth weight (53.8%)
and high vitality scores (93%) at birth, but these scores were not confirmed on
the first day of life. Nearly 17% of our late preterm babies were admitted to
the ICU in the first hours after birth due to a deterioration of respiratory
functions, a larger percentage of them were born at 36 weeks irrespective of mode
of birth. This contradicts the conclusions of other studies [16, 21]. This is
partially a consequence of the non-implementation of antenatal protection during
pregnancy, which has proven to be significant in the reduction of the incidence
of respiratory disorders in late preterm infants [21]. This concurs with the
conclusions that infants born before 39 weeks are at a higher risk of developing
pathological conditions [22, 23]. This is similar to our findings where only 19%
of the late preterm infants had no pathological conditions and required no
therapy. Studies indicate that 47% of newborn born at the gestational age of 34
weeks and 11% of those born at 36 weeks were admitted to ICUs [24, 25], whereas
our study shows that only 40% of the third group did not require intensive care.
Hyperbilirubinemia was the most frequent pathological condition in our study,
which is similar to the findings of other studies [1] and was most probably the
result of milk intolerance. While this is the most common reason for readmittance
to hospital [26], suspected milk aspiration was the most frequent reason for
readmittance to hospital in our study. Furthermore, a factor for concern is the
finding that 15% of the late preterm infants had brain hemorrhaging of different
degrees, diagnosed across all gestational ages. A possible explanation for this
lies in the infants’ undeveloped brain, and its vulnerability to harmful factors
which affect critical phases of development, and which can result in different
neurological outcomes later in life [27]. The third group sample was most
frequently treated with a combination of medications (antibiotics and other
supportive therapy). A possible explanation of such a result could be that the
course of the pregnancy may not have been considered risky, nor was a
deterioration of the clinical state of the infants born at 36 weeks expected.
Possible reasons for such poor outcomes can be identified in the better care and
monitoring of risky pregnancies before 34 weeks in comparison to the pregnancies
at 36 weeks of gestation where a good outcome is expected. This may likely be the
result of a superficial understanding of such pregnancies, a lack of critical
supervision of them and the lack of foresight for potential poor outcomes.
However, our findings suggest that late preterm infants are a group at risk,
irrespective of their gestational age, because they behave like premature infants
born before 34 weeks. The conclusion of the 2022 study is that the risk of
iatrogenic preterm birth
The study concludes that half of the pregnant women had risk factors which were the bases for preterm delivery and the development of complications in their late preterm infants. Furthermore, despite good birth weight and vitality scores at birth, only one fifth of the late preterm infants were not administered medication or developed pathological conditions, and only one third required no intensive care treatment. Therefore, it is necessary to monitor and understand these pregnancies better, to administer antenatal corticosteroid protection, to educate parents and to provide long-term and more frequent pediatric monitoring of late preterm infants.
MJR, KŠ, ŽP, VM, TB and SG designed and wrote the research study. All authors read and approved the final manuscript.
This retrospective study was conducted according to all the ethical principles of the University Clinical Hospital Mostar. Ethical Approval was obtained from the Ethics Committee of the Clinical Hospital Center Mostar (reference number 1071/22, dated 07/03/2022).
We would like to express our gratitude to all those who helped us during the writing of this manuscript. Thanks to all the peer reviewers for their opinions and suggestions.
This research received no external funding.
The authors declare no conflict of interest.
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