Infantile hypertrophic pyloric stenosis (IHPS) remains, in some ways, an enigmatic condition. In fact, as a medical community, we seem to simultaneously know both so much and yet so little about this disease. On 1 hand, we know how to diagnose this condition: through a careful history, physical examination, and abdominal ultrasound. We can also effectively manage this condition through intravenous fluid resuscitation and pyloromyotomy.1,2  In addition to being efficient,2  our treatment strategy is also extremely safe, with few reported complications.2,3  Yet, on the other hand, there are some mysteries regarding IHPS that we cannot put to rest. Namely, we still cannot predict which infants will develop this condition, and the effort to pinpoint a definitive cause remains equally elusive. In addition, although authors of multiple studies,47  including at least 2 randomized controlled trial,8,9  have attempted to determine the best method for feeding these infants postoperatively, this too remains a point of debate in many institutions.

For decades, the trajectory of the incidence of IHPS has remained 1 of these unsettled questions. Whereas multiple reports from several Western nations have documented a declining incidence, other reports have painted a more mixed picture.10  Recently, Kapoor et al11  determined the incidence of IHPS to be decreasing in a study in which the authors evaluated >29 000 cases among a group of 14.7 million live births. However, the findings of this study were based on data from only 11 states and, in addition, have not been confirmed by other recent reports.12 

The authors of the article “Pyloric Stenosis: National Trends in the Incidence Rate and Resource Use in the United States from 2012 to 2016”13  in this issue of Hospital Pediatrics are to be commended for their efforts to definitively answer this lingering question. In their study, they use the National Inpatient Sample (NIS) to analyze >32 000 cases distributed among 20.8 million live births, making it the largest population-based analysis of IHPS in the United States in recent medical literature. In addition, the NIS contained data from a minimum of 44 states throughout the entirety of the period analyzed, making the current study nationally representative and highly relevant to our entire community. This study documents the decrease in incidence of IHPS from 1.76 to 1.57 cases per 1000 live births in the United States from 2012 to 2016. The authors use these data to suggest that the incidence of IHPS is definitively declining across the country at the present time. Although they may in fact be correct, one must exercise caution when making this conclusion. The most profound difference in IHPS incidence occurred during the first 2 years of the study period, during which the incidence declined from 1.76 cases per 1000 live births in 2012 to 1.57 cases per 1000 live births in 2013. However, according to the current study, the incidence has essentially remained unchanged from 2013 to 2016. Herein lies the difficulty in attempting to make such definitive population-based conclusions with only 5 years of applicable data. In fact, among the other studies that have revealed a declining incidence of IHPS, none of the researchers used a study period shorter than 9 years.11,1417  Although the authors may be correct in their assertion that the IHPS incidence is decreasing, only time can conclusively prove their argument. For instance, repeating the same study over a longer period of time would allow for comparison of 5-year intervals. Undoubtedly, comparing the median incidence of IHPS in 2012 to 2016 versus 2017 to 2021 would provide a better statistical evaluation of whether this disease is becoming more or less prevalent over time. Although that analysis cannot be performed for years, the authors could have, in fact, also chosen to compare the median incidence in 2012 to 2016 versus 2007 to 2011. Although the NIS did undergo significant design changes in 2012, these data could still potentially yield results that would have, in fact, bolstered the authors’ arguments.

Drs Coakley and Reppucci conceptualized the manuscript, drafted the initial manuscript, and approved the final manuscript as submitted.

FUNDING: No external funding.

1
Kamata
M
,
Cartabuke
RS
,
Tobias
JD
.
Perioperative care of infants with pyloric stenosis
.
Paediatr Anaesth
.
2015
;
25
(
12
):
1193
1206
2
Sathya
C
,
Wayne
C
,
Gotsch
A
,
Vincent
J
,
Sullivan
KJ
,
Nasr
A
.
Laparoscopic versus open pyloromyotomy in infants: a systematic review and meta-analysis
.
Pediatr Surg Int
.
2017
;
33
(
3
):
325
333
3
Kelay
A
,
Hall
NJ
.
Perioperative complications of surgery for hypertrophic pyloric stenosis
.
Eur J Pediatr Surg
.
2018
;
28
(
2
):
171
175
4
Sullivan
KJ
,
Chan
E
,
Vincent
J
,
Iqbal
M
,
Wayne
C
,
Nasr
A
;
Canadian Association of Paediatric Surgeons Evidence-Based Resource
.
Feeding post-pyloromyotomy: a meta-analysis
.
Pediatrics
.
2016
;
137
(
1
):
e20152550
5
Graham
KA
,
Laituri
CA
,
Markel
TA
,
Ladd
AP
.
A review of postoperative feeding regimens in infantile hypertrophic pyloric stenosis
.
J Pediatr Surg
.
2013
;
48
(
10
):
2175
2179
6
Juang
D
,
Adibe
OO
,
Laituri
CA
,
Ostlie
DJ
,
Holcomb
GW
 III
,
St Peter
SD
.
Distribution of feeding styles after pyloromyotomy among pediatric surgical training programs in North America
.
Eur J Pediatr Surg
.
2012
;
22
(
5
):
409
411
7
Adibe
OO
,
Nichol
PF
,
Lim
FY
,
Mattei
P
.
Ad libitum feeds after laparoscopic pyloromyotomy: a retrospective comparison with a standardized feeding regimen in 227 infants
.
J Laparoendosc Adv Surg Tech A
.
2007
;
17
(
2
):
235
237
8
Markel
TA
,
Scott
MR
,
Stokes
SM
,
Ladd
AP
.
A randomized trial to assess advancement of enteral feedings following surgery for hypertrophic pyloric stenosis
.
J Pediatr Surg
.
2017
;
52
(
4
):
534
539
9
Adibe
OO
,
Iqbal
CW
,
Sharp
SW
, et al
.
Protocol versus ad libitum feeds after laparoscopic pyloromyotomy: a prospective randomized trial
.
J Pediatr Surg
.
2014
;
49
(
1
):
129
132
;
discussion 132
10
Pedersen
RN
,
Garne
E
,
Loane
M
,
Korsholm
L
,
Husby
S
;
EUROCAT Working Group
.
Infantile hypertrophic pyloric stenosis: a comparative study of incidence and other epidemiological characteristics in seven European regions
.
J Matern Fetal Neonatal Med
.
2008
;
21
(
9
):
599
604
11
Kapoor
R
,
Kancherla
V
,
Cao
Y
, et al
.
Prevalence and descriptive epidemiology of infantile hypertrophic pyloric stenosis in the United States: a multistate, population-based retrospective study, 1999-2010
.
Birth Defects Res
.
2019
;
111
(
3
):
159
169
12
Stark
CM
,
Rogers
PL
,
Eberly
MD
,
Nylund
CM
.
Association of prematurity with the development of infantile hypertrophic pyloric stenosis
.
Pediatr Res
.
2015
;
78
(
2
):
218
222
13
Donda
K
,
Asare-Afriyie
B
,
Ayensu
M
, et al
.
Pyloric stenosis: national trends in the incidence rate and resource use in the United States from 2012 to 2016
.
Hosp Pediatr
.
2019
;
9
(
12
)
14
Yau
A
,
Cha
R
,
Jayaratnam
S
, et al
.
Declining incidence of pyloric stenosis in New Zealand [published online ahead of print August 26, 2019]
.
ANZ J Surg
. doi:10.1111/ans.15377
15
de Laffolie
J
,
Turial
S
,
Heckmann
M
,
Zimmer
KP
,
Schier
F
.
Decline in infantile hypertrophic pyloric stenosis in Germany in 2000-2008
.
Pediatrics
.
2012
;
129
(
4
).
16
Svenningsson
A
,
Svensson
T
,
Akre
O
,
Nordenskjöld
A
.
Maternal and pregnancy characteristics and risk of infantile hypertrophic pyloric stenosis
.
J Pediatr Surg
.
2014
;
49
(
8
):
1226
1231
17
Rosenthal
YS
,
Chodick
G
,
Grossman
Z
,
Shalev
V
,
Koren
G
.
The incidence of infantile hypertrophic pyloric stenosis and its association with folic acid supplementation during pregnancy: a nested case-control study
.
J Pediatr Surg
.
2019
;
54
(
4
):
701
706

Competing Interests

POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.

FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.