**4. Discussion**

Different studies have been conducted in different parts of India, thus correlating pre-pregnancy BMI and GWG with the pregnancy outcomes. But very few or we can say no study have been conducted in Gujarat region which covers all such parameters affecting pregnancy. Thus we had conducted such as study which determines the prevalence and risk factors for BMI ranges like underweight, normal, overweight and obese. And also studies the GWG and correlation between GWG, pre-pregnancy BMI and different pregnancy outcomes. So we conducted a prospective, multicentric study including pregnant women in Ahmedabad for getting a better idea regarding GWG and pre-pregnancy BMI.

Our study possesses maximum population (62%) in normal BMI range followed by underweight, then overweight and finally least population was in obese BMI. A similar distribution of pre-pregnancy BMI was observed in a study conducted in Maharashtra in 2013, where amongst 400 pregnant women more than 50% had normal BMI and less than 10% population was found obese [18].

It was observed that in all the BMI ranges, there were more of women who had completed secondary or college or higher education compared to primary education. Same as that, there were nearly <10% males in all population range who either illiterate or were just primarily educated.

In present study, the upper socio-economic class showed higher incidences of pre-term delivery. A partial negative (r = −0.116) was observed between socioeconomic status and term of delivery. In a similar study conducted by Wood et al., observed a modest increase in the risk of spontaneous preterm birth with low socio-economic status [19]. Regarding socio-economic status and type of delivery, decreasing incidence of normal delivery was observed from lower to upper socioeconomic class. A partial positive correlation (r = 0.177), thus is obtained between socio-economic class and type of delivery.

Unlike this, a study by Gissler et al., concluded that women with the lowest socio-economic status were more likely to give birth by caesarean section delivery, indicating that increase in pregnancy complications increases the need for the same [20]. Socio-economic status showed no significant correlation to GWG. On an average, every BMI range belonging to every socio-economic class gained similar gestational weight during pregnancy. In contrast to this, a study by Andersson et al., observed that the mothers belonging to low socio-economic class gained only 5.5 kg weight during pregnancy while women from affluent societies gain about 12.5 kg.

They stated that the low gestational weight gain in low socio-economic family may be due to lack of food [21].

During our study, it was found that the incidence of caesarean type of delivery was more in nuclear family as compared to joint family. A fractional positive correlation (r = 0.16) was observed between type of family and type of delivery. Whereas in a study by Kilic, observed no correlation between type of family and type of delivery [22].

It was observed during the study that in women with previous caesarean section delivery, the risk of current delivery to be of caesarean section type increases. No significant correlation was observed between number of abortions/miscarriage and term of delivery. It was observed that as the number of abortions/miscarriage increases, the chances of caesarean section increases. Bhattacharya et al. [23], observed that the risk of preterm birth after abortion/miscarriage is lower than that after miscarriage but higher than that in a first pregnancy or after a previous live birth. This risk is not increased further in women who undergo two or more consecutive abortions [23]. Also in our study the incidence of increase in caesarean section and decrease in normal type of delivery is observed on increase in number of abortions.

Regarding stress, a partial positive correlation is observed in physical stress and GWG (r = 0.115) and type of delivery (r = 0.10). Thus as stress increase, there is increase in GWG. There is no correlation of physical stress with infant birth weight, whereas a negative partial correlation (r = −0.13) is observed with term of delivery. Any type of mental stress has no correlation with any of the outcomes such as GWG, type of delivery, term of delivery or infant birth weight. Study by Dole et al., stated that any psychosocial stress or anxiety is related to risk of pre-term delivery [24] another study by Zhu et al., observed that prenatal severe life events may increase the risk of pre-term birth or low birth weight infant [25].

The present study concluded that the risk of LBW infant in women who consumed 1 or 2 glass of milk daily was comparatively less than women who did not consumed milk at all. Also the risk of LBW infant decreases if minimum of 1 fruit is consumed everyday. No major deviation was observed in women who ate junk food as compared to them who did not have it. The occurrence of normal delivery is high in women consuming 1 glass of milk and 1 fruit daily.

Statistically no correlation was obtained between haemoglobin level and type of delivery. This is in contrast to the results obtained by Francis et al., who reported a significant relationship between maternal haemoglobin level and type of delivery [26]. It was observed during the study that no specific correlation occurs between haemoglobin level and term of delivery. A similar non-correlation was obtained between haemoglobin and term of delivery in a meta-analysis performed by Haider et al. [27] and Koura et al. [28]. Whereas a study by Bakhtiar et al. [29], observed that decrease in haemoglobin concentration can cause pre-term birth. No correlation was observed in present study between haemoglobin level and GWG [29]. Also no correlation has been found between haemoglobin level and GWG.

In our study a partial negative correlation (−0.474) was observed between GWG and pre-pregnancy BMI. As pre-pregnancy BMI increases, the gestational weight gain decreases. This is in contrast to study performed by Joshi et al. 2013, where they obtained significant association between prepregnancy BMI and GWG (P < 0.001). They suggested that the women with normal pre-pregnancy BMI gained adequate weight while women with low BMI gained inadequate weight and high BMI patients tend to move towards increased weight gain [18]. Another study by Montpetit et al., also observed a positive correlation (r = 0.35, P = 0.007) between pre-pregnancy BMI and GWG [30]. Unlike this, a study by Nohr et al. 2008, found high variation in weight gain, and it also increased across BMI groups. They observed that nearly 50% of underweight and normal weight women gained 10–15 kg, and that the low

*Association of Pre-Pregnancy Body Mass Index and Gestational Weight Gain with Preterm… DOI: http://dx.doi.org/10.5772/intechopen.96922*

gain was more common among overweight and obese women than among underweight and normal weight women, and also that 40% of the obese women gained <10 kg [4].

The study shows a partial positive correlation (r = 0.421) between GWG and infant birth weight. However, a study by Chiba et al., observed no correlation between birth weight and GWG [31]. On contrary, a study by Mamun et al., found that mothers who gained excessive weight were more likely to have had higher birth weight infants [12]. A study by Rao et al., also found that with an increase in weight gain during pregnancy from 5 to 11 kg or more, there was a corresponding increase in mean birth weight. This increase was statistically significant (P < 0.05) [32].

Present study shows partial positive correlation (r = 0.166) between term of delivery and pre-pregnancy BMI. Various studies have been suggestive of effect of BMI on term of delivery. A study by Li et al. [3], suggested a positive association between maternal pre-pregnancy BMI and pre-term delivery (P < 0.001). Another study by Simas et al. also concluded the same association between BMI and term of delivery [11].

Present study found that the incidence of LBW (33.33%) and HBW (20%) was more in obese women compared to women with normal or underweight BMI. A study in Gorakhpur analysed maternal and foetal complications in overweight and obese women and observed that macrosomia and LBW were significantly (<0.05) more in overweight and obese women in contrast to normal BMI women [33]. Another study by Prabha et al. 2014, noted that LBW seemed to be more common with higher BMI groups; it was found to be non-significant after adjusting for confounders. However, macrosomia was more common and significant in the overweight and obese groups with ORs of 3.36 (95% CI: 1.51–7.49) and 8.30 (95% CI: 2.99–23.03) respectively, compared with the normal BMI group [34].
