Congenital malformations are defined as structural or functional abnormalities of prenatal origin which are present at birth1. They are also called congenital disorders, birth defects, or congenital anomalies2.

The global estimate of congenital anomalies in neonates is 6% and few of them are severe enough to cause death3. The deaths are approximated to be 303,000 new borns per year. According to World Health Organization (WHO), congenital anomalies contribute to 17% — 42% of Infant Mortality4. As per the Global Burden of Disease Study 2013, it is among the top ten causes of deaths below five years of age5. In India, congenital malformations were found to be the fifth largest cause of neonatal deaths5.

The etiology can be pre-conceptional, mainly genetic, or can occur during or after conception, which is most likely due to environmental factors. Multifactorial inheritance is said to be the underlying culprit in many cases6.

The first four major causes of neonatal deaths in India are preterm births, intra partum complications, pneumonia and neonatal sepsis. With the advancement of technology and science, there seems to be a decrease in mortality due to the other causes, and hence an increasing concern about congenital anomalies5.

This transition propounds the need for sufficient data on the frequency and risk factors of congenital defects. The burden of birth defects has been described extensively in recent years worldwide4, 6, 7, 8, 9, 10, 11. However, there is a paucity of recent literature in India as most of the published reports are more than 5 years old5, 12, 13, 14.

About 60% of the malformations can be prevented through proper education of the mother and by following timely preventive measures9, 15, 16. Therefore, it is vital to understand the most common factors associated with congenital malformations.

Post-delivery, after thorough hand washing, the neonate was assessed, and the basic steps of essential newborn care was performed. The newborn was examined systemically from head to toe, and all the findings were noted. Similarly, any outside-born (extramural) baby admitted in RLJH was examined systemically, and findings were noted. If the newborn was found to be having a structural birth defect, informed consent of the parent was taken, and the neonate was included in the present study. A detailed history of the neonate was taken, including family history, antenatal history, birth history and risk factors, and entered in the study proforma. Findings of the antenatal scan were also noted. Relevant interventions were done on a per needful basis.

The study was conducted at R L Jalappa Hospital and Research Center (RLJH&RC). Out of 2400 deliveries in our hospital during the study period, 33 neonates had congenital anomalies (Intramural). There were 3 neonates (extramural and admitted in RLJH during the neonatal period) with congenital anomalies. A total of 36 neonates were included in the study.

The 36 neonates in our study included: 34 Live babies, 1 Still birth, 1 Abortus

In our study, there was a male predominance of 61.1%. According to the gestational age, 81% of the neonates were delivered at term gestation (37 weeks to 41 weeks 6 days), whereas, 11% of the neonates were delivered late preterm (34 weeks to 36 weeks 6 days), 5% of the neonates were extreme preterm (< 28 weeks) and 3% were delivered post term (>42 weeks). Among the mothers, 41.7% of the mothers were primiparous, 41.7% were P2 and 16.7% of the mothers were P3.

History of serious maternal illness was noted in 13.9% of the mothers, of which, diabetes was majorly associated (8.4%). One previous abortion was noted in 8.3% of mothers, while two previous abortions were noted for 5.6% of mothers. The remaining 86.1% of the mothers had no history of previous abortions. None of the mothers in the study group had a history of still birth.

In our study participants, 2.8% had a congenital anomaly in the siblings, while 5.6% of the study participants had a history of congenital malformation in the family, excluding siblings.

The majority of the anomalies in our study were single anomalies (75%), whereas 25% of the neonates had multiple anomalies.

Among our study participants, 66.6% had no associated risk factors. The remaining neonates (33.4%) had at least one associated risk factor. Among the associated risk factors, third degree consanguinity accounted for 11.1% of the neonates, while second degree consanguinity accounted for 8.3% of the neonates. Diabetes was seen in three of the mothers, while one mother had a bicornuate uterus. There was oligohydramnios in one pregnancy, and one of the mothers had hepatitis B infection. This association was statistically significant (p <0.001) — Table 1.

As per the system wise distribution, Musculoskeletal system accounted to majority of the anomalies (63.9%), followed by Cardiovascular system (11.1%), Central Nervous System (CNS) (8.3%), Genital (8.3%), Lymphatic (5.2%), Cutaneous (2.8%), Gastrointestinal (2.8%), Oral cavity (2.8%) and Syndromic (2.8%) — Table 2.

Congenital anomalies in neonates are considered as one of the major causes of neonatal deaths today. The underlying causes of these anomalies continue to remain obscure, and over 50% of them are of unknown etiology9. Investigating the risk factors can help us to comprehend the patterns and help in prevention.

In the present study, the frequency of congenital anomalies among intramural neonates during the study period of 18 months was 1.3%. A study conducted in Iran by Sedighi I et al. showed a prevalence of 0.85%11, while another study conducted in Morocco had a prevalence rate of 1.02%9. The difference in the prevalence in various studies could be attributed to population differences and risk factors.

In our study, there were a total of 36 cases, of which 34 (94.4%) were live born neonates, one was an abortus at 15 weeks of gestation (2.8%) and the other was a still birth at 23 weeks of gestation (2.8%).

The majority (81%) of the babies in our study were born at term. In a retrospective study done in Ethiopia, around 82% of the babies with congenital anomalies were born at term which is similar to our study4. Preterm babies with congenital anomalies were present in 8.3% of neonates in our study. In contrast, a retrospective study done in Morocco showed 17.4% of babies with anomalies remains preterm9. In a case control study from Ethiopia by Abebe S et al, among 251 cases with congenital anomalies, preterms constituted 47.6%8. The association between congenital anomalies and gestational age remain unknown.

The majority (86.1%) of the mothers in our study had no history of serious illness and the remaining mothers (13.9%) had an associated serious illness. The most common maternal illness noticed was gestational diabetes in the mother (8.4%). The results of the present study were in conformity to a study published in 2020, to detect birth defects in women with diabetes, where gestational diabetes was found in 5.3% of mothers17. In another case control study done in South-western Ethiopia, Diabetes was found in 1.6% of neonates with congenital malformations8. The findings of these studies were in close proximity to the ones in our study.

Among siblings of our study participants, 2.8% had anomalies. Research done to find out about the lethal congenital malformations in North India showed 25% of babies with congenital malformation in siblings18. The wide difference seen could be because our study involved all anomalies, both minor as well as major, and their study included only lethal malformations.

Among the family members of our study participants, excluding siblings, 5.6% had congenital anomalies and 94.4% had no congenital anomalies. Another study was conducted using case control model. In their study, among controls, 1.7% had a family history of congenital anomalies, as opposed to 3.8% in that of cases8. Even though our study had a slightly higher association of family history with congenital anomalies, the difference is not significant enough.

Among the study participants of our study, 38.9% had risk factors. The most common risk factor was seen in 11.1% of the babies, which is 3^rd degree consanguinity. Followed by that, the next common risk factor was 2^nd degree consanguinity seen in 8.3% of the babies. In a study done in North India to study the lethal malformations, 10.5% of the parents had consanguinity18. Our study was conducted in South India. The concept of consanguineous marriages is more in South India compared to North India, which could have attributed to higher percentage of consanguinity in our study19.

Our study involved the following systems in order.

Musculoskeletal system — 63.9%, Cardiovascular — 11.1%, CNS — 8.3%, Genital — 8.3%, Lymphatic — 5.2%, Cutaneous — 2.8%, Gastrointestinal — 2.8%, Oral cavity — 2.8%, Syndromic — 2.8%

There is a wide variation among different studies based on the system involved.

In few studies, Nervous system was most commonly involved4, 7, 8, 9, 18, 20, 21.

Few other studies had predominantly Musculoskeletal system involvement12, 14, 18, 22.

One study had a predominant Cardiovascular system involvement5.

Most of the studies had either the nervous system or musculoskeletal system as the most common abnormality. Our study also had musculoskeletal cases in the majority and among CNS, we had only sacral dimple as opposed to many other studies which had many other cases like anencephaly or holoprosencephaly or neural tube defects among CNS disorders7, 8.

There are few possible explanations for this. In our study, all the mothers had a history of folic acid intake. Hence, this greatly reduces the chances of neural tube defects. The exclusion criteria in our study are those neonates where consent could not be obtained. Most of the CNS anomalies are not compatible with life and there was a need for an autopsy on these infants. There was difficulty in obtaining consent for these babies, hence they had to be excluded from the study population. There could have been more prevalence of lethal anomalies, especially nervous system anomalies in reality.

The frequency of congenital malformations in our study was 1.3% of live born neonates, during the study period. The majority of them involved the musculoskeletal system, followed by the cardiovascular system and CNS involvement.

The major factors associated with congenital anomalies were 3rd degree consanguinity, followed by 2nd degree consanguinity.

Other risk factors found to be associated with congenital anomalies were diabetes in the mother, bicornuate uterus, oligohydramnios, Hepatitis B infection. The association between the risk factors and the presence of a congenital anomaly was found to be statistically significant.