A study of Maternal BMI as Determinant of Pregnancy & Perinatal Outcomes in Hazaribagh Medical College and Hospital,

Introduction: Maternal nutrition plays an important role in maternal and fetal outcomes. The low maternal BMI or Obesity are both associated with adverse outcomes. Objectives: To evaluate the impact of the maternal body mass index on the pregnancy outcome and neonatal outcomes. Materials and Methods: This is a prospective cohort study in which a total of 200 patients meeting the inclusion criteria were enrolled in the study after informed consent of which 100 patients enrolled after 18 weeks of gestation had a low BMI and 100 patients with a higher BMI than normal. Results: Pregnant females having low BMI as baseline had more risk of IUGR, fetal distress and low birth weight in newborns while those having high maternal BMI had more incidence of PIH in mothers, oligohydramnios, increased birth weight, increased risk of LSCS and NICU admissions and delayed maternal wound healing. Conclusion: The health of women, throughout their childbearing ages, should be cared, to improve their obstetrical and perinatal outcomes. Also, the high-risk groups should be managed properly.


Introduction
According to the WHO, obesity is one of the most common and most neglected public health problems in both developing and developed countries [1].
Globally 1 out of 6 adults is obese, Due to obesity nearly 2.8 million individuals die each year [2].
India, is having the second highest population overload in the world and malnutrition due to poverty which dominated in the previous years, is being rapidly transmitted by obesity associated with affluence [3].
The risk for obesity related obstetric complications appear to start from a BMI of about. 21 kg/m2. There is increase in obesity in Indian women from 10.6% to 14.8% during last decade in urban areas at the same time in rural area, 48.2% of prepregnant women are underweight [8,9]. Maternal malnutrition is the most important underlying determinant factor in adverse maternal and fetal outcome A malnourished mother gives birth to undernourished infant who struggle to thrive. The low maternal BMI is associated with increased risk of abortion and intrauterine growth restriction anemia, which may further cause low Apgar scores and increased early neonatal deaths [10,11].
As maternal nutrition and weight gain during pregnancy are modifiable factors, so the knowledge of association between maternal weight gain during pregnancy, obstetric complications and fetal outcomes becomes essential. The objectives of the study were to evaluate the impact of the maternal body mass index on the pregnancy outcome and neonatal outcomes.

Methodology
This is a prospective cohort study conducted in the  suggested that the pre pregnancy BMI was associated with the gestational weight gain and that the weight gain was " dose dependent" since it was an effect of the nutritional status of these patients.

Gain
The gestational weight gain was seen in different age groups in different BMI groups, and we observed that, almost 95% of the patients in the age group of less than 20 in the Low BMI had a weight gain less than recommended, which.
suggested that these patients were at a higher risk due to adolescent pregnancies, whereas on the other extreme, group C had 5 out of 8 patients who were >30 years of age, gained weight much more than the recommended guidelines. These factors suggested that not only was gestational weight gain associated with maternal BMI, but also, that the maternal age played an important role.

BMI & age correlation with Maternal Anemia
Maternal anaemia was assessed and it was found that it was present in all the groups, However, patients with low BMI had 84% of the total number of anemic patients in our study. Out of 100 patients with low BMI, 37 were anemic as compared to 7 out of 100 of high BMI. However, it was noteworthy that 3 out of 15 patients i.e., 20% of obese patients were anemic.
The presence of anemia was not only maximum in low BMI patients, but it was specifically highest in patients with a low BMI and a gestational weight gain which was lower than the recommended guidelines. In the obese BMI category, patients who had a gestational weight gain more than recommended were more prone to develop anemia.

Correlation of maternal BMI and GWG with birth weight
It was found that of the 78 cases of low birth weight in newborns of the study groups patients, 61.54% i.e., 48 cases were in the A1 group implying that low BMI was directly proportional to low birth weight in neonates. However, higher birth weight in newborns was noted in the obese group C with 4 out of 15 cases.

APGAR Score of babies of maternal group @ 10 min (APGAR score less than 8 after 10 mins)
The incidence of newborns with APGAR <8 after 10 minutes was highest in Group A with low BMI followed by overweight group B as given in table. 4 This shows that low BMI associated with low GWG leads to increased rates of neonatal distress.

Correlation of Maternal BMI and Oligohydramnios
Group C who was obese with high BMI had 46.67% incidence of oligohydramnios suggesting.
Its direct correlation when compared to low BMI groups as given in table 5:   Both lean and obese women carry a risk for adverse pregnancy outcomes [13]. An increasing BMI is associated with an increased incidence of preeclampsia, gestational hypertension, macrosomia, induction of labour and caesarean deliveries [14].

Discussion
The BMI is a simple index of the weight-for-height and it is calculated by dividing a person's weight in kilograms by the square of their height in meters (kg/m2).
Underweight (a BMI of < 19.9 kg/m2) has been shown to be associated with an increased risk of preterm deliveries, low birth weight and anaemia and a decreased risk of pre-eclampsia, gestational diabetes, obstetric intervention, and post-partum haemorrhage [15].
The available data showed that in India, prevalence of overweight was low while that of under nutrition remained high. Overweight was more prevalent among female [16]. Overweight and obesity in Indian women have increased from 10.6 to 14.5 %.
The obesity epidemic affects all including women on reproductive age [17].
In India more than high pre pregnancy weight and as a result high BMI is less encountered by obstetricians due to poor socioeconomic conditions and hence, low maternal BMI poses a bigger issue.

A study conducted by N.J. Sebire et al in 2001
wherein the main objective of the study was to assess whether underweight mothers really posed a risk to adverse pregnancy outcome, revealed that it certainly was responsible for adverse fetal and perinatal outcomes [18].
The study demonstrated that the main adverse outcome associated with maternal underweight was the delivery of a low-birth-weight baby and preterm delivery. It confirmed that a low maternal weight resulted in a low birth weight of the fetus [19,20].

Correlation of NICU Admission in Different
Maternal BMI Group The rates of newborns with NICU admissions were highest in Group C i.e.,

46.67%, followed by 24% in Group A and 20% in
Group B. Some of the reasons causing NICU admissions were respiratory distress syndrome, meconium aspiration, hypoglycemia, and birth Asphyxia.
Group B who are overweight reported 82.35% of RDS (Respiratory Distress Syndrome) and 5.88% of hypoglycaemia, 14.29% birth asphyxia was seen in Group C (obese) and 39.29% meconium aspiration were reported in Group A (low BMI). The study showed that obesity was more common in elderly primigravida > 30 years of age. Maternal obesity (high BMI) is an important risk factor that can lead to obesity in offspring as per Strauss RS et al [22] and this coupled with excessive gain of weight in pregnancy, also results in long-term obesity for such pregnant women as suggested by Mamun AA et al [23].
It was noted that there is a higher instance of low BMI i.e. A1 in patients lesser than 20 years of age. Maternal anemia is significantly higher in patients with low BMI and this association was noted in 84.09% of the patients. The prevalence of anemia was low in obese patients was low at 6.82%. It was noted that all obese patients (n=15) underwent LSCS whereas the incidence of LSCS was 25.88% in overweight patients and 6% in underweight patients. Oligohydramnios with IUGR in 36.57%, failed induction in 36.57%, cephalo-pelvic disproportion in 19.51% and premature rupture of membranes in 7.32% of the patients were noted in patients who underwent LSCS. IUGR was noted in fetus of mothers whose BMI was low as in Group A1. Obesity had higher incidences of poor wound healing.8 patients in over weight category had perineal injuries due to normal delivery out of 9 patients (88.89%).The incidence of preterm delivery in was highest in obese group with higher preponderance to high birth weight in newborns while low BMI group A had increased rates of low birth weight who had low Apgar score suggestive of increased fetal distress with meconium aspiration.
There is a growing evidence from both animal and human studies suggesting that maternal obesity has an impact on offspring health, which has profound implications for public health policy. Of particular concern is the increased risk of obesity and metabolic sequelae in the offspring of obese mothers reported in both animal and human studies, which has the potential to result in an 'intergenerational cycle' affecting obesity and cardiovascular disease risk across several generations [24].

Study Limitations
The present study had few limitations. The sample was not homogeneous about age, education, and socio-economic status. All these factors may impact quality of life and BMI and, hence the study results. We suggest to future researchers to consider other effective factors besides BMI such as age, education, economic status, quality of life on pregnancy outcomes, progression to metabolic syndrome post pregnancy and in the offspring. The sample size was of 200 patients and hence certain areas of interest did not show significance statistically.

Conclusion
The study concludes that underweight as well as obese mothers have higher incidences of adverse maternal and neonatal outcomes.
What does the study add to the existing knowledge?
There is an association of higher instances of preterm deliveries, low birth weight, post-operative. with other essential parameters should be screened adequately.